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Changes in phenolic content and antioxidant property of Melon seed (Citrullus vulgaris Schred) fermented to produce Ogiri: a local condiment. La Rivista Italiana delle Sostanze Grasse
Abstract
The present study investigated the effect of fermentation on the phenolic content and antioxidant properties of condiment (Ogiri) produced from melon seed (Citrullus vulgaris Schred). Aqueous extracts of fermented and unfermented melon seed were subjected to phenolic content determination and antioxidant analysis evaluation. The result of the study revealed that fermented melon seeds had significantly higher (P<0.05) total phenol content (2.23 mg/g) and total flavonoid (0.78 mg/g) than the unfermented melon seeds [total phenol (1.36 mg/g) and total flavonoid (0.55 mg/g)]. The fermented melon seeds also had significantly higher (P<0.05) free radical scavenging ability (DPPH, ABTS and OH radicals) and Fe 2+ chelating ability than the unfermented melon seed. Conclusively, it was found that in this case fermentation increases the phenolic content and antioxidant capacity. Hence, fermented melon seed could be a cheap source of dietary antioxidants.
... contents were found in Yellow winter. Ademiluyi and Oboh (2011) found that the total phenolic content and total flavonoid contents of non-fermented melon seeds were 1,360 mg/kg and 550 mg/kg, respectively. Seymen, Uslu, Türkmen, Aljuhaimi, and Özcan (2016) found that the total phenol content of the seeds in the study of pumpkin seeds was 56.94-87.15 ...
The moisture content of seeds of the melon varieties varied between 4.8%–6.3%, the ash interval 2.5%–3.5%, the crude oil 19.4%–33.0%, the crude protein 30.4%–37.2%, and the crude cellulose value 1.5%–2.7%. Flavonoid contents of seeds were found between 134 and 257 mg CE/kg, and the total phenol contents were found between 615 and 850 mg GAE/kg. The phosphorus contents of melon seeds changed between 5,912 and 8,964 mg/kg. The seed oils contained 57.1%–74.7% linoleic, 13.0%–28.4% oleic, and 7.0%–10.1% palmitic acids. While α‐tocopherol contents of oils varied between 1.8 mg/kg (Kırkağaç‐Dalaman) and 10.4 mg/100 g (Çankırı winter), γ‐tocopherol contents of oils changed between 6.6 mg/100 g (Mühürlü) and 30.0 mg/100 g (Çankırı winter). The cholesterol, brassicasterol, campesterol, stigmasterol, sitosterol, and sitostanol contents were the main sterols for Chocolate variety oil (13.73, 14.21, 27.41, 38.05, 152.04, and 117.57 mg/kg, respectively).The ∆5‐avenasterol (116.62 mg/kg) and ∆7‐avenasterol (31.28 mg/kg) were significantly (p < .05) high in Çankırı winter. ∆7‐stigmastenol content was dominated in Kırkağaç‐Dalaman seed oil (143.69 mg/kg). Seeds belonging to Cucurbitaceae family are known to be as rich in oil. The fatty acid profile plays an important role in their stabiliy and nutritional value. The high content oil showing useful characteristics such as odorlessness, good color. Melon seed oil rich in the bioactive components. These seeds suitable for oil industrial applications. Because many of these oils were used as cooking oil in some countries in Africa and in the Middle East, the melon seed oils could be developed into the commercial products to serve as alternate vegetable oils.
In view of the growing demand for vegetable oil, currently exploration of some non-conventional oils is of great concern. This study firstly analyzed the contents of fatty acids, phytosterols, and tocopherols in Catalpa ovata seed oil collected from four different Provinces in China. Then the composition of flavonoids as well as their antioxidant activities in defatted seed meal was determined. The results showed that the relative oil content in C. ovata seeds ranged from 24.0 to 36.0 % and seed oil was mainly composed of fatty acids linoleic acid (43.4-50.1 %), α-linolenic acid (23.8-24.4 %), and oleic acid (13.1-16.2 %). The content of unsaturated fatty acids was up to 85.0 %. Sterol in seed oil mainly contained campesterol, stigmasterol, and β-sitosterol. β-sitosterol accounted for 74.0 % of the total sterol. The tocopherol content was 173.0-225.7 mg/100 g. Defatted seed meal from Hubei Province showed the highest content of total flavonoids (11 mg/g) and the strongest activities for DPPH radicals scavenging, ABTS radicals scavenging, and ferric reducing antioxidant power compared with other defatted seed meal in this study. Seven flavonoids were identified from C. ovata seed meal. These results suggest that C. ovata seeds may be developed as a new source of oil and can also be properly used in pharmaceuticals and cosmetics.
The physicochemical properties, fatty acid, tocopherol, thermal properties, (1)H NMR, FTIR and profiles of non-conventional oil extracted from Citrullus colocynthis (L.) Schrad seeds were evaluated and compared with conventional sunflower seed oil. In addition, the antioxidant properties of C. colocynthis seed oil were also evaluated. The oil content of the C. colocynthis seeds was 23.16%. The main fatty acids in the oil were linoleic acid (66.73%) followed by oleic acid (14.78%), palmitic acid (9.74%), and stearic acid (7.37%). The tocopherol content was 121.85mg/100g with γ-tocopherol as the major one (95.49%). The thermogravimetric analysis showed that the oil was thermally stable up to 286.57°C, and then began to decompose in four stages namely at 377.4°C, 408.4°C, 434.9°C and 559.2°C. The present study showed that this non-conventional C. colocynthis seed oil can be used for food and non-food applications to supplement or replace some of the conventional oils.
The relationship between the structural characteristics of 29 flavonoids and their antiradical activity
was studied. The obtained results suggest that the free radical scavenger potential of
these polyphenolic compounds closely depends on the particular substitution pattern of free
hydroxyl groups on the flavonoid skeleton. The possible mechanism of action of flavonoids
lacking B ring OHs as free radical scavengers has been proposed.
