Plant-part specific in vitro antibacterial activity of crude ethanolic extracts of Mangifera indica against Salmonella typhi: an exploratory study

Medicinal plants remain widely used in the management of infectious diseases, but evidence on the antibacterial activity of specific plant parts is often inconsistent. This study evaluated the plant-part-specific in vitro antibacterial activity of crude ethanolic extracts of Mangifera indica against Salmonella typhi . An exploratory in vitro study was conducted using crude ethanolic extracts prepared from the seed kernel, stem bark, root, and a combined extract (1:1:1 mixture) of Mangifera indica ( M. indica ). Antibacterial activity was assessed using the agar well diffusion method. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined using broth microdilution and sub-culture methods. Assays were performed in triplicate. Data were analysed using the Kruskal–Wallis test followed by Dunn’s post-hoc pairwise comparisons with Holm adjustment. The seed kernel extract showed the largest mean zone of inhibition (18.0 ± 0.5 mm, strong activity), followed by tetracycline (14.0 ± 0.5 mm, moderate activity) and the combined extract (11.5 ± 0.5 mm, moderate activity). Stem bark, root, and Dimethyl sulfoxide (DMSO) showed no detectable inhibition. Overall differences among treatments were statistically significant (Kruskal–Wallis test: H = 16.76, df = 5, p = 0.005). Dunn’s post-hoc test showed that the seed kernel extract produced significantly larger inhibition zones than the combined extract (adjusted p = 0.0219). The seed kernel and combined extracts had MIC values of 16.67 mg/mL and MBC values of 33.34 mg/mL, with an MBC/MIC ratio of 2, indicating bactericidal activity. Crude ethanolic extracts of M. indica showed plant-part-specific antibacterial activity against S. typhi in vitro. The seed kernel was the most active plant part and warrants further phytochemical, toxicity, and in vivo evaluation before any therapeutic application can be inferred.