Chia oil prevents chemical and immune-mediated inflammatory responses in mice: Evidence for the underlying mechanisms

Abstract

Chia (Salvia hispanica L.) is an herbaceous plant used as omega-3 polyunsaturated fatty acid (ω-3 PUFA) source that presents a range of beneficial effects on human health. Herein, it was used a chia oil containing over than 62% of α-linolenic acid (ALA), a compound widely related to anti-inflammatory actions. Chia oil effect was tested using paw edema and mechanical hyperalgesia induced by carrageenan, and ear edema induced by croton oil, histamine, and capsaicin. Croton oil was used in both preventive and therapeutic treatment schedules of chia oil while histamine and capsaicin were used only in preventive treatment schedule. Chia oil mechanism of action was investigated using nociception and paw edema response induced by intraplantar injection of acidified saline (ASIC activator), PGE2 (prostaglandin pathway), cinnamaldehyde (TRPA1 activator), bradykinin (BK pathway), menthol (TRPM8 activator), and capsaicin (TRPV1 activator). Further, RT-PCR for inflammatory mediators (TRPA1, NF-κB, PPAR-γ, COX-2, IL-6, TNF, FPR2, FAAH, MAGL, and IL-12A) induced by carrageenan, NLRP3 inflammasome activation, and the cell viability were then accessed. Later, chia oil actions were evaluated in the experimental autoimmune encephalomyelitis (EAE), a multiple sclerosis (MS) model. Chia oil showed anti-edematogenic and anti-hyperalgesic effects when administered 1 h before pro-inflammatory stimulus – particularly carrageenan and croton oil. Moreover, chia oil upregulated the mRNA levels of COX-2 and formyl peptide receptor 2 (FPR2) while reduced IL-6 expression in the spinal cord of mice submitted to i.pl. injection of carrageenan. Interestingly, chia oil mediates antinociceptive effects in mice decreasing the nociceptive response induced by acidified saline, PGE2, and cinnamaldehyde, but not by bradykinin, menthol, and capsaicin. On the EAE model, chia oil preventively administered attenuated EAE-induced motor deficits and mechanical hyperalgesia in mice, suggesting a valuable effect of chia oil supplementation in regulating inflammatory responses and some immune functions during immune-mediated inflammatory disorders (IMID). Nonetheless, additional reports will need to assess the effect of chia oil in well-controlled clinical trials performed in MS patients.