Abstract:
Mimosa pudica. L is one of the important herbal plants, used extensively in indigenous medicine
with various therapeutics activities. Though antibacterial and antioxidant activity of M. pudica L
in Sri Lanka has been evaluated, the level of antibacterial and antioxidant activity in acetone and
methanolic leaf extracts of M. pudica has not been investigated so far. Therefore, this study
intended to focus on the in vitro screening of the antioxidant and antibacterial activities of
different solvent extracts of leaf of M. pudica present in the Batticaloa district, Sri Lanka. The
fresh and healthy leaves of M. pudica were collected from Ampilanthurai, Batticaloa District,
dried under shade, extracted by percolating separately with methanol, acetone and petroleum
ether and filtered followed by removing the solvents with a rotary evaporator. The 2, 2-diphenyl-
1-picrylhydrazyl (DPPH) radical scavenging assay and antibacterial assay were performed
separately on the leaf extracts of M.pudica to determine their antioxidant and antibacterial
activities by employing ascorbic acid and ciprofloxacin as the standard respectively. The half
inhibition concentration (IC50) values for the leaf extracts were calculated from the respective
DPPH assays and the diameter of the complete zone of bacterial growth inhibition was
measured. The results were analyzed with one-way ANOVAs. The leaves extracted in methanol,
acetone and petroleum ether
revealed the half inhibition concentration (IC50) values 16.87, 161.0 and 219.87 μg/ml
respectively. The antioxidant activity of extracts showed significant difference (P > 0.05)
between them and methanolic extract was found to be similar to that of the standard (ascorbic
acid). Further,
the high mean value of inhibition zone was observed for the methanolic extract (13.67±3.78 and,
13.33±1.15 mm) compared to acetone (9.67±2.88 and 0 mm) and petroleum ether (0 and 0 mm)
extracts at high concentration (100 μg/ml) against Staphylococcus aureus and Pseudomonas
aeruginosa respectively. Methanolic extract showed a significant difference in the activity with
the standard for both bacteria. Hence, the leaf methanolic extracts of leaf of M. pudica was found
to possess good antioxidant activity and revealed antibacterial property against the tested
bacterial
strain.
