Immunomodulatory potential of Ocimum tenuiflorum extracts in bovine peripheral blood mononuclear cells in vitro Shynu M1,*, Gupta Praveen K1,**, Sharma Bhaskar1, Saini Mohini1,*** 1Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, (UP), INDIA. ***E-mail: mohini@ivri.up.nic.in
*Present address: Department of Veterinary Biochemistry, College of Veterinary and Animal Sciences, Pookkot, Wyanad-673 576 (Kerala), INDIA. **Present address: Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar, (UP), INDIA. Abstract The immunomodulatory activity of seed and leaf extracts of Ocimum tenuiflorum with respect to lymphoproliferation and nitric oxide production was studied in vitro. Peripheral blood mononuclear cells, 5 × 105 cells/100 μl in quadruplicate wells of a 96 well cell-culture plate were stimulated with various concentrations of six different extracts. Lymphoproliferation was measured following MTT dye reduction after 72 h incubation at 37°C in 5% CO2 and the stimulation index was calculated. Similarly, 2 × 105 cells in each well of a 96 well microtitre plate were stimulated independently with six different extracts viz., aqueous extract (47.38 μg/ml), ethanol extract (11.78 μg/ml), fresh aqueous (14.06 μg/ml), fresh aqueous boiled (15.63 μg/ml) decoction of fresh leaves and seed extract (20.80 μg/ml). Nitric oxide was determined as stable end product nitrite at 24, 48 and 72 h after incubation at 37°C. ConA (10 μg/ml) and PHA (5 μg/ml) were used as positive controls. The extracts were used to stimulate the cells individually and in combination with mitogens as well. All the extracts were found to increase lymphoproliferation and also potentiate mitogen-induced proliferation of PBM cells. Likewise, the extracts were found to increase the nitric oxide production at all incubation intervals. When nitric oxide production was measured at 72 h in the presence of 1 mM N-W-nitro-L-Arginine (LNNA), a reversible inhibitor of inducible nitric oxide synthase (iNOS), no increase caused earlier by the extracts was observed. Thus, nitric oxide production was induced by O. tenuiflorum extracts in stimulated peripheral blood mononuclear cells in vitro. Identification of active component(s) responsible for immunomodulatory action will pave a long way for the rational use of natural drugs from this plant. Top Key words PBM cells, Bovine, Lymphoproliferation, Nitric oxide, Ocimum tenuiflorum, Immunomodulation. Top |