Antioxidant and antimicrobial effect of alkaloid bulbs extract of Polianthes tuberosa L. (Amaryllidaceae) cultivated in Algeria

Abstract

Polianthes tuberosa L. (Amaryllidaceae) is an ornamental and medicinal plant. Its flowers and bulbs are used traditionally as a diuretic, emetic, against rashes and gonorrhea. The aim of this work was, to evaluate the antioxidant and antimicrobial activities of bulbs and bulbils alkaloid extracts of P. tuberosa. Antiradical effect was assessed against DPPH radical. However, antimicrobial activity was measured through the disc diffusion method against Escherichae coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Staphylococcus aureus resistant to Methicillin (MRSA) and Candida albicans ATCC 90028. The scavenging effect against DPPH showed that the bulbs and bulbils alkaloids extracts exhibited an antiradical effect with IC50 = 0.231±0.017 mg/mL and 0.233±0.093 mg/mL respectively, less than the effect of vitamin C with IC50 = 0.0194±0.0002 mg/mL. Antimicrobial activity results reveal that both alkaloid bulbs extracts at 50 mg/mL did not have any inhibitory effect against the studied strains using the disc diffusion method. According to this work, bulbs and bulbils alkaloid extracts show a moderate antioxidant effect; that could be recommended as a natural antioxidant. Although tuberose bulbs were used traditionally as a soap substitute; bulbs alkaloid extract has no antimicrobial effect. Keywords: Polianthes tuberosa L., bulbs, bulbils, alkaloids, antiradical activity, antimicrobial activity.