Evaluation of Moringa Oleifera Leaf Extract for its In vitro Antibacterial Properties, Mechanism of Action, and In vivo Corneal Ulcer Healing Effects in Rabbits’ Eyes

Abstract: M. oleifera is the most adapted tree species in different medicinal eco-systems and has resilience against climate changes. This multiple-use tree provides healthy foods, snacks, honey, and fuel. Besides this, it has immense promising applicationsby offering antimicrobial and antibacterial activities for targeted uses. This validates the court of Hippocrates that let food be the medicine and medicine be the food for which moringa qualifies. In view of this, the antioxidant and in vitro antibacterial potency of the hydro-ethanolic extract of M. oleifera was evaluated on clinically isolated multidrug-resistant strains of Staphylococcus aureus. Furthermore, in vivo, the healing response of M. oleifera extract was analysed on corneal ulcers induced in rabbit eyes infected with methicillin-resistant Staphylococcus aureus. TheM. oleifera extract exhibited exponential antioxidant activity. In-vitro antibacterial activity was evaluated by agar well diffusion assay showing zone of inhibition ranging from 11.05±0.36 to 20±0.40 mm at concentrations of 20, 40, 80, and 160 mg/ml, whereas, in our finding, no zone of inhibition was observed below 20 mg/ml concentration, which indicated that there is threshold limit below which the antibacterial activity of M. oleifera extract is not observed. Furthermore, continuous application of 3% and 5% M. oleifera extract (eye drop) four times a day for 14 consecutive days showed a significant healing response of the eyes of rabbits with corneal ulcers. These results suggest that M. oleifera extract could be a viable alternative to existing antibacterial therapies for corneal ulcers. Additionally, there is a possibility of commercial formulation of M. oleifera extract in the form of deliverable pharmaceutical products; therefore, it should be explored further.