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Leonurus japonicus, Leonurus cardiaca, Leonotis leonurus: A novel HPLC study on the occurrence and content of the pharmacologically active guanidino derivative leonurine
Abstract
Leonurine is a prominent pharmacologically active guanidine alkaloid (4-{[amino(imino)methyl]amino} butyl-4-hydroxy-3,5-dimethoxybenzoate), mainly exerting cardiovascular, hypotensive, uterotonic, and neuroprotective effects. It is commonly regarded as the predominant active principle of Leonurus and Leonotis drugs (subfamily Lamioideae), though its presence has only been unambiguously proven for the aerial parts of Leonurus japonicus Houtt. (yimucao/Chin.Ph.,DAB), used in TCM/Kampo for the treatment of various gynaecological and cardiovascular disorders. Although a series of claims concerning the occurrence of leonurine in European Leonurus cardiaca L. (Ph.Eur.) can be found describing it as an important active principle, this has never been conclusively demonstrated. The same holds true for the officinal Leonurus japonicus fruits (chongweizi/Chin.Ph.) and the closely related South African herb Leonotis leonurus (L.) R.Br. Since no reliable HPLC determination and quantification method for leonurine has been published up to now, in the present study, a highly reproducible RP-HPLC method was newly developed using a special octadecyl-bonded stationary phase and an acetonitrile/water gradient (adjusted to pH 2.5 by phosphoric acid) as mobile phase (DAD/277nm). In particular, this use of reversed phase packing with hydrophilic endcapping clearly contributes to an improved peak shape for leonurine, to our knowledge the first application of this technique on a natural zwitterionic analyte, and clearly enhances the selectivity of separation compared to classical RP-phases. The method was shown to be precise with respect to concentration, exhibiting a linear response in the range of 2.5-12.5 microg/ml leonurine, detection limit well below 0.5 microg/ml, and correlation coefficients constantly higher than 0.99 (5 levels, n = 3) over numerous inter day repetitions, demonstrating the robustness of the newly developed HPLC protocol. Thus, nine samples of L. japonicus aerial parts, two of L. japonicus fruits, four of L. cardiaca aerial parts, as well as one sample each of L. cardiaca fruits, and Leonotis leonurus aerial parts were examined. No leonurine could be detected in any sample of L. cardiaca in contrast to newly published official drug assessments, which consequently have to be revised. Leonotis leonurus and surprisingly, seeds of L. japonicus did not contain leonurine, either. However, in aerial parts of L. japonicus drug samples, obtained from China and Japan, leonurine contents between 0.001 and 0.049% were determined, while L. japonicus from domestic cultivation displayed significantly higher amounts of at least 0.1%. Thus, the HPLC method described above could be used for quality control of leonurine contained in TCM/Kampo medicines and in pharmacopeial analytics for the differentiation of L. japonicus and L. cardiaca samples.
... These are in fact all a single plant species, Leonurus japonicus (Harley and Paton, 2001). Kuchta, Ortwein andRauwald, 2012 (andcited by Qui et al., 2014), found leonurine only present in the aerial parts of Leonurus japonicus by RP HPLC, when examining Leonurus japonicus, Leonurus cardiaca L., and L. leonurus extracts. ...
... These are in fact all a single plant species, Leonurus japonicus (Harley and Paton, 2001). Kuchta, Ortwein andRauwald, 2012 (andcited by Qui et al., 2014), found leonurine only present in the aerial parts of Leonurus japonicus by RP HPLC, when examining Leonurus japonicus, Leonurus cardiaca L., and L. leonurus extracts. ...
... Continuing research reports yielded many other compounds from L. leonurus, but leonurine (20) (Table 3), which is a mildly psychoactive guanidino alkaloid, was documented only to have been isolated from related species (He et al., 2012). Kuchta et al., (2012) confirmed that no leonurine (20) could be detected in the aerial parts of L. leonurus using a newly developed sensitive and highly reproducible novel RP-HPLC analytical method. Bienvenu et al. (2002) determined the chromatographic profile of L. leonurus leaves using high performance liquid chromatography (HPLC) and identified the groups of chemical compounds present in the aqueous extract using the standard compendial phytochemical tests. ...
Ethnopharmacological relevance:
Leonotis leonurus, locally commonly known as "wilde dagga" (=wild cannabis), is traditionally used as a decoction, both topically and orally, in the treatment of a wide variety of conditions such as haemorrhoids, eczema, skin rashes, boils, itching, muscular cramps, headache, epilepsy, chest infections, constipation, spider and snake bites. The dried leaves and flowers are also smoked to relieve epilepsy. The leaves and flowers are reported to produce a mild euphoric effect when smoked and have been said to have a similar, although less potent, psychoactive effect to cannabis.
Aim of the review:
To amalgamate the botanical aspects, ethnopharmacology, phytochemistry, biological activity, toxicity and commercial aspects of the scientific literature available on Leonotis leonurus.
Methods:
An extensive review of the literature from 1900 to 2015 was carried out. Electronic databases including Scopus(®), SciFinder®, Pubmed(®), Google Scholar(®) and Google(®) were used as data sources. All abstracts, full-text articles and books written in English were considered.
Results:
The phytochemistry of particularly the non-volatile constituents of Leonotis leonurus has been comprehensively investigated due to interest generated as a result of the wide variety of biological effects reported for this plant. More than 50 compounds have been isolated and characterised. Leonotis leonurus contains mainly terpenoids, particularly labdane diterpenes, the major diterpene reported is marrubiin. Various other compounds have been reported by some authors to have been isolated from the plant, including, in the popular literature only, the mildly psychoactive alkaloid, leonurine. Leonurine has however, never been reported by any scientific analysis of the extracts of L. leonurus.
