ABSTRACT
Pumpkin seed has been associated with myriad of medicinal uses in different part of the world. In this study, phenolic composition and Fe2+ induced thiobarbituric acid reactive species (TBARS) inhibitory ability of methanolic extract from pumpkin seeds in rat’s testes homogenates were determined. The extract was prepared with 80% methanol (v/v) and the radicals [(1,1-diphenyl–2 picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS)] scavenging, Fe2+ chelation and ferric reducing abilities of the extract were carried out. The phenolics composition was also investigated using gas chromatography couple with flame ionization detector (GC-FID). The GC analysis revealed the presence of vallinic, coumaric protocatechuic, caffeic, ferulic and sinapinic acids, and apigenin, quercetin, luteolin, kaempferol as the dominant phenolic compounds. The results revealed that the extract inhibited Fe2+-induced TBARS, scavenge DPPH radical and chelate Fe2+ in a dose dependent manner. The extract also scavenged ABTS radical and reduced Fe2+ to Fe3+. Although, the standard used had higher effect compared to the extract, nevertheless, the TBARs inhibitory potential of the extracts clearly gives an insight on the protective potentials against oxidative induce testicular damage that might lead to male infertility if unchecked. These abilities could however be linked to the presence of polyphenolic compounds.
ABSTRACT
Traditionally, miracle berry leaves are mostly used as food wrappers in order to increase the shelf life of the food. Therefore, this study sought to investigate the antioxidative properties and protective effect of phenolic extracts from two species of miracle berry leaves namely; Thaumatococcus daniellii (Benn) Benth and Megaphrynium macrostachyum (Benth) Milne-Redh on some pro-oxidant induced oxidative stress in rat pancreas in vitro. The phenolic extract was prepared with 80% acetone (v/v); thereafter, ability of the extracts to inhibit some pro-oxidants (FeSO4 and Sodium nitroprusside, SNP) induced lipid peroxidation in rat’s pancreas was assessed. Furthermore, antioxidative properties of the phenolic extracts were evaluated. The result revealed that both leaves extracts inhibit Fe2+ and SNP-induced lipid peroxidation on rat’s pancreas in a dose dependent manner (0 – 0.5 mg/mL) and also exhibit antioxidant properties as typified by their Fe2+ chelating, DPPH and OH radical scavenging abilities, however, M. macrostachyum leaf had a significantly (P<0.05) higher Fe2+ and SNP-induced lipid peroxidation on rat’s pancreas and antioxidant properties than T. daniellii leaf in vitro. The inhibition of Fe2+ and SNP-induced lipid peroxidation in rat’s pancreas by both leaves could be attributed to their reducing power, chelating and radical scavenging abilities. Therefore, this antioxidative potential of both M. macrostachyum and T. daniellii leaves clearly gives us an insight that they could be used to prevent degenerative disease associated with oxidative stress. Hence, this antioxidant effect could be some possible mechanism by which they are used as food wrappers in order to increase the shelf life of food.
ABSTRACT
Objective: To investigate the phenolic compounds composition and the inhibitory activity ofMangifera indica (M. indica) and Mucuna urens (M. urens) seeds extracts against some key enzymes (α-amylase, α-glucosidase and aldose reductase) implicated in the pathology and complications of type 2 diabetes in vitro. Methods: Reverse phase chromatographic quantification of the major flavonoids and phenolic acids in the seeds extracts was carried out using high performance liquid chromatography coupled with diode array detection. The inhibitory activities of the seeds extracts against α-amylase andα-glucosidase were estimated using soluble starch and ρ-nitrophenylglucopyranoside as their respective substrates. Inhibition of aldose reductase activity by the extracts was assayed using partially purified lens homogenate of normal male rat as source of enzyme; inhibition of Fe2+-induced lipid peroxidation by extracts was tested in rat pancreas homogenate.Results:The chromatography result revealed that extracts of both seeds had appreciable levels of some major flavonoids and phenolic acids of pharmacological importance, including gallic acid, chlorogenic acid, caffeic acid, ellagic acid, catechin, rutin, quercitrin, quercetin and kaempferol. Extracts of both seeds effectively inhibited α-amylase, α-glucosidase and aldose reductase activities in a dose-dependent manner, having inhibitory preference for these enzymes in the order of aldose reductase>α-glucosidase>α-amylase. With lower half-maximal inhibitory concentrations (IC50) against α-amylase, α-glucosidase, and aldose reductase, M. indica had stronger inhibitory potency against these enzymes than M. urens. Extracts of both seeds also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern, with M. indica being more potent than M. urens.Conclusions:The results obtained provide support for a possible use of M. indica and M. urens seeds in managing hyperglycemia and preventing the complications associated with it in type 2 diabetes.
