Article

Pharmacological characterization of the diuretic effect of Hibiscus sabdariffa Linn (Malvaceae) extract

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Hibiscus sabdariffa L. (Malvaceae) populary known in Mexico as "Jamaica", "flor de Jamaica", has widely used in Mexican Traditional Medicine as antihypertensive and diuretic, although the latter activity has been reported the present work show evidence about the diuretic, natriuretic and potassium-sparing effects. To evaluate the diuretic activity of Hibiscus sabdariffa aqueous extract on in vivo and in situ models. The Hibiscus sabdariffa aqueous extract was administrated in increasing doses and evaluated the diuresis produced and disposal of electrolytes. Moreover, in isolated kidney was determined the renal filtration rate with plant extract, furosemide and amiloride. The yield of Hibiscus sabdariffa aqueous extraction was 28.3% and the chemical standardization from 1 g of extract was: 56.5 mg delphinidin-3-O-sambubioside, 20.8 mg/g cyanidin-3-O-sambubioside, 3.2 mg/g quercetin, 2.1 mg/g rutin and 2.7 mg/g chlorogenic acid. The diuretic and natriuretic effect of Hibiscus sabdariffa aqueous extract showed a dose-dependent behavior. The pharmacological constants of natriuretic effect was ED50=86 mg/kg and Emax=0.9 mEq/100 g/5 h. In the model of kidney in situ was observed that renal filtration increased 48% with the aqueous extract of Hibiscus sabdariffa and an additive effect when was perfuse with furosemide. The compound presents in Hibiscus sabdariffa as quercetin had effect on the vascular endothelium causing oxide nitric release, increasing renal vasorelaxation by increasing kidney filtration. Therefore, the diuretic effect of Hibiscus sabdariffa may be mediated by nitric oxide release.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Several studies identified delphinidin-3-sambubioside and cyanidin-3-sambubioside as the major anthocyanins in HS calyx extracts (20,31). ...
... Hibiscitrin, sabdaritrin, gossypitrin, gossytrin, quarcetin, luteolin, chlorogenic acid, procatechuic acid, pelagonidic acid and eugenol have been described in HS extracts (32). Alarcon-Alonso, Zamilpa (31) reported that the amount of quercetin present in the aqueous extracts of HS calyces was 3.2mg/g while rutin was 2.1mg/g. Quercetin and its conjugated glycosides as well as rutin were also identified in aqueous extracts of HS calyces together with kaempferol (20). ...
... HS calyces and leaves contain chlorogenic acid; a phenolic (35) which belongs to a family of esters formed between certain transcinnamic and quinic acids (36). The amount of chlorogenic acid in HS extract was reported to be 2.7mg/g (31). ...
Article
Hibiscus sabdariffa (HS) is a plant from the Malvaceae family that is grown widely in most of Asia and tropical Africa. The various parts of the plant are used traditionally as food in form of beverages or salads and as medicine. In folklore, HS has been used to treat many ailments including cardiac and nerve ailments, induction of diuresis and lactation among others. Scientific studies have also demonstrated the antihypertensive, antidiabetic, anti-obesity and anti-hyperlipidaemic properties of HS. These biological activities are thought to be as a result of the battery of phytochemicals in HS that have strong antioxidant activity and that inhibit α-amylase, α-glucosidase, angiotensin converting enzyme, calcium channel blockage and direct vasorelaxant effects. Some of the phytochemicals that are thought to be responsible for these biological effects include anthocyanins, flavonoids and organic acids. There is however the need for more robust researches including controlled clinical trials to validate these biological activities with a view to bringing the benefits closer to the bedside.
... Several studies identified delphinidin-3-sambubioside and cyanidin-3-sambubioside as the major anthocyanins in HS calyx extracts (20,31). ...
... Hibiscitrin, sabdaritrin, gossypitrin, gossytrin, quarcetin, luteolin, chlorogenic acid, procatechuic acid, pelagonidic acid and eugenol have been described in HS extracts (32). Alarcon-Alonso, Zamilpa (31) reported that the amount of quercetin present in the aqueous extracts of HS calyces was 3.2mg/g while rutin was 2.1mg/g. Quercetin and its conjugated glycosides as well as rutin were also identified in aqueous extracts of HS calyces together with kaempferol (20). ...
... HS calyces and leaves contain chlorogenic acid; a phenolic (35) which belongs to a family of esters formed between certain transcinnamic and quinic acids (36). The amount of chlorogenic acid in HS extract was reported to be 2.7mg/g (31). ...
Article
Full-text available
Hibiscus sabdariffa (HS) is a plant from the Malvaceae family that is grown widely in most of Asia and tropical Africa. The various parts of the plant are used traditionally as food in form of beverages or salads and as medicine. In folklore, HS has been used to treat many ailments including cardiac and nerve ailments, induction of diuresis and lactation among others. Scientific studies have also demonstrated the antihypertensive, antidiabetic, anti-obesity and anti-hyperlipidaemic properties of HS. These biological activities are thought to be as a result of the battery of phytochemicals in HS that have strong antioxidant activity and that inhibit α-amylase, α-glucosidase, angiotensin converting enzyme, calcium channel blockage and direct vasorelaxant effects. Some of the phytochemicals that are thought to be responsible for these biological effects include anthocyanins, flavonoids and organic acids.There is however the need for more robust researches including controlled clinical trials to validate these biological activities with a view to bringing the benefits closer to the bedside.
... Kaempferol in a methanolic extract was confirmed as a potential antihypertensive through ACEI activity [38]. Quercetin functions as a diuretic through a oxide nitric mechanism that will increase the renal vasorelaxation [156] and as an antidiabetic through the inhibition of α-amylase and α-glucosidase activity [57]. Myricetin has potential as an antiaging agent [129]. ...
... These antidiuretic, as well as natriuretic, properties would augment the ACEI activity and support the antihypertensive and reno-protective action of roselle extract-namely, through vascular smooth muscle relaxation. The quercetin content in the extract was assumed to influence the vascular endothelium, resulting in NO release, and the inhibition of ATPase activity, affecting the Na+/K+ concentration gradient in the tubular epithelial cells of the nephron [156]. ...
Article
Full-text available
Roselle (Hibiscus sabdariffa L.), as an edible flower, has long provided an array of positive effects on human health. This benefit is a result of phenolic compounds that are naturally present mainly in the calyx. Plentiful medicinal remedies and functional foods based on this flower are available worldwide, as supported by the studies of phenolic compounds in recent decades. This paper aims to provide a comprehensive review of the composition, biological activity, and beneficial effects on human health of phenolic compounds in roselle. This review was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A structured search in the published literature for phenolics compositions in roselle was required prior to the evaluation on the validity of the reported analytical methods. Reliable identification and quantification of phenolic compounds in roselle can be achieved by employing the proper extraction and separation methods. With ample alternative analytical methods discussed here, this review provided an aid for comprehending and selecting the most appropriate method for a particular study. The applications of the analytical methods highlighted indicated that phenolic acids, flavonoids, and their derivatives have been identified and quantified in roselle with a range of biological activities and beneficial effects on human health. It was also disclosed that the composition and concentration of phenolic compounds in roselle vary due to the growth factors, cultivars, and environmental influence. Finally, apart from the research progress carried out with roselle during the last ten years, this review also proposed relevant future works.
... Terpenes such as geraniol and farnesol are PPARα/γ agonists [15], and unsaturated fatty acids such as linoleic acid are PPARγ agonists [10]. In relation to H. sabdariffa, phytochemical studies have been focused on primarily characterizing the compounds in the aqueous extract, including polyphenols [16], anthocyanins such as delphinidin 3-sambubioside and cyanidin 3-sambubioside [1], and some organic acids [16,17]. However, the phytochemistry of the lesser polar extracts of H. sabdariffa has not, to our knowledge, been well studied and, at present, compounds have not yet been proposed with dual agonist action of PPARδ and PPARγ from this plant. ...
... Compounds proposed from medicinal plants, such as vaticanol C, a tetramer of resveratrol, activate PPARα and PPARδ in bovine arterial endothelial cells [39]. Curcumin produces PPARγ expression in rats [40], chlorogenic acid increases PPARα and PPARγ expression in adipocytes 3T3-L1 [41], geraniol and geranylgeraniol increase PPARα and PPARγ expression in hepatocytes HepG2 [17], and γ-mangostine activates PPARα and PPARδ in the GAL4/ PPAR chimera system with COS-1 cells [10], among others. H. sabdariffa has demonstrated many beneficial properties for human health, mainly in the treatment of metabolic disorders such as T2D and obesity. ...
Article
BACKGROUND. Hibiscus sabdariffa L. has been traditionally used in stews and drinks. Pharmacological studies support its anti-inflammatory, anti-oxidant, diuretic, antihypertensive, anti-adipogenic and anti-diabetic effects. These two latest activities supporting the participation of PPARdelta and PPARgamma. PPARs are factors of transcription that modulate the lipid and glucose metabolism, key elements for increasing insulin sensitivity. Therefore, development of new PPARdelta/gamma dual agonists from H. sabdariffa should be considered. The aim of this research was evaluate the dichloromethane extract from H. sabdariffa (HS-DCM) in anti-hyperglycemic test, and evaluate constitutive compounds with potential dual agonist of PPARdelta/gamma. METHODS. Oral glucose tolerance tests (OGTT) were performed in normal CD1 mice, which received HS-DCM, and pioglitazone (positive control). HS-DCM was fractionated, obtaining four fractions which were evaluated on the expression of PPARdelta/gamma in myocytes C2C12. Fraction F10 was selected and fractioned, obtaining two sub-fractions that were analyzed by high performance liquid chromatography coupled to mass spectrometry. The principal identified compounds were: linoleic acid, oleic acid, and palmitic acid were found in F10-1; alpha-amyrin and lupeol in F10-2. With these compounds was performed a molecular docking. Finally, evaluate the effect on mRNA expression for PPARdelta, PPARgamma, FATP and GLUT4 by qPCR-RT was evaluated. In addition protein of PPARdelta and PPARgamma were determined by western blot. RESULTS. In the (OGTT), the HS-DCM avoided hyperglycemic peak like pioglitazone. F10, F10-1 and F10-2 exhibited PPARdelta/gamma dual activity. By molecular docking, Linoleic acid, palmitic acid, oleic acid, alpha-amyrin and lupeol exhibited high affinity for both isoforms PPARdelta/gamma. Linoleic acid, oleic acid, alpha-amyrin and lupeol, incremented the expression of PPARdelta, PPARgamma, and downstream genes FATP and GLUT 4 and PPARdelta and PPARgamma protein. Palmitic acid had no effect on PPARdelta/gamma expression. CONCLUSIONS: HS-DCM had a similar anti-hyperglycemic effect to pioglitazone. Molecular docking suggested that linoleic acid, oleic acid, alpha-amyrin, and lupeol act as PPARdelta/gamma dual agonists. alpha-amyrin and lupeol shown higher activity than pioglitazone and L-165041 (PPARdelta agonist) in mRNA and protein expression. These compounds should be considered for the development of new treatments for DM2 and other diseases associated with metabolic syndrome.
... This protection was associated with improvement in lipid profile and correction of glomerular filtration rate (Melchert al., 2016). Besides, the Roselle has been investigated for its diuretic activity in a rat model (Alarcón-Alonso et al., 2012). The natriuretic and diuretic effects of the aqueous extracts displayed dose-dependent behavior. ...
... The dose-dependent behavior was observed for natriuretic and diuretic effects with a potassium-sparing effect. Moreover, the renal filtration was increased up to 48% with the consumption of Roselle aqueous extract, while the additive effect when witnessed was perfused with furosemide (Alarcón-Alonso et al., 2012). ...
Chapter
The consumption of nutraceutical foods, like Roselle extracts (Hibiscus sabdariffa) from calyces and other parts, positively influences human health and prevents several diseases. This is partly due to the activities of anthocyanins, which contain appealing colorants. Also, Roselle calyces contain substantial amounts of phytochemicals, including phenolics and flavonoids. These bioactive compounds have functional applications such as antihypertensive, antioxidants, and hyperlipidemia and against low-density lipoprotein oxidation. However, they exhibit sensitivity in ultraviolet rays, high temperatures, and oxygen, which affect the quality and consequently the longevity. Furthermore, these substances deteriorate fast when subjected to varying internal and external conditions, particularly during the preparation of certain products. Therefore, to avoid quality loss and extend the shelf life of Roselle products available, various processing techniques have been proposed. This chapter reports several processing options, including heating, encapsulation, acidification, and carrier agents, for the purposes of maintaining the quality of Roselle products and quality measurement indices. Most measurement methods are explored; emphasis is given to spectrophotometric methods, particularly 1,1-diphenyl-2-picrylhydrazyl since it is simple to use.
... This protection was associated with improvement in lipid profile and correction of glomerular filtration rate (Melchert al., 2016). Besides, the Roselle has been investigated for its diuretic activity in a rat model (Alarcón-Alonso et al., 2012). The natriuretic and diuretic effects of the aqueous extracts displayed dose-dependent behavior. ...
... The dose-dependent behavior was observed for natriuretic and diuretic effects with a potassium-sparing effect. Moreover, the renal filtration was increased up to 48% with the consumption of Roselle aqueous extract, while the additive effect when witnessed was perfused with furosemide (Alarcón-Alonso et al., 2012). ...
Chapter
Full-text available
The international demand for Hibiscus sabdariffa is high due to its valuable health properties derived from the polyphenols content available in different parts of the plant but mainly in the fruit calyx. In this chapter review, we discuss how the Roselle plant and its extracts can be used as food and raw materials in food, pharmaceuticals, and agricultural applications for health and economic benefits. The versatility of Roselle continues to attract significant research work toward the development of value-added products.