Conclusion:
Despite the publication of various papers on L. leonurus, there is still, however, the need for definitive research and clarification of other compounds, including alkaloids and essential oils from L. leonurus, as well as from other plant parts, such as the roots which are extensively used in traditional medicine. The traditional use by smoking also requires further investigation as to how the chemistry and activity are affected by this form of administration. Research has proven the psychoactive effects of the crude extract of L. leonurus, but confirmation of the presence of psychoactive compounds, as well as isolation and characterisation, is still required. Deliberate adulteration of L. leonurus with synthetic cannabinoids has been reported recently, in an attempt to facilitate the marketing of these illegal substances, highlighting the necessity for refinement of appropriate quality control processes to ensure safety and quality. Much work is therefore still required on the aspect of quality control to ensure safety, quality and efficacy of the product supplied to patients, as this plant is widely used in South Africa as a traditional medicine. Commercially available plant sources provide a viable option for phytochemical research, particularly with regard to the appropriate validation of the plant material (taxonomy) in order to identify and delimit closely related species such as L. leonurus and L. nepetifolia which are very similar in habit.
... In 2012, Kuchta et al. published a high-performance liquid chromatography method. Kuchta et al. used 120 ml of boiling water to extract 6 g of the plant powder under reflux for 1 h and fixed it with a special octadecyl-bonded stationary phase and an acetonitrile/ water gradient as fluidity yielded approximately 3 mg of leonurine (Kuchta et al., 2012). In 2017, Jiang et al. used a two-phase system of ethyl acetate-n-butanol-water (3:2:5) as high-speed countercurrent chromatography to obtain 68 mg of leonurine from 2.48 g of the plant crude extract, and the purity is about 96.2% (Jiang, 2017 (Cao et al., 2018). ...
... In the past, the traditional identification method of leonurine was to use reverse silica gel thin layer chromatography plate (60 F254) and MeOH:CH 2 Cl 2 :NH 3 25% (8:2:3) as mobile phase, under 154 nm UV lamp, leonurine was identified with the Rf value of 0.31 (Kuchta et al., 2012). Nowadays, the identification of leonurine relies more on HPLC, MS, and NMR. ...
Natural products, those molecules derived from nature, have been used by humans for thousands of years to treat ailments and diseases. More recently, these compounds have inspired chemists to use natural products as structural templates in the development of new drug molecules. One such compound is leonurine, a molecule isolated and characterized in the tissues of Herb leonuri . This molecule has received attention from scientists in recent years due to its potent anti-oxidant, anti-apoptotic, and anti-inflammatory properties. More recently researchers have shown leonurine to be useful in the treatment of cardiovascular and nervous system diseases. Like other natural products such as paclitaxel and artemisinin, the historical development of leonurine as a therapeutic is very interesting. Therefore, this review provided an overview of natural product discovery, through to the development of a potential new drug. Content will summarize known plant sources, the pathway used in the synthesis of leonurine, and descriptions of leonurine’s pharmacological properties in mammalian systems.
... LEO is a specific alkaloid only found in Leonurus japonicus Houtt. Modern pharmacological studies have shown that it has a variety of biological activities such as vasodilation [12], antiplatelet aggregation and inhibition of vasoconstriction [13][14][15][16], anticoagulant [17], anti-inflammatory [18], antioxidative [19], anti-ischemia, antiapoptosis [20,21], and heart protection [22]. However, whether it can repair vascular endothelial cell injury and promote angiogenesis through antioxidant stress has not been clarified. ...
Thrombus is considered to be the pathological source of morbidity and mortality of cardiovascular disease and thrombotic complications, while oxidative stress is regarded as an important factor in vascular endothelial injury and thrombus formation. Therefore, antioxidative stress and maintaining the normal function of vascular endothelial cells are greatly significant in regulating vascular tension and maintaining a nonthrombotic environment. Leonurine (LEO) is a unique alkaloid isolated from Leonurus japonicus Houtt (a traditional Chinese medicine (TCM)), which has shown a good effect on promoting blood circulation and removing blood stasis. In this study, we explored the protective effect and action mechanism of LEO on human umbilical vein endothelial cells (HUVECs) after damage by hydrogen peroxide (H2O2). The protective effects of LEO on H2O2-induced HUVECs were determined by measuring the cell viability, cell migration, tube formation, and oxidative biomarkers. The underlying mechanism of antioxidation of LEO was investigated by RT-qPCR and western blotting. Our results showed that LEO treatment promoted cell viability; remarkably downregulated the intracellular generation of reactive oxygen species (ROS), malondialdehyde (MDA) production, and lactate dehydrogenase (LDH); and upregulated the nitric oxide (NO) and superoxide dismutase (SOD) activity in H2O2-induced HUVECs. At the same time, LEO treatment significantly promoted the phosphorylation level of angiogenic protein PI3K, Akt, and eNOS and the expression level of survival factor Bcl2 and decreased the expression level of death factor Bax and caspase3. In conclusion, our findings suggested that LEO can ameliorate the oxidative stress damage and insufficient angiogenesis of HUVECs induced by H2O2 through activating the PI3K/Akt-eNOS signaling pathway.
... The results indicated that leonurine occurred in different drought-stressed ecotypes of L. cardiaca. The result of present study is inconsistent with the findings of Kuchta et al. (2012). The amount and percentage of leonurine affected by drought and increased so that the maximum amount of leonurine was observed in the treatment of mild stress and the lowest one in control plants. ...
