Screening of plant Macaranga peltata for its antioxidant, antimicrobial and cytotoxicity activity

The plant Macaranga peltata (Euphorbiaceae) leaves and stem bark was tested for its in vitro antioxidant, antimicrobial and cytotoxicity activity using different methods. In vitro anti oxidant activity stem bark extract showed inhibitory concentration 50% (IC50) value of 10.13 than the leaf extract IC50 = 14.85 for DPPH assay. Standard ascorbic acid showed IC50 = 7.28. For ABTS free radical scavenging activity leaf extract IC50 = 7.61 showed better activity than the stem bark extract IC50 = 9.77. Standard anti-oxidant ascorbic acid showed IC50 = 11.76. The nitric oxide radical inhibition activity was better shown by stem bark extract IC50 = 573.39 than leaf extract IC50 ?1000. Whereas IC50 value for the standard anti-oxidant ascorbic acid was 127.16. Scavenging of superoxide radical by alkaline DMSO method i.e. NBT Assay showed better activity for leaf extract IC50 = 54.12 than stem bark extract IC50 = 55.52. But both stem bark and leaf extract showed very good activity for NBT assay and their IC50 values were very close to the standard anti-oxidant Rutin IC50=49.73. In anti microbial activity MIC for leaf extract was between 62.5 ?g/ml to 125 ?g/ml for Escherichia coli, 125 ?g/ml to 250 ?g/ml for Pseudomonas aeruginosa, 62.5 ?g/ml to 125 ?g/ml for Bacillus subtilis and 31.25 ?g/ml to 62.5 ?g/ml for Staphylococcus aureus. Whereas MIC for stem bark extract was between 500 ?g/ml to 1000 ?g/ml for Escherichia coli, 250 ?g/ml to 500 ?g/ml for Pseudomonas aeruginosa, 62.5 ?g/ml to 125 ?g/ml for Bacillus subtilis and 62.5 ?g/ml to 125 ?g/ml for Staphylococcus aureus. Ciprofloxacin used as standard antibiotic showed MIC between 1.953 ?g/ml to7.813 ?g/ml for all four bacterial strains. Cytotoxicity of Macaranga peltata leaf and stem bark extracts was tested on human liver cancer cell line HepG2. Four concentrations (1000 ?g/ml, 500 ?g/ml, 250 ?g/ml and 125 ?g/ml) of both extract were tested for the activity by MTT assay. Both leaf and stem bark extracts showed very good cytotoxicity activity and their CTC50 value was 51.07 ?g/ml and 22.32 ?g/ml respectively.