Polyphenols exhibit a wide range of biological effects because of their antioxidant properties. The study sought to carry out a comparative studies on the protective ability of free and bound polyphenol extracts of red Capsicum annuum var. aviculare (Tepin) on brain and liver – in vitro. Free polyphenols of red Capsicum annuum var. aviculare (Tepin) were extracted with 80% acetone, while the bound polyphenols were extracted with ethyl acetate from acid and alkaline hydrolysed residue from free polyphenols extract. The phenol content, Fe(II) chelating ability, OH radical scavenging ability and protective ability of the extract against some pro-oxidant (25 μM Fe(II), 7 μM sodium nitroprusside and 1 mM quinolinic acid)-induced lipid peroxidation in brain and liver was subsequently determined. The results of the study revealed that the free polyphenols (218.2 mg/100 g) content of the pepper were significantly higher (PPCapsicum annuum var. aviculare (Tepin) contains 83.7% free soluble polyphenol and 16.3% bound polyphenols. In addition, both polyphenolic extracts inhibit the various pro-oxidant agents (Fe2+, sodium nitroprusside and quinolinic acid) induced lipid peroxidation in brain and liver tissues in a doe-dependent manner. However, the free polyphenols had higher protective ability than the bound polyphenols. The main mechanism through which they are carry out their protective effect against lipid peroxidation in the brain and the liver is by Fe(II) chelating ability, OH and NO radicals scavenging ability and inhibition of over-stimulation of NMDA receptor.
The antioxidant activities of methanolic extract of kinema, fermented using Bacillus subtilis, and cooked non-fermented (CNF) soybean were evaluated by four in vitro methods, namely stable DPPH-scavenging activity, Fe3+-reducing power, Fe2+-chelating activity, and activity in linoleic acid emulsion system. The total phenol content of kinema was 144% higher than that of CNF soybean (3.3 mg g−1 dry weight). At all the tested concentrations (10–50 mg ml−1), kinema extract was found to be a better free radical scavenger, which increased in a time and dose-dependent manner, than the CNF soybean extract. The reducing power of kinema was 147% higher than that of CNF soybean (3.8 mg ascorbic acid equivalents g−1 dry weight). At 10 mg ml−1, the kinema extract exhibited 64% metal-chelating effect which was much higher than the effect shown by CNF soybean (22%). At 50 mg ml−1, after 24 h, while kinema exhibited antioxidant activity with 44% inhibition of linoleic acid peroxidation, CNF soybean exhibited 36% inhibition. The inhibition of both of them was found to decline with time and reached 26% after 72 h. The total phenol contents of kinema and CNF soybean were positively correlated (P < 0.01) with the respective values of free radical-scavenging activity (r = 0.96 and 0.82), reducing power (r = 0.94 and 0.82), metal-chelating activity (r = 0.95 and 0.76), and lipid peroxidation inhibitory activity (r = 0.91 and 0.82). Whereas the total phenol content in CNF soybean accounted for 68% of each of free radical-scavenging activity and reducing power, 58% of Fe2+-chelating activity and 66% of lipid peroxidation inhibitory activity, that in kinema could reflect 83–92% of all the antioxidant parameters studied. The data also revealed a significant correlation (P < 0.01) between any two of these five parameters, indicating while total phenol content as the independent variable, all other parameters as the dependent variables. Thus, kinema may be exploited as a functional food to alleviate oxidative stress.
The chemical (proximate composition, pH, total tocopherol, acid and iodine values, total and reducing sugars) and biochemical (alpha-amylase, sucrase and protease) changes occurring during the fermentation of locust bean and melon to the condiments - iru and ogiri respectively were monitored. Processing locust bean to the condiment involved boiling for 12 hours, soaking the seeds in water, dehulling, boiling for another 6 hours and fermentation for 3-4 days while melon is boiled for 6 hours, cooled and fermented. Boiling, soaking (in water) and dehulling of locust bean resulted in reduction of ash, crude fibre (CF) and total tocopherol but increased ether extract. Fermentation increased the pH value, crude protein (CP), reducing sugar, alpha-amylase, sucrase, protease and free amino acid, decreased the total sugar in both samples and also increased the CF of locust bean sample but had no effect on the CF in melon. Fermentation had no effect on total tocopherol content in both samples. Heat treatment and fermentation employed in processing both samples increased the acid value with a corresponding decrease in iodine value. High negative correlation was observed between acid and iodine values while a high positive correlation was observed between tocopherol and iodine value.
Reactive oxygen or nitrogen species (ROS/RNS) generated endogenously or in response to environmental stress have long been implicated in tissue injury in the context of a variety of disease states. ROS/RNS can cause cell death by nonphysiological (necrotic) or regulated pathways (apoptotic). The mechanisms by which ROS/RNS cause or regulate apoptosis typically include receptor activation, caspase activation, Bcl-2 family proteins, and mitochondrial dysfunction. Various protein kinase activities, including mitogen-activated protein kinases, protein kinases-B/C, inhibitor-of-I-kappaB kinases, and their corresponding phosphatases modulate the apoptotic program depending on cellular context. Recently, lipid-derived mediators have emerged as potential intermediates in the apoptosis pathway triggered by oxidants. Cell death mechanisms have been studied across a broad spectrum of models of oxidative stress, including H2O2, nitric oxide and derivatives, endotoxin-induced inflammation, photodynamic therapy, ultraviolet-A and ionizing radiations, and cigarette smoke. Additionally ROS generated in the lung and other organs as the result of high oxygen therapy or ischemia/reperfusion can stimulate cell death pathways associated with tissue damage. Cells have evolved numerous survival pathways to counter proapoptotic stimuli, which include activation of stress-related protein responses. Among these, the heme oxygenase-1/carbon monoxide system has emerged as a major intracellular antiapoptotic mechanism.
Fermented foods constitute a significant component of African diets. Many fermented foods are known, some serve as main course meals, others as beverages while others are highly prized food condiments. Those which serve as main meals and beverages are usually products of carbohydrate-rich raw materials. Some of the most important ones in this group include ‘gari’ from cassava, ‘ogi’ and ‘mahewu’ from maize and ‘kaffir’ beer from sorghum. Those which serve as food condiments are usually made from the fermentation of protein rich seeds. These include ‘iru’ from African locust bean; ‘ugba’ from African oil bean and ‘ogiri’ from melon seeds among others. All are known to be good sources of proteins and vitamins.
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
Products of browning reaction of glucosamine were prepared from glucosamine-HCl by incubating it at 37°C for 0-30 days, and the antioxidative activity, reducing power, degree of browning, aminosugar contents, pH, moisture and total nitrogen contents of the products were measured. In addition, the brown products prepared from glucosamine by incubation at 37°C for 0, 15 and 30 days were fractionated by gel filtration using Sephadex G-15, and the antioxidative activity, reducing power, degree of browning and pH of each fraction were also measured.
The results obtained were as follows:
1) When white powder of free glucosamine was allowed to stand for 3 days at 37°C, it transformed to a brown paste.
2) The strongest antioxidative activity was observed in the product obtained after incubation between 20 and 30 days.