Purpose: Motherwort (Leonurus cardiaca), a medicinal plant of the Lamiaceae family, has a great diversity and wide distribution in Iran. It is essential due to having leonurine with blood dilution and muscle relaxation effects. Research method: To evaluate the response of the Iranian Motherwort ecotypes in drought environments, an experiment was carried out in split plot design based on RCBD with three replications. Three irrigation levels were considered as main plots, including %100, one-third, and two-third of field capacity, and four ecotypes as sub-plots including Kerman, Taleghan, Sarab and Khansar. The experiment was conducted at Horticultural Research Station, the University of Tehran, in Karaj. Findings: The results showed that water stress affected morphological traits significantly. Water stress had a significant increasing effect on the phenolic and flavonoid contents and antioxidant activity of Motherwort ecotypes. The highest and the lowest total phenol content were observed in Taleghan and Kerman ecotypes, 7.34 and 4.21 mg/mg fresh weight, respectively. The amount and the percentage of leonurine were increased by water stress. The highest and the lowest values of leonurine were observed in the ecotypes of Taleghan and Sarab, respectively, in all three levels of irrigation. There were significant correlations between dry weight (-0.43), antioxidant (0.36), proline (-0.35), catalase (0.4), and the percentage of leonurine. Research limitations: There were no limitations to the report. Originality/Value: It was found a significant variation among the ecotypes in response to water stress. The ecotypes of Taleghan and Sarab were the most tolerant and the most susceptible ecotypes to drought stress among the studied ecotypes.
... (Pitschmann et al., 2017) As the major bioactive component in L. japonicus, leonurine is used for quality control of the herb in China, with the standard content of >0.05% (National Pharmacopoeia Committee, 2015). However, in the European motherwort L. cardiaca, the content of leonurine is very low (Wojtyniak et al., 2013) or even undetectable (Kuchta et al., 2012), which shows a major difference between the L. japonicus and the L. cardiaca. The verified structure of leonurine was reported by Sugiura et al. in 1969(S.Sugiura et al., 1969, then three guanidine derivatives of leonurine were isolated from L. sibiricus in 1971 by Reuter and Diehl (1971). ...
Plants belonging to the genus Leonurus, also named motherwort, are traditionally used for anti-gynecological disorder in East Asia, and for sedative in Europe. Chemical investigation of the genus Leonurus not only enriched the natural products library, but also enlarged the pharmacological application of this traditional herb. In this review, we systematically summarized the structures of 259 compounds isolated from the genus Leonurus, featured with 147 labdane diterpenoids. The reported bioactivity studies up to 2017 are presented in the second part, with the main focus on the isolated compounds and also concerning the extracts. In addition to the traditional uterine contraction and sedative activity, recently the cardiovascular protection effect of leonurine has drawn most attention. Other than that, neuroprotection, anti-inflammation, anti-cancer, anti-platelet aggregation and many other activities have been assigned to various compounds from the genus Leonurus. Among 70 bioactivity references cited in this review, 57% of them were concentrated on two alkaloids (leonurine and stachydrine), whereas only 20% are about the 147 diterpenoids. Anti-inflammation is the major bioactivity discovered so far for the labdane diterpenoids from the genus Leonurus, whose further therapeutic potential still remains for exploration.
... A fairly recent chromatographic analysis of Leonurus species found that only L. japonica's aerial parts (not the fruit) contains leonurine, not L. cardiaca. 46 This is intriguing, as another paper found that leonurine accounted in part for the non-benzodiazepine GABA A receptor agonist effects of L. japonica but not for extracts of L. cardiaca. 47 However, L. cardiaca extracts still had activity in this model, despite the absence of leonurine. ...
Herbal medicines show much promise for helping patients with atrial fibrillation (AF). Nao Xīn Tōng Náng (Brain and Heart Connected Capsule) formula with aspirin, lumbrokinase, and nattokinase are all natural anticoagulants, with varying degrees of evidence supporting their use or potential use in AF patients. The modern Chinese herbal formula Wen Xin Ke Li looks promising for maintaining sinus rhythm in paroxysmal AF patients, as does Shan Sōng Yczng Xīn Capsule. Anti-arrhythmic herbs, both for heart rate and for heart rhythm control (as well as preventing paroxysmal AF from recurring), generally used historically and not studied in clinical trials but with substantial supporting preclinical information on their actions, include Leonurus cardiaca (motherwort), L. japonicus (Chinese motherwort), Lycopus virginicus (sweet bugleweed) and related species, Corydalis yanhusuo (Chinese corydalis, yán hú suc), Stephania tetrandra (fěn fáng jc, hàn fáng jc, stephania), Rauvolfia serpentina (Indian snakeroot, rauwfolia), Crataegus spp (hawthorn), and Cinchona spp. (Peruvian bark). The isolated herbal alkaloids berberine and tetrahydropalmatine have shown promise for AF or related conditions. Further research is needed to determine the full potential of these herbs.
... The Lamioideae are characterised by tricolpate and binucleate pollen, albuminous seeds, spatulate embryos, the presence of iridoid glycosides and lower content of essential oils (Erdtman, 1945). The alkaloid leonurin seems to be the major bioactive principle of the genus Leonurus (Kuchta et al., 2012). The most investigated species of the this genus, L. cardiaca L., contains terpenes such as monoterpenes (iridoids), diterpenes (clerodane, furanolabdane and labdane types), triterpenes (ursolic and oleanolic acids), nitrogen-containing compounds (leonurine and stachydrine), phenylpropanoids (lavandulifolioside), as well as flavonoids, phenolic acids, volatile oils, sterols and tannins (Wojtyniak et al., 2013;Shang et al., 2014). ...
Introduction:
The genus Leonurus L. (fam: Lamiaceae) is represented in Uzbekistan by two species, L. panzerioides Popov. and L. turkestanicus V. I. Krecz. & Kuprian, which are used to treat nervous disorders and also as sedative and hypotensive agents.
