In vitro assessment of antibacterial and antioxidant activities of ethanolic leaves extracts of Paullinia pinnata Linn (Sapindaceae)
This study aimed at investigating the in vitro antibacterial and antioxidant activities of ethanolic leaves of Paullinia pinnata. Antibacterial assay was performed using agar well diffusion and microdilution methods against seven clinical isolates namely Enterobacter cloacae, Klebsiella pneumoniae, Escherichia coli, Shigella flexneri, Proteus mirabilis, Salmonella typhi and Bacillus cereus. Total phenol content was determined by the Folin-Ciocalteu test while antioxidant activity was evaluated by DPPH, FRAP and ABTS methods. S. typhi and B. cereus were sensitive to agar diffusion with an inhibition diameter zone of 13.67 ± 1.64 and 13.33 ± 1.43 mm respectively. S. flexneri was most sensitive with MIC of 195 µg/ml by microdilution. The total phenol content was found to be 226.748 ± 08.11 mg ascorbic acid equivalent/g of dry material. The scavenging kinetics of DPPH showed a steady state at 60 minutes while EC50 was 0.89 x 103 g/mol in DPPH. FRAP assay showed an absorbance of 0.4 at 50 µg/ml. ABTS test displayed an inhibition percentage of 55.92% at 4.54 µg/ml. These results justify its traditional use to heal infectious diseases. P. pinnata leaves are a potential source of antibacterial and antioxidant compounds to be exploited.
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