3) The increase in antioxidative activity of the products of browning reaction was accompanied by the increase in the degree of browning.
4) The brown products prepared from glucosamine by long incubation were fractionated into fractions according to their molecular weights.
Antioxidative activity was detected in the fractions corresponding to intermediate molecular weight.
The antioxidant action of medicinal herbs used in Ghana for treating various ailments was evaluated in vitro and in vivo. Five plants, Desmodium adscendens, Indigofera arrecta, Trema occidentalis, Caparis erythrocarpus, and Thonningia sanguinea were tested for their free radical scavenging action by their interaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH). Of these five plants, only Thonningia sanguinea was found to scavenge the DPPH radical. Lipid peroxidation in liver microsomes induced by H2O2 was also inhibited by T. sanguinea. The hepatoprotective effect of T. sanguinea was studied on acute hepatitis induced in rats by a single dose of galactosamine (GalN, 400 mg/kg, IP) and in mice by carbon tetrachloride (CCl4, 25 μl/kg, IP). GalN induced hepatotoxicity in rats as evidenced by an increase in alanine aminotransferase (ALT) and glutathione (GSH) S-transferase activities in serum was significantly inhibited when T. sanguinea extract (5 ml/kg, IP) was given to rats 12 hr and 1 hr before GalN treatment. The activity of liver microsomal GSH S-transferase, which is known to be activated by oxidative stress, was increased by the GalN treatment and this increase was blocked by T. sanguinea pretreatment. Similarly, T. sanguinea pretreatment also inhibited CCl4-induced hepatotoxicity in mice. These data indicate that T. sanguinea is a potent antioxidant and can offer protection against GalN- or CCl4-induced hepatotoxicity.
The effect of fermentation on the polyphenol distribution and antioxidant activity of four underutilized legumes [Cajanus cajan L. Millsp (Pigeon pea), Vigna subterranea L. Verdc (Bambara groundnut), Sphenostylis stenocarpa Harms (African yam bean), and Phaseolus vulgaris L. (Kidney bean)] were investigated. The beans were cooked (12 h), soaked in boiled water (12 h), dehulled, and then cooked again (2 h). The cotyledons were drained, wrapped in jute sacks and left to ferment at 37°C (4 days) to produce condiments. The distribution of free and bound phenolic compounds in the fermented and unfermented beans was determined; thereafter the free radical scavenging ability, reducing power, and the ability of the free and bound phenolic compounds of the fermented and unfermented beans to inhibit lipid peroxidation were determined. The results of the study revealed that fermentation caused a significant increase (p
This present study was carried out to investigate the effect of natural fermentation on the nutritive value (proximate composition), polyphenolic distribution, and antioxidant properties of African locust beans (Parkia biglobosai). African locust bean (ALB) seeds were boiled for 12 h, dehulled and subjected to natural solid substrate fermentation without any inoculation for 4 days. The proximate composition of the fermented and unfermented locust bean seeds was subsequently determined. Thereafter, the polyphenol distribution, reducing power, DPPH free-radical scavenging antioxidant activity, and inhibition of lipid peroxidation were determined for soluble free and bound polyphenol extracts. The results of the study revealed that fermentation caused a significant increase (P < 0.05) in the ALB protein content with 18.3% in unfermented and 36% in fermented. The fat content in unfermented was 13.2% versus 26.8% in fermented, while there was no significant changes (P > 0.05) in ash, crude fiber, or moisture content. However, there was a significant decrease (P < 0.05) in the carbohydrate content. The total phenolic content, reducing ability and free-radical scavenging ability were high in both the fermented and unfermented ALB. Fermentation caused a significant increase (P < 0.05) in the free phenolic content of the ALB and a significant decrease (P < 0.05) in the bound phenolic content of ALB. The free-phenolic fraction from both fermented and unfermented ALB had high reducing power, free radical scavenging ability, and inhibition of lipid peroxidation using cow brain tissues. Free phenolic extract from the fermented ALB had a significantly higher (P < 0.05) antioxidant activity than that of unfermented ALB. Results suggest that fermentation will increase the nutritive values, free phenolic and antioxidant activity of the African locust bean, making it a potential functional food in addition to its traditional role of dietary protein source.
Previous research has suggested a relationship between free phenolic content and β-glucosidase activity in solid-state fermented food substrates and to amylase activity in germinating soybeans. This study was undertaken to examine the role of a number of carbohydrate-cleaving enzymes in phenolic antioxidant mobilization from whole soybean during solid-state fermentation. In addition to total soluble phenolic content, α- and β-glucosidase, α-amylase, and β-glucuronidase activities were measured in extracts of soybean fermented with a food-grade fungus, Rhizopus oligosporus. Antioxidant activity of the extracts was determined as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability. Our results demonstrate that while total soluble phenolic content increased 120–135% in the extracts, increased antioxidant activity (+61%) was limited to the early fermentation period, with activity decreasing with increased culture time. Higher antioxidant activity was linked to increased glucosidase and glucuronidase activities, while high total phenolic content partly linked to increased amylase activity. The overall results (enzymatic activities and phenolic antioxidant contents) suggest the possible involvement of lignin remobilization and/or degradation activities, as well as phenolic detoxification activities, by Rhizopus oligosporus in phenolic antioxidant mobilization from fermented whole soybean.
Cranberry pomace is a byproduct of the cranberry processing industry that can be targeted for production of value-added phenolic ingredients. Bio-processing of pomace by solid state fermentation (SSF) using food grade fungi provides unique strategies to improve nutraceutical properties and to produce functional phenolic ingredients. Several functional phenolic phytochemicals exist as glycosides or as other conjugated forms with reduced biological activity. We hypothesize that during SSF the fungal glycosidases mobilize some phenolic antioxidants in cranberry pomace and their activity by hydrolysis via β-glucosidase and releasing the aglycone. To develop this strategy we used food grade fungus Rhizopus oligosporus. Our goal was to target the release of simple phenolic aglycones and mobilized diphenyls. SSF of cranberry pomace was done for 16 days with nitrogen sources, ammonium nitrate (NH4NO3) and fish protein hydrolysate (FPH). The two nitrogen treatments increased water extractable phenolics by 15–26% by day 10 in the pomace. Antioxidant protection factor was highest on day 10 for both nitrogen treatments and was 20–25% higher than control for water extracts and 16.5–19.5% for ethanol extracts. The DPPH radical inhibition (DRI) capacity increased by 5% only for the NH4NO3 treatment and gradually decreased for FPH treatment in water extracts. There was no significant change in DRI of the ethanol extracts. The β-glucosidase activity increased by 60-fold for NH4NO3 treatment and by over 100-fold for FPH treatment and correlated well with the increase in the extractable phenolics and antioxidant activity. Changes in diphenyl profiles during the solid-state process analyzed using HPLC indicated that ellagic acid increased by 4–5 fold in water extracts for both the nitrogen treatments. This increase was between 15–27% in the ethanol extracts. We conclude that SSF of cranberry pomace increased the antioxidant activity concurrent with increased β-glucosidase activity. The HPLC profile showed ellagic acid, a compound with anti-carcinogenic properties was enriched. The antioxidant function has implications for prevention of major oxidation-linked diseases such as cancer and CVD. This value-added SSF strategy is an innovative approach to enhance nutraceutically-relevant functional phytochemicals for food and feed applications.