Objectives:
To establish the taxonomic status of Leonurus panzerioides and L. turkestanicus based on their chemical constituents analysed by GC-MS and q-NMR.
Materials and methods:
Quantitative (1) H-NMR (q-NMR) was used to identify and quantify known major components in the methanol extracts of these two species. Additionally, the chemical composition of the essential oils obtained from the aerial parts of these plants were analysed by GC-MS.
Results:
The q-NMR analyses of Leonurus panzerioides and L. turkestanicus revealed the presence of 8-acetylharpagide, harpagide, leonurine and stachydrine as major components. Using the GC-MS method, overall 24 and 39 constituents were identified, respectively, from L. panzerioides and L. turkestanicus oils. The major constituents of the essential oil of L. panzerioides were eugenol (30.9%) and p-vinyl guaiacol (15.8%), whereas thymol (40.1%) and octen-3-ol (13.1%) were the principal compounds in the essential oil of L. turkestanicus.
Conclusion:
The major components in Leonurus panzerioides and L. turkestanicus as identified by the GC-MS and q-NMR analyses, were similar to those present in other Leonurus species and thus provided chemotaxonomic evidence for the placement of these species under the genus Leonurus. Copyright © 2016 John Wiley & Sons, Ltd.
... However, its clinical use was more often for completely different purposes than similar in most cases. Table 1 shows different usages of the same or related species [2] Double quotation marks mean that the effects are based on the Oriental Medicine standpoints. Shoma (Shenma) is an Oriental herb, which has anti-inflammatory effect, and its related species called black cohosh is used as an estrogen receptor. ...
Objective: Diabetic peripheral neuropathy is the most common long term complications associated with reduced nerve conduction and blood flow. The present study was designed to investigate the effect of oral supplementation of α-lipoic acid (600 mg/day) on peripheral, sensory and motor nerve conduction and glycaemic control in type 2 diabetes mellitus with peripheral neuropathy. Methods: A total of 20 patients were enrolled in this study, then randomly allocated to two groups control (n=10) and intervention group (n=10). Patients in control group received only oral hypoglycaemic treatment and in intervention group received α-lipoic acid (600 mg/day) oral supplementation along with their oral hypoglycaemic treatment for a period of 3 months. Nerve conduction and glycaemic control were measured at the base line and at the end of 3 months by using specific methods. Results: In intervention group α-lipoic acid supplementation significantly improves 6 of 15 electrophysiological parameters of nerve conduction. Distal latency of peroneal (mean ± SD 5.13 ± 0.52 vs 4.92±0.55; p<0.02), median (mean ± SD 3.66 ± 0.76 vs 3.53±0.63; p<0.03) & ulnar motor nerves (mean ± SD 2.91 ± 0.32 vs 2.82±0.36; p<0.01), and Nerve Conduction Velocity of peroneal (mean ± SD 42.0 ± 3.07 vs 43.4±2.13; p<0.03), median (mean ± SD 51.4 ± 3.31 vs 52.2±3.59; p<0.01) & ulnar motor nerves (mean ± SD 51.0 ± 5.84 vs 52.1±5.46; p<0.03) shows significant improvement. Conclusion: Oral supplementation of α-lipoic acid was found to be effective in improving motor nerve conduction of upper and lower extremities in patients with diabetic peripheral neuropathy.
... Should therefore, due to the ever-increasing role of TCM in modern health care systems and the rising demand for L. japonicus by European TCM practitioners, a regulation of its stachydrine content by Ph.Eur.analogous to Chin.Ph.become necessary, there is now for the first time a reproducible method for achieving this aim. As far as further N-containing analytical, active markers of L. japonicus are concerned, we recently reported the development of a specialised HPLC characterisation technique for the guanidino derivative leonurine [23]. All in all, the strategic and analytical concept described in this paper fully complies with the "integrated standardisation concept", recently published and exemplified for Angelica botanicals using quantitative NMR [24]. ...
... Its presence has only been unambiguously proven for the aerial parts of Leonurus japonicus Houtt. [5] Leal et al. found a decreasing trend in the discovery of new alkaloids between 2000 and 2009, contrasting with an increasing number of new terpenoids [6] . Alvarado et al. have reported that a sponge of the Spongosorites, which contains the nortopsentin and topsentin class of bisindole imidazole alkaloids, exhibits potent inhibition of Plasmodium falciparum growth [7] . ...
Natural products have begun to gain popularity worldwide for promoting healthcare as well as disease prevention. Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloids isolated from natural herbs exhibit antiproliferation, antibacterial, antiviral, insecticidal and antimetastasis effects on various types of cancers both in vitro and in vivo. This paper focuses on the naturally derived alkaloids such as berberine, matrine, piperine, fritillarine and rhynchophylline, etc, and summarizes the action mechanisms of these compounds. Based on the information in the literature that is summarized in this paper, the use of alkaloids as drugs is very promising, but more research and clinical trials are necessary before final recommendations on specific alkaloids can be made. Following this, it is hoped that as a result of this review, readers will have a greater awareness of the excellent promise that natural product alkaloids show for use in the therapy of diseases.
