In vitro and in vivo antibacterial activities of root extract of tissue cultured Pluchea indica (L.) Less. against bacillary dysentery

The methanolic root extract of tissue cultured Pluchea indica (L.) Less was tested for its antibacterial potentiality against 18 strains of Shigella species which is well known gram-negative bacillus functioning as common pathogen in humans. In the in vitro MIC study total 18 shigella strains were tested, among them Sh. boydii 10, Sh. dysenteriae 1, Sh. dysenteriae 7 and Sh. flexneri 2a NK 307 were inhibited at 250 μg/ml. Again Sh. boydii 8, Sh. boydii 10, Sh. boydii B 22461, Sh. dysenteriae 1, Sh. dysenteriae 2, Sh. dysenteriae 3, Sh. dysenteriae 6, Sh. flexneri 5a 18603 were inhibited at a concentration of 500 μg/ml, while the stain like Sh. boydii D 13624, Sh. dysenteriae 8 were inhibited at a concentration of 1000 μg/ml. The extract was found to be bacteriostatic in nature against Sh. flexneri 2a NK 307. In the in vivo experiment using the rabbit ileal loop model two different dosages of P. indica root extract (500 μg/ml and 1000μg/ml) were able to protect the animals when they were challenged with Sh. flexneri 2a NK 307 in the ileum. The results obtained suggest marked antibacterial activity of the root extract of tissue cultured Pluchea indica.