The present study was aimed at evaluating the in vivo effects in rats of a diet rich in antioxidant dietary fiber (AODF) from grapes on antioxidant (glutathione) concentration, antioxidant enzymes (catalase, glutathione reductase, glutathione peroxidase and superoxide dismutase) activity in liver homogenates, and the plasma and liver antioxidant capacity (measured by the ferric reducing antioxidant power and the ABTS–2,2′-azinobis-3-ethylbenzothioline-6-sulphonic acid- assays). Additionally, the potential protective effect against oxidative stress of grape AODF was tested in rats submitted to acute oxidative stress induced by acetaminophen. Feeding rats with an AODF-rich diet for 3 weeks did not modify the plasma antioxidant capacity. It did evoke an increase of the steady-state activity of glutathione peroxidase but did not affect the activity of the other enzymes nor the glutathione concentration in the liver. No protective effect of polyphenol-rich grape AODF was seen, since it did not change the response of the hepatic antioxidant system against an acetaminophen-induced oxidative stress.
Publisher Summary This chapter discusses the analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Analyses of the Folin-Ciocalteu (FC) type are convenient, simple, and require only common equipment and have produced a large body of comparable data. Under proper conditions, the assay is inclusive of monophenols and gives predictable reactions with the types of phenols found in nature. Because different phenols react to different degrees, expression of the results as a single number—such as milligrams per liter gallic acid equivalence—is necessarily arbitrary. Because the reaction is independent, quantitative, and predictable, analysis of a mixture of phenols can be recalculated in terms of any other standard. The assay measures all compounds readily oxidizable under the reaction conditions and its very inclusiveness allows certain substances to also react that are either not phenols or seldom thought of as phenols (e.g., proteins). Judicious use of the assay—with consideration of potential interferences in particular samples and prior study if necessary—can lead to very informative results. Aggregate analysis of this type is an important supplement to and often more informative than reems of data difficult to summarize from various techniques, such as high-performance liquid chromatography (HPLC) that separate a large number of individual compounds .The predictable reaction of components in a mixture makes it possible to determine a single reactant by other means and to calculate its contribution to the total FC phenol content. Relative insensitivity of the FC analysis to many adsorbents and precipitants makes differential assay—before and after several different treatments—informative.
BACKGROUND: The higher consumption of vegetables and fruits could be a practical approach to the management of oxidative stress. The present study sought to compare the antioxidant properties of polar and non-polar constituents of some tropical green leafy vegetables (Struchium sparganophora, Amaranthus cruentus, Telfairia occidentalis, Ocimum gratissimum, Talinium triangulare, Cnidoscolous aconitifolius and Vernonia amygdalina).
RESULTS: The polar antioxidant constituents (total phenol (3330–17 572 mg kg−1), total flavonoid (1668–4306 mg kg−1) and vitamin C (224–642 mg kg−1)) were higher than the non-polar antioxidant constituents (total phenol (703–3115 mg kg−1), total flavonoid (130–1303 mg kg−1) and carotenoids (132–1303 mg kg−1)). Furthermore, the polar extracts had a significantly higher (P < 0.05) 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability (except T. triangulare), total antioxidant capacity, reducing power (except T. triangulare and A. cruentus) and Fe(II) chelating ability (except C. aconitifolius and S. sparganophora). However, the polar and non-polar extract of O. gratissimum had the highest antioxidant properties while that of T. triangulare had the least antioxidant properties.
CONCLUSION: The polar extract of most of the vegetables had higher antioxidant properties than the non-polar extract, with O. gratissimum extracts having the highest antioxidant properties. Copyright
During gastrointestinal digestion or food processing of proteins, small peptides can be released and may act as regulatory compounds with hormone-like activities. Numerous biologically active peptides (bioactive peptides) have been identified. Most bioactive peptides are derived from milk and dairy products, with the most common being angiotensin converting enzyme inhibitory peptides. Soybean protein and soybean derived peptides also play an important role in soybean physiological activities, particularly those related to the prevention of chronic diseases. However, the bioactive potential of soybean derived bioactive peptides is yet to be fully appreciated. After a general introduction of approaches and advances in bioactive peptides from food sources, this review focuses on bioactive peptides derived from soybean proteins and their physiological properties. Technological approaches to generate bioactive peptides, their isolation, purification, characterization, and quantification, and further application in food and drug design are also presented. Safety concerns, such as potential toxicity, allergenicity, and sensory aspect of these peptides are likewise discussed.
Bambusae caulis in Liquamen (BCL) is a nutritious liquid that can be extracted from heat-treated bamboo stems. It is also an important herbal medicine in Asia. In this study, antioxidant and angiotensin I converting enzyme (ACE) inhibitory activity of BCL were investigated. BCL significantly quenched DPPH and peroxyl radicals measured by electron spin resonance (ESR) spectroscopy, while IC50 values were 79.85 and 28.85 μg/ml, respectively. The ability of BCL to inhibit the oxidative damage of DNA was assessed in vitro by measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular form. It was found that BCL significantly protected hydroxyl radical-induced DNA damage in a dose-dependant manner, while also inhibiting apoptosis in hydrogen peroxide-induced PC-12 cells and angiotensin I converting enzyme (ACE) activity. These findings suggest that BCL may be a beneficial ingredient in functional foods and/or pharmaceuticals.
