Lipolytic enzymes, including secreted phospholipase A2 (sPLA2), yield lysophospholipids and nonesterified fatty acids such as arachidonic acid. Arachidonic acid eventually yields prostaglandins and leukotrienes, 2 proinflammatory mediators, whereas lysophospholipids are precursors to platelet-activating factor, also noted in inflammatory processes. However, sPLA2s have also been shown to release n-3 polyunsaturated fatty acids in vitro, which may be anti-inflammatory. The definitive role ofsPLA2s in vivo is yet unclear.
This double-blind crossover study examined the effects of sPLA2 inhibitor (sPLA2i) supplementation on gut permeability, inflammation, oxidative stress, and systemic fatty acid profile in dogs. Obese (n = 7) and lean (n = 7) beagles were fed either an sPLA2i-supplemented diet or a control diet.
Gut permeability and apparent digestibility were assessed. Blood samples were taken to measure antioxidant levels (vitamins A, C, and E and glutathione peroxidase). Red blood cell omega-3 index, serum fatty acids, total plasma malondialdehyde, plasma fibrinogen, C-reactive protein (CRP), and serum retinol binding protein 4 were also measured.
Gut permeability and apparent digestibility did not significantly differ between the 2 diets, and CRP levels were the same in both groups regardless of diet. A higher proportion of the saturated fatty acid, myristic acid, and a lower proportion of the omega-6 fatty acid, linoleic acid, were observed in the dogs fed with the sPLA2i diet as compared with dogs fed with the control diet. In obese dogs, the sPLA2i diet decreased