Antibacterial, Antifungal, Antiviral, and Anthelmintic Activities of Medicinal Plants of Nepal Selected Based on Ethnobotanical Evidence.

BACKGROUND

Infections by microbes (viruses, bacteria, and fungi) and parasites can cause serious diseases in both humans and animals. Heavy use of antimicrobials has created selective pressure and caused resistance to currently available antibiotics, hence the need for finding new and better antibiotics. Natural products, especially from plants, are known for their medicinal properties, including antimicrobial and anthelmintic activities. Geoclimatic variation, together with diversity in ethnomedicinal traditions, has made the Himalayas of Nepal an invaluable repository of traditional medicinal plants. We studied antiviral, antibacterial, antifungal, and anthelmintic activities of medicinal plants, selected based upon ethnobotanical evidence.

METHODS

Ethanolic and methanolic extracts were tested (1) on a panel of microbes: two Gram-positive bacteria ( and ), four Gram-negative bacteria (, , , and ), and one fungal species: ; (2) against three different viruses: yellow fever, chikungunya, and enterovirus; and (3) on the nematode . Also, cytotoxicity was assessed on human hepatoma (Huh), rhabdosarcoma (RD), and Vero (VC) cell lines.

RESULTS

Of 18 plants studied, and inhibited (MIC 35 g/mL and 649 g/mL, respectively) and (MIC 15 g/mL and 38 g/mL, respectively). and inhibited (MIC 285 g/mL and 326 g/mL, respectively). , and were active against chikungunya virus, and was active against yellow fever virus (EC 15.9 g/mL); was active against enterovirus (EC 10.6 g/mL). , and significantly reduced motility, comparable to levamisole.

CONCLUSIONS

In countries like Nepal, with a high burden of infectious and parasitic diseases, and a current health system unable to combat the burden of diseases, evaluation of local plants as a treatment or potential source of drugs can help expand treatment options. Screening plants against a broad range of pathogens (bacteria, viruses, fungi, and parasites) will support bioprospecting in Nepal, which may eventually lead to new drug development.