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Comparative analyses of the antioxidant and membrane stabilizing activities of ethanolic extracts of leaf and root of Cyphospenna adenocaulis (Steud) were investigated with a view to further investigate the biological activities of the plant. Both the leaf and root of C. adenocaulis were extracted with 70% ethanol to yield the ethanolic leaf extract (ELE) and ethanolic root extract (ERE) respectively. Phytochemical analyses of the ELE and ERE revealed the presence of flavonoids, tannins, saponins and cardiac glycosides while alkaloids were present in the ERE. The total phenolic and flavonoid contents of the ELE was estimated as 108.0 ± 0.27 mg/g TAE (tannic acid equivalent) and 33.4± 0.32 mg/g QE (Quercetin equivalent) while the ERE contained 182.6 ±0.38 mg/g TAE and 103± 0.43 mg/g QE, respectively. The antioxidant activities of ELE and ERE were investigated using various in vitro assay systems. Both extract exhibited dose-dependent DPPH radical scavenging activity, appreciable reducing power and inhibition of lipid peroxidation in bovine liver homogenate. ELE and ERE were able to protect red blood cell (RBC) membrane against hypotonic and heat induced lyses in a concentration dependent manner. The modes of action were monophasic at various concentrations assayed and were comparable to the standard non-steroidal anti-inflammatory drug used as positive control. The extracts (ELE and ERE) of C. adenocaulis possess appreciable and potent antioxidant and membrane stabilization potentials, however, the ERE displayed a stronger antioxidant and membrane stabilizing activities.

The study investigated the antioxidant potential as well as the inhibitory potential of the seed extracts of Picralima nitida on α-amylase and α-glucosidase enzymes. The methanolic, aqueous and coconut water extracts were obtained using 70% methanol, distilled water and coconut water, respectively. Antioxidant properties were studied in vitro using DPPH (1, 1-diphenyl-2-pricrylhydrazyl) radical scavenging, Ferric Reducing Antioxidant Power (FRAP), Total Antioxidant Capacity (TAC), Hydroxyl Radical Averting Capacity (HORAC), Total Phenol Content (TPC), and Total Flavonoid Content (TFC) assays. Different concentrations (0.1 -0.5 mg/ml) of the extracts were subjected to α-amylase and αglucosidase inhibitory assays using acarbose as standard. Absorbance was measured at 540 (for αamylase) and 405 nm (α-glucosidase). The percentage of α-amylase and α-glucosidase inhibitory activity of the extracts and their IC 50 values were determined. The seed extracts of P. nitida showed significant antioxidant potential. The inhibitory activity of the extracts on α-amylase and α-glucosidas compared favourably with acarbose with the methanolic extract possessing the highest inhibitory activity. The methanolic extract also possessed the highest antioxidant capacity with the lowest IC 50 value among the extracts. The results indicate that the seed extracts of P. nitida possess significant antioxidant properties and are effective inhibitors of α-amylase and α-glucosidase enzymes.

Citrullus lanatusextracts (100, 200 and 400 mg/kg, orally) on a-amylase and a-glucosidase were assessed in glucose and sucrose-induced hyperglycaemic rats using glimepiride (25 mg/kg) and acarbose (50 mg/kg), as positive controls. membrane stability, xanthine oxidase inhibition and inhibition of denaturation of albumin models. Their antioxidant potentials were determined using standard methods and theirThe extracts gave a comparable (p>0.05) hyperglycaemia lowering and a-glucosidase inhibitory activities to glimepiride (25 mg/kg) and acarbose (50 mg/kg), respectively. However, C. papaya gave a significantly (p<0.05) higher a-amylase inhibitory activity than C. lanatus at all concentrations. The seed extract of C. papaya was significantly more active in red blood cell membrane stabilizing activity at all concentrations than C. lanatus and ibuprofen while their order of xanthine oxidase inhibitory activities was: allopurinol > C. papaya > C. lanatus. In albumin denaturation assay, C. papaya gave a comparable activity to the positive control at 0.25 -1.00 µg/ml and significantly higher effect at 0.0625-0.125 µg/ml while in the 1, 1, diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, total antioxidant capacity (TAC) and ferric reducing antioxidant power (FRAP) assays, the order of antioxidant activities was, ascorbic acid (positive control) > C. papaya > C. lanatus. The total phenolic and flavonoid contents of C. papaya expressed as gallic acid and quercetin equivalents were found to be 82.00 and 35.00 mg/g respectively; while those of C. lanatus were 40.00 and 20.00 mg/g, respectively. The results showed the seed extract of C. papaya to be a better anti-hyperglycaemic, antiinflammatory and antioxidant agent than C. lanatus and suggested that their high flavonoid and phenolic contents could be responsible for these activities. ABSTRACTThe study investigated the anti-hyperglycaemic, anti-inflammatory and antioxidant potentials of methanolic seed extracts of Carica papaya and . The inhibitory effects of the The anti-inflammatory activities were evaluated by total phenolic and flavonoid contents were also estimated. 207