Antimycobacterial Activity of Phytochemical Extracts from Herbs against the Non-tuberculous Mycobacterium fortuitum Infecting Fish

Background: Non-tuberculous mycobacteriosis (NTM) is widespread in natural and grown edible and ornamental fish and is caused by Mycobacterium fortuitum. Mycobacterial infection in fish causes clinical signs like discoloration of the skin and exposed sores affecting the commercial value of fish. Moreover, mycobacteriosis is thought as a zoonotic disease making it much worse for edible fishes. Methods: The antimycobacterial efficacy of the phytochemical extracts from Tribulus terrestris, Mimosa pudica, Leucas aspera, Foeniculum vulgare, Cinnamomum verum and Acorus calamus was studied against Mycobacterium fortuitum secluded from a diseased ornamental fish, Betta splendens. The antimycobacterial efficiency of extracts of these herbs made with water and methanol was estimated in vitro using a 96-well microplate assay technique with a Resazurin dye. Result: The aqueous and methanolic extracts of Acorus calamus, Mimosa pudica and Cinnamomum verum (50 μg/ml) exhibited the highest antimycobacterial activity after that Foeniculum vulgare and Tribulus terrestris (100 μg/ml). The least inhibition activity was exhibited by Leucas aspera (200 μg/ml). These results revealed that the extracts of Acorus calamus, Cinnamomum verum and Mimosa pudica can be used as an alternative to the present antimycobacterial drugs for the treatment of Mycobacteriosis in edible and ornamental fish. However, further studies on the active compounds involved in the antimycobacterial activities of these herbs are needed.