... This protection was associated with improvement in lipid profile and correction of glomerular filtration rate (Melchert al., 2016). Besides, the Roselle has been investigated for its diuretic activity in a rat model (Alarcón-Alonso et al., 2012). The natriuretic and diuretic effects of the aqueous extracts displayed dose-dependent behavior. ...
... The dose-dependent behavior was observed for natriuretic and diuretic effects with a potassium-sparing effect. Moreover, the renal filtration was increased up to 48% with the consumption of Roselle aqueous extract, while the additive effect when witnessed was perfused with furosemide (Alarcón-Alonso et al., 2012). ...
Chapter
Full-text available
Roselle (Hibiscus sabdariffa) is a useful plant with different parts utilized in several ways. The useful parts include leaves and tender shoots, stems, calyces, and seeds. They are sources of anthocyanins, flavonoids, polyphenols, organic acids, and fiber which are single-stand products, and beverages and medicinal products are obtained from them. Some products of Roselle include sauces, vegetable salads, fruit salads, creams, perfumes, marmalade, seasoning products, fibers, spices, sauces, and vegetable oils. Harvesting and postharvest procedures have a profound influence on the qualities of harvested Roselle produce: this ranges from harvesting time and standard postharvest processing procedures. Furthermore, postharvest handling has an influence on the storage time and marketability of Roselle products. However, there are huge knowledge gaps on the appropriate procedures in harvesting and processing Roselle produce. This chapter explores knowledge on harvesting, storage, postharvest management, and marketing of useful parts of Roselle (Hibiscus sabdariffa), where we focus on leaves, tender shoots, stems, calyces, and seeds. It combines information from a wide range of literature sources from several countries practicing Roselle cultivation.
... All reports agreed that Hibiscus Sabdariffa has antihypertensive, antioxidant and hypocholestrolemic effect. and amiloride (potassium sparing diuretic ) 15 . ...
... Also urinary excretion of electrolytes after treatment with HsAq revealed a different pattern for each ion (sodium, potassium and chloride). Sodium excretion increased significantly with rising doses (p < 0.05), in case of the potassium electrolyte urinary excretion levels showed no differences with different doses of Hibiscus Sabdariffa aqueous extract in addition HsAq induced an increment in the urinary Chloride excretion levels in the high doses15 . This study showed that hibiscus act as diuretic same as furosemide but it have an advantage over furosemide that it maintain the potassium level same without causing hypokalemia as furosemide do.(Ferrer ...
Article
Full-text available
Hypertension is a global health problem with significant magnitude of morbidity and mortality, in recent years, most of the developing countries such as Sudan depend largely on the herbal remedies which are used for the treatment of hypertension such as: Hibiscus Sabdariffa. In folk medicine it is used for variety aspects such as: wound dressing, bronchitis and diabetes. The extract of this plant exerts its antihypertensive activity by at least three major specific mechanisms of action: diuretic, vasodilator and angiotensin converting enzyme inhibitor (ACE inhibitor).The object of the work was to to discuss and evaluate the effectiveness of Hibiscus Sabdariffa as antihypertensive agent. In vitro, H. sabdariffa (HS) act as a vasodilator via relaxed the pre-contracted endothelium-intact and endothelium-denuded aortic rings. In man and laboratory animals, aqueous extraction of HS significantly reduced BP in essential hypertensive man, and the calyx extract reduced BP in the spontaneously hypertensive rat. It's also significantly reduced BP in normal rats and anesthetized cats. In addition, there are an evidence reports that the regular use of (HS) can protected the body from the cardiovascular disorder by lowering: total cholesterol, low-density lipoprotein cholesterol (LDL-C) and triglycerides in the majority of normolipidemic, hyperlipidemic and diabetic animal models. All the studies had agreed that Hibiscus Sabdariffa can significantly reduce the blood pressure, but all the problems that reported later on in the discussion that have founded on the conducted articles need further evaluation of this herbal remedy to be approved as an effective antihypertensive agent.
... Hibiscus sabdariffa has been used historically as a folk remedy for different diseases [23]. Although HS has been validated as an anti-obesity agent [24], there have been conflicting reports on its effect on body weight. Some studies reported a significant decrease in body weight following treatment with HS [24], others have reported a significant increase in body weight [25]. ...
... Although HS has been validated as an anti-obesity agent [24], there have been conflicting reports on its effect on body weight. Some studies reported a significant decrease in body weight following treatment with HS [24], others have reported a significant increase in body weight [25]. In this present study, treatment with 200 and 400 mg/kg MEHS caused no significant change in the body weight when the preadministration body weight was compared to the postadministration body weight (p=0.058, ...
Article
Full-text available
Objectives: This study investigated the Kiss1 gene expression in the ovary, following the administration of Methanolic extract of Hibiscus sabdariffa (MEHS) in Wistar rats. Methods: Fifteen (15) rats with an average weight of 148 g were randomly divided into three (3) groups (n=5), A-C. Group A was given no treatment and served as the normal control group. Groups B and C received oral administration of 200mg/kg and 400mg/kg of MEHS respectively. The extract was administered once a day for 21 days. Result: No significant difference was observed in the relative ovarian weight, reproductive hormone levels, and ovarian antioxidant levels in all the treatment groups compared to the control (p>0.05). There is a significantly lower intensity of expression of the Kiss1 gene in the ovarian tissue of group C (p=0.011) when compared to the control group. There is no significant correlation between the relative intensity of Kiss1 gene expression in the ovary and the reproductive hormones of all the experimental groups (p =0.879, 0.534, 0.133; r=0.081, 0.322,-0.686). MEHS caused no histopathological changes in the ovary at both treatment doses (200mg/kg and 400mg/kg). Conclusion: MEHS shows the potential of downregulating the expression of the Kiss1 gene in the ovary, albeit at a higher dose. However, this effect lacks a regulatory mechanism on the reproductive hormones and ovarian antioxidative levels.
... 75 It has been shown that HS contains a compound that causes the release of nitric oxide from the vascular endothelium and increases renal filtration, thereby lowering blood pressure. 76 It has also been exhibited that HS can decrease the systolic and diastolic blood pressure (BP). 77 Consumption of HS with adapted doses between 10-20 g daily for one month was associated with an improvement in both diastolic and systolic BP, even in patients simultaneously taking antihypertensive medications. ...
... Releases nitric oxide from vascular endothelium and increases renal filtration 76 HS Human Decreases the systolic and diastolic blood pressure (BP) 77 Sour tea Human Improves both diastolic and systolic BP, even in patients simultaneously taking antihypertensive medications 78 Aqueous extract Rat Antioxidants act as free radical scavengers in 2K-1C hypertension 79 Extract The consumption of current antihypertensive medications has inherent limitations and side effects. ...
Article
Full-text available
High blood pressure is the main risk factor for cardiovascular disease and should be controlled primarily by changes in lifestyle, such as regular exercise, a low-salt diet, and weight loss in overweight or obesity. If lifestyle changes are not enough, many types of medications can be used to control high blood pressure; however, side effects constitute one of the most critical limitations of conventional medicines associated with high blood pressure. For this reason, the use of traditional and herbal medicines has been welcomed by the public for many years. Sour tea (Hibiscus sabdariffa) is one of the most suitable herbal medicines for hypertension. According to research results, sour tea has the same effect as conventional medicines without serious side effects. The present study introduces sour tea as a suitable herbal medicine for high blood pressure to provide readers of this article with a comprehensive understanding of the medicinal properties of sour tea for the treatment of hypertension and its effects on several other common diseases, including cancer.
... [39] reported that a root decoction of Roselle has also been used for a similar application. Ethno botanical information of Roselle plant revealed diuretic, diaphoretic, uricosuric, antibacterial, antifungal agent, mild laxative, sedative, antihypertensive, antitussive, gastrointestinal disorder treatment, hypercholesterolemia treatment, kidney stone treatment, liver damage treatment, agent for decreasing the viscosity of the blood, and agent for treating the after effects of drunkenness [40,41]. Roselle is consumed as hot and cold drinks to its uses in folk medicine. ...
... Anthocyanins and proanthocyanidins compounds of the Roselle calyces, could be the bioactive compounds responsible for lowering the blood pressure [44]. Quercetin of Roselle has an effect on the vascular endothelium, [41]. They mentioned oxide nitric increasing renal vasodilatation and kidney filtration. ...
... β-sitosterol, ergosterol [93,94], quercetin, luteolin, and its glycoside [95] were also detected in separate studies of HS extracts. Similarly, [96] found an appreciable concentration of quercetin and rutin: 3.2 mg/g and 2.1 mg/g, respectively. Some important compounds in different HS species have been extensively reviewed [97]. ...
Article
Full-text available
Sorghum beer (pito) is an indigenous alcoholic beverage peculiar to northern Ghana and parts of other West African countries. It is overwhelmed with calories, essential amino acids (such as lysine, etc.), B-group vitamins, and minerals. In recent years, there has been a growing demand for highly flavoured yet functional pito in Ghana; however, the local producers lack the prerequisite scientific expertise in designing such products. We propose the utilization of Tetrapleura tetraptera (TT) and Hibiscus sabdariffa (HS) as cheap and readily available materials in designing functional flavoured pito. The addition of TT and HS would not alter the fermentation profile but rather augment the starter with nutrients, thus improving the fermentation performance and shelf life of the final pito. In vitro and in vivo studies provide substantive evidence of antioxidant, nephro-and hepato-protective, renal/diuretic effect, anticholesterol, antidiabetic, and antihypertensive effects among others of the TT and HS, hence enriching the pito with health-promoting factors and consequently boosting the health of the consumer. Herein, we summarise the phytochemical, biological, pharmacological, and toxicological aspects of TT and HS as well as the technology involved in brewing the novel bioactive-flavoured pito. In addition, we also report the incidence of heavy metal in conventional pito.
... Furthermore, there was no evidence of adverse clinical or metabolic effects. It was concluded that Hibiscus tea consumption may decrease the BP of hypertensive patients due to the NO increased production, Ca 2+ channels inhibition and the KATP channels opening [112]. ...
... They are associated with the prevention of illnesses generated by oxidative stress (Heba et al., 2014). Pharmacological studies have demonstrated the antihypertensive effect produced by Hibiscus sabdariffa extracts (Onyenekwe et al., 1999;Odigie et al., 2003;McKay et al., 2010;Alonso et al., 2012). H. sabdariffa calyx extracts have been studied extensively as a food colorant (Duangmal et al., 2008;Alobo and Offonry, 2009) and found to be a suitable replacement for various artificial colorants. ...
... Flowers of Hibiscus safdariffa has various phenolic compounds like flavonols, flavones, anthocyanins, phenolic acids, flavanols etc. leading to its antioxidant, anti-cancer, anti-inflammatory, antiobesity properties, and also possess neuro-protective effect 6,27 . It has also displayed many other health benefits like nephroprotective and hepatoprotective effect 40,41 . Fixed oils extracted from spadix of Alocasia fornicata possess antioxidant and antibacterial property 42 . ...
Article
Full-text available
The edible flowers consumed by indigenous people of Mizoram were assessed from Aizawl and Champhai districts of Mizoram during 2015-2016. Altogether, 59 species of edible flowers under 50 genera and 29 families are recorded. Dominant families include Apiaceae, Lamiaceae and Leguminosae with 9% followed by Brassicaceae and Zingiberaceae scoring 7% each. Based on habit and occurrence, plants are categorized into wild (30), cultivated (21) and semi-cultivated (8). Among these plants, 30 species are marketable and 29 species are non-marketable. The study envisaged to highlight the importance of edible flowers in local cuisines of Mizo people and its potential as an additional source of food. It also attempted to document a first-hand report on the traditional knowledge on plant usage for consumption by the people of Mizoram.
... They are associated with the prevention of illnesses generated by oxidative stress (Heba et al., 2014). Pharmacological studies have demonstrated the antihypertensive effect produced by Hibiscus sabdariffa extracts (Onyenekwe et al., 1999;Odigie et al., 2003;McKay et al., 2010;Alonso et al., 2012). H. sabdariffa calyx extracts have been studied extensively as a food colorant (Duangmal et al., 2008;Alobo and Offonry, 2009) and found to be a suitable replacement for various artificial colorants. ...
Preprint
Full-text available
Roselle (Hibiscus sabdariffa L.) belongs to the family Malvaceae and is a popular vegetable in Indonesia, India, West Africa, and many tropical regions. The calyces of roselle are rich in anthocyanin, ascorbic acid, and other phenolic compounds. It is water soluble with brilliant and attractive red color and with sour and agreeable acidic taste, which aid digestion. Roselle has been used by people for preparing soft drinks and in traditional medicine. It has been observed that its components, such as vitamins (C and E), polyphenols acids and flavonoids, mainly anthocyanins, have functional properties. They contribute benefit to health as a good source of anti-oxidants as well as a natural food colorant. The other health benefits of this plant include diuretic and choloratic properties, intestinal antiseptic, and mild laxative actions. It also used in treating heart and nerve disorder, high blood pressure, and calcified arteries. Due to perceived safety and physiological advantage of the natural colorants over synthetic ones, interest is being geared into the search of new natural colorants and the verification of the safety of existing ones. In this respect, roselle calyces appear to be good and promising sources of water-soluble red colorants that could be utilized as natural food colorants. Anthocyanins present in Roselle are delphinidin 3-sambubioside, cyanidin 3-sambubioside, delphinidin 3-glucoside, and cyanidin 3-glucoside.
... [27] Moreover, it has been showed that H. sabdariffa has a compound that causes nitric oxide release from vascular endothelium which follows by kidney filtration increase, a mechanism that clears its diuretic effect so on blood pressure. [28] The main limitation of suggesting H. sabdariffa as a blood pressure lowering agent or an anti lipidemic medication is the heterogeneity of clinical trials' protocols. Different therapeutic doses has been reported for achieving the beneficial effect of sour tea. ...