The prospect of creating a new medicine with psychotropic activity is shown as a result of studying the chemical composition and pharmacological activity of modified dry extracts of motherwort (Leonurus cardiaca L.) tincture. The most promising substances were the dry extracts, modified by adding small amounts of arginine, valine, phenylalanine, glycine, lysine, and alanine. A total of 15 main phenolic substances were found in the extracts, and eight of them were identified. There were also 10 hydroxycinnamic acids in these extracts, three of which were identified (chlorogenic, caffeic, and rosmarinic acids). The dominant hydroxycinnamic acids were chlorogenic and caffeic acids. Among flavonoids, catechin, hyperoside, and rutin were identified. It should be noted that the extracts had a significant content of ellagic acid. On the basis of the results of the phytochemical analysis of the extracts, it can be concluded that the composition of phenolic compounds does not differ significantly, and the main differences are related to amino acids, which obviously have an impact on the overall pharmacological effect. The results obtained indicate the presence of anxiolytic activity in the motherwort extracts studied in complex with amino acids. The extracts with glycine, valine, and arginine were more effective in reducing anxiety in animals.
This paper serves to fill a gap in the literature regarding evidence for the use of botanical remedies in the promotion of fertility. It examines the botanical remedies that were used in North America (1492–1900) for all stages of reproduction from preconception to birth, and discusses their potential for future use with present-day infertility treatments. Each medicinal plant discussed in this paper is assessed using an ethnomedicinal methodology that entails examining the published ethnobotanical, phytochemical and pharmacological data. A few clinical trials have shown that there is potential for medicinal plants to improve the success rate of assisted reproductive technology (ART) treatment if used in an integrated manner, similar to the integrated use of traditional Chinese medicine with ART treatment. For example, research has shown that older women who become pregnant have a high miscarriage rate, and this is one area that complementary and alternative medicines can address.
Ethnopharmacological relevance:
Traditional medicine plays a major role for primary health care worldwide. Cancer belongs to the leading disease burden in industrialized and developing countries. Successful cancer therapy is hampered by the development of resistance towards established anticancer drugs.
Aim:
In the present study, we investigated the cytotoxicity of 29 extracts from 26 medicinal plants of South-Africa against leukemia cell lines, most of which are used traditionally to treat cancer and related symptoms.
Material and methods:
We have investigated the plant extracts for their cytotoxic activity towards drug-sensitive parental CCRF-CEM leukemia cells and their multidrug-resistant P-glycoprotein-overexpressing subline, CEM/ADR5000 by means of the resazurin assay. A panel of 60 NCI tumor cell lines have been investigated for correlations between selected phytochemicals from medicinal plants and the expression of resistance-conferring genes (ABC-transporters, oncogenes, tumor suppressor genes).
Results:
Seven extracts inhibited both cell lines (Acokanthera oppositifolia, Hypoestes aristata, Laurus nobilis, Leonotis leonurus, Plectranthus barbatus, Plectranthus ciliates, Salvia apiana). CEM/ADR5000 cells exhibited a low degree of cross-resistance (3.35-fold) towards the L. leonurus extract, while no cross-resistance was observed to other plant extracts, although CEM/ADR5000 cells were highly resistant to clinically established drugs. The log10IC50 values for two out of 14 selected phytochemicals from these plants (acovenoside A and ouabain) of 60 tumor cell lines were correlated to the expression of ABC-transporters (ABCB1, ABCB5, ABCC1, ABCG2), oncogenes (EGFR, RAS) and tumor suppressors (TP53). Sensitivity or resistance of the cell lines were not statistically associated with the expression of these genes, indicating that multidrug-resistant, refractory tumors expressing these genes may still respond to acovenoside A and ouabain.
Conclusion:
The bioactivity of South African medicinal plants may represent a basis for the development of strategies to treat multidrug-resistant tumors either by phytotherapeutic approaches with whole plant preparations or by classical drug development with isolated compounds such as acovenoside A or ouabain.
Leonurus sibiricus, also called motherwort, is a
well-known functional food and medicinal herb. It has been known to possess beneficial properties for women’s health, especially for aged women. Estrogen deficiency in the menopause could induce lipid metabolic abnormalities in body fat, resulting in obesity. In this study, the inhibitory effects of L. sibiricus on obesity after the menopause were investigated. Female C57BL/6 mice were ovariectomized and fed high-fat diet (HFD) for 12 weeks. Following an induction period, aqueous extracts of L. sibiricus (LS) were orally administrated for 6 weeks. The body, uterine, and visceral fat weights were measured immediately after the animals were killed. Histological analysis was performed to monitor fat and liver. Serum levels of glucose, triglyceride, total cholesterol, and LDL-cholesterol were evaluated. In addition, the expression of lipases was analyzed. Total body weight was significantly decreased by LS treatment. Histological changes in adipocyte size were shown along with a decrease of visceral fat weight in the LS-treated group. In addition, the fat infiltration of liver was reduced by LS administration. LS-treated mice experienced decreases of serum triglyceride, total cholesterol, and LDL-cholesterol levels. The expression of HSL and ATGL was significantly increased by LS treatment. These results suggest that LS could regulate the lipid metabolism via an increase of lipases expression in ovariectomized and HFD-fed mice. LS might be a novel candidate for a functional food to inhibit weight gain after the menopause.
