Mineral pitch stimulates humoral,cellular and innate immune responses in mice

Abstract

Context: Mineral pitch (MP), a traditional medicine, is proposed to boost immunity in conditions that suppress Th1 cytokines such as AIDS/HIV, tuberculosis, leishmaniasis and cancer.

Objective: This study investigates the immunoregulatory mechanisms of MP in innate, humoral and cell-mediated immunity.

Materials and methods: Mice given MP (100, 200, 300 or 400?mg/kg, orally) for 10 consecutive days were immunized intravenously with goat RBC or ovalbumin, and investigated for plaque-forming cells (PFC), hemagglutination titer, hypersensitivity response, lymphocyte proliferation and macrophage function.

Results: MP increased PFC (330.2 versus 182.2/10⁶ splenocytes) in mice immunized with goat RBC and elicited ovalbumin-specific IgG titer at 400?mg/kg. Increase in Th1 immunity was correlated with the increased level of IFN-γ (724 versus 470?pg/ml) and decreased IL-4 (96 versus 178?pg/ml). CD4⁺/CD3⁺ ratio and delayed-type hypersensitivity response also increased to, respectively, 20.62?±?0.59 (versus 16.47?±?0.72) and 1.59?±?0.12 (versus 0.87?±?0.10?mm) in MP-treated mice. MP increased lymphocyte proliferation (11.14?±?0.60 versus 5.81?±?0.40 SI) and macrophage phagocyte response (0.24?±?0.02 versus 0.15?±?0.009), expressed as absorbance at 570?nm, but decreased nitrite production (17.4?±?1.10 versus 24.3?±?1.30?µM/10⁶ cells). We also observed an increased bone marrow cellularity (24.5?±?1.10 versus 17.10?±?0.70 cells/femur) and WBC count (12?667?±?377 versus 9178?±?213 cells/mm³) following MP treatment. There was no sign of toxicity at 400?mg/kg, 1/12th of reported LD₅₀.

Conclusion: MP elicits a dose-dependent Th1 immune response.