ABSTRACT
OBJECTIVE: To determine the acetylcholinesterase inhibitory (AChEI) and antioxidant activity of the ethyl acetate and methanol extracts of 12 traditional medicinal plants used in the treatment of neurological disorders. METHODS: AChEI activity was determined spectrophotometrically using the Ellman's colorimetric method. Antioxidant activity was carried out by determining the ability of the extracts to scavenge 2,2-diphenyl-1-picryl hydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. The levels of total phenols, flavonoids and flavonols were determined quantitatively using spectrophotometric methods. RESULTS: AChEI was observed to be dose-dependent. Lannea schweinfurthii (L. schweinfurthii) (Engl.) Engl. and Scadoxus puniceus (S. puniceus) (L.) Friis & I. Nordal. root extracts showed the lowest IC(50) value of 0.000 3 mg/mL for the ethyl acetate extracts while Zanthoxylum davyi (Z. davyi) (I. Verd.) P.G. Watermann had the lowest IC(50) value of 0.01 mg/mL for the methanol extracts in the AChEI assay. The roots of Piper capense (P. capense) L.f., L. schweinfurthii, Ziziphus mucronata (Z. mucronata) Willd., Z. davyi and Crinum bulbispermum (C. bulbispermum) (Burm.f.) Milne-Redh. & Schweick. showed noteworthy radical scavenging activity and good AChEI activity. CONCLUSIONS: Five plants show good antioxidant and AChEI activity. These findings support the traditional use of the plants for treating neurological disorders especially where a cholinesterase mechanism and reactive oxygen species (ROS) are involved.
Subject(s)
Acetylcholinesterase/metabolism , Cholinesterase Inhibitors/pharmacology , Plant Extracts/pharmacology , Plants, Medicinal , Acetates , Africa, Southern , Benzothiazoles/antagonists & inhibitors , Biphenyl Compounds/antagonists & inhibitors , Colorimetry , Dose-Response Relationship, Drug , Flavonoids/analysis , Flavonols/analysis , Free Radicals/antagonists & inhibitors , Fruit/chemistry , Humans , Inhibitory Concentration 50 , Methanol , Phenols/analysis , Picrates/antagonists & inhibitors , Plant Roots/chemistry , Reactive Oxygen Species/antagonists & inhibitors , Solvents , Spectrophotometry/methods , Sulfonic Acids/antagonists & inhibitorsABSTRACT
OBJECTIVE: To investigate the antidiabetic properties of aqueous extract of stem bark of Afzelia africana (A. africana) and its beneficial effect on haematological parameters in streptozotocin induced diabetic rats. METHODS: A total of 30 rats including 24 diabetic and 6 normal rats were used for this study. Diabetes was induced in male Wistar rats by intraperitoneal injection of streptozotocin. After being confirmed diabetic, animals were orally treated with distilled water or extracts at 100 or 200 mg/kg body weight daily for 10 days. The haematological parameters including red blood and white blood cells and their functional indices were evaluated in diabetic treated groups compared with the controls. RESULTS: The extract significantly reduced the blood glucose levels while the best result was obtained at 200 mg/kg body weight. The feed and water intake in diabetic rats were significantly reduced while weight loss was minimized at both dosages. Similarly, the levels of red blood, white blood cells and their functional indices were significantly improved after extract administration at both doses. CONCLUSIONS: It can be concluded that the aqueous extract of bark of A. africana possesses antihyperglycemic properties. In addition, the extract can prevent various complications of diabetes and improve some haematological parameters. Further experimental investigation is needed to exploit its relevant therapeutic effect to substantiate its ethnomedicinal usage.