The chemical composition and antioxidant properties of a water-soluble extract of Moldavian balm (Dracocephalum moldavica L., syn. Moldavian dragonhead) prepared by hydrodistillation are presented in this study. The total phenol content was estimated as gallic acid equivalents by the Folin-Ciocalteu reagent method, while the qualitative–quantitative composition of the extract was determined by high performance liquid chromatography coupled with photodiode array detection. The antioxidant properties assessed included iron(III) reduction and iron(II) chelation and 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) and superoxide anion free radical scavenging. In addition, the ability of the extract to protect 2-deoxy-d-ribose and bovine brain-derived phospholipids against hydroxyl radical-mediated degradation was assessed. The extract principally contained polar compounds including hydroxycinnamic acids and flavonoids, with caffeic and ferulic acids, luteolin-7-O-glucoside, rosmarinic acid, luteolin and apigenin being identified from their chromatographic behavior and spectral characteristics. The Moldavian balm extract demonstrated activity in all the antioxidant assays; however, it was not as potent as the positive control except in the phospholipid-based assay where its hydroxyl radical scavenging activity was statistically indistinguishable from that demonstrated by Pycnogenol.
Satureja hortensis L. (summer savory) is an annual herb belonging to the family Lamiaceae. It is used as a condiment and as a plant in traditional folk medicine to treat infectious diseases and disorders. A number of studies have suggested that the activity of Satureja hortensis may relate to the antioxidant properties of its secondary metabolites. Therefore, this study attempts to characterise the antioxidant properties of an acidified aqueous methanol extract from commercially available material using Fe(III) reductive and DPPH, ABTS+ and hydroxyl free radical-scavenging assays. The crude extract demonstrated promising in vitro activity and thus was further fractionated, by liquid–liquid partitioning against water, to determine which fraction possessed the most potent activity. The ethyl acetate-soluble fraction was the most effective fraction, with reductive activity of 2648 ± 41.4 μmol ascorbic acid/g extract, and DPPH and hydroxyl radical-scavenging IC50 concentrations of 138 ± 6.0 and 45.0 ± 7.0 μg/ml, respectively. The TEAC value for this fraction was 2.59 ± 0.06 mM Trolox. The experimental results are discussed and potential applications are explored.
Several honey samples (27) from Burkina Faso were analyzed to determine their total phenolic, flavonoid and proline contents as well as their radical scavenging activity. These samples consisted of 18 multifloral, 2 honeydew and 7 unifloral honeys, derived in the latter cases from flowers of Combretaceae, Vitellaria, Acacia and Lannea plant species. The total phenolic contents varied considerably with the highest values obtained for honeydew honey. Similarly, much variation was seen in total flavonoid and proline content, with Vitellaria honey having the highest proline content. Vitellaria honey was also found to have the highest antioxidant activity and content. The correlation between radical scavenging activity and proline content was higher than that for total phenolic compounds. This suggests that the amino acid content of honey should be considered more frequently when determining its antioxidant activity.
Carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin, were determined in 10 varieties of five fruit species (orange, pear, peach, apple and cherry) and five varieties of four species of vegetables (Portuguese coles, turnip greens, purslane, leaf beet and beetroot leaves) cultivated in Portugal and country traditional, the fruits being of protected designation of origin or of protected geographical indication. The determination was done by high performance liquid chromatography, using two metal free reverse phase columns, an organic mobile phase based on acetonitrile, methanol and dichloromethane and a UV–vis photodiode array detector. Identification was done by retention time and spectral analysis and quantification was based on peak area at 450 nm by external calibration. The analysed leafy vegetables are a very good source of lutein (0.52–7.2 mg/100 g) and β-carotene (0.46–6.4 mg/100 g) while the analysed fruits have a considerably lower content of carotenoids (lutein, 0.0032–0.16 mg/100 g and β-carotene, 0.010–0.17 mg/100 g) and a complex and variable qualitative and quantitative carotenoid composition. Most estimated relative measurement expanded uncertainties were between 0.10 and 0.31. Results indicate that the carotenoid content of the analysed items could vary with species, varieties, geographical place of production (region, site) and time of harvest, and should be addressed in the eventual production of data for food composition data bases.
Soybean broth (SB) and fermented soybean broth (FSB), at 100% exhibited good antioxidant activities of 0.85 and 0.80, respectively. Only FSB exhibited an excellent reducing power of 0.76–0.86 at 5–100%. FSB showed an excellent scavenging activity on 1,1-diphenyl-2-picrylhydrazyl radicals (100%) at 20–100%, while SB only at 100%. FSB at 20–100% inhibited the production of superoxide anion radicals by 81–93% but SB showed no inhibition. As its concentrations increased from 2–100%, the scavenging effect of FSB on hydroxyl radicals increased from 30–96%, whereas that of SB increased from 5–76%. Both FSB and SB were good chelators for ferrous ions. For cupric ions, SB showed significantly higher chelating effect than did FSB. These results showed that FSB was superior to SB in most antioxidant properties and that SB and FSB, more specifically FSB, might be potential antioxidants for application in food products.
Iron is an essential metal for normal cellular physiology, but excess iron results in cell injury; it reacts with superoxide anions (O2) and hydrogen peroxide (H2O2) to produce the hydroxyl radical (OH) and other reactive oxygen species (ROS) which can cause damage to body cells. Free radical damage can be prevented by food rich in antioxidants such as fruit and vegetables. In the present study, the ability of aqueous extracts of ripe (red) and unripe (green) hot peppers [Capsicum annuum, Tepin (CAT) and Capsicum chinese, Habanero (CCH)] (3.3–16.7 mg/ml) to prevent 25 μM Fe2+-induced lipid peroxidation in Rat’s brain (In vitro) were assessed using TBARS (Thiobarbituric acid reactive species). The total phenol and vitamin C content, as well as Fe2+-chelating ability, and the ability of the pepper extracts to prevent Fe2+/H2O2-induced decomposition of deoxyribose was also determined. The results of the study revealed that incubating the brain tissues in the presence of 25 μM Fe2+ caused a significant increase (p < 0.05) in MDA (Malondialdehyde) production in the rat’s brain (260%) when compared with the basal (100%). However, the pepper extracts (unripe and ripe) caused a significant decrease (p < 0.05) in the MDA production in both the basal and the Fe2+-induced lipid peroxidation in the Rat’s brain. However, CAT [ripe and unripe] had a significantly (p < 0.05) higher inhibitory effect on both basal and Fe2+-induced lipid peroxidation in the brain tissues than that of CCH (ripe and unripe). In addition, CAT (ripe and unripe) had a significantly higher (p < 0.05) total phenol, vitamin C and Fe2+ chelating ability than CCH (ripe and unripe). The unripe CAT had a significantly (p < 0.05) higher total phenol, Fe2+ chelating ability and inhibitory effect on the basal and Fe2+-induced lipid peroxidation in the brain tissues than the ripe pepper, while the reverse is the case with CCH where the red pepper had a higher values for the same parameters. However, ripe CAT and CCH had a significantly higher (p < 0.05) vitamin C content than the unripe; meanwhile both ripe and unripe peppers (CAT&CCH) did not significantly inhibit (p < 0.05) Fe2+/H2O2-induced decomposition of deoxyribose (Fenton reaction). The inhibitory effect of the pepper on lipid peroxidation (basal and Fe2+ induced) and Fe2+ chelating effect of the extracts were dose dependent. It was therefore concluded that hot peppers prevent Fe2+-induced lipid peroxidation, however CAT (ripe and unripe) are more potent inhibitors of Fe2+-induced lipid peroxidation than CCH (unripe and ripe), meanwhile unripe CAT had the highest protective ability and this is probably due to its higher total phenol content and Fe2+ chelating ability.