A main traditional use of European Leonurus cardiaca and East Asian Leonurus japonicus is in the treatment of neurological disorders such as anxiety, depression, nervousness, and as a sedative for insomnia. However, their mechanism of action is still under discussion. As anxiety and depressive disorders are increasingly being recognized as connected to dysfunctions of the gamma-aminobutyric acid system, the in vitro effects of standardized L. cardiaca and L japonicus extracts as well as five of their isolated constituents, namely, the labdane-type isoleosibirin, the novel iridoid 7R-chloro-6-desoxy-harpagide, the phenylethanoid lavandulifolioside, and the N-containing compounds stachydrine and leonurine, on this type of neuronal receptor were investigated for the first time. Extracts of L. cardiaca and L. japonicus, characterized by reversed-phase high-performance liquid chromatography determination, as well as their above named isolated, possible active constituents of different chemical nature were tested in several receptor binding assays at rat GABAA receptors using [(3)H]-SR95 531 and [(3)H]-Ro-15-1788 (flumazenil)/diazepam control. The L. cardiaca and L. japonicus extracts as well as leonurine inhibited the concentration-dependent binding of [(3)H]-SR95 531 to the gamma-aminobutyric acid site of the gamma-aminobutyric acid type A receptor with a high binding affinity: IC50s 21 µg/ml, 46 µg/ml, and 15 µg/ml, respectively. In contrast, binding to the benzodiazepine site of the rat gamma-aminobutyric acid type A receptor had a 15 to 30 times lower binding affinity than to the gamma-aminobutyric acid site. The presented experiments provide hints that the neurological mechanism of action of L. cardiaca and L. japonicus may essentially be based on their interaction to the gamma-aminobutyric acid site of the gamma-aminobutyric acid type A receptor, while the benzodiazepine site most probably does not contribute to this effect. In the case of L. japonicus, these effects can be at least partially explained by its leonurine constituent, whereas the active principle of L. cardiaca, which does not contain leonurine, is subject to further research as none of the other investigated individual constituents displayed significant activity in the applied test system.
Georg Thieme Verlag KG Stuttgart · New York.
Leonurus japonicus Houtt. (Labiatae), commonly called Chinese motherwort (), is an herbaceous flowering plant native to Asia. For thousands of years in China, the aerial part of L. japonicus has been used to treat menoxenia, dysmenorrhea, amenorrhea, lochia, edema of the body, oliguresis, sores, ulcerations and other diseases in women. Now, L. japonicus is listed in the Pharmacopoeia of the People's Republic of China. The present paper reviewed the ethnopharmacology, phytochemistry, biological actions and toxicology of L. japonicus.
Information on L. japonicus was gathered via the Internet (using Elsevier, ACS, Medline Plus, CNKI, VIP, Web of Science, Google Scholar and Baidu Scholar) and libraries.
Approximately 140 chemical compounds have been isolated from L. japonicus, and the major components have been determined to be alkaloids, diterpenes and flavones. Among these active compounds, the effects of leonurine and stachydrine have been widely investigated. The primary active components in L. japonicus possess wide pharmacological actions, such as effects on the uterus as well as cardioprotective, anti-oxidative, neuroprotective and anti-cancer activities.
Modern pharmacological studies have demonstrated that L. japonicus has marked bioactivities, especially on the uterus and as a cardioprotective agent. These activities are related to its traditional use and provide prospects for the development of novel drugs, therapeutics and health care products for women. However, the toxicity of L. japonicus will require further study, and the nomenclature for L. japonicus will require additional clarification.
Leonurus cardiaca L. (Lamiaceae) is used traditionally for its sedative, hypotensive and cardiotonic effects. Due to the lack of clinical data regarding its effect in patients, a study was carried out to assess the clinical efficacy of Leonurus oil extract (LOE) in patients with arterial hypertension stages 1 and 2, accompanied by anxiety and sleep disorders.
Fifty patients were treated for 28 days with 1200 mg LOE per day. Positive effects of LOE on psycho-emotional status and arterial blood pressure in patients with stage 1 hypertension were observed 1 week earlier than in patients with stage 2 hypertension. According to the Clinical Global Impression (CGI) scale, a significant improvement in the symptoms of anxiety and depression was observed in 32% of patients, a moderate improvement in 48% and a weak effect in 8%; 12% of patients did not respond to therapy. Side effects were minimal in all groups.
Leonurus oil extract may therefore be a potentially effective therapeutic agent for patients with arterial hypertension and concurrent psycho-neurological disorders. Copyright
To establish a high-performance liquid chromatography (HPLC) for determining stachydrine and leonurine contents in the crude drug of Yimu Cao, a Chinese motherwort herb(Herba Leonuri, the aerial part of Leonurus japonicus).
The sample was obtained from the crude drug by ultrasonic extraction with ethanol after decolorization with ethyl acetate. YMC-Park CN column (250.0 mm x 4.6 mm) was used with the mobile phase for stachydrine of 0.00125 mol/L SDS:C2H5CN (90:10) at the flow rate of 1.5 ml/min with the wavelength for detection of 201.7 nm, and that for leonurine of 0.00125 mol/L SDS (containing 0.05% HClO4):CH4OH(90:10) at the flow rate of 1 ml/min with the wavelength for detection of 282 nm. The sensitivity was 0.1 AUFs and the column temperature was 20 degrees Celsius;.
With the injection amount (mg) as the abscissa and the peak area as the ordinate, the regression equation of the calibration curve for stachydrine was Y=1,187.542 3X-168.9822, and that for leonurine was Y=5,202.654X-221.141 (r=0.9998) with the linearity scope of 2.5-12.5 mg, detective limit of 0.15 mg, and recovery of (99.03+/-2.744) %. The analysis of extracted drug samples from 18 regions indicated that the alkaloids contents in Yimu Cao varied significantly, i.e. stachydrine within a range of 0.1%-0.2% while leonurine content, which was much lower, within 0.01%-0.05%. In general, the alkaloid contents were higher in the drug produced in northern China than in those produced in southern China. L. japonicus and the variant L. japonicus albiflorus had total alkaloid contents around 0.3%, which was higher than the contents of other species.
As a convenient and feasible means for determining the alkaloid contents in Yimu Cao, HPLC produces accurate and reliable results and can be more effective than the formerly used methods.
For the quality control of Leonuri Herba, alkaloid compound, leonurine, was isolated from the MeOH extract of Leonurus sibiricus L. (Labiatae) and identified by the spectroscopic analysis. A quantitative analysis of leonurine using HPLC method showed that the average contents were 0.124± 0.065% in 34 samples collected throughout the regions of Korea.
