Volume 19, Issue 44, July - December, 2025

Solvent-Dependent In Vitro Antimicrobial Potential of Aqueous and Ethanolic Extracts of Nicotiana tabacum and Sesamum alatum

Lawrence Luka¹, Chika Attama^2♦

¹Department of Chemistry, Adamawa State College of Education, Hong-Adamawa, Nigeria.
²Department of Chemistry, Adamawa State University, Mubi, Nigeria

^♦Corresponding author
Chika Attama, Department of Chemistry, Adamawa State University, Mubi, Nigeria

ABSTRACT

This study evaluates the antimicrobial properties, phytochemical composition, and thin-layer chromatographic (TLC) profiles of aqueous and ethanol leaf extracts of Nicotiana tabacum and Sesamum alatum. The preliminary phytochemical screening showed that alkaloids, tannins, saponins, flavonoids, glycosides, carbohydrates, proteins, terpenoids, and anthraquinones were present in both plants. Phytosterols were detected only in N. tabacum. TLC analysis of ethanol extracts revealed five phytocompounds for N. tabacum with Rf values of 0.06, 0.08, 0.12, 0.76, and 0.90, and six for S. alatum at 0.05, 0.10, 0.13, 0.21, 0.72, and 0.97. Antimicrobial analysis against some selected microorganisms showed that both extracts demonstrated concentration-dependent inhibition activities. In N. tabacum, the ethanolic extract showed the highest zone of inhibition (18 mm) against Staphylococcus aureus, while the aqueous extract showed more potency against Proteus vulgaris (15 mm). For S. alatum, the ethanol extract exhibited microbial inhibition against Klebsiella pneumoniae (23 mm), while the aqueous extract showed moderate inhibition with a highest value of 14 mm against Salmonella typhi. No inhibition was demonstrated at concentrations of 0.1 and 0.3 g/mL each for either plant. The results supports the prospect of antimicrobial potential of these medicinal plants, with ethanol extracts being more active.

Keywords: Antimicrobial Activity; Antibiotics; Inhibition; Nicotiana tabacum, Sesamum alatum

Drug Discovery, 2025, 19(44), e13dd2079

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Published: 12 July 2025