Article
Full-text available
Using different drug regimens has been proved to have effective effects on lowering blood pressure, but the adverse effects of long-term usage such medications is evident. According to recent trend in suing herbal and traditional medicines, researchers have been focused on evaluating the effect of different herbals on managing hypertension. The aim of the present study is the evaluation of the antihypertensive effect one of these herbs, sour tea (Hibiscus sabdariffa), on stage one hypertension. Patients with stage one hypertension who were diagnosed by a cardiologist has been included in the present clinical trial after giving informed consent. The patients were divided into two groups. The control and case group received the same lifestyle and dietary advices for controlling blood pressure. The case group received two standard cup of sour tea every morning for 1 month. The blood pressure of both groups was documented at baseline and at the end of the study and the results were analyzed using SPSS software. A total of 46 patients participated in this study and there was no significant difference in terms of age and body mass index between groups. There was a significant reduction in systolic blood pressure in both groups, but the mean reduction in systolic and diastolic blood pressure was significantly higher in the case group (P = 0.004 and P < 0.001, respectively). Using H. sabdariffa as sour tea two times a day can be effective in managing blood pressure in stage one hypertension along with lifestyle and dietary modification.
... It was observed that both treatment plants produced similar concentrations of chlorogenic acid with an overall range between 0.50 to 0.74 mg/g DW. On the contrary, Alarcon-Alonso et al. [49] reported that the amount of chlorogenic acid in roselle which originated from Mexico was much higher with 2.70 mg/g DW. Chlorogenic acid has a potential protective effect on human health, act as an antioxidant by scavenging radicals, and chelating metals [50,51]. ...
Article
The impact of global climate change on plants which has been widely reported can exhibit significant changes on the growth, yield and metabolite production. Studies on the impact of elevated carbon dioxide concentration, [CO2] on plant growth and production of phenolic constituents in Hibiscus sabdariffa var. UKMR-2 has not been reported in any previous studies. This study investigated the growth quality and production of phenolic constituents of UKMR-2 under different [CO2]. The cultivation was subjected to two atmospheric [CO2]; ambient (400 µmol/mol), and elevated (800 µmol/mol). Selected parameters for growth performance were recorded throughout the plant development. UKMR-2 calyx extract was analysed for total phenolic, total anthocyanins, antioxidant activity, and evaluated based on HPLC-PDA method. The results revealed that UKMR-2 responded differently to the [CO2] treatments. The results clearly showed that exposure to elevated [CO2] increased calyx yields, production of phenolic constituents, and antioxidant activity. Furthermore, different [CO2] had significant interaction on the production of phenolic constituents, and antioxidant activity (p < 0.05), except for plant growth. The HPLC-PDA showed the presence of delphinidin-3-O-sambubioside, cyanidin-3-O-sambubioside, ascorbic acid, caffeic acid, and chlorogenic acid. Therefore, increased [CO2] may have significant effects on UKMR-2 to not only produce higher production yields, but also on the production of phenolic constituents with potential physiological impact to human health.
... Anti-oxidant activity Kenaf phenolic fraction [20] Seed Antibacterial activity Hibiscus cannabinus stem-assisted silver and gold nanoparticles [21] Stem Dye removal activity graft copolymerization [22] Fiber Cytotoxic activity acetone extraction [23] Core and bark Cytotoxic effect Supercritical carbon dioxide extraction fluid [24] Whole plant Inhibitory activity against porcine pancreatic α-amylase 50% methanol and acetone extracts [26] Seed and plant calyx Anti-oxidant Methanolic extract [27] Whole plant Diuretic Aqueous extract [28] leaves Phytochemistry Leaf extract [29] leaves Antioxidant capacity Leaf extract leaves Total phenolic content Leaf extract leaves Anti-inflammatory activity Leaf extract ...
... Ethnobotanical information of the roselle plant revealed that it can be used for treating the after effects of drunkenness, decreasing blood viscosity, and treating gastrointestinal disorders, kidney stone, and liver damage. This is because the roselle plant possesses hypercholesterolemic, antitussive, antihypertensive, sedative, mild laxative, antifungal, antibacterial, uricosuric, diaphoretic, and diuretic properties (Alarcon-Aguilar et al., 2007;Alarcón-Alonso et al., 2012). Roselle is used in folk medicine as hot and cold beverages or drinks to treat hypertension, hypercholesterolemia, fever, liver diseases, and gastrointestinal disorders (Ojeda et al., 2010). ...
Chapter
The totalnumberof Hibiscus species, tropical and subtropical, exceeds 300 (Anderson, 2006). Jamaica sorrel (Hibiscus sabdariffa), or roselle, is a rare plant bred in many temperate climates for its seeds, stems, leaves, and calyces; the dried calyces are used to make drinks, syrups, jams, and jellies (Eslaminejad & Zakaria, 2011). Roselle is an annual plant that takes approximately 6 months to grow (Ansari, 2013). The morphologic features of this plant are shown in Fig. 1.1. The leaves of roselle are separated into three to five lobes on the stem and arranged alternately (Ansari, 2013). In each calyx lobe of the roselle flower, there is a notable center and two marginal ribs (Ansari, 2013). This trait puts the plant in the Furcaria group (America et al., 1993). The color of the flower ranges from white to pale yellow, with delicate and fleshy calyces, while the petals might differ from white to pink, red, yellow, orange, or purple (Ansari, 2013). The fruit’s bright red color indicates it is a ripe fruit (Chin et al., 2016; Halimatul et al., 2007; Morton, 1987). Roselle is recognized throughout the Indian subcontinent traditionally as “Mesta” and “Meshta” (Grubben & Denton, 2004; Halimatul et al., 2007; Udayasekhara Rao, 1996). In different nations, roselle is generally called by many names, as shown in Table 1.1 (Ansari, 2013). Owing to its market value as a natural food and staining component that could replace a variety of synthetic products, this plant has gained the attention of food, beverage, and pharmaceutical companies (Eslaminejad & Zakaria, 2011). This chapter is a review of the production and applications of roselle plants and points out roselle as a promising crop for medicinal uses and polymer composites, which is an aspect that has not been widely studied to date.
... In addition, research showed that H. sabdariffa has a compound that causes nitric oxide release from the vascular endothelium followed by kidney filtration increase, a mechanism that clears its diuretic effect on the blood pressure [36,37]. Another study reported a significant decrease in the blood pressure of patients treated with HS, reporting differences between both the control group and the experimental group. ...
Article
Full-text available
Hypertension is an important factor of cardiovascular diseases and contributes to their negative consequences including mortality. The World Health Organization estimated that 54% of strokes and 47% of cases of ischemic heart illness are related to high blood pressure. Recently, Hibiscus sabdariffa (HS) and Lippia citriodora (LC) have attracted scientific interest, and they are recognized for their high content of polyphenols as these may prevent several disease factors, such as hypertension. The aim of the present study is to determine if supplementation with an HS-LC blend (MetabolAid®) may be effective for the treatment of type 1 hypertensive sedentary populations. A total of 80 type 1 hypertensive subjects of both sexes were included in the study and were treated with placebo or the HS-LC extract, and both groups were treated over 84 days. The blood pressure (diastolic, systolic, and pulse pressure) was measured throughout the day, for each of the days of the study duration and determined using Ambulatory Blood Pressure Monitoring (ABPM). Physical activity was determined throughout the study to ensure similar conditions related to exercise. The results showed the capacity for reducing the blood pressure parameters in the case of the HS-LC extract. The daily consumption of the HS-LC extract but not the placebo over 84 days was able to reduce the daytime parameters related to blood pressure. The most remarkable results were observed in the measurements performed during the daytime, especially in the systolic blood pressure showing statistically significant variation.
... Some studies propose these effects are due to improved vasodilation 21,22 through inhibiting calcium influx into vascular smooth muscle cells 23,24 or by acting as a diuretic through increased excretion of sodium and chloride and increased kidney filtration. 25 In tandem with these previous studies, delphinidin 3-sambubioside and cyanidin 3-sambubioside have been shown to compete with the substrate at the active site of the angiotensinconverting enzyme (ACE) in an in vitro enzyme inhibition model, 26 suggesting that hibiscus may act as a competitive inhibitor of ACE, preventing the production of angiotensin II. Moreover, antihypertensive effects of the anthocyanins cyanidin and delphinidin have been shown via direct inhibition of the reninangiotensin system in vitro, 27 through upregulation of endothelial nitric oxide synthase 28 and inhibition of inflammation, 29 all contributing toward a multifaceted approach to BP management. ...
Article
Context: Hibiscus sabdariffa (hibiscus) has been proposed to affect cardiovascular risk factors. Objective: To review the evidence for the effectiveness of hibiscus in modulating cardiovascular disease risk markers, compared with pharmacologic, nutritional, or placebo treatments. Data sources: A systematic search of the Web of Science, Cochrane, Ovid (MEDLINE, Embase, AMED), and Scopus databases identified reports published up to June 2021 on randomized controlled trials using hibiscus as an intervention for lipid profiles, blood pressure (BP), and fasting plasma glucose levels in adult populations. Data extraction: Seventeen chronic trials were included. Quantitative data were examined using a random effects meta-analysis and meta-regression with trial sequential analysis to account for type I and type II errors. Data analysis: Hibiscus exerted stronger effects on systolic BP (-7.10 mmHg [95%CI, -13.00, -1.20]; I2 = 95%; P = 0.02) than placebo, with the magnitude of reduction greatest in those with elevated BP at baseline. Hibiscus induced reductions to BP similar to that resulting from medication (systolic BP reduction, 2.13 mmHg [95%CI, -2.81, 7.06], I2 = 91%, P = 0.40; diastolic BP reduction, 1.10 mmHg [95%CI, -1.55, 3.74], I2 = 91%, P = 0.42). Hibiscus also significantly lowered levels of low-density lipoprotein compared with other teas and placebo (-6.76 mg/dL [95%CI, -13.45, -0.07]; I2 = 64%; P = 0.05). Conclusions: Regular consumption of hibiscus could confer reduced cardiovascular disease risk. More studies are warranted to establish an effective dose response and treatment duration. Systematic review registration: PROSPERO registration no. CRD42020167295.
... Even in the in vivo test, Chrysanthemum indicum Linne, which contains coumarin, trans-cinnamic acid, etc., can reduce serum uric acid levels [117]. Moreover, the flavonoids in Hibiscus sabdariffa L. are also able to reduce uric acid levels in the body by providing a diuretic effect [118]. However, seeing the results shown above, it may be that phenolic compounds from various edible flowers also have potential as uricosuric agents, and this needs further research. ...
Article
Full-text available
Edible flowers have been widely consumed for ages until now. The attractive colors and shapes, exotic aroma, and delightful taste make edible flowers very easy to attain. Moreover, they also provide health benefits for consumers due to the unique composition and concentration of antioxidant compounds in the matrices. Knowing the bioactive compounds and their functional properties from edible flowers is necessary to diversify the usage and reach broader consumers. Therefore, this reported review could be useful for functional product development, engaging the discussed edible flowers. We present a comprehensive review of edible flower composition and the functional properties of their antioxidant compounds, mainly phenolics.
... In addition, their extracts are at present promoted as supplements due to their apparent potential health benefit. Thus, it has also been reported that these flowers, which are usually used to prepare beverages in several countries, have some therapeutic qualities such as hypertension treatment, antiinflammatory, and diuretics (Alarcón-Alonso et al., 2012;Hopkins et al., 2013). ...
Article
The aim of this study was to determine the effect of roselle (Hibiscus sabdariffa L.) aqueous extracts addition on the chemical, physico‐chemical and sensorial properties of frankfurters‐type sausages. For that, five formulations were prepared: the original mixture was used as control sample (CS). The other samples were formulated added roselle extract at 2% (RAE2), 4% (RAE4), 6% (RAE6), and 8% (RAE8). No differences were found in proximate composition between CS and samples added with roselle extracts. However, the residual nitrite levels decreased from 88.41 mg NaNO2/kg in CS to 69.82 mg NaNO2/kg in RAE8. Compared with CS, reformulated samples showed similar emulsion stability, water activity, and fatty acid profile while lipid oxidation values lipid oxidation values progressively increased with the roselle extract addition (0.23 and 0.32 mg malonaldehyde/kg sample, for CS and RAE8, respectively). Regarding the sensory analysis of the frankfurters, CS and RAE4 samples scored significantly higher than other samples.
Article
Background : Medicinal plants or herbs produce a bounty of bioactive phytochemicals. These phytochemicals can influence a variety of physiological events related to cardiovascular health through multiple underlying mechanisms, such as their role as antioxidative, anti-ischemic, anti-proliferative, hypotensive, anti-thrombotic, and anti-hypercholesterolemic agents. Purpose : The purpose of this review is to summarize and connect evidences supporting the use of phytotherapy in the management of some of the most common cardiovascular impairments, molecular mechanisms underlying cardio-protection mediated by herbs, and clinical studies which are positively linked with the use of herbs in cardiovascular biology. Additionally, we also describe several adverse effects associated with some of the herbal plants and their products to provide a balanced set of studies in favor or against phytotherapy in cardiovascular health that may help global discourses on this matter. Methods : Studies relating to the use of medicinal plants were mined by strategically searching scientific databases including Google Scholar, PubMed and Science Direct. Investigations involving approximately 175 articles including reviews, research articles, meta-analyses, and cross-sectional and observational studies were retrieved and analyzed in line with the stated purpose of this study. Results : A positive correlation between the use of medicinal plants and cardiovascular health was observed. While maintaining cardiovascular physiology, medicinal plants and their derivatives seem to govern a variety of cellular mechanisms involved in vasoconstriction and vasorelaxation, which in turn, are important aspects of cardiovascular homeostasis. Furthermore, a variety of studies including clinical trials, cross-sectional studies, and meta-analyses have also supported the anti-hypertensive and thus, cardio-protective effects, of medicinal plants. Apart from this, evidence is also available for the potential drawbacks of several herbs and their products indicating that the unsupervised use of many herbs may lead to severe health issues. Conclusions : The cardio-protective outcomes of medicinal plants and their derivatives are supported by ever-increasing studies, while evidences exist for the potential drawbacks of some of the herbs. A balanced view about the use of medicinal plants and their derivative in cardiovascular biology thus needs to be outlined by researchers and the medical community. The novelty and exhaustiveness of the present manuscript is reflected by the detailed outline of the molecular basis of “herbal cardio-protection”, active involvement of several herbs in ameliorating the cardiovascular status, adverse effects of medicinal plants, and the clinical studies considering the use of phytotherapy, all on a single platform.
