Phytochemical and Antimicrobial Properties of Lawsonia inermis (Henna) Leaf Extracts Against Skin Pathogens in Katsina State, North West Nigeria

Lawsonia inermis, widely known as henna, occupies a prominent place in the cultural and medicinal practices of communities in Katsina State, North West Nigeria, where it is applied topically for skin beautification as well as the treatment of fungal and bacterial skin infections. This study evaluates the phytochemical constituents and antimicrobial activity of aqueous and methanol leaf extracts of Lawsonia inermis against clinically relevant skin pathogens. Leaf samples were collected from cultivated plants in Katsina and Daura local government areas. Standard phytochemical screening procedures detected lawsone, tannins, flavonoids, alkaloids, and saponins. Antimicrobial activity was evaluated against Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, and Trichophyton mentagrophytes using the agar diffusion method. MIC determination was performed using the broth microdilution technique. Both extracts showed moderate to strong activity against all tested organisms. The methanol extract recorded the greatest inhibition zone of 22 mm against S. aureus and was effective against T. mentagrophytes at 12.5 mg/mL. Lawsone and tannin-rich fractions were identified through column chromatography and tentatively attributed to the observed antimicrobial effects. The outcomes of this study validate the traditional antimicrobial applications of henna in Katsina and support further pharmaceutical development of standardised Lawsonia inermis formulations. Keywords: Lawsonia inermis, henna, antimicrobial, skin pathogens, Katsina State