Hypoglycaemic and amylase inhibitory activities of leaves of Spondias mombin Linn.

Suppressing the production of glucose by inhibiting a-amylase / a-glucosidase activity is one of the therapeutic approaches for decreasing postprandial hyperglycaemia and a strategy for evaluating antidiabetic activity. We investigated leaves of Spondias mombin because our previous ethnobotanical survey showed that it is used by traditional healers to manage diabetes in South West Nigeria. We report a bioactivity-guided study of S. mombin using glucose loading (1 g/kg) alloxan-induced diabetic rats and inhibition of a-amylase as basis for isolation of active constituents. Hyperglycaemia was induced in albino rats and blood glucose levels monitored for 180 mins using a glucometer. Powdered leaves were macerated with 80% Methanol. The active extract was fractionated on column chromatography packed with silica gel G6OA eluting with gradient mixtures of pet. ether and ethylacetate. The most active a-amylase inhibiting fraction was purified on thin layer chromatography (TLC) and pure compound identified by spectroscopy. Peak decrease in blood glucose of 41.4% (p < 0.05) was recorded after 60 mins. This activity-guided study produced an active TLC band (69.8% amylase inhibition, p < 0.05) from which a-sitosterol was characterized as the main inhibitor. This is first report of hypoglycaemic and amylase inhibitory activities of S. mombin. The role of phytosterols in control of diabetes mellitus is discussed. This study justifies the ethnopharmacological use of this species in recipes for management of diabetes mellitus.

Ethnobotanical studies of medicinal plants used in the management of diabetes mellitus in South Western Nigeria.

This survey was carried out in targeted areas of South West Nigeria in order to inventory plants used by traditional healers in the area for the management of diabetes mellitus. One hundred traditional healers who know and use medicinal plants for treating diabetes mellitus were interviewed. The inventory contains scientific, vernacular, common names of the plants used and method of preparation. Thirty-one plants commonly used by traditional healers in the region were identified. The survey shows plants from the Rutaceae, Leguminosae and Cucurbitaceae families are commonly used by traditional healers in South West Nigeria for the treatment of diabetes mellitus.

COMPARATIVE ASSESSMENT OF TOTAL PHENOLIC CONTENT IN SELECTED MEDICINAL PLANTS.

This study was to compare the total phenolic (TP) content in extracts from eleven plant materials collected at different geographical locations in Kenya, Nigeria, and USA. These plants have been selected because the majority of them are highly pigmented, from yellow to purple, and would therefore have economic value in industries for producing antioxidants and surfactants. Two of them were collected from the industrial and domestic waste outlets. Each analysis was achieved using the Folin-Ciocalteau technique. The order of decreasing phenolic acid content as gallic acid concentration (mg/g dry weight) was Prunus africana (55.14) > Acacia tortilis (42.11) > Khaya grandifoliola (17.54) > Curcuma longa (17.23) > Vernonia amygdalina (14.9)> Russelia equisetiformis (14.03) > Calendula officinalis (7.96) >Phragmites australis (control) (7.09) > Rauwolfia vomitoria (6.69) > Phragmites australis (industrial) (6.21) > Cnidoscolus aconitifolius (5.6). The TP contents of Spartina alterniflora species were below the detection limit.