Article
Several exotic plants (non‐native) are used in Brazilian traditional medicine and are known worldwide for their possible diuretic actions. Among the wide variety of plants, standing out Achillea millefolium L., Camellia sinensis L. Kuntze, Crocus sativus L., Hibiscus sabdariffa Linn., Petroselinum crispum (Mill.) A.W. Hill, Taraxacum officinale (L.) Weber, and Urtica dioica L., whose effects have already been the subject of some scientific study. In addition, we also discussed other exotic species in Brazil used popularly, but that still lack scientific studies, like the species Arctium lappa L., Carica papaya L., Catharanthus roseus (L.) G. Don, Centella asiatica (L.) Urb, Citrus aurantium L., and Persea americana Mill. However, generally, clinical studies on these plants are scarce. In this context, different plant species can be designated for further comprehensive studies, therefore, promoting support for developing an effective medicine to induce diuresis.
Article
El potencial farmacológico de los extractos del cáliz de Hibiscus sabdariffa L. en alteraciones metabólicas como hipertensión, dislipidemia e hiperuricemia, ha sido demostrado in vitro, in vivo y en ensayos clínicos, observándose una estrecha relación con la estabilidad química, en la extracción y almacenaje de los compuestos bioactivos, así como en su comportamiento en los compartimientos biológicos. Los extractos de sus cálices se caracterizan por un bajo grado de toxicidad, con una DL50 en ratas por encima de 5000 mg/kg. En vista de sus propiedades farmacológicas, y su alta seguridad reportada, los extractos y sus compuestos aislados podrían ser una fuente de productos terapéuticamente útiles. El objetivo de ésta revisión es examinar la evidencia de los compuestos bioactivos, los factores que influyen en su potencial farmacológico, y la efectividad y seguridad terapéutica de H. sabdariffa demostrada a nivel in vivo y en ensayos clínicos.
Article
In recent years, a new trend in the food industry is the use of flowers in food production. Although currently consumed on a relatively small scale around the world, edible flowers have been a source of nutritional diets since ancient times due to their aesthetic appeal and desirable aroma. The importance of color acceptability and the need to meet and attract more consumers to market have led to the development of new pigments for industrial products. Due to the instability of natural pigments, physical and chemical changes during processing, several pre‐preservation techniques that yield high quality product cost‐effectively have been proposed to improve the stability, phytochemicals, nutritional and functional characteristics of several commonly consumed edible flowers are discussed. This article comprehensively reviewed the recently developed processing and preservation technologies for color retention, anthocyanin degradation and anthocyanin‐related enzyme inactivation as well as various methodologies for the extraction of anthocyanins from edible flowers. It should be noted that not all flowers are safe to consume due to potential presence of natural toxins.
Article
Hypertension has become the leading risk factor for worldwide cardiovascular diseases. Conventional pharmacological treatment, after both dietary and lifestyle changes, is generally proposed. In this review, we present the antihypertensive properties of phytocomplexes from thirteen plants, long ago widely employed in ethnomedicines and, in recent years, increasingly evaluated for their activity in vitro and in vivo, also in humans, in comparison with synthetic drugs acting on the same systems. Here, we focus on the demonstrated or proposed mechanisms of action of such phytocomplexes and of their constituents proven to exert cardiovascular effects. Almost seventy phytochemicals are described and scientifically sound pertinent literature, published up to now, is summarized. The review emphasizes the therapeutic potential of these natural substances in the treatment of the 'high normal blood pressure' or 'stage 1 hypertension', so-named according to the most recent European and U.S. guidelines, and as a supplementation in more advanced stages of hypertension, however needing further validation by clinical trial intensification.
Article
In this study, aqueous and ethanol extracts of Iranian produced green tea, black tea and roselle calyces were considered for measurements with respect to their total phenol content (TPC), total flavonoids content (TFC), total tannin content (TTC), total anthocyanins content (TAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. In addition, the concentrations of copper (Cu), iron (Fe), and zinc (Zn) were quantified. High-performance liquid chromatography (HPLC) analysis protocols were optimized for the quantification of 17 phenolic acids and flavonoids compounds. The highest TPC and TFC were observed in the ethanol extract of green tea. The aqueous extract of green tea showed the maximum TTC. The highest TAC was obtained in the aqueous and ethanol extracts of roselle calyces. HPLC analysis of the methanolic extract showed the presence of caffeic acid, quercetin, hesperidin and hesperetin in all of the studied samples. The minerals were present at concentrations well below the acceptable daily consumption level recommended by health limitation guidelines.
Article
Roselle ( Hibiscus sabdariffa ) is a native plant in Malaysia and it is often reported on its nutritional and medicinal values. To date, numerous studies have been conducted on roselle, both calyx and seed, and it is proven that the major bioactive compounds in calyx are ascorbic acid and anthocyanin, whereas the seed is rich in carbohydrates, proteins and unsaturated fatty acids, which are a good source of minerals and antioxidants. The utilization of roselle is commonly noticeable in food, cosmetic and personal care industries. It is interesting to note that the constituents present in roselle calyx and seed extract, which are anthocyanin, fatty acids and tocopherol, make it possible to be exploited in the pharmaceutical industry. Thus, this paper discusses the potential of roselle extract to be used as a health supplement, by reviewing its extraction methods, selected phytochemicals and also its future perspective in the pharmaceutical industry.
Article
• The present study aimed to determine the effect of Hibiscus sabdariffa and Zingiber officinale on antihypertensive activity and pharmacokinetic of losartan in hypertensive rats. • Hypertension was induced in rats by oral administration of L-NAME (40 mg/kg per day). Pharmacodynamics and pharmacokinetics of losartan were evaluated without and with herbal treatment in hypertensive rats. • Treatment of hypertensive rats with investigated herbs substantially reduced systolic blood pressure (SBP), and diastolic blood pressure (DBP) of rats. Treatment of rats (n = 5) with L-NAME plus H. sabdariffa plus losartan and L-NAME plus Z. officinale plus losartan reduced SBP by 16.20% and 14.88% and DBP by 14.82% and 17.52% respectively after 12 h, as compared to L-NAME alone treated rats. In a pharmacokinetic study, the Cmax and AUC0-t of losartan in L-NAME plus H. sabdariffa plus losartan and L-NAME plus Z. officinale plus losartan treated rats was increased by 0.7, 1.99 and 1.51, 3.00 fold respectively in comparison to the Cmax and AUC0-t obtained for L-NAME plus losartan treated group. In conclusion, both the investigated herbs significantly increased the antihypertensive effect and plasma concentration of losartan in L-NAME induced hypertensive rats. The current study predicted that the herb-drug interaction between H. sabdariffa-losartan and Z. officinale-losartan could occur; hence these results in rats may warrant further studies in humans, either in humans or in in vitro human liver microsomes.
Article
Calyx of Hibiscus Sabdariffa is found to possess ‘anthocyanin’ as major pigment and has been chosen as the natural dye for the present investigation. The calyx is found to contain both cyanidin and delphidin complexes usually in the form of glycosides and are bound to acyl functional groups. These functional groups contribute to the colour stability of the extract of Hibiscus Sabdariffa and are helpful in easy bonding with TiO2 molecules. In this study, undoped and doped TiO2 nanostructures have been synthesized by simple hydrothermal method. Structural studies reveal the presence of rutile phase and formation of secondary phase in case of doped samples. Morphological analysis revealed the formation of nanorods and nanoflowers depending on the dopant concentration. The photoelectric conversion efficiency of 6% sodium doped TiO2 based DSSC was 1.65% and is 79% higher than the undoped TiO2 based DSSC that exhibited an efficiency of 0.92%. This efficiency value has been further found to improve by doping yeast and 6% sodium+6% yeast doped TiO2 based DSSC was found to exhibit an improved performance of 2.40%. Even dye stability studies of doped TiO2 based DSSC revealed that the fabricated DSSCs are stable even after a period of 11 weeks.
Article
Full-text available
Demand for more attractive and high quality food is growing every day. The increasing interest in functional foods and nutraceuticals has exaggerated exploration into new foods that have positive effects on human wellbeing. Even more we see edible flowers as a new way of nutritional health. Edible flowers are non-poisonous, giving any dish new colour, texture and freshness, and apart from the "alluring" factor, they are potential sources of phytochemicals. Various phytochemicals such as flavonoids, anthocyanins, carotenoids and phenolics are responsible for health promoting effects of edible flowers. Novel evidence regarding the composition and health benefits of edible flowers is imperative and epitomizes an ample cause for their ingestion. However, due to short blossoming period or most of the flowers are consumed by local people as food and medicine. There have been few attempts to use edible flowers, but remaining are still unexplored and need to be exploited in order to attain food and nutritional security and to upsurge the work opportunities for rural people. Hence, to accomplish this, the present review article was aimed to present the research work on edible flowers such as various species of edible flowers, nutritional and phytochemical composition, health benefits of edible flowers, traditional usage, pre and post-harvest technology, functional food products incorporated with edible flowers, marketing and toxicological aspects. This article helps to popularize the edible flowers among consumers and food industry which are very potent source of nutraceutical compounds.
Article
Full-text available
Hibiscus species (Malvaceae) have been long used as an antihypertensive folk remedy. The aim of our study was to specify the optimum solvent for extraction of the angiotensin-converting enzyme inhibiting (ACEI) constituents from Hibiscus sabdariffa L. The 80% methanol extract (H2) showed the highest ACEI activity, which exceeds that of the standard captopril (IC50 0.01255 ± 0.00343 and 0.210 ± 0.005 µg/mL, respectively). Additionally, in a comprehensive metabolomics approach, an ultra-performance liquid chromatography (UPLC) coupled to the high resolution tandem mass spectrometry (HRMS) method was used to trace the metabolites from each extraction method. Interestingly, our comprehensive analysis showed that the 80% methanol extract was predominated with secondary metabolites from all classes including flavonoids, anthocyanins, phenolic and organic acids. Among the detected metabolites, phenolic acids such as ferulic and chlorogenic acids, organic acids such as citrate derivatives and flavonoids such as kaempferol have been positively correlated to the antihypertensive potential. These results indicates that these compounds may significantly contribute synergistically to the ACE inhibitory activity of the 80% methanol extract.
Article
Context The impact of food and drinks on body fluid metabolism is of direct clinical relevance but current evidence remains fragmented. Aim Synthesize current evidence on the role of food and drinks in urine production. Methods Systematic review as per PRISMA guidelines using MEDLINE and EMBASE databases (completed October 2019). Studies reporting on the effect of food, food constituents, and drinks on urine production were included. Two authors performed an independent extraction of relevant articles using predetermined datasets and completed quality‐of‐study indicators. Results A total of 49 studies were included, of which 21 enrolled human subjects, and 28 were clinically‐ relevant animal studies (all of which utilized rodent models). The included studies were determined to be of variable quality. High dietary sodium, as well as wine, spirits, high‐caffeine coffee, and caffeinated energy drinks, increased urine production in human studies. Decreased urine production was associated with low dietary sodium and consumption of milk, orange juice, and high‐salt/high‐sugar drinks. In animal models, a variety of fruits, vegetables, herbs, spices, and honey were associated with increased urine production. Conclusion Current evidence suggests that although several types of food and drinks may impact body fluid metabolism, the quality of the data is variable. Urine production appears to be influenced by multiple factors including composition (i.e., moisture, macronutrients, and electrolytes), metabolite load, and the presence of specific diuresis‐promoting substances (e.g., caffeine, alcohol) and other bioactive phytochemicals. Future research is needed to support current evidence and the physiologic mechanisms underlying these findings.
Article
Hypertension is a critical health problem and worse other cardiovascular diseases. It is mainly of two types: Primary or essential hypertension and Secondary hypertension. Hypertension is the primary possibility feature for coronary heart disease, stroke and renal vascular disease. Herbal medicines have been used for millions of years for the management and treatment of hypertension with minimum side effects. Over aim to write this review is to collect information on the anti-hypertensive effects of natural herbs in animal studies and human involvement as well as to recapitulate the underlying mechanisms, from the bottom of cell culture and ex-vivo tissue data. According to WHO, natural herbs/shrubs are widely used in increasing order to treat almost all the ailments of the human body. Plants are the regular industrial units for the invention of chemical constituents, they used as immunity booster to enhance the natural capacity of the body to fight against different health problems as well as herbal medicines and food products also. Eighty percent population of the world (around 5.6 billion people) consume medicines from natural plants for major health concerns. This review provides a bird's eye analysis primarily on the traditional utilization, phytochemical constituents and pharmacological values of medicinal herbs used to normalize hypertension i.e.
