Aseer Manilal, Mohammedaman Mama, Tigist Gezmu, Behailu Merdekios, Gemechu Ameya, Shiju Easo John, Akbar Idhayadhulla
Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increasing polarity such as diethyl ether, chloroform, acetone, dichloromethane: methanol and methanol. The obtained extracts were evaluated for antibacterial and brine shrimp cytotoxicity assays. It was found that methanolic extract of P. tetrastromatica exhibited the broadest and highest range of antibacterial activity. In cytotoxic activity, the methanolic extract of P. tetrastromatica showed significant activity (LD50=354.4 μg/mL). Based on the present findings, it could be inferred that the bioassay guided purification and fractionation of crude methanolic extract of P. tetrastromatica may bring forth potent novel antibiotic and anticancer leads.