Biological properties and safety profile of extracts from locally grown banana leaves in Arusha, Tanzania

A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Master’s in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyThe current study assessed the biological properties and safety profile of extracts from locally grown banana leaves in Arusha (Tanzania) to affirm their possible use for wound dressing. Phytoconstituents screening from studied banana plant species, ijihu inkundu (IJ), mlelembo (ML), and kimalindi (KIM), revealed the presence of secondary metabolites: anthraquinones, alkaloids, flavonoids, tannins, terpenoids, phenols, phytosterol, and saponins. Susceptibility of microorganisms to studied banana varieties were in the order of KIM > ML > IJ. One-way analysis of variance (ANOVA) revealed a statistical difference of mean among all extracts (p < 0.05). Moreover, results also revealed that all tested organisms were susceptible to the studied banana extracts, and their susceptibility was in the order of C. albicans > C. neoformans > S. aureus > S. typhi >E. coli > P. aeruginosa. These results suggest that the studied leaves, especially kimalindi, may be used to dress wounds involving fungal infections (C. albicans and C. neoformans) and bacterial infections (S. aureus), all of which are common wound infections. Antioxidant activity was evaluated by measuring the ability of extracts to scavenge the 2, 2- diphenylpicrylhydrazyl (DPPH) free radical. Results revealed that the scavenging of DPPH free radical was in the order of kimalindi> ijihu inkundu> mlelembo, these results also affirming that kimalindi extract had better scavenging of DPPH radical, and hence presents better antioxidant activity. Brine shrimp results for toxicity showed that almost all banana leaves extracts were practically non-toxic to the shrimps, exhibiting mild toxicity by giving the LC50 values higher than 100 µg/mL