ANTIOXIDANT, INHIBITION OF ADVANCED GLYCATION END-PRODUCT FORMATION AND ANTIMICROBIAL ACTIVITIES OF OCIMUM GRATISSIMUM (SCENT LEAF) METHANOLIC LEAF EXTRACT AGAINST Escherichia coli AND Bacillus SPP

The study investigates the antioxidant, inhibition of advanced glycation end-product formation and antimicrobial activities of methanolic leaf extract of Ocimum gratissimum. GC-MS, qualitative, antioxidant scavenging and antiglycation activities of the extract of Ocimum gratissimum were determined using standard procedures. The antimicrobial activity was evaluated by agar well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using standard methods. The GC-MS analysis of Ocimum gratissimum leaf revealed the presence of 49 compounds with P –cymene been the most abundant. The phytochemical screening of the extract shows the presence of alkaloids, tannins, phenolic, flavonoids, saponins etc. The in-vitro antioxidant assay of the extract was found to have ?-carotene, lycopene, total phenolic compounds, total flavonoid compounds, reducing power and DPPH scavenging activities. The extract showed significant inhibitory effects on the formation of compounds containing two carbonyl groups and Advanced Glycated End products formation with IC50 of 75.85 ±4.87 µg/mL. Agar well diffusion assay was characterized by inhibition zones of 21.0 ± 0.30, 19.66 ± 0.20, 33.78± 0.30 and 33.25 ± 0.40 mm for Escherichia coli and Bacillus spp respectively at 250 mg/ml for Ocimum gratissimum and 25 mg/ml for tetracycline solution. The MIC values for E.coli and Bacillus spp were 33.33, 66.67, 0.78 and 0.78 for both extract and tetracycline while their MBC values were 66.67, 133.00, 1.56 and 1.56 respectively. MBC/ MIC values showed that Ocimum gratissimum extract and tetracycline had bactericidal effects. These results indicated that Ocimum gratissimum possesses antioxidant, prevents glycation and has antimicrobial activities.