Effects of co-administration of Ganoderma terpenoid extract with chloroquine on inflammatory markers and antioxidant status in Plasmodium berghei-infected mice

Objective: To understand the protective effects of Ganoderma terpenoid extract (GTE) against Plasmodium berghei-malarial infection in mice, the present study was carried out to evaluate the effects of GTE in combination with chloroquine disulphate (CQ) on erythrocyte-selected inflammatory markers and antioxidant defense status in P. berghei-infected mice.

Methods: P. berghei-infected mice were divided into six groups: infected control (IC) group, administered 1 mL Tween 20; GTE₁₀₀ and GTE₂₅₀ groups, administered 100 and 250 mg/kg GTE, respectively; GT₁₀₀ + CQ and GT₂₅₀ + CQ groups, co-administered 100 and 250 mg/kg GTE plus 30 mg/kg CQ, respectively; and CQ group, administered 30 mg/kg CQ. A separate group of non-infected mice were given 1 mL Tween 20, and served as a normal control group (NC). Extract and drug were dissolved in Tween 20 and administered orally once daily for 12 consecutive days. At the end of the treatment period, mice were anesthetized with chloroform and sacrificed by cervical dislocation. Plasma was prepared from blood obtained from each mouse. Parameters evaluated at the end of the treatment period include parasitemia, red blood cell count, hematocrit, malondialdehyde (MDA), glutathione (GSH), catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10).

Results: Infected mice treated with a combination of GTE and CQ (GT₁₀₀ + CQ and GT₂₅₀ + CQ groups) showed significantly reduced parasitemia levels (P < 0.05) compared to those administered GTE alone as well as IC. Significant improvement in body weight (P < 0.05) was also observed in infected mice treated with a combination of GTE and CQ (GT₁₀₀ + CQ and GT₂₅₀ + CQ groups), compared to mice receiving GTE alone (GTE₁₀₀ and GTE₂₅₀ groups). Plasma MDA and TNF-α concentrations were significantly lowered, and IL-10 concentration was significantly increased in GT₁₀₀ + CQ and GT₂₅₀ + CQ groups, relative to the IC group (P < 0.05). GSH concentration and SOD, CAT and GPx activities were significantly higher in GT₁₀₀ + CQ and GT₂₅₀ + CQ groups compared to the GTE₁₀₀, GTE₂₅₀, IC and NC groups (P < 0.05).

Conclusion: Data generated in this study showed that GTE enhanced the anti-plasmodial action of CQ in mice through its anti-inflammatory and antioxidant activities.

Keywords: Anti-inflammatory agents; Antioxidants; Ganoderma; Malaria; Oxidative stress; Terpenes.