In-vitro evaluation of Indigofera heterantha extracts for antibacterial, antifungal and anthelmintic activities.

Background: Multidrug-resistant bacterial strains cause several serious infections that can be fatal, such as Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae (often referred to as ESKAPE pathogens). Since ancient times, several indigenous medical systems in India have utilized diverse medicinal plants (approximately 80,000 species) as conventional treatments for a variety of illnesses. A member of the Fabaceae family, also referred to as "Himalayan indigo," Indigofera heterantha Wall, is well known for its therapeutic properties.

Methods: The present study investigated the antibacterial, antifungal and antihelmintic properties of the roots, bark, leaves, and flowers of I. heterantha from the Kashmir Himalayas. The effectiveness of the extracts against bacteria, fungi, and earthworms. Three of the tested organisms for bacteria were ESKAPE pathogens, as they are responsible for creating fatal bacterial infections. The antifungal potency of I. heterantha aqueous and methanolic extracts was evaluated using the Agar Well Diffusion Assay. The antihelmintic activity was carried out on an adult Pheretima posthuma Indian earth worm, which shares physiological and anatomical similarities with human intestinal roundworm parasites.

Results: The methanolic extracts of root and bark have shown prominent activity against all bacterial strains, whereas aqueous extracts of flower, root, and leaves have shown promising activity against Staphylococcus aureus. The aqueous extract demonstrated good activity against S. cerevisiae at a concentration of 200 mg/ml with a zone of inhibition of 16 mm, while the methanolic extract displayed comparable activity against the fungal strains. The remaining two strains, P. crysogenum and A. fumigatus, were only moderately active in response to the extracts. All the extracts have shown anthelmintic activity except aqueous flower.

Conclusion: These results will pave the way for the bioassay-guided isolation of bioactive constituents that may act as hits for further development as potential antibacterial agents against drug-resistant microbial and helminthic infections.