Article
Full-text available
This research aims to describe using techniques of scientific and technological forecasting information about the vegetable species Hibiscus sabdariffa L. present on the banks of national and international data evaluating its chemical aspects and pharmacological/medical applications. For this, searches were conducted in scientific data bases Web of Science and Scopus and patent banks: National Institute of Industrial Property (INPI) and World Intellectual Property Organization (WIPO). The bases studied, Scopus and WIPO were obtained which results in more number of publications and patents filed. Nigeria was the country that published on hibiscus in the 2007-2017 period, followed by India and Taiwan. China was the country with the highest number of registered patents, holding 53% of the results. Brazil has a low proportion in the number of deposits. Documents found in the WIPO classified into sections A and C of the IPC classification, with most of them included in subclass A61K (preparations for medical, dental or hygienic purposes).
Chapter
The Roselle (Hibiscus sabdariffa) is being extensively used in folk medicine owing to its rich phytochemical profile including polyphenols, especially anthocyanins, organic acids, and polysaccharides, thereby offering greater prospects in therapeutic and medicinal uses. The Roselle infusions or decoctions present significant therapeutic options against various degenerative ailments such as hyperlipidemia, hypertension, diabetics, cancer, hepatoprotection, nephroprotection, and many others. The previous work supports the scientific hypothesis that Roselle plant enriched with bioactive constituents plays an imperative role in the management of degenerative and chronic diseases that are associated with oxidative stress. However, well-designed animal and human studies are underway to precisely quantify the therapeutic potential of purified phytochemical preparations. This work aims to review and document the scientific evidence about the potential therapeutic uses of the Roselle plant.
Article
Cardiovascular diseases (CVD) are the foremost cause of death worldwide. The main risk factor for CVD is uncontrolled hypertension (HTN). The prescription of only anti-hypertensive regimens in the management of HTN is becoming more challenging due to the high cost and adverse effects linked to the persistent usage of the drugs. Eighteen participants completed the study by consuming 2g of Hibiscus sabdariffa or oolong tea twice daily for six weeks. We lost an additional twelve participants in the study due to the COVID-19 pandemic. Central arterial stiffness was analyzed as cfPWV using applanation tonometry technique. The HS tea intervention (n=11) had a significant positive effect on SBP (P =0.02), DBP (P =0.001) and HR (P =0.03). Also, the HS tea consumption led to a non-significant (p=0.44) reduction in cfPWV (-0.5m/s) when compared to control tea (+0.3m/s). Although, the decease in cfPWV could be clinically significant, but will need to be verified with larger sample size.
Article
Full-text available
Hypertension is a critical health problem and worse other cardiovascular diseases. It is mainly of two types: Primary or essential hypertension and Secondary hypertension. Hypertension is the primary possibility feature for coronary heart disease, stroke and renal vascular disease. Herbal medicines have been used for millions of years for the management and treatment of hypertension with minimum side effects. Over aim to write this review is to collect information on the anti-hypertensive effects of natural herbs in animal studies and human involvement as well as to recapitulate the underlying mechanisms, from the bottom of cell culture and ex-vivo tissue data. According to WHO, natural herbs/shrubs are widely used in increasing order to treat almost all the ailments of the human body. Plants are the regular industrial units for the invention of chemical constituents, they used as immunity booster to enhance the natural capacity of the body to fight against different health problems as well as herbal medicines and food products also. Eighty percent population of the world (around 5.6 billion people) consume medicines from natural plants for major health concerns. This review provides a bird’s eye analysis primarily on the traditional utilization, phytochemical constituents and pharmacological values of medicinal herbs used to normalize hypertension i.e. Hibiscus sabdariffa , Allium sativum, Andrographis paniculata, Apium graveolens, Bidenspilosa, Camellia sinensis, Coptis chinensis, Coriandrum sativum, Crataegus spp., Crocus sativus, Cymbopogon citrates, Nigella sativa, Panax ginseng,Salviaemiltiorrhizae, Zingiber officinale, Tribulus terrestris, Rauwolfiaserpentina, Terminalia arjuna etc. Graphic Abstract
Article
Full-text available
Roselle, Hibiscus sabdariffa L., is cultivated extensively for food and income generation in Africa, but research on biotic constraints to its production has been scanty. A 48-plot (5m×5m wide each) field experiment laid in randomized complete block design was used to document the relative abundance (% RA), diversity, richness, and temporal spread of insect species infesting the crop at Makurdi, Nigeria. The insects were collected from all parts of early- and late-sown green-calyx (H. sabdariffa var. sabdariffa) and red-calyx (H. sabdariffa var. altissima) Roselle shoots. About 101 species (81 herbivores, 18 predators, 1 parasitoid, and 1 pollinator) in 45 families and 8 orders were collected. Shannon’s diversity index (2.1-2.4) and Margalef’s richness index (8.3-10.0) indicate a rich diversity of species on the crop. However, evenness of species, measured by Buzas and Gibson’s index, was low (0.1-0.41). The orders Coleoptera and Hemiptera accounted for 72.0% of the collection. Nineteen species were moderately (≥1 RA<5%) to highly abundant (RA≥10%) on the crop and among them Monolepta thompsoni Allard and Nisotra sjostedti Jac. were ubiquitous causing extensive leaf perforation all through the entire crop growth period. At the reproductive stage of growth, Dysdercus volkeri Fab., Oxycarenus hyalinipennis Costa and Earias sp. were the dominant insects causing fruit and seed damage. The frequency of occurrence and densities of M. thompsoni Allard, N. sjostedti Jac., D. volkeri Fab., O. hyalinipennis Costa and Earias sp. as well as their extensive damage, indicate that they are the key field pests of Roselle at Makurdi.
Article
Full-text available
Development and identification of molecular compounds capable of killing or inhibiting transformed cells promoting carcinogenesis without inducing toxic effects to the normal cells are of utmost significance. A systematic review was conducted in screening for important literature was extensively performed by searching the Web of Science, Ovid, BMC Springer, Elsevier, Embase, and MEDLINE databases for optimum selectivity. Google Scholar was also used to supplement information. Pharmacotherapeutic biomolecules active against colon cancer carcinogenesis in Musa acuminata and Musa balbisiana (bananas), Punica granatum L (pomegranate), Glycine max (Soybean), Brassica oleracea L var. italica Plenck (Broccoli), and Hibiscus rosa-sinesis and Hibiscus sabdariffa (hibiscus) were evaluated. Signaling pathways like phosphatidylinositol 3-kinase (PI3K), mitogen-activated protein kinase (MAPK), protein kinase B (AKT), and nuclear factor-kappa B (NFκB) correlate the mediation of COX-2 expression. Increased levels of COX-2 are correlated with the occurrence and progression of colon cancer. Natural antioxidants in herbal plants including polyphenols and carotenoids inhibit the oxidation of lipids, proteins, and nucleic acids and thereby preventing the initiation of oxidizing chain reactions. These bioactive compounds should be considered an important dietary supplement.
Article
Ethnopharmacological relevance Hibiscus species (Family: Malvaceae) have long been used in traditional medicine to treat a variety of maladies such as abscesses, bilious conditions, cancer, cough, fatigue, gastrointestinal discomfort, fever, veisalgia, cardiovascular disorders, neurosis, scurvy, and urinary tract disorders. Its antioxidants have the capacity to destroy free radicals that damage cells and increase risk of inflammatory conditions such as metabolic syndrome, cancer, and cardiovascular disease. Aim of the study: This review synthesizes findings from animal studies and clinical trials to assess effectiveness of hibiscus for treating biomarkers of metabolic syndrome including hyperglycemia, hypertriglyceridemia, low high-density lipoprotein, obesity, and hypertension. Materials and methods We searched for 12 edible species of hibiscus in the Google Scholar database. Each scientific name of these species, their common names, and their edible plant parts were searched in conjunction with fourteen key words associated with metabolic syndrome. A total of 68 articles met all inclusion criteria for this review, including 18 that tested human subjects, 48 that tested other animals, one that tested humans and other animals, and one that did not specify. Results Hibiscus often improved blood glucose, total cholesterol, high-density lipoprotein cholesterol, triglycerides, blood pressure, weight, lipid absorption and oxidation of fatty acids within vital organs around the abdominal cavity. Higher doses led to greater benefits in some cases, especially for body mass of animals, but lower doses were often equally effective. Hibiscus was often equally or more effective than pharmaceuticals in improving some biomarkers of metabolic syndrome, especially blood glucose and insulin sensitivity. Conclusion Hibiscus shows great promise for improving biomarkers of metabolic syndrome, but there are limitations that need to be addressed by future work, including increasing the number and size of human clinical trials, expanding human trials to include people from a greater diversity of ethnicities, taking into account the health and physical activity of human participants, investigating the influence of growing conditions and extraction/preparation techniques on nutrients in hibiscus, comparing the efficacy of several plant parts and plant products of hibiscus to a reference control group within the same experiment, incorporating rigorous statistical analysis of treatments and investigating the influence of dosage.
Article
Hibiscus sabdariffa L. (HS) calyx extracts have been well-documented for the treatment of hypertension, liver dysfunctions, and diabetes among others. An updated concise review of HS regarding phytoconstituents, and involved putative mechanisms of potential biological activities is presented. HS showed other food and other industrial applications, including the preparation of metallic nanoparticles. These activities were explained by the presence of a broad spectrum of valuable phytochemicals, including the red pigments anthocyanins, phenolic, and organic acids and polyphenolics (e.g., flavonoids and tannins). Most of the bioactivities were found to be associated with anthocyanins-rich extracts. Anthocyanins were found to have various mechanisms for the treatment of hypertension, including direct vasodilation and inhibition of angiotensin-converting enzyme (ACE). However, leaves and seeds showed also other potential applications in food industry, owing to the significant amounts of phenolic antioxidant compounds. Therefore, valorization and optimization of bioactive constituents’ extraction from plant biowastes should be considered for maximizing the benefits of HS extracts.
Article
Hibiscus sabdariffa, this beverage has been used for millennia as both a delicious cultural beverage and an ancient medicinal therapy. In recent years, many studies have investigated the uses and mechanisms of action of Hibiscus sabdariffa to treat common chronic diseases. In this literature review, we place the spotlight on Hibiscus sabdariffa's medical effect on common chronic diseases, the flower commonly used to make hibiscus tea. The databases PubMed, MEDLINE, Clinical Key, and CINAHL were searched for studies related to Hibiscus sabdariffa's compounds, antioxidative and anti-inflammatory features, mechanism of action on common chronic diseases including hypertension, hyperlipidemia, obesity, diabetes, and Alzheimer's disease. Hibiscus sabdariffa antihypertensive potentials originate from the vasodilator activity, diuretic efficacy, functionality as an ACE inhibitor, adipocyte differentiation inhibitor, heart rate reduction ability, and anti-inflammatory mechanistic. The antihyperlipidemic effect is dose-dependent and stems from the antioxidative effect and the activation of AMPK through phosphorylation and the inhibition of regulatory adipogenic transcription factors PPAR-γ, C/EBP-α, and SREBP-1c, which altogether results in lipid-lowering effect. As an antihyperglycemic, Hibiscus sabdariffa serves as anti-insulin resistance by inhibition of the phosphorylation of IRS-1 beside a similar effect to gliptins. Finally, Hibiscus sabdariffa was proven to protect against neuroinflammation in microglial cell culture exposed to LPS by decreasing IL-1, IL-6, TNF-α expression, and the protective effect against glucotoxicity, improve memory function by inhibiting the formation of hyperphosphorylated tau proteins in the mouse brain. Regular consumption of hibiscus tea or extract is beneficial for a reduction in chronic disease risk and diagnosis. • Key teaching points • Hibiscus sabdariffa, or hibiscus, has been used for millennia as both a delicious cultural beverage and an ancient medicinal therapy. Recent studies have investigated the uses of Hibiscus sabdariffa to treat common chronic diseases. • Its antihypertensive potential originates from the vasodilator activity, diuretic efficacy, functionality as an ACE inhibitor, adipocyte differentiation inhibitor, heart rate reduction ability, and anti-inflammatory mechanistics. • The antihyperlipidemic effect is dose-dependent and stems from the antioxidative effect and the activation of AMPK through phosphorylation and also the inhibition of regulatory adipogenic transcription factors PPAR-γ, C/EBP-α and SREBP-1c which all together results in lipid-lowering effect. • As an antihyperglycemic, Hibiscus sabdariffa serves as anti-insulin resistance by inhibition of the phosphorylation of IRS-1 beside the similar effect to gliptins. • Hibiscus sabdariffa was proven to protect against neuroinflammation in microglial cell culture exposed to LPS by decreasing IL-1, IL-6, TNF-α expression, and the protective effect against glucotoxicity, improve memory function by inhibiting the formation of hyperphosphorylated tau proteins in the mouse brain.