Unshelled melon seeds (ex Fiditi Nigeria) fumigated and stored at ambient conditions for 10 months in five different containers (metal drum, plastic bucket, clay pot, polythene lined jute bag and ordinary jute bag) were sampled at 3 monthly intervals for chemical, microbiological and entomological analyses. The oil content of the seeds in all containers increased by 0·37–3·03%, while the protein content of the seeds rose by 5·8–7·48%. No container effect on the chemical composition of the seeds was apparent. External and internal mouldiness of the seeds increased by 39–59% and 12·4–19·4% respectively in all the containers. Aflatoxin contamination was not detected in the seeds. The high level of mouldiness was reflected in the increase in the free fatty acid content of the seeds (4·23–5·57%) in all containers.Insect damage to seeds was 14·0% in jute bags after 9 months in storage. The initial germinability of the seeds was 70%. There was a significant decrease in germinability at the end of the storage period being lowest (8·0%) in the clay pot and jute bag.
Chemical antioxidant activity assays are used extensively to evaluate the potential bioactivity of plant foods and their phytochemical constituents, but they do not mimic the complexity of biological systems. The cellular antioxidant activity (CAA) activity assay was developed to be a more biologically relevant model to measure antioxidant activity. Structure-activity relationships of flavonoids have been determined in many chemistry antioxidant activity assays, and they vary with the protocols. The objective of this study was to determine structure-activity relationships of selected flavonoids in the CAA assay. The structures that conferred flavonoids with the most antioxidant activity in the CAA assay were a 3',4'- o-dihydroxyl group in the B-ring, a 2,3-double bond combined with a 4-keto group in the C-ring, and a 3-hydroxyl group. Isoflavones had no cellular antioxidant activity. Flavanols with a galloyl moiety had higher antioxidant activity than those without, and a B-ring 3',4',5'-trihydroxyl group further improved their efficacy. ORAC values for flavonoids were not related to their CAA values. Knowledge of structure-activity relationships in the CAA assay may be helpful in assessing potential in vivo antioxidant activity of flavonoids.
Chelation by citrate was found to promote the autoxidation of Fe2+, measured as the disappearance of 1,10-phenanthroline-chelatable Fe2+. The autoxidation of citrate-Fe2+ could in turn promote the peroxidation of microsomal phospholipid liposomes, as judged by malondialdehyde formation. At low citrate-Fe2+ ratios the autoxidation of Fe2+ was slow and the formation of malondialdehyde was preceded by a lag phase. The lag phase was eliminated by increasing the citrate-Fe2+ ratio, which also increased the rate of Fe2+ autoxidation. The Fe2+ autoxidation product required for the initiation of lipid peroxidation was characterized as being Fe3+. As direct evidence of this, linear initial rates of lipid peroxidation were obtained via the combination of citrate-Fe2+ and citrate-Fe3+, optimum activity occurring at a Fe3+-Fe2+ ratio of 1:1. Evidence is also presented to suggest that the superoxide and the hydrogen peroxide that are formed during the autoxidation of citrate-Fe2+ can either stimulate or inhibit lipid peroxidation by affecting the yield of citrate-Fe3+ from citrate-Fe2+. No evidence was obtained for the participation of the hydroxyl radical in the initiation of lipid peroxidation by citrate-Fe2+.
A wide variety of oxygen free radicals and other reactive oxygen species can be formed in the human body and in food systems. Transition metal ions accelerate free-radical damage. Antioxidant defenses, both enzymic and nonenzymic, protect the body against oxidative damage, but they are not 100% efficient, and so free-radical damage must be constantly repaired. Nonenzymatic antioxidants are frequently added to foods to prevent lipid peroxidation. Several lipid antioxidants can exert prooxidant effects toward other molecules under certain circumstances, and so antioxidants for food and therapeutic use must be characterized carefully. Methods of measuring oxidative damage and trapping free radicals in vivo are briefly discussed. Such methods are essential in checking proposals that increased intake of food-derived antioxidants (such as antioxidant vitamins) would be beneficial to humans.
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
The antioxidant action of medicinal herbs used in Ghana for treating various ailments was evaluated in vitro and in vivo. Five plants, Desmodium adscendens, Indigofera arrecta, Trema occidentalis, Caparis erythrocarpus, and Thonningia sanguinea were tested for their free radical scavenging action by their interaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH). Of these five plants, only Thonningia sanguinea was found to scavenge the DPPH radical. Lipid peroxidation in liver microsomes induced by H2O2 was also inhibited by T. sanguinea. The hepatoprotective effect of T. sanguinea was studied on acute hepatitis induced in rats by a single dose of galactosamine (GalN, 400 mg/kg, IP) and in mice by carbon tetrachloride (CCl4, 25 microl/kg, IP). GalN induced hepatotoxicity in rats as evidenced by an increase in alanine aminotransferase (ALT) and glutathione (GSH) S-transferase activities in serum was significantly inhibited when T. sanguinea extract (5 ml/kg, IP) was given to rats 12 hr and 1 hr before GalN treatment. The activity of liver microsomal GSH S-transferase, which is known to be activated by oxidative stress, was increased by the GaIN treatment and this increase was blocked by T. sanguinea pretreatment. Similarly, T. sanguinea pretreatment also inhibited CCl4-induced hepatotoxicity in mice. These data indicate that T. sanguinea is a potent antioxidant and can offer protection against GalN- or CCl4-induced hepatotoxicity.
