Biological activity of alkaloids from Solanum dulcamara L

Alkaloids are well known for their antimicrobial activity. Though all natural alkaloids come from plants, not all plants produce alkaloids. Plants of the Solanaceae family are known for their high alkaloid content. Alkaloids are found in all plant parts like roots, stems, leaves, flowers, fruits and seeds. In the present study, those plant parts of Solanum dulcamara were selected which have been reported to produce a high content of a specific alkaloid: solanine (from unripe fruits), solasodine (from flowers) and beta-solamarine (from roots). These alkaloids were extracted from various parts of S. dulcamara by well-established methods and were screened for their antibacterial activity. Human pathogenic bacteria, viz., Enterobacter aerogenes, Escherichia coli, Staphylococcus aureus, were selected for the study. All three alkaloids inhibited the growth of E. coli and S. aureus. However, no significant activity was observed against E. aerogenes. Minimum inhibitory concentration and minimum bactericidal concentration were also evaluated.