Azadirachta indica (A. Juss.) and Curcuma longa (L.) modulate immunoglobulin and cytokine levels in Plasmodium berghei-infected mice

Plasmodium infection causes inflammation in the host. A combination of herbs like Azadirachta indica and Curcuma longa may have beneficial effect in remediating inflammation in malaria disease. The aim of this study is to investigate the immunomodulatory and synergistic effects of the association of Azadirachta indica and Curcuma longa in experimental Plasmodium berghei infection. Fifty male Swiss mice were infected with chloroquine susceptible (NK 65) strain of Plasmodium berghei intraperitoneally. Parasitemia was confirmed using microscopy and the animals were grouped (n = 5), treated once daily and orally for 7 days with 200 and 400 mg/kg of A. indica and C. longa methanol extracts. Four hundred milligrams per kilogram A. indica was combined with the two doses of C. longa methanol extract and fractions. Negative control was treated with 10 mL/kg 5% (v/v) dimethyl sulfoxide (DMSO, vehicle) while positive control was treated with artemether–lumefantrine (10 mg/kg) and normal control not infected with parasites was treated with distilled water only. Animals were sacrificed on day 7, and blood serum was obtained. Serum immunoglobulins G (IgG) and immunoglobulin M (IgM), C-reactive protein (CRP), tumour necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) were assayed using ELISA techniques. Combination of A. indica and C. longa significantly increased (P < 0.05) IgG and TNF-α than separate treatment while IgM increased albeit insignificantly (P < 0.05); CRP and IL-1β decreased significantly relative to control (P < 0.05) while IL-6 levels was modulated both in separate and combined therapy. Separate administration and combinations of A. indica and C. longa have immunomodulatory effects in malaria-infected mice.