Antimicrobial and Immunostimulatory Effects of Senna occidentalis Ethanolic Extract against Aspergillus flavus-Induced Mycotic Keratitis: A Promising Therapeutic Approach

Background: Mycotic keratitis (MK) poses a significant risk as a severe and difficult-to-treat corneal infection with potentially life-threatening consequences. Fungi are commonly implicated as causative agents. Additionally, improper care of contact lenses increases the susceptibility to MK. Aim: This study aimed to investigate the phytochemical composition and therapeutic potential of Senna occidentalis ethanolic leaf extract in the treatment of Aspergillus flavus-induced mycotic keratitis. Methodology: The selected plant extract was tested for antimicrobial activity, analyzed for active ingredients and evaluated in vivo for physiological (Kidney and liver functions), histological (corneal tissue healing rates) and immunological responses (IgM levels). Results: The GC/MS analysis revealed high levels of some active components, including o-methyl glucose, tetramethyl hexadecenol, hexadecenoic acid, and octadecatrienoic acid. The ethanolic extract of S. occidentalis demonstrated potent antimicrobial activity against A. flavus in an albino rabbit model. Treatment with the extract at a concentration of 12.5 mg/ml resulted in a significant healing rate without any side effects, as evidenced by reduced levels of blood urea, creatinine, AST, and ALT in infected rabbits. Moreover, S. occidentalis extract effectively stimulated the immune system, as indicated by increased levels of IgM in both infected and non-infected rabbits. Histopathological analysis of the eye cornea further confirmed the complete disappearance of inflammation and restoration of normal tissue appearance and layer arrangement. Conclusions: These findings highlight the potential of S. occidentalis extract as a safe, affordable, and easily accessible treatment for A. flavus-induced mycotic keratitis, owing to its rich content of safe and bioactive phytochemicals.