The author describes several commercially available novel phases for high performance liquid chromatography separations. Novel phases can provide an alternative and complementary separation for many analyses performed on C8 or C18 columns. Many of the separations discussed in the article could not be accomplished on C8, C18, or even phenyl phases.
Confusion is still prevalent over the correct name for the common weedy Leonurus in the tropics; the relevant literature is in Russian. The correct name of the tropical plant previously misidentified as Leonurus sibiricus L. is Leonurus japonicus Houtt.
Ischemic brain is particularly susceptible to free radicals mediated secondary neuronal damage, especially mitochondrial dysfunctions. Chinese Herbal Medicine with antioxidant properties is believed to have potential therapeutic effect. Leonurine, an alkaloid present in Herba Leonuri (HL), has shown biological effects such as antioxidant, anticoagulant, anti-apoptosis and protection against ischemic heart disease. In this study, neuroprotective effects of leonurine against cerebral ischemia/reperfusion-induced mitochondrial dysfunctions in cortex were evaluated. We used transient rat middle cerebral artery occlusion (MCAO) model of brain ischemia. The rats were treated with their respective treatments for 1 week prior to the MCAO. We found that leonurine significantly improved neurological outcome and reduced ischemia/reperfusion (I/R)-induced cerebral infarction 24 h after MCAO. Leonurine decreased reactive oxygen species (ROS) level in mitochondria isolated from ischemic cortex, which was increased by MCAO. Terminal deoxyuridine triphosphate (dUTP) Nick-End Labeling (TUNEL) staining showed anti-apoptotic effect of leonurine on ischemic cortex. Western blot analysis showed a marked decrease in the expression of Bax and an increase of Bcl-2 as a result of leonurine treatment. The attenuation of mitochondrial membrane swelling, restore of mitochondrial membrane potential and content of cytochrome c (Cyt-C) in mitochondria isolated from ischemic cortex could also be observed in leonurine treated group. The findings of this study suggest that leonurine has promising therapeutic effect for ischemic stroke treatment through antioxidant and anti-apoptotic mechanisms.
The present study was designed to investigate the protective effects of 4-guanidino-n-butyl syringate (leonurine), a compound in Herba Leonuri (HL) on ischemic rat heart to determine the protective mechanisms associated with ischemic rat hearts. Rat heart ischemia was induced by ligation of the left coronary artery. Creatine kinase (CK) and lactate dehydrogenase (LDH) in plasma and superoxide dismutase (SOD) activity in heart homogenates were measured. We found leonurine significantly decreased levels of LDH and CK activities in plasma. This observation corresponded with decreased infarct size of ischemic rat heart induced by ligation of the left coronary artery. Moreover, the mRNA expression of the pro-apoptotic gene Bax was significantly down-regulated by 0.68-fold (p < 0.05) and the anti-apoptotic gene Bcl-2 was up-regulated by 1.41-fold (p < 0.05) in the leonurine treated groups as compared with acute myocardium ischemia (MI) controls measured by RT-PCR. Correspondingly, Bcl-2 and Bax protein levels detected by Western blotting coincided with gene expression levels. In addition, the mRNA expression level of the antioxidant enzyme Mn-SOD was significantly increased 1.23-fold (p < 0.05) and this finding corresponded with an observed increase in SOD activity and also with a committed decrease in lipid peroxidation. Taken together, our results demonstrated that leonurine attenuated myocardium injury during MI via antioxidative and anti-apoptotic effects and leonurine might become a useful adjuvant cardioprotective agent.
In the present study, we examined the ability of a chemically synthesized compound based on the structure of leonurine, a phytochemical component of Herba leonuri, to protect H9c2 rat ventricular cells from apoptosis induced by hypoxia and serum deprivation, as a model of ischemia. The results revealed a concentration-dependent increase in cell viability associated with leonurine treatment, accompanied by a consistent decline in lactate dehydrogenase leakage into the culture medium. The fraction of annexin V-fluorescein isothiocyanate-positive cells was increased by hypoxia but reduced by leonurine. These changes were associated with increased expression of the antiapoptotic gene, Bcl-2, and reduced expression of the proapoptotic gene, Bax. Leonurine also reduced the cytosolic Ca overload induced by hypoxia. These results suggest that leonurine elicits potent cardioprotective effects in H9c2 cells, and these effects may be mediated by inhibition of intracellular Ca overload and apoptosis during hypoxia.
