In Vitro Antimicrobial and Cytotoxic Effects of Solvent-Fractionated Extracts from Raphionacme hirsuta (E.Mey.) R.A.Dyer (Apocynaceae) Bulbs

Antimicrobial resistance in various microorganisms and opportunistic pathogens associated with HIV/AIDS poses a serious threat to human life and healthcare systems worldwide. Different forms of cancer are likely to arise in immunocompromised patients. The antimicrobial and anticancer effects of methanol extract and fractions from Raphionacme hirsuta have been investigated. The carbon tetrachloride fraction showed a remarkably low minimum inhibitory concentration (MIC) of 0.02 mg/mL against Escherichia coli, Mycoplasma hominis, and Cryptococcus neoformans, while the n-hexane fraction showed a similar MIC against C. neoformans. Furthermore, the carbon tetrachloride fraction exhibited promising IC₅₀ values of 18.21 and 25.22 µg/mL against HeLa and MCF-7 cancerous cell lines, respectively. The fraction was subjected to GC-TOF-MS and yielded four major compounds, including 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-2,8-dione (5.322%), Hexanedial (3.691%), 4-(4-tert-Butylphenyl)-1,3-thiazol-2-ylamine (3.329%), and Di-n-decylsulfone (3.201%). These substances could potentially account for the plant species’ initial biological activity, which is why it is necessary to investigate their in vivo actions. The gummy extract had less biological activity than the fractions. To the best of our knowledge, this is the first study to report the antimicrobial and anticancer activities, as well as the phytochemistry, of the plant species.