Spirulina polysaccharide as adjuvant therapy enhances the TNF-α, IFN-γ response and improve liver and spleen histopathological of mice (Mus musculus) infected with Plasmodium berghei

The use of adjuvant therapy can be combined with primary anti-malarial drugs to increase the efficacy and effectiveness of anti-malarial drugs and reduce more severe complications caused by their pathogenicity. This study aims to evaluate the potential of PSP (polysaccharide spirulina) as an adjuvant therapy in the response of TNF-α, IFN-γ and histopathological changes in the liver and spleen of mice infected with Plasmodium berghei. This experimental involving forty mices, divided into eight treatment groups: A1: Mice not infected. A2: Mice infected. B1: Mice infected and treated with artemisinin (ART) at a dose of 40 mg/kg BW. B2: Mice infected and treated with PSP at a dose of 600 mg/kg BW. B3, B4 and B5: Mice infected and treated with ART dose 40 mg/kg BW and PSP 400 mg/kg BW, 600 mg/kg BW and 800 mg/kg BW. B6: Mice not infected but treated with PSP (600 mg/kg BW). Mice were infected with 0.2 ml of 1×10⁷ parasitized red blood cells (PRBCs) of Plasmodium berghei. Treatments were administered for 10 days. Following this, histopathological changes and immunohistochemical staining were examined to be analysed. These results showed that the uninfected groups (A1 and B6) showed significantly reduced levels of hemozoin, sinusoid congestion, Kupffer cell hyperplasia, and portal inflammation (p < 0.05) compared to the infected groups (A2, B1, B2, B3, B4, and B5). The spleen hemozoin and the diameter of the white pulp in group A1 were significantly different (p < 0.05) compared to all other groups (A2, B1, B2, B3, B4, B5, and B6). Expression of TNF-α and IFN-γ in liver and spleen cells was significantly lower (p < 0.05) in the negative control group (A1) compared to groups A2, B2, B3, B4, and B5. This study conlcudes that spirulina polysaccharide (PSP) as an adjuvant therapy could enhance the expression of TNF-α and IFN-γ in liver and spleen cells infected with Plasmodium berghei. The combination of ART and PSP at an effective dose of 400 mg/kg BW reduced hemozoin accumulation and improved liver and spleen histopathology associated with Plasmodium berghei infection.