From Antimicrobial Action to Antiproliferative Potential: Functional Characterization of Scadoxus multiflorus Bulb Lectin (SmL)

Abstract

Introduction

Lectins are plant-derived proteins known for their wide range of biological activities, particularly antimicrobial and antiproliferative properties. Scadoxus multiflorus is a medicinal plant reported to contain lectins with potential therapeutic value. However, limited information is available regarding their biological efficacy.

Objectives

This study aimed to evaluate the antimicrobial and Antiproliferative properties of the bulb lectin (SmL) isolated and purified from S. multiflorus.

Methods

The antibacterial activity of SmL was assessed using the agar well diffusion method against Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Antifungal activity was evaluated against Aspergillus flavus, Aspergillus niger, and Candida albicans using standard antifungal assays, with clotrimazole as the reference drug. Cytotoxic effects were determined by MTT assay on HeLa (human cervical cancer) and HEK-293 (normal human embryonic kidney) cell lines, and IC₅₀ values were calculated.

Results

SmL exhibited strong antibacterial activity against S. aureus (20 mm) and S. pyogenes (22 mm), with moderate inhibition of K. pneumoniae (15 mm) and P. aeruginosa (16 mm). Antifungal activity was comparatively weak, with inhibition zones of 9 mm for A. flavus, 8 mm for A. niger, and 8 mm for C. albicans, compared with clotrimazole. Cytotoxicity analysis demonstrated potent inhibition of HeLa cell proliferation, with an IC₅₀ of 0.0095 µg/100 µL after 48 h, while HEK-293 cells showed negligible toxicity even at concentrations up to 50 µg/500 µL.

Conclusion

The findings demonstrate the dual bioactivity of SmL as an effective antibacterial agent and a selective cytotoxic molecule. These results suggest that SmL may represent a promising candidate for further investigation into its mechanisms of action and potential therapeutic applications.