Article
The aqueous calyx extract of Hibiscus sabdariffa (HS) is widely consumed as a beverage in Northern Nigeria and other parts of the world. HS has been reported to lower blood pressure (BP) in animals and man. However, not much is known about the effect of HS on BP in different postures. We tested the hypothesis that HS may lower BP, heart rate (HR) and heart rate-pressure product or double product (DP) by attenuating the discharge of the autonomic nervous system in different postures. Experiments were performed in accordance with the Principles of the Declaration of Helsinki. Following ethical approval and informed consent, BP and HR were measured in different postures (supine, sitting and standing) in apparently healthy human subjects (n=20) before and after (+HS) the oral administration of 15mg/Kg HS. Mean arterial pressure (MAP; taken as representative BP) and DP were calculated. Results are expressed as mean ±SEM. Paired t test and ANOVA with a post hoc Bonferroni test were used for statistical analyses. P<0.05 was considered significant. In the supine position MAP, HR and DP were significantly (P<0.0001 each) reduced in the presence of HS (85.6±1.7mmHg, 72.1±1.1/min and 8716±320mmHg.bpm) compared to its absence (89.6±2.0mmHg, 73.7±1.6/min and 8921±444mmHg.bpm). Similar trends were observed in the sitting position in the presence of HS (85.4±2.7mmHg, 73.7±1.8/min and 9098±345mmHg.bpm vs its absence: 91.4±2.3mmHg, 77.1±1.9/min and 9388±478mmHg.bpm; P<0.0001, P<0.0001 and P=0.007 respectively) and in the standing position (+HS: 89.3±2.0mmHg, 78.1±1.8/min and 10164±230mmHg.bpm vs its absence: 94.3±2.1mmHg, 81.8±2.3/min and 10742±268mmHg.bpm; P<0.0001, P<0.0001 and P=0.007 respectively). In the absence of HS, HR and DP were significantly higher in the standing posture (81.8±2.3/min, 10742±268mmHg.bpm) compared to the sitting (77.1±1.9/min, 9388±478mmHg.bpm; P<0.05 and P<0.0001 respectively) and the supine (73.7±1.6/min, 8921±444mmHg.bpm; P<0.001 each) postures while the BP remained similar. A similar trend was observed across the three postures in the presence of HS although the parameters were significantly lower. It is concluded that HS lowered BP, HR and DP by modulating autonomic mechanisms through the inhibition of both parasympathetic withdrawal and sympathetic nervous system discharge across the postures. Also the standing posture is associated more with a higher sympathetic nervous system discharge and a higher cardiac oxygen demand and workload than the sitting and supine postures in the absence or presence of HS.
Article
Full-text available
Background: Dietary sodium restriction enhances the antiproteinuric and blood pressure lowering effect of ACE inhibition. In clinical practice, however, long-term compliance to a low-sodium diet may be difficult to obtain. We therefore investigated whether the blunting of the antiproteinuric and blood pressure lowering efficacy of ACE inhibition by high sodium intake can be restored by the addition of a diuretic. Patients and methods: Seven proteinuric patients with non-diabetic renal disease on chronic ACE inhibition were studied during three consecutive 4-week periods: low sodium (50 mmol/day), high sodium (200 mmol/day) and high sodium plus hydrochlorothiazide (50 mg o.i.d.). Results: During low sodium intake proteinuria was 3.1 (0.7-5.2) g/day, during high sodium intake proteinuria increased to 4.5 (1.6-9.2) g/day (P < 0.05). Interestingly, addition of hydrochlorothiazide again reduced proteinuria to 2.8 (0.6-5.8) g/day (P < 0.05). Mean arterial blood pressure was 89 (84-96), 98 (91-104) and 89 (83-94) mmHg (P < 0.05) during the three periods, respectively. Conclusion: Addition of hydrochlorothiazide can overcome the blunting of the therapeutic efficacy of ACE inhibition on proteinuria and blood pressure by a high sodium intake.
Article
Full-text available
The effect of quercetin, a plant-derived bioflavonoid with documented positive effect on the cardiovascular system, was examined after 4-week supplementation in the dose of 20 mg kg(-1) x day(-1) to young male normotensive control (C) and to spontaneously hypertensive rats (SHR) over the period of their 5(th)-8(th) week of age. The study was focused on the influence of quercetin on properties of the renal Na,K-ATPase, a key system in maintaining the homeostasis of sodium in the organism. Spontaneous hypertension by itself enhanced the activity of Na,K-ATPase probably as a consequence of a higher number of active enzyme molecules, as suggested by the 15% increase of V(max), along with improved affinity to ATP, as indicated by the 30% decrease in the value of Michaelis-Menten constant K(m) in untreated SHR vs. untreated normotensive rats. Quercetin induced a decrease of Na,K-ATPase activity in the presence of all ATP and Na(+) concentrations investigated. Evaluation of kinetic parameters resulted in a constant V(max) value. The ATP-binding properties of the enzyme were not influenced by quercetin, as suggested by statistically insignificant changes in the value of K(m) both in controls and in SHR. On the other hand, the affinity to sodium decreased, as suggested by an increase in the K(Na) value by 22% and 31% in normotensive and hypertensive groups, respectively. This impairment in the affinity of the Na(+)-binding site of Na,K-ATPase molecules was probably responsible for the deteriorated enzyme function in the kidneys of quercetin treated animals.
Article
Full-text available
In vitro studies show Hibiscus sabdariffa L., an ingredient found in many herbal tea blends and other beverages, has antioxidant properties, and, in animal models, extracts of its calyces have demonstrated hypocholesterolemic and antihypertensive properties. Our objective in this study was to examine the antihypertensive effects of H. sabdariffa tisane (hibiscus tea) consumption in humans. A randomized, double-blind, placebo-controlled clinical trial was conducted in 65 pre- and mildly hypertensive adults, age 30-70 y, not taking blood pressure (BP)-lowering medications, with either 3 240-mL servings/d of brewed hibiscus tea or placebo beverage for 6 wk. A standardized method was used to measure BP at baseline and weekly intervals. At 6 wk, hibiscus tea lowered systolic BP (SBP) compared with placebo (-7.2 +/- 11.4 vs. -1.3 +/- 10.0 mm Hg; P = 0.030). Diastolic BP was also lower, although this change did not differ from placebo (-3.1 +/- 7.0 vs. -0.5 +/- 7.5 mm Hg; P = 0.160). The change in mean arterial pressure was of borderline significance compared with placebo (-4.5 +/- 7.7 vs. -0.8 +/- 7.4 mm Hg; P = 0.054). Participants with higher SBP at baseline showed a greater response to hibiscus treatment (r = -0.421 for SBP change; P = 0.010). No effects were observed with regard to age, gender, or dietary supplement use. These results suggest daily consumption of hibiscus tea, in an amount readily incorporated into the diet, lowers BP in pre- and mildly hypertensive adults and may prove an effective component of the dietary changes recommended for people with these conditions.
Article
Full-text available
Effects of L-arginine (ARG) infusion on renal and systemic hemodynamics were studied in 12 anesthetized dogs. The experiment was performed in two groups of dogs. The dogs of group 1 (n = 6) received intravenous ARG at 2.5 mmol/kg followed by indomethacin (IND) injection (10 mg/kg) and were rechallenged with ARG at the same amount. The dogs of group 2 (n = 6) received intravenous ARG at 5 mmol/kg followed by IND injection (10 mg/kg) and were later infused with ARG at the same dose. In group 1, the first ARG infusion caused no significant changes in renal and systemic hemodynamics. During the second ARG infusion, glomerular filtration rate (GFR) and renal plasma flow (RPF) were significantly increased when compared with the IND-treated period. In group 2, the first ARG infusion increased cardiac output (CO) and decreased total peripheral resistance (TPR) without significant changes in GFR and RPF. The second ARG infusion induced acute rise of both GFR and RPF approximately twofold, compared with the IND-treated period. CO was also increased significantly. Plasma glucagon levels determined in 2 dogs showed an increase following both ARG infusions. These results indicate that an acute ARG loading induces renal and systemic vasodilatation in a dose-dependent manner despite IND effect, and would indicate that increased renal hemodynamics are not prostaglandin-mediated.
Article
Full-text available
Through ethnobotanical surveys in Guatemala, about 250 plants were identified for use in the treatment of urinary ailments. From 67 of these, aqueous extracts were prepared to investigate their oral diuretic activity in albino rats after a dose equivalent to 1 g/kg of dried plant material. The trials demonstrated that in 33 cases urinary excretion was not significantly increased (less than 90%), in 20 cases intermediate activity was seen (90-189%) and in 14 cases high diuretic activity was noted (greater than 189%). Control treatment increased urine output an average of 36% while 25 mg/kg hydrochlorothiazide treatment increased urine output by 286%. In a select group of the most used local plants, ethanol extracts were tested for their effect on urinary excretion of uric acid and electrolytes. Of these, three plants significantly increased uric acid excretion as did the reference drug, probenecid, 25 mg/kg.
Article
Full-text available
The objective of this study was to evaluate the changes of urine in normal subjects after consuming roselle juice in different concentrations and durations which may help the treatment and prevention of renal stone disease. Thirty-six healthy men participated in the study, in which urinalysis, urine electrolytes and indices for measurements of concentration of urine were determined before, during and after roselle juice consumption. The urine after consumption of roselle juice showed a decrease of creatinine, uric acid, citrate, tartrate, calcium, sodium, potassium and phosphate but not oxalate in urinary excretion. The CPR values of the majority of each individual increased and means PI values decreased in phase 1. Contrarily, the CPR values of the majority of volunteers decreased and means PI values increased in phase 2. In conclusion a low dose of roselle juice (16 g/day) caused more significant decrease in salt output in the urine than a high dose (24 g/day). The urinary changes were similar to the observations on villagers with and without stones in northeastern Thailand.
Article
Full-text available
Endothelial nitric-oxide synthase (eNOS) generates the key signaling molecule nitric oxide in response to intralumenal hormonal and mechanical stimuli. We designed studies to determine whether eNOS is localized to plasmalemmal microdomains implicated in signal transduction called caveolae. Using immunoblot analysis, eNOS protein was detected in caveolar membrane fractions isolated from endothelial cell plasma membranes by a newly developed detergent-free method; eNOS protein was not found in noneaveolar plasma membrane. Similarly, NOS enzymatic activity was 9.4-fold enriched in caveolar membrane versus whole plasma membrane, whereas it was undetectable in non-caveolar plasma membrane. 51-86% of total NOS activity in postnuclear supernatant was recovered in plasma membrane, and 57-100% of activity in plasma membrane was recovered in caveolae. Immunoelectron microscopy showed that eNOS heavily decorated endothelial caveolae, whereas coated pits and smooth plasma membrane were devoid of gold particles. Furthermore, eNOS was targeted to caveolae in COS-7 cells transfected with wild-type eNOS cDNA. Studies with eNOS mutants revealed that both myristoylation and palmitoylation are required to target the enzyme to caveolae and that each acylation process enhances targeting by 10-fold. Thus, acylation targets eNOS to plasmalemmal caveolae. Localization to this microdomain is likely to optimize eNOS activation and the extracellular release of nitric oxide.
Article
Full-text available
Dietary sodium restriction enhances the antiproteinuric and blood pressure lowering effect of ACE inhibition. In clinical practice, however, long-term compliance to a low-sodium diet may be difficult to obtain. We therefore investigated whether the blunting of the antiproteinuric and blood pressure lowering efficacy of ACE inhibition by high sodium intake can be restored by the addition of a diuretic. Seven proteinuric patients with non-diabetic renal disease on chronic ACE inhibition were studied during three consecutive 4-week periods: low sodium (50 mmol/day), high sodium (200 mmol/day) and high sodium plus hydrochlorothiazide (50 mg o.i.d.). During low sodium intake proteinuria was 3.1 (0.7-5.2) g/day, during high sodium intake proteinuria increased to 4.5 (1.6-9.2) g/day (P < 0.05). Interestingly, addition of hydrochlorothiazide again reduced proteinuria to 2.8 (0.6-5.8) g/day (P < 0.05). Mean arterial blood pressure was 89 (84-96), 98 (91-104) and 89 (83-94) mmHg (P < 0.05) during the three periods, respectively. Addition of hydrochlorothiazide can overcome the blunting of the therapeutic efficacy of ACE inhibition on proteinuria and blood pressure by a high sodium intake.
Article
Full-text available
Considering the high prevalence of hypertension, its debilitating end organ damage, and the side effects of chemical drugs used for its treatment, we conducted this experimental study to evaluate the effect of sour tea (Hibiscus sabdariffa) on essential hypertension. For this purpose, 31 and 23 patients with moderate essential hypertension were randomly assigned to an experimental and control group, respectively. Patients with secondary hypertension or those consuming more than two drugs were excluded from the study. Systolic and diastolic blood pressures were measured before and 15 days after the intervention. In the experimental group, 45% of the patients were male and 55% were female, and the mean age was 52.6 +/- 7.9 years. In the control group, 30% of the patients were male, 70% were female, and the mean age of the patients was 51.5 +/- 10.1 years. Statistical findings showed an 11.2% lowering of the systolic blood pressure and a 10.7% decrease of diastolic pressure in the experimental group 12 days after beginning the treatment, as compared with the first day. The difference between the systolic blood pressures of the two groups was significant, as was the difference of the diastolic pressures of the two groups. Three days after stopping the treatment, systolic blood pressure was elevated by 7.9%, and diastolic pressure was elevated by 5.6% in the experimental and control groups. This difference between the two groups was also significant. This study proves the public belief and the results of in vitro studies concerning the effects of sour tea on lowering high blood pressure. More extensive studies on this subject are needed.
Article
Full-text available
As new drugs are developed, it is essential to appropriately translate the drug dosage from one animal species to another. A misunderstanding appears to exist regarding the appropriate method for allometric dose translations, especially when starting new animal or clinical studies. The need for education regarding appropriate translation is evident from the media response regarding some recent studies where authors have shown that resveratrol, a compound found in grapes and red wine, improves the health and life span of mice. Immediately after the online publication of these papers, the scientific community and popular press voiced concerns regarding the relevance of the dose of resveratrol used by the authors. The animal dose should not be extrapolated to a human equivalent dose (HED) by a simple conversion based on body weight, as was reported. For the more appropriate conversion of drug doses from animal studies to human studies, we suggest using the body surface area (BSA) normalization method. BSA correlates well across several mammalian species with several parameters of biology, including oxygen utilization, caloric expenditure, basal metabolism, blood volume, circulating plasma proteins, and renal function. We advocate the use of BSA as a factor when converting a dose for translation from animals to humans, especially for phase I and phase II clinical trials.
