In Vitro Antioxidant and Antibacterial Properties of The Leaf Extracts of Cactus Plant (Opuntia Ficus Indica)

Opuntia ficus-indica has been reported to be used in folk medicine due to its diverse pharmacological effects. Maceration method was employed in the determination of antioxidant activity and antibacterial effects of the plant leaf using Three (3) different solvents (methanol, ethanol and aqueous). The following isolates; S. aureus, S. pneumoniae, K. pneumonia, E. coli and S. typhi were tested using agar well diffusion method. Meanwhile, the antioxidant activity of the plant extract was carried out through the determination of total antioxidant capacity assay and reducing power assay. Hence, the leaf extracts showed various levels of activity on the different test organisms; The methanolic leaf extract showed highest antibacterial activity against all tested organisms followed by ethanolic extract and finally aqueuos extract with least antibacterial activity against the tested bacterial isolates as showed in S. pneumoniae methanol extracts (17.5±0.66mm), ethanol extract recorded 15.2±0.76mm in S. aureus, and aqueuos extract showed 10.7±0.76mm in both E. coli and S. typhi. On the other hand, the minimum inhibitory concentration in methanolic extract indicated least value in K. pneumoniae with 6.2±0.03 mg\mL, followed by ethanolic extract with 12.4±0.32mg\ml in S. typhi, and aqueuos extract with 29.5±0.12mg\mL in E. Coli. The ability of the methanolic extract to reduce Fe3+ to Fe2+ and Cu2+to Cu+ in reducing power assay and total antioxidant capacity respectively using ascorbic acid as a standard reveal it’s antioxidant property. The present study suggests that the methanolic leaf extract of Opuntia ficus-indica may contain compounds that can form the basis for the development of a chemopreventive agent against free radical damage and development of novel antibacterial chemotherapeutic agent.