A comparative study of the antioxidant, antimicrobial and thrombolytic activity of the bark and leaves of lannea coromandelica (anacardiaceae)

The present study was designed to compare the antioxidant, antimicrobial and thrombolytic effects of the Lannea coromandelica bark and leave extracts. After the initial phytochemical screening, the ethanolic fractions of the L. coromandelica bark and leaves were partitioned by solvents of different polarity. Methods used to evaluate the antioxidant potential of the extracts were total phenolic content, total flavonoid content, free radical scavenging capacity, total antioxidant capacity and reducing power assay. Total phenol and total flavonoid contents were found to be the highest for bark and leaves in the ethyl acetate fraction and lowest in the n-Hexane fraction. In DPPH free radical scavenging test, the lowest IC50 value was found in the ethyl acetate fraction of the bark and leaf, resulting IC50 value of 3.8 +/- 0.14 mu g/ml and 6 +/- 0.32 mu g/ml respectively. In the same vein, ethyl acetate fraction of both leaf and bark showed the highest antioxidant capacity and reducing power. Reducing power of both bark and leaves were found to be concentration dependent and most prominent was observed with the fractions of higher polarity both in case of bark and in case of leaves. Furthermore, the leaf extracts produced moderate antimicrobial activity whereas the bark extracts showed weak antimicrobial activity. Dichloromethane fraction of leaf showed the most potent antimicrobial activity with zone of inhibition ranging from 8 mm to 21 mm at a dose of 400 mu g/disc and 10 mm to 23 mm at a dose of 800 mu g/disc. In addition, extracts from both parts of L. coromandelica produced good thrombolytic activity compared with streptokinase