Article
Full-text available
Orthosiphon stamineus (Labiatae) is a traditional folk medicine widely used in Southeast Asia for the treatment of several kidney disorders, gout and as a diuretic. This study was conducted to examine the diuretic and hypouricemic effects of Orthosiphon stamineus leaf extracts. The diuretic effect of different methanol extracts was examined by treating different groups of Sprague-Dawley rats with single (2g/kg) oral doses of methanol and methanol:water (1:1) extracts. Hydrochlorothiazide (10mg/kg) was used as positive control in acute study. Methanol and methanol water (1:1) extracts at 0.5 g/kg were administered for a period of 7 consecutive days. Cumulative urine volume and electrolytes (Na+ and K+) concentrations at different time intervals were measured. On the other hand, hypouricemic activity of methanol:water extract (1:1) was experimented using different oral single doses (0.25, 0.5, 1 and 2g/kg). Allopurinol was used as positive control. Uric acid concentration in serum was analyzed by using RP-HPLC at 280 nm. Sodium and potassium excretion increased significantly (p<0.05 and <0.01) in the first 8h of treatment with a single dose (2g/kg) of the extracts in a pattern comparable to that of the known diuretic hydrochlorothiazide. Meanwhile, repeated administration of 0.5 g/kg methanol:water (1:1) extract showed a significant increase in urine volume (from day 3 to day 7) (p<0.01) and electrolytes excretion (Na+ and K+) from day 2 to day 7 (p<0.05 and <0.01). On the other hand, 0.5, 1 and 2g/kg of methanol:water (1:1) extract and the standard allopurinol reduced the serum urate level in hyperuricemic rats at hour 6. These results provided an evidence of the high tendency of methanol:water (1:1) extract of Orthosiphon stamineus towards diuretic and hypouricemic effects in rats.
Article
eNOS generates the key signalling molecule nitric oxide (NO) in response to intralumenal hormonal and mechanical stimuli. We designed studies to determine whether eNOS is localized to caveolae, which are invaginated plasma membrane (PM) microdomains implicated in signal transduction. Using immunoblot analysis, eNOS protein was detected in caveolar membrane (CM) fractions isolated from endothelial cell PM by a newly-developed detergent-free method; eNOS protein was not found in noncaveolar plasma membrane (NCPM). Similarly, NOS enzymatic activity was 9.4-fold enriched in CM versus PM, and it was undetectable in NCPM. 51-86% of total NOS activity in postnuclear supernatant was recovered in PM, and 57-100% of activity in PM was recovered in CM. Immunoelectron microscopy for eNOS localized the enzyme to endothelial caveolae, whereas coated pits and smooth PM were devoid of immunosignal. Furthermore, eNOS was targeted to caveolae in COS-7 cells transfected with wild-type eNOS cDNA. Studies with eNOS mutants revealed that both myristoylation and palmitoylation are required to target eNOS to caveolae, and that each acylation process enhancing targeting by 10-fold. Thus, acylation targets eNOS to caveolae. Localization to this microdomain is likely to optimize eNOS activation and extracellular NO release.
Article
Inhibitors of the angiotensin-converting enzyme (ACE) acutely increase sodium excretion. Whether or not continued treatment induces net negative sodium balance is not clear, and may depend on initial sodium balance. We therefore investigated the effects of 8 days of treatment with enalapril, 10 mg b.i.d., on sodium balance in 10 subjects with uncomplicated essential hypertension, in balance on a low (50 mmol sodium/24 h) and a liberal (200 mmol sodium/24 h) sodium intake. Sodium excretion exceeded intake during the first days of treatment, amounting to sodium losses of 101 +/- 24 and 112 +/- 15 mmol in the low and the liberal sodium diets, respectively. The sodium loss was accompanied by a fall in body weight with both regimens. The blood pressure response to enalapril was potentiated by the sodium-restricted diet. The net increase in sodium excretion after enalapril administration, however, was similar for both diets. This was particularly true for individual patients, suggesting an individual response pattern to ACE inhibition.
Article
The folklorically acclaimed diuretic activity of the petal extract of Hibiscus sabdariffa was verified in saline-loaded albino rats (80 – 220 g; n=5) according to the method of De la Peurta Vazquez et al, 1989. A methanolic extract of the dried petals was prepared, and, upon lethal toxicity testing, was found to be very safe – LD50 >5,000 mg/kg, i.p. A metabolic assay was conducted using graded doses (5 mg/kg – 160 mg/kg) The urine produced over a period of six hours was collected per animal and its volume, density, pH, and electrolyte concentrations (Na+, K+ and C-) were determined using standard techniques. The effect of the most active dose level was compared to those of frusemide 3 mg/kg, mannitol 200 mg/kg, hydrochlorothiazide 10 mg/kg, and spironolactone 3 mg/kg. The extract was found to cause a dose-dependent increase in urine mobilization, which peaked at a dose of 40 mg/kg. At this dose level, .the extract showed a significant (p<0.05) aquaretic action characterized by a 300-fold increase in urine production, a slight fall in density and a fall in urine pH, relative to the control group. Although the extract did not increase the mobilization of the urinary electrolytes assayed, as did the standard diuretics used, the observed effects somewhat justify its ethnomedicinal use in the management of oedematous conditions.
Article
The response of renal hemodynamics and sodium excretion (NaU) to an infusion of L-arginine, in the presence (experiment I) or absence (experiment II) of endogenous insulin secretion and during a sustained hyperinsulinemic euglycemic state (experiment III), was studied in 10 age-matched beagle dogs. The experiments were preceded by a standard oral glucose tolerance test (OGTT), performed 1 week before experiment I. One week resting periods were allowed between experiments I, II, and III. No differences in renal hemodynamics and NaU were observed between basal (experiment I) and insulin secretion suppressed states (experiment II). L-Arginine infusion increased renal plasma flow (RPF), glomerular filtration rate (GFR), and NaU to a similar extent in both experiments. The hyperinsulinemic-euglycemic state (experiment III) induced a decrease in renal hemodynamics and NaU. In this situation, the infusion of L-arginine increased NaU, but was unable to increase RPF and GFR. Our data suggest that a sustained hyperinsulinemic state can interact with the physiological vasoactive mechanisms involved in the regulation of renal vasculature. These results may be pertinent to human disease, especially in pathological conditions in which insulin resistance is present. Am J Hypertens 1996;9:681–686
Article
The response of renal hemodynamics and sodium excretion (NaU) to an infusion of L-arginine, in the presence (experiment I) or absence (experiment II) of endogenous insulin secretion and during a sustained hyperinsulinemic euglycemic state (experiment III), was studied in 10 age-matched beagle dogs. The experiments were preceded by a standard oral glucose tolerance test (OGTT), performed 1 week before experiment I. One week resting periods were allowed between experiments I, II, and III.No differences in renal hemodynamics and NaU were observed between basal (experiment I) and insulin secretion suppressed states (experiment II). L-Arginine infusion increased renal plasma flow (RPF), glomerular filtration rate (GFR), and NaU to a similar extent in both experiments. The hyperinsulinemic-euglycemic state (experiment III) induced a decrease in renal hemodynamics and NaU. In this situation, the infusion of L-arginine increased NaU, but was unable to increase RPF and GFR.Our data suggest that a sustained hyperinsulinemic state can interact with the physiological vasoactive mechanisms involved in the regulation of renal vasculature. These results may be pertinent to human disease, especially in pathological conditions in which insulin resistance is present. Am J Hypertens 1996;9:681–686Keywords: L-Arginine; hyperinsulinemia; renal function; renal vasculature; sodium excretion; beagle dogs
Article
The renal actions of brain natriuretic peptide (BNP) in congestive heart failure (CHF) are associated with increased diuresis and natriuresis, preserved glomerular filtration rate (GFR), and lack of activation of the renin-angiotensin-aldosterone system (RAAS). In contrast, diuretic-induced natriuresis may be associated with reduced GFR and RAAS activation. The objective of this study was to test the hypothesis that exogenous BNP enhances the renal diuretic and natriuretic actions of furosemide (Fs) and retards the activation of aldosterone in a model of CHF. CHF was produced in 2 groups of dogs by ventricular pacing. One group received continuous (90-minute) intravenous Fs (1 mg x kg(-1) x h(-1)). A second group (Fs+BNP) received 45-minute intravenous coinfusion of Fs (1 mg x kg(-1) x h(-1)) and low-dose (2 pmol x kg(-1) x min(-1)) BNP followed by 45-minute coinfusion of Fs (1 mg x kg(-1) x h(-1)) and high-dose (10 pmol x kg(-1) x min(-1)) BNP. Fs increased urinary flow, but the effect of Fs+BNP was greater. Similarly, urinary sodium excretion was higher in the Fs+BNP group. Although GFR tended to decrease in the Fs group, it increased in the Fs+BNP group (35+/-3 to 56+/-4*) (* indicates P<0.05 versus baseline) (P<0.0001 between groups). Plasma aldosterone increased with Fs (41+/-10 to 100+/-11* ng/dL) but was attenuated in the Fs+BNP group (44+/-11 to 54+/-9 ng/dL low-dose and to 47+/-7 ng/dL high-dose) (P=0.0007 between groups). Fs+BNP has more profound diuretic and natriuretic responses than Fs alone and also increases GFR without activation of aldosterone. Coadministration of BNP and loop diuretic is effective in maximizing natriuresis and diuresis while preserving renal function and inhibiting activation of aldosterone.
Article
Extracellular fluid volume is highly regulated, at least in part, by peripheral resistance and renal function. Nitric oxide (NO) produced by NO synthase type 3 (NOS 3) in the nonrenal vasculature may promote fluid retention by reducing systemic vascular resistance and arterial pressure. In contrast, NO produced by renal NOS 3 promotes water excretion by reducing renal vascular resistance, increasing glomerular filtration, and inhibiting reabsorption along the nephron. Thus, the net effect of NO from NOS 3 on urinary volume (UV) is unclear. We hypothesized that NO produced by NOS 3 promotes water excretion primarily due to renal tubular effects. We gave conscious wild-type and NOS 3 -/- mice an acute volume load and measured UV, blood pressure, plasma renin concentration (PRC), Na(+), vasopressin, and urinary Na(+) and creatinine concentrations. To give the acute volume load, we trained mice to drink a large volume of water while in metabolic cages. On the day of the experiment, water was replaced with 1% sucrose, and mice had access to it for 1 h. Volume intake was similar in both groups. Over 3 h, wild-type mice excreted 62 +/- 10% of the volume load, but NOS 3 -/- excreted only 42 +/- 5% (P < 0.05). Blood pressure in NOS 3 -/- was 118 +/- 3 compared with 110 +/- 2 mmHg in wild-type mice (P < 0.05), but it did not change following volume load in either strain. PRC, vasopressin, and glomerular filtration rate were similar between groups. Urinary Na(+) excretion was 49.3 +/- 7.0 in wild-type vs. 37.8 +/- 6.4 mumol/3 h in NOS 3 -/- mice (P < 0.05). Bumetanide administration eliminated the difference in volume excretion between wild-type and NOS 3 -/- mice. We conclude that 1) NO produced by NOS 3 promotes water and Na(+) excretion and 2) the renal epithelial actions of NO produced by NOS 3 supersede the systemic and renal vascular actions.
Article
The beverages of Hibiscus sabdariffa calyces are widely used in Mexico as diuretic, for treating gastrointestinal disorders, liver diseases, fever, hypercholesterolemia and hypertension. Different works have demonstrated that Hibiscus sabdariffa extracts reduce blood pressure in humans, and recently, we demonstrated that this effect is due to angiotensin converting enzyme (ACE) inhibitor activity. The aim of the current study was to isolate and characterizer the constituents responsible of the ACE activity of the aqueous extract of Hibiscus sabdariffa. Bioassay-guided fractionation of the aqueous extract of dried calyces of Hibiscus sabdariffa using preparative reversed-phase HPLC, and the in vitro ACE Inhibition assay, as biological monitor model, were used for the isolation. The isolated compounds were characterized by spectroscopic methods. The anthocyanins delphinidin-3-O-sambubioside (1) and cyanidin-3-O-sambubioside (2) were isolated by bioassay-guided purification. These compounds showed IC(50) values (84.5 and 68.4 microg/mL, respectively), which are similar to those obtained by related flavonoid glycosides. Kinetic determinations suggested that these compounds inhibit the enzyme activity by competing with the substrate for the active site. The competitive ACE inhibitor activity of the anthocyanins 1 and 2 is reported for the first time. This activity is in good agreement with the folk medicinal use of Hibiscus sabdariffa calyces as antihypertensive.
Article
Epidemiological studies have reported an inverse association between dietary flavonoid intake and mortality for ischemic heart disease. Quercetin reduces blood pressure and restores endothelial dysfunction in hypertensive animals. However, quercetin (aglycone) is usually not present in plasma, but it is rapidly metabolized during absorption by methylation, glucuronidation and sulfation. We have analyzed the vasorelaxant effects and the role on NO bioavailability and endothelial function of quercetin and its conjugated metabolites (quercetin-3-glucuronide, isorhamnetin-3-glucuronide and quercetin-3'-sulfate) in rat aorta. Thoracic aortic rings isolated from Wistar rats were mounted for isometric force recording and endothelial function was tested by measuring the vasorelaxant response to acetylcholine. NADPH-enhanced O(2)(-) release was quantified in homogenates from cultured aortic smooth muscle cells using lucigenin chemiluminescence. Unlike quercetin, the conjugated metabolites had no direct vasorelaxant effect, and did not modify endothelial function or the biological activity of NO. However, all metabolites (at 10 micromol/L) prevented, at least partially, the impairment of endothelial-derived NO response under conditions of high oxidative stress induced by the SOD inhibitor DETCA. Furthermore, they protected the biological activity of exogenous NO when impaired by DETCA. Quercetin and quercetin-3'-sulfate (>or=10 micromol/L) or quercetin-3-glucuronide (100 micromol/L) inhibited NADPH oxidase-derived O(2)(-) release. Quercetin and quercetin-3-glucuronide (1 micromol/L) prevented the endothelial dysfunction induced by incubation with ET-1. These data indicate, for the first time, that the conjugated metabolites could be responsible for the in vivo protective activity of quercetin on endothelial dysfunction.