Solvent-extracted bamboo leaf extract (BLE) containing chlorogenic acid, caffeic acid, and luteolin 7-glucoside was evaluated in vitro for free radical scavenging and antioxidant activities using a battery of test methods. BLE exhibited a concentration-dependent scavenging activity of DPPH radical. BLE prolonged the lag phase and suppressed the rate of propagation of liposome peroxidation initiated by peroxyl radical induced by 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH) at 37 degrees C. BLE also prevented human low-density lipoprotein oxidation, mediated by Cu(2+), which was monitored by the lower formation of conjugated diene and fluorescence and a reduced negative charge of apo-B protein. Finally, BLE protected supercoiled DNA strand against scission induced by AAPH-mediated peroxyl radical. Prooxidant activity of BLE was seen in a Cu(2+)-induced peroxidation of structured phosphatidylcholine liposome, indicating catalytic peroxidation due to a relatively high reducing power of BLE. It was concluded that the BLE has both antioxidant activity and prooxidant activity; the antioxidant activity was attributed to free radical scavenging activity, and the prooxidant activity, albeit minor, resulted from the reducing power of plant phenolics in the presence of transitional metal ions.
To examine isolates of Bacillus subtilis and B. pumilus predominant in Soumbala for their ability to degrade African locust bean proteins (ALBP).
Agar diffusion test in casein and ALBP agar was used for screening of isolates. The profiles of water-soluble proteins and free amino acids (FAA) during the fermentation of ALBP by the Bacillus isolates were studied by SDS-PAGE and cation exchange chromatography. The profile of soluble proteins changed with the fermentation time and varied depending on the isolate. The quantity of total FAA and essential FAA such as lysine was increased sharply between 24 and 48 h of fermentation and differed among the isolates. Simultaneously, a pH increase was observed. Cysteine, methionine, leucine, isoleucine, tyrosine and phenylalaline appeared during fermentation.
The Bacillus isolates studied degraded ALBP leading to a profile of soluble proteins and FAA specific for each isolate.
This study contributes to the selection of Bacillus strains to be used as starter cultures for controlled production of Soumbala.
The study of free radicals and antioxidants in biology is producing medical revolution that promises a new age of health and disease management. From prevention of the oxidative reactions in foods, pharmaceuticals and cosmetics to the role of reactive oxygen species (ROS) in chronic degenerative diseases including cancer, autoimmune, inflammatory, cardiovascular and neurodegenerative (e.g. Alzheimer's disease, Parkinson's disease, multiple sclerosis, Downs syndrome) and aging challenges continue to emerge from difficulties associated with methods used in evaluating antioxidant actions in vivo. Our interest presently is focused on development of neurodegeneration models based on the integrity of neuronal cells in the central nervous system and how they are protected by antioxidants when challenged by neurotoxins as well as Fenton chemistry models based on the profile of polyunsaturated fatty acids (PUFAs) for the assessment of antioxidant actions in vivo. Use continues to be made of several in vitro analytical tools to characterise the antioxidant propensity of bioactive compounds in plant foods and supplements. For example, the oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), total oxidant scavenging capacity (TOSC), the deoxyribose assay, assays involving oxidative DNA damage, assays involving reactive nitrogen intermediates (e.g. ONOO(-)), Trolox equivalent antioxidant capacity (TEAC) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. There is need to agree governance on in vitro antioxidant methods based on an understanding of the mechanisms involved. Because some of the assays are done in non-physiological pH values, it is impossible to extrapolate the results to physiological environment. The consensus of opinion is that a mix of these tools should be used in assessing the antioxidant activities in vitro. The proof of bio-efficacy must emanate from application of reliable in vivo models where markers of baseline oxidative damage are examined from the standpoint of how they are affected by changes in diet or by antioxidant supplements.
Epidemiological studies have shown that consumption of fruits and vegetables is associated with reduced risk of chronic diseases. Increased consumption of fruits and vegetables containing high levels of phytochemicals has been recommended to prevent chronic diseases related to oxidative stress in the human body. In this study, 10 common vegetables were selected on the basis of consumption per capita data in the United States. A more complete profile of phenolic distributions, including both free and bound phenolics in these vegetables, is reported here using new and modified methods. Broccoli possessed the highest total phenolic content, followed by spinach, yellow onion, red pepper, carrot, cabbage, potato, lettuce, celery, and cucumber. Red pepper had the highest total antioxidant activity, followed by broccoli, carrot, spinach, cabbage, yellow onion, celery, potato, lettuce, and cucumber. The phenolics antioxidant index (PAI) was proposed to evaluate the quality/quantity of phenolic contents in these vegetables and was calculated from the corrected total antioxidant activities by eliminating vitamin C contributions. Antiproliferative activities were also studied in vitro using HepG(2) human liver cancer cells. Spinach showed the highest inhibitory effect, followed by cabbage, red pepper, onion, and broccoli. On the basis of these results, the bioactivity index (BI) for dietary cancer prevention is proposed to provide a simple reference for consumers to choose vegetables in accordance with their beneficial activities. The BI could be a new alternative biomarker for future epidemiological studies in dietary cancer prevention and health promotion.
Sun-drying of green leafy vegetables is popularly practised in many homes in Nigeria, as a way of preserving green leafy vegetables for future use. This project sought to investigate the effect of this method of preservation of vegetables on the antioxidant phytoconstituent (Vitamin C and Total phenol) and activity (reducing property and free radical scavenging ability) of some commonly consumed green leafy vegetables in Nigeria namely Structium sparejanophora (Ewuro-odo), Amarantus cruentus (Atetedaye), Telfairia occidentalis (Ugu), Baselia allia (Amunu tutu), Solanum macrocarpon (Igbagba), Corchorus olitorius (Ewedu), Vernonia anygdalina (Ewuro) and Occimum graticimum (Efinrin). The edible portions of the green leafy vegetables were sun-dried for seven days before determining the Vitamin C and total phenol content, as well as the reducing property and free radical scavenging ability. The result of the study revealed that sun-drying of green leafy vegetables cause a significant (P < 0.05) decrease in the Vitamin C content (16.67-64.68% loss). Conversely it leads to a significant increase in the total phenol content (6.45-223.08% gain), reducing property (16.00-362.50% gain) and free radical scavenging ability (126.00-5757.00% gain) of the green leafy vegetables. It could therefore be concluded that a significant decrease (P < 0.05) in Vitamin C content caused by sun- drying will not reduce the antioxidant activity of the green leafy vegetable, moreover, the phenol constituent of the green leafy vegetables contributes more to the antioxidant properties of vegetables than ascorbic acid, as its increase on sun-drying cause a significant (P < 0.05) increases in the antioxidant properties of the green leafy vegetables, irrespective of the decrease in the ascorbic acid content.
