RESUMO
Objective The bulb of Albuca bracteata Jacq., and Albuca setosa commonly used in Eastern Cape Province of South Africa for the treatment of several types of disease conditions including diabetes, was investigated for their phytochemical contents and antioxidant activities. Methods The antioxidant activity was determined by evaluating the effect of various solvent extracts (acetone, methanol, ethanol and water) on 2,2 – diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, 2,2′ – azino-bis (3-ethylbenzthiazoline-6-sulfonic acid diammonium salt (ABTS), ferric reducing power, hydrogen peroxide and nitric oxide scavenging activity while the various extracts were also analysed for phytochemical their contents. Results The results obtained indicate that polyphenols, proanthocyanidins, saponins and alkaloids are present in higher concentrations. The composition of phenols (117 mg/g), flavonols (26.28 mg/g), proanthocyanidins (84.85 mg/g) and flavonoids (5.36 mg/g) were significantly higher in the acetone extract while saponin and alkaloids contents were higher in the aqueous extract. Antioxidant studies of the extracts for nitric oxide, hydrogen peroxide, ABTS and DPPH showed high antioxidant potential in a concentration-dependent manner that was not significantly different from Vitamin C, BHT and Rutin used as standard references. The methanol extract showed higher ferric reducing potential compared to the aqueous extract but was significantly different from Vitamin C, BHT and Rutin. Conclusion This implies that the bulb of Albuca bracteata may serve as a natural source of antioxidants, which together with the numerous phytochemicals present, could account for its folkloric use as a medicinal plant.
RESUMO
Objective To investigate the antioxidant, antibacterial and phytochemical properties of ethanol extracts of Brachylaena elliptica and Brachylaena ilicifolia against wound infecting bacteria normally found in diabetic patients. Methods The in vitro antioxidant activity of the two plants extracts were investigated spectrophotometrically using 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) diammonium salt, hydrogen peroxide (H
RESUMO
Strychnos henningsii Gilg is recommended among other remedies for the treatment of diabetes in traditional medicine of Southern Africa. The antidiabetic effect of oral administration of aqueous bark extract of the plant at 125, 250 and 500 mg/Kg body weight was investigated in diabetic rats induced with streptozotocin-nicotinamide for 15 days. The extract decreased the blood glucose level, feed and water intake as well as triacylglycerol at the three doses investigated while the best result was obtained at 250 mg/Kg. Similarly, the extract was able to lower the cholesterol level appreciably at 500 mg/Kg while the remaining doses did not have any significant effect as compared with diabetic untreated groups. In addition, the weight loss of diabetic-treated rats was markedly normalized at all doses. The glucose tolerance level of diabetic animals was effectively reduced to near normal level after 90 min of extract administration especially at the dose of 250 and 500 mg/Kg. The phytochemical screening of S. henningsii revealed the presence of flavonoids, tannins and saponins which have been reported to increase the insulin secretion. The results obtained from this study demonstrated that the aqueous extract of S. henningsii possess antihyperglycemic and antilipidemic properties and thus could prevent various complications of diabetes. Generally, this study has validated the traditional use of this plant for the treatment of diabetes mellitus