Article
Addition of an aqueous extract of Hibiscus sabdariffa calyces (2.5 ml/bath approximately 125 mg of starting crude material) inhibited the tone of various isolated muscle preparations (rabbit aortic strip, rhythmically contracting rat uterus, guinea-pig tracheal chain and rat diaphragm). Other muscles were stimulated (quiescent rat uterus and frog rectus abdominis). Intravenous injection of the extract to anaesthetized cats lowered the blood pressure in a dose-response manner. The inhibitory effects were resistant to a number of standard receptor blockers but the hypotensive influence was partially blocked by atropine and the tonic effects on rat uterus were partially reduced by hydrocortisone and indomethacin.
Article
A crude hydroalcoholic extract from Hibiscus sabdariffa L. calyces showed in vitro an appreciable enzyme-inhibiting activity towards the Angiotensin I Converting Enzyme (ACE), attributable to flavones, but weak inhibiting activities towards elastase, trypsin and alpha-chymotrypsin. The angioprotective activity in vivo, also important, was due to flavones and anthocyanins.
Article
Inhibitors of the angiotensin-converting enzyme (ACE) acutely increase sodium excretion. Whether or not continued treatment induces net negative sodium balance is not clear, and may depend on initial sodium balance. We therefore investigated the effects of 8 days of treatment with enalapril, 10 mg b.i.d., on sodium balance in 10 subjects with uncomplicated essential hypertension, in balance on a low (50 mmol sodium/24 h) and a liberal (200 mmol sodium/24 h) sodium intake. Sodium excretion exceeded intake during the first days of treatment, amounting to sodium losses of 101 +/- 24 and 112 +/- 15 mmol in the low and the liberal sodium diets, respectively. The sodium loss was accompanied by a fall in body weight with both regimens. The blood pressure response to enalapril was potentiated by the sodium-restricted diet. The net increase in sodium excretion after enalapril administration, however, was similar for both diets. This was particularly true for individual patients, suggesting an individual response pattern to ACE inhibition.
Article
We studied the efficacy of the ACE inhibitor lisinopril in treating overt proteinuria in comparison with the NSAID indomethacin, and evaluated some of the conditions that could influence this antiproteinuric effect. In 12 patients with a proteinuria varying from 3.2 to 10.5 g/24 hr, a diastolic BP ranging from 64 to 105 mm Hg, and a GFR varying from 34 to 127 ml/min, the effect of different lisinopril doses and of changing dietary sodium intake was evaluated. Proteinuria fell by 27 +/- 20% from 6.1 +/- 2.1 to 4.5 +/- 1.9 g/24 hr on a low dose (median 5 mg/day) lisinopril and by 50 +/- 17% to 3.1 +/- 1.4 g/24 hr on a higher dose (median 10 mg/day), irrespective of initial proteinuria, BP, or GFR. This antiproteinuric effect was abolished by increasing salt intake from 50 to 200 mmol/day, and was recovered again by re-instituting the sodium restricted diet. The antiproteinuric effect of 10 mg/day lisinopril was comparable to the reduction in proteinuria (by 57 +/- 21% to 2.8 +/- 2.0 g/24 hr) on 150 mg/day indomethacin, while adverse effects were less and renal hemodynamic effects were more favorable during lisinopril. In some patients it took several weeks before the effect of the ACE inhibitor on proteinuria was stabilized. Thus, the antiproteinuric effect of the ACE inhibitor lisinopril appears to be dose and time related, and is strongly dependent on dietary sodium restriction, whereas it does not depend on initial proteinuria, BP, or GFR. The effect is comparable to that of indomethacin, while adverse effects are less.
Article
1. This study has compared the effects of ibuprofen and indomethacin upon renal haemodynamics, electrolyte excretion and renin release in the presence and absence of frusemide under sodium replete conditions in eight healthy volunteers. 2. Neither ibuprofen (400 mg and 800 mg) nor indomethacin (50 mg) affected renal blood flow, glomerular filtration rate or electrolyte excretion in the basal state. 3. Frusemide had no effect on renal blood flow, but significantly increased glomerular filtration rate. This latter change was suppressed significantly only by ibuprofen 400 mg. Frusemide-induced diuresis was inhibited by all treatments, while natriuresis following frusemide was inhibited by indomethacin only. 4. Significant increments in plasma renin activity, which were suppressed by all treatments, were observed after frusemide. The degree of inhibition of the renin responses was significantly greater in the presence of indomethacin than with either dose of ibuprofen. 5. In a sodium replete setting in healthy volunteers, indomethacin and ibuprofen had no detrimental effects on basal renal function. In the presence of frusemide, indomethacin had more anti-natriuretic and renin-suppressing effect than ibuprofen. There was no evidence for a dose-related effect of ibuprofen.
Article
The diuretic and saluretic activity of ITA 529 (Ethyl-beta-[(5-tert-butyl-3-chloro-2-hydroxy)benzylamino]crotonate++ +) in rat, rabbit and monkey is described in this study. In rat, the diuretic ED50 of ITA 529 was 1.23 mg/kg p.o. and its ED100 1.69 mg/kg p.o. The diuretic ED50 of furosemide was 18.48 mg/kg p.o. and its ED100 22.38 mg/kg p.o. Their effect lasted approximately 3 hours. In monkey, the diuretic ED50 of ITA 529 was 2.29 mg/kg p.o. and its ED100 6.54 mg/kg p.o. while for furosemide its ED50 was 2.44 mg/kg p.o. and its ED100 5.72 mg/kg p.o. In rabbit the ED50 of ITA 529 was 1.83 mg/kg p.o. and its ED100 3.37 mg/kg p.o. For furosemide, its ED50 was 2.25 mg/kg p.o. and its ED100 7.13 mg/kg p.o. The natriuretic activity of ITA 529 was reduced by indomethacin.
Article
One of the controversies in preventive medicine is whether a general reduction in sodium intake can decrease the blood pressure of a population and thereby reduce the number of strokes and myocardial infarctions. In recent years the debate has been extended by studies indicating that reduced sodium intake has adverse effects. To estimate the effects of reduced sodium intake on systolic and diastolic blood pressure (SBP and DBP), body weight, and plasma or serum levels of renin, aldosterone, catecholamines, cholesterols, and triglyceride, and to evaluate the stability of the blood pressure effect in relation to additional trials. MEDLINE search from 1966 through December 1997 and reference lists of relevant articles. Studies randomizing persons to high-sodium and low-sodium diets were included if they evaluated at least one of the effect parameters. Two authors independently recorded data. In 58 trials of hypertensive persons, the effect of reduced sodium intake as measured by urinary sodium excretion (mean, 118 mmol/24 h) on SBP was 3.9 mm Hg (95% confidence interval [CI], 3.0-4.8 mm Hg) (P<.001) and on DBP was 1.9 mm Hg (95% CI, 1.3-2.5 mm Hg) (P<.001). In 56 trials of normotensive persons, the effect of reduced sodium intake (mean, 160 mmol/24 h) on SBP was 1.2 mm Hg (95% CI, 0.6-1.8 mm Hg) (P<.001) and on DBP was 0.26 mm Hg (95% CI, -0.3-0.9 mm Hg) (P=.12). The cumulative analysis showed that this effect size has been stable since 1985. In plasma, the renin level increased 3.6-fold (P<.001), and the aldosterone level increased 3.2-fold (P<.001); the increases were proportional to the degree of sodium reduction for both renin (r=0.66; P<.001) and aldosterone (r=0.64; P<.001). Body weight decreased significantly, and noradrenaline, cholesterol, and low-density lipoprotein cholesterol levels increased. There was no effect on adrenaline, triglyceride, and high-density lipoprotein cholesterol. These results do not support a general recommendation to reduce sodium intake. Reduced sodium intake may be used as a supplementary treatment in hypertension. Further long-term studies of the effects of high reduction of sodium intake on blood pressure and metabolic variables may clarify the disagreements as to the role of reduced sodium intake, but ideally trials with hard end points such as morbidity and survival should end the controversy.
Article
The LD(50) of roselle calyx extract and its effect on blood pressure were determined. The LD(50) was found to be above 5000 mg kg(-1). Roselle calyx infusion was found to lower significantly (p<0.05) both systolic and diastolic pressure in spontaneously hypertensive and normotensive Wistar-Kyoto rats at tested doses of 500 and 1000 mg kg(-1) body weight. The reduction in blood pressure in both groups was positively correlated with weight. Continuous consumption of the infusion at 1000 mg kg(-1) was discovered to lead to sudden death in spontaneously hypertensive rats but not in Wistar-Kyoto rats. Water intake was not significantly different (p>0.05) in the control groups of the two strains of rats used, neither was there a significant difference in their urine output. The water intake in the treated spontaneously hypertensive and normotensive rats was not different from the corresponding control groups. However the urine output of the treated spontaneously hypertensive rats was significantly higher. A significant decrease in serum creatinine, cholesterol, and glucose in the treated rats compared with the control as well as a significant increase in serum uric acid was observed. The serum proteins (albumin and total protein) in the treated rats when compared with the control groups was not changed significantly.
Article
The antihypertensive effect of aqueous extracts of the calyx of Hibiscus sabdariffa (HS) has been investigated in anaesthetized rats. Hibiscus sabdariffa caused a dose-dependent decrease in mean arterial pressure (MAP) of the rats. Sectioning of the right and left vagi nerves did not have a significant effect on the fall in MAP produced by HS. Cholinergic blockade with 0.2 mgkg-1 atropine and histaminergic blockade with 1 mgkg-1 cimetidine and 15 mgkg-1 promethazine significantly attenuated the hypotensive response to HS. Pretreatment of the rats with 20 mgkg-1 HS extract did not have a significant effect on increase in blood pressure induced by bilateral carotid occlusion (48.05 +/- 6.83 mmHg vs 46.53 +/- 7.49 mmHg). The cumulative addition of HS to noradrenaline precontracted aortic rings produced dose-dependent relaxation of the rings. The maximum relaxation response was 86.96 +/- 5.20% and this was observed at the dose of 1.70 mgml-1. These findings suggest that the antihypertensive effect of the extracts of calyx of HS is not mediated through inhibition of the sympathetic nervous system but it could be mediated through acetylcholine-like and histamine-like mechanisms as well as via direct vaso-relaxant effects.
Article
The RALES study showed that spironolactone, added to conventional therapy for chronic heart failure, dramatically reduced mortality. We tested the hypothesis that this benefit was partially due to improvement in endothelial function and/or to amplified suppression of the vascular renin-angiotensin axis. We performed a randomized, placebo-controlled, double-blind crossover study on 10 patients with NYHA class II to III chronic heart failure on standard diuretic/ACE inhibitor therapy, comparing 50 mg/d spironolactone (1 month) versus placebo. Forearm vasculature endothelial function was assessed by bilateral forearm venous occlusion plethysmography using acetylcholine and N-monomethyl-L-arginine (L-NMMA), with sodium nitroprusside as a control vasodilator. Also, vascular ACE activity was assessed by use of angiotensin (Ang) I, with Ang II as a control vasoconstrictor. Spironolactone significantly increased the forearm blood flow response to acetylcholine (percentage change in forearm blood flow [mean+/-SEM], 177+/-29% versus 95+/-20%, spironolactone versus placebo; P<0.001), with an associated increase in vasoconstriction due to L-NMMA (-35+/-6% versus -18+/-4%; P<0.05). The Ang I response was also significantly reduced with spironolactone (P<0.05), with Ang II responses unaltered. Spironolactone improves endothelial dysfunction, increases NO bioactivity, and inhibits vascular Ang I/Ang II conversion in patients with heart failure, providing novel mechanisms for its beneficial effect on cardiovascular mortality.
Article
Hypertensive (n=93) and normotensive (n=39) white individuals were given a high sodium intake of approximately 350 mmol/d for 5 days followed by a low sodium intake of 10 to 20 mmol/d for 5 days. With this acute and large reduction in salt intake, no significant change was seen in blood pressure in the normotensive individuals, but blood pressure decreased in the hypertensive individuals. Compared with normotensive subjects, hypertensive patients had a 7/7-mm Hg greater fall in blood pressure (P<0.05 for systolic and P<0.01 for diastolic, adjusted for age), with similar changes in urinary sodium excretion. From the high-salt to low-salt diet, plasma renin activity rose from 0.90 to 5.99 ng. mL(-1). h(-1) in normotensives, whereas in hypertensives it rose from 0.73 to only 3.14 ng. mL(-1). h(-1) (P<0.05 between hypertensives and normotensives). Plasma aldosterone rose by 1396 pmol/L in normotensive subjects and by 511 pmol/L in hypertensive patients (P<0.05). Significant inverse correlations were obtained for all subjects between the fall in blood pressure from the high-salt to low-salt diet and the rise in plasma renin activity and aldosterone that occurred in addition to the absolute level on the low-salt diet. These results demonstrate that the larger fall in blood pressure with an acute reduction in salt intake in hypertensives compared with normotensives is, at least in part, due to a less-responsive renin-angiotensin-aldosterone system in the hypertensive patients.
Article
Opinions about the impact of dietary salt on blood pressure have dominated the debate regarding 'salt sensitivity', which can be broadly defined as the blood pressure response to changes in sodium intake among individuals in a population. However, the larger question is whether salt consumption exerts significant biological effects independent of changes in blood pressure. Provisional answers to this question are reviewed based on newly discovered links between sodium metabolism and the generation of reactive oxygen species. These links suggest that, in a subset of the general population, salt consumption is a determinant in cardiovascular ageing.