ABSTRACT
To evaluate and compare antioxidant activities of the aqueous extracts of unripe plantain (Musa paradisiaca), assess their inhibitory action on sodium nitroprusside induced lipid peroxidation in rat pancreas in vitro and to characterize the main phenolic constituents of the plantain products using gas chromatography analysis. Methods: Aqueous extracts of plantain products (raw, elastic pastry, roasted and boiled) flour of 0.1 g/mL (each) were used to determine their total phenol, total flavonoid, 1,1 diphenyl-2 picrylhydrazyl (DPPH) and hydroxyl (OH) radical scavenging ability. The inhibitory effect of the extracts on sodium nitroprusside induced lipid peroxidation was also determined. Results: The results revealed that all the aqueous extracts showed antioxidant activity. The boiled flour had highest DPPH and OH radical scavenging ability while raw flour had the highest Fe2+ chelating ability, sodium nitroprusside inhibitory effect and vitamin C content. The antioxidant results showed that elastic pastry had the highest total phenol and total flavonoid content. Characterization of the unripe plantain products for polyphenol contents using gas chromatography showed varied quantity of apigenin, myricetin, luteolin, capsaicin, isorhaemnetin, caffeic acid, kampferol, quercetin, p-hydroxybenzoic acid, shogaol, glycitein and gingerol per product on the spectra. Conclusions: Considering the antioxidant activities and ability to inhibit lipid peroxidation of unripe plantain, this could justify their traditional use in the management/prevention of diseases related to stress.
ABSTRACT
To investigate and compare the inhibitory properties of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes (alpha-amylase & alpha-glucosidase) and Fe2+-induced lipid peroxidation in rat pancreas in vitro. Methods: The free phenolics were extracted with 80% (v/v) acetone, while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate. Then, the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed. Thereafter, the total phenolic contents and antioxidant activities of the extracts were determined. Results: The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner. However, the alpha-glucosidase inhibitory activity of the extracts were significantly (P<0.05) higher than their alpha-amylase inhibitory activity. The free phenolics (31.67 mg/g) and flavonoid (17.28 mg/g) contents were significantly (P<0.05) higher than bound phenolic (23.52 mg/g) and flavonoid (13.70 mg/g) contents. Both extracts also exhibited high antioxidant activities as typified by their high reducing power, 1,1 diphenyl-2- picrylhydrazyl (DPPH) and 2, 2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate (ABTS) radical scavenging abilities, as well as inhibition of Fe2+-induced lipid peroxidation in rat pancreas in vitro. Conclusions: This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.
ABSTRACT
Cassava pulp was fermented with pure strains of Saccharomyces cerevisae and two bacteria namely Lactobacillus delbruckii and Lactobacillus coryneformis for 3 days. The squeezed liquid from the fermented pulp was used to ferment cassava peels for 7 days. Analysis of the dried fermented peels revealed that there was a significant (P < 0.05) increase in the protein content of the cassava peels fermented with squeezed liquid from the inoculated cassava pulp (21.5%) when compared with the unfermented cassava peel (8.2%). Moreover, the treatment equally brought about a significant (P < 0.05) decrease in the cyanide (6.2 mg/kg) and phytate content (789.7 mg/100g) when compared with the unfermented cassava peels, which had 44.6 mg/kg cyanide and 1043.6 mg/100g phytate. The fermented cassava peels could be a good protein source in livestock feeds.