The aim of this study was to investigate the effect of Krebs cycle intermediates on basal and quinolinic acid (QA)- or iron-induced TBARS production in brain membranes. Oxaloacetate, citrate, succinate and malate reduced significantly the basal and QA-induced TBARS production. The potency for basal TBARS inhibition was in the order (IC50 is given in parenthesis as mM) citrate (0.37) > oxaloacetate (1.33) = succinate (1.91) > > malate (12.74). alpha-Ketoglutarate caused an increase in TBARS production without modifying the QA-induced TBARS production. Cyanide (CN-) did not modify the basal or QA-induced TBARS production; however, CN- abolished the antioxidant effects of succinate. QA-induced TBARS production was enhanced by iron ions, and abolished by desferrioxamine (DFO). The intermediates used in this study, except for alpha-ketoglutarate, prevented iron-induced TBARS production. Oxaloacetate, citrate, alpha-ketoglutarate and malate, but no succinate and QA, exhibited significantly iron-chelating properties. Only alpha-ketoglutarate and oxaloacetate protected against hydrogen peroxide-induced deoxyribose degradation, while succinate and malate showed a modest effect against Fe2+/H2O2-induced deoxyribose degradation. Using heat-treated preparations citrate, malate and oxaloacetate protected against basal or QA-induced TBARS production, whereas alpha-ketoglutarate induced TBARS production. Succinate did not offer protection against basal or QA-induced TBARS production. These results suggest that oxaloacetate, malate, succinate, and citrate are effective antioxidants against basal and iron or QA-induced TBARS production, while alpha-ketoglutarate stimulates TBARS production. The mechanism through which Krebs cycle intermediates offer protection against TBARS production is distinct depending on the intermediate used. Thus, under pathological conditions such as ischemia, where citrate concentrations vary it can assume an important role as a modulator of oxidative stress associated with such situations.
The objective of this study was to elucidate the potential role of novel synthesized aminosteroidal heterocyclic compounds 2, 5, 9b and 10c against iron-induced oxidative stress with particular insight on erythrocyte ghosts in male rats. Chronic iron supplementation (3000 mg kg(-1) diet) for 6 weeks significantly increased plasma iron and ferritin levels. It also produced significant increase in plasma TNF-alpha and NO levels. Lipid metabolism was also affected by excess iron, so that plasma and erythrocyte membrane total cholesterol, triglycerides, phospholipids and total lipid levels were significantly elevated. In consequence, a significant increase in plasma leptin level was detected. Iron overload clearly induces oxidative stress as indicated by the significant increase in both plasma and erythrocyte membrane lipid peroxidation levels. Noteworthy, excess iron not only decreased the mean value of erythrocyte membrane protein but also caused marked alterations in the membrane protein fractions with concomitant inhibition in erythrocyte membrane ATPases activity. On the other hand, treatment with the aminosteriodal heterocyclic compounds especially compounds 5, 2, and 10c in an oral dose of 5 mg kg(-1) B.W. per day could ameliorate almost all of the changes in plasma and erythrocyte ghosts components induced by iron overload. The efficacious role of these novel synthesized aminosteriods in preventing iron-induced oxidative stress may be mediated through their iron chelating properties, anti-lipid peroxidation activities and membrane stabilizing actions. The encouraging results obtained in the present study lend credence to substantial investigation to assess the use of these compounds as a potent line of therapy to retard the pathogenesis of iron overload diseases.
In the present study, soybean koji fermented with various GRAS filamentous fungi, including Aspergillus sojae BCRC 30103, Aspergillus oryzae BCRC 30222, Aspergillus awamori, Actinomucor taiwanensis and Rhizopus sp. These organisms are commonly used as starters in the fermentation of many traditional, oriental food products. The growth of starter organisms, total phenolic content, and antioxidative activities of the methanol extract of these kojis are compared with specific reference to alpha-diphenyl-2-picryl-hydrozyl (DPPH) radicals scavenging effects, Fe2+-chelating ability, and reducing power. Depending on starter organism, various extents of mycelia propagation (35.23-86.29 mg/g koji) were noted after 3 days of fermentation. Total phenolic content increased in soybean after fermentation. Koji also displayed enhanced antioxidative activates in comparison with the non-fermented soybean. Among the five kinds of koji tested, those fermented with Asp. awamori exhibited the highest levels of DPPH-free radicals scavenging activity, Fe2+-chelating ability and reducing power. The DPPH-free radicals scavenging activity and Fe2+-chelating ability of this soybean koji was ca. 8.9 and 6.7 fold that of the control. Analysis of the dose-response effect also revealed that before reaching a threshold point, there is a linear relationship between increases in antioxidative activity and increases in the concentration of the koji extract. These results show the potential for developing a healthy food supplement with soybean fermented by the GRAS filamentous fungi.
Methodological considerations for characterizing potential antioxidant actions of bioactive components in plant foods Free radicals and antioxidants i n food an in vivo: what they do and how they work
- O I Aruoma ] B
- H A Halliwell
- S Murcia
- O I Chirco
- Aruoma
O.I. Aruoma, Methodological considerations
for characterizing potential antioxidant
actions of bioactive components in plant
foods. Mutation Research, 523, 9-20 (2003)
[2]
B. Halliwell, H.A. Murcia, S. Chirco, O.I.
Aruoma, Free radicals and antioxidants i n
food an in vivo: what they do and how they
work. CRC Critical Review in Food Science
and Nutrition, 35, 7–20 (1995)
[3]
Novel synthesized amino steroidal heterocycles intervention for inhibiting iron induced oxidative stress Solid-state production of phenolic antioxidants from cranberry pomace by Rhizopus oligosporus
- G A Elmegeed
- H A Ahmed
- J S Hussein
G.A. Elmegeed, H.A. Ahmed, J. S. Hussein,
Novel synthesized amino steroidal heterocycles intervention for inhibiting iron induced
oxidative stress. European Journal of Medicinal Chemistry, 40, 1283–1294 (2005)
[36] D.A. Vattem, K. Shetty, Solid-state production of phenolic antioxidants from cranberry
pomace by Rhizopus oligosporus. Food
Biotechnology, 16, 189–210 (2002)
- K L Wolfe
- R H Liu
K.L. Wolfe, R.H. Liu, Structure-Activity Relationships of Flavonoids in the Cellular Antioxidant Activity Assay. Journal of Agricultural
and Food Chemistry, 56, 8404-8411 (2008)