Effects of lime (Citrus aurantifolia) peel to the expression of mRNA toll‑like receptors 4 in balb/c mice‑infected Salmonella typhi

Lime peel contains metabolic compounds that have lethal effects of bacterial cells, but its effect as an antibacterial modulate innate immunity pathways, especially toll‐like receptor 4 (TLR‐4) signaling pathway, is unclear. This study examined the effects of lime peel extract (LPE) on the activity of TLR 4 in Balb/c mice induced by Salmonella typhi. Mice were induced intraperitoneally and then 3 days after induction, LPE was given orally on two doses (510 and 750 mg/kg BW). The number of bacterial colonization was counted using peritoneal fluid samples by the method of plate count agar. Intervention LPE for 5 days can degrade TLR‐4 and the number of colonies of S. typhi. On day 3 after was induced S. typhi, TLR-4 gene expression of Balb/c mice is increased. Postintervention LPE for 5 days, the expression of TLR‐4 gene decreased, significantly different at a dose of 750 mg/kg BW (P = 0.04). There was a positive correlation between the expression of TLR-4 gene by the number of bacterial colonization, decreasing gene expression of TLR-4, the number of bacterial colonization is also getting smaller (P = 0.013, r = 0.408). LPE can modulate the TLR‐4 signaling pathway in host immunity so that the gene TLR‐4 is expressed fewer in numbers. This mechanism causes the bacterial colony number to decrease, not even growth.