Development and Evaluation of a Cassia alata L. Ethanolic Leaf Extract-Based Liquid Disinfectant with Broad-Spectrum Antimicrobial Activity

Cassia alata L. (ringworm or candle bush) is a tropical medicinal plant traditionally used for treating skin infections, wounds, and fungal diseases. This study developed a plant-based liquid disinfectant using the ethanolic leaf extract of C. alata as the primary antimicrobial agent, formulated to mimic the efficacy of commercial disinfectants such as Dettol. Leaves were collected, shade-dried, powdered, and extracted with 95% ethanol. The extract (5–10% w/v) was emulsified into a base containing ethanol, pine oil, glycerol, and Tween 80. Phytochemical analyses confirmed the presence of flavonoids, anthraquinones, terpenoids, saponins, and phenolics, with a total phenolic content of 150–250 mg GAE/g extract. The extract exhibited broad-spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria as well as dermatophytic fungi. Staphylococcus aureus showed the highest sensitivity with an MIC of 0.313 mg/mL, followed by Streptococcus pyogenes at 0.483 mg/mL. Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa were moderately sensitive, each with MIC values of 0.625 mg/mL, while Candida albicans required a higher concentration (1.25 mg/mL) for inhibition. These variations reflect the increased structural resistance of fungi and Gram-negative organisms due to their complex cell walls and efflux mechanisms. Overall, the MICs obtained were comparable to those reported for chloroxylenol-based disinfectants. Toxicity evaluation in rats revealed an LD₅₀ > 5000 mg/kg and no significant adverse effects on biochemical or histological parameters. The findings suggest that C. alata ethanolic leaf extract is a safe, eco-friendly alternative for topical disinfectant formulations and warrants further clinical trials for commercialization.