Although several antiarrhythmic drugs of chemical origin are in clinical use since decades, their application is often limited by their adverse effects and especially by their inherited proarrhythmic risk, which can lead to a significantly increased mortality in patients receiving these compounds. On the other hand, aqueous extracts from the aerial parts of the European Lamiaceae Leonurus cardiaca (Ph.Eur.) have been used for centuries as a remedy against tachyarrhythmia and other cardiac disorders. Nevertheless, a scientific basis for the claim of direct cardiac electrophysiological, antiarrhythmic, or functional effects of Leonurus cardiacae herba (LCH) preparations has not been established until now. In order to enrich the active constituents from the primary extract which was tested as the most cardioactive, namely the aqueous Soxhlet extract, and to eliminate undesired substances such as the dichloromethanic fraction or potassium, a bioassay guided fractionation procedure was applied, resulting in the development of a Leonurus cardiaca refined extract (LCRE) which was characterised together with Leonurus crude extracts by a newly developed gradient elution HPLC fingerprint analysis for separation and quantification of six major phenolics as well as by qNMR for determining the stachydrine content. This refined extract was applied intracoronarily in isolated rabbit hearts perfused according to the Langendorff technique. Mapping experiments with 256 electrodes on the heart surface showed a reduction of left ventricular pressure and an increase of relative coronary flow at concentrations of 1.0 and 2.0 mg/mL LCRE. Furthermore, the PQ-interval was prolonged and both the basic cycle length and the activation recovery interval increased. In addition, voltage-clamp measurements were performed on the following cell models in order to characterise the electrophysiological profile of LCRE: neonatal rat ventricular cardiomyocytes to investigate the effect on I(Na) and I(Ca.L), sinoatrial node cells and ventricular myocytes isolated from adult guinea pigs to test effects on I(f) and action potential (AP) duration, as well as HERG-transfected HEK 293 cells to analyse the influence on the I (K.r). In these voltage clamp experiments LCRE exerted a calcium-antagonistic activity by I(Ca.L) blockade, reduced the repolarising current I(K.r), and prolonged the AP-duration, while I(Na) was not affected. Although LCRE displayed only weak effects on the I(f) amplitude and voltage dependence, it significantly prolonged the activation time constant of I(f). Thus, LCRE acts on multiple electrophysiological targets, specifically I(Ca.L), I(K.r), and I(f), observed both at whole organ and single cell level.
Previous studies have shown that extracts of Herba leonuri , predominantly containing the phytochemical components leonurine and stachydrine, provide protective effects in the ischaemic myocardium by acting as free radical scavengers and inhibiting the formation of reactive oxygen species.
The present study was designed to investigate the cardioprotective effects of 10 ⁻⁶ mol/L leonurine on neonatal rat cardiomyocytes treated with hypoxia plus serum deprivation, a component of ischaemia, and to determine the mechanisms underlying the protective effects with regard to cardiac anti‐oxidant enzymes and apoptosis genes. Cardiomyocytes were treated with leonurine 8 h prior to exposure to hypoxia. In addition, we investigated the effects of 7.5 and 15 mg/kg leonurine, administered to rats i.p. for 7 days prior to left coronary artery ligation, on subsequent infarct size of the ischaemic heart.
Leonurine significantly increased the viability of cardiomyocytes injured by hypoxia. In the leonurine‐treated group, gene expression levels of pro‐apoptotic genes, namely Bax and Fas , were significantly downregulated (by 0.95‐ and 0.72‐fold, respectively; P < 0.001) compared with the hypoxic control group, whereas the expression of Bcl‐2 and Bcl‐xl was upregulated following leonurine treatment (by 1.03‐ and 1.07‐fold, respectively; P < 0.05). Correspondingly, leonurine treatment increased Bcl‐2 protein levels and decreased Bax protein levels. Assays investigating cardiac anti‐oxidant enzymes provided further evidence for a protective effect of leonurine, as indicated by the induction of the anti‐oxidant enzymes superoxide dismutase and catalase. Furthermore, leonurine decreased infarct size in ischaemic rat heart.
The results of the present study suggest that the mechanisms of action of leonurine in hypoxic neonatal rat cardiomyocytes and infarcted rat heart may be related to its anti‐oxidant and anti‐apoptotic properties.
Leonurine, a plant alkaloid present in Chinese motherwort, induced concentration- dependent and endothelium-independent relaxation of phenylephrine (PE)- pretreated rat aortic arterial rings. The IC50 values for leonurine were 86.4+/-10.4 and 85.9+/-17.2 microM in the presence and absence of endothelium respectively. It inhibited the responses of aortic smooth muscle to PE in Ca2+ free medium containing 100 microM EGTA, suggesting a possible action on the release of intracellular Ca2+. Leonurine is not a specific alpha-adrenoceptor blocker, since it also caused a concentration-dependent inhibition of vascular contractile responses to KCl with an IC50 value of 96.4+/-13.4 microM, suggesting that leonurine also blocks the L-type Ca2+-channel. In addition, leonurine relaxed the aortic contraction induced by prostaglandin F2alpha (PGF2alpha). These inhibitory effects of leonurine were reversible and did not affect the resting tension. In conclusion, these findings suggest that leonurine is an effective inhibitor of vascular smooth tone, probably acting by inhibiting the Ca2+ influx and the release of intracellular Ca2+.
Amongst the numerous base-deactivated ODS phases obtained by increasing the bonding density or/and by efficient endcapping treatments, some particular stationary phases have been developed, to limit the additional interactions of basic compounds with residual silanols, to work at extreme pH or with rich water mobile phases. Horizontal polymeric phases, sterically protected ones, hybrid silicas, propylene bridge, are particularly used for this purpose. Octadecyl chains with embedded polar groups and hydrophilic endcapping are also used in this goal. The properties of these phases were studied with a simple test consisting in the injection of carotenoid pigments in Subcritical Fluid Chromatography. The molecules used and the nature of the mobile phase allow the determination of hydrophobicity, polar site accessibility and type or/and bonding density of the stationary phases. Whatever the type of the phases, the particular stationary phases do not show any remarkable property, in comparison to other base-deactivated C18-bonded phases. On the other hand, embedded and polar-endcapped phases display a specific behaviour in regard of hydrophilic interactions, which are highlighted by the absence of water in the subcritical fluid. Additional properties of these phases are described, such as steric recognition and retention performances. As expected, polar-embedded phases are less retentive than classical ODS ones, but are sometimes able to provide greater steric recognition. On the other hand, the polar-endcapped phases display greater hydrophobicity than polar-embedded ones. From a simple classification diagram based on chromatographic properties, differences can be noticed between the polar-embedded groups (amide, carbamate, ether, sulfonamide) and between embedded and endcapped phases. Surprising behaviours are also noticed for some on the tested phases.