Antimicrobial Activity of Alkaloids of Tridax Procumbens L. against Human Pathogens

Tridax procumbens L. is a well known medicinal plant. In the present study alkaloids from pedicle and buds of the plant were extracted and evaluated for antimicrobial activity by ‘Disc Diffusion Assay’ against selected bacteria (Escherichia coli, Staphylococcus aureus and Proteus mirabilis) and fungi (Aspergillus flavus, Aspergillus niger, Candida albicans and Trichophyton mentagrophytes). Minimum inhibitory concentration, minimum bactericidal/fungicidal concentration and total activity of each active extract were also evaluated. Significant antibacterial activity was recorded by alkaloids of pedicle against P. mirabilis (IZ 20mm, AI 0.83 and same MIC, MBC 0.039 mg/ml) and antifungal activity was recorded by buds against C. albicans (IZ 9.2mm, AI 0.92, MIC 0.625 mg/ml and MFC 1.25 mg/ml). MIC ranged from 0.039 mg/ml-0.625 mg/ml and MBC/MFC ranged from 0.039 mg/ml-1.25 mg/ml against susceptible pathogens. It is noteworthy that MIC values of active extracts was found very low (0.039 mg/ml-0.625 mg/ml) and was recorded below 1 mg/ml against inhibited pathogens, thus ascertain their strong antimicrobial potential against selected microbes. Thus, the result of the present study advocates the exploitation of alkaloid extracts of T. procumbens for future antimicrobial drugs. INTRODUCTION: Nature has been a source of medicinal agents for thousands of years. Folk medicines of almost all civilizations of the world abound in herbal remedies. Majority of the traditional medicines used in healthcare are obtained from plants . In spite of several advancements in the field of synthetic drug chemistry and antibiotics, plants continue to be one of the major raw materials for drugs treating various ailments of humans. Clinical and pharmaceutical investigations have in fact elevated the status of medicinal plants by identifying the role of active principles present in them and elaborating on their mode of action in human and animal systems . Tridax procumbens is a pantropical weed, belonging to the family Asteraceae. It has slender taproot, perennial herb and well adapted to coarse-textured soils. It is frequently found in annual crops, roadsides, pastures and waste areas. In Nigeria, plant is used as feed for livestock and stops bleeding 3, . It has been used in traditional Chinese medicine by the native populations to treat bronchitis, dysentery and diarrhea and to prevent hair loss.