Fish oil concentrate delays sensitivity to thermal nociception in mice

Abstract

Fish oil has been used to alleviate pain associated with inflammatory conditions such as rheumatoid arthritis. The anti-inflammatory property of fish oil is attributed to the n-3 fatty acids docosahexaenoic acid and eicosapentaenoic acid. Contrarily, vegetable oils such as safflower oil are rich in n-6 fatty acids which are considered to be mediators of inflammation. This study investigates the effect of n-3 and n-6 fatty acids rich oils as dietary supplements on the thermally induced pain sensitivity in healthy mice. C57Bl/6J mice were fed diet containing regular fish oil, concentrated fish oil formulation (CFO) and safflower oil (SO) for 6 months. Pain sensitivity was measured by plantar test and was correlated to the expression of acid sensing ion channels (ASICs), transient receptor potential vanilloid 1 (TRPV1) and c-fos in dorsal root ganglion cells. Significant delay in sensitivity to thermal nociception was observed in mice fed CFO compared to mice fed SO (p<0.05). A significant diminution in expression of ion channels such as ASIC1a (64%), ASIC13 (37%) and TRPV1 (56%) coupled with reduced expression of c-fos, a marker of neuronal activation, was observed in the dorsal root ganglion cells of mice fed CFO compared to that fed SO. In conclusion, we describe here the potential of fish oil supplement in reducing sensitivity to thermal nociception in normal mice.

Dietary fish oil inhibits mechanical allodynia and thermal hyperalgesia in diabetic rats by blocking nuclear factor-κB-mediated inflammatory pathways

“…For the treatment of various painful conditions in clinical placebo-controlled studies, the consumption of FO supplementation of human is equivalent to EPA/DHA 45-100 mg/kg body weight per day [10,11,24]. According to the previous studies [25,26], we chose 4% FO supplementation to investigate the effect on the PDN and its mechanisms. The present study demonstrated that FO could attenuate both mechanical allodynia and thermal hyperalgesia of diabetic rats, which is probably a sum of its anti-inflammatory and modulating insulin signaling actions.…”

Laboratory environmental factors and pain behavior: the relevance of unknown unknowns to reproducibility and translation

“…Failure to provide bedding material for a rat to make a nest for her pups can lead to hyperalgesia in those pups when they become adults 55,56 , and the handling of young animals (for example, related to injections, and involving the stress of maternal separation) can cause long-term alterations in pain sensitivity 41,[57][58][59][60][61][62][63] . A growing literature also documents the effect of diet on pain sensitivity [64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80] . In one case, differences in the soy content of rat chow turned out to be wholly responsible for a failure to replicate in Baltimore the findings of studies originally performed in Jerusalem 65 .…”

Innovations in Pain Management: Morphine Combined with Omega-3 Fatty Acids

“…ASICs are excitatory cation channels directly gated by extracellular protons of many painful conditions [117,118]. However, recent studies have demonstrated that omega-3 PUFAs decrease the mRNA expression of ASIC1a, ASIC3 and TRPV1, suggesting a reduced inflammatory status, which may be the reason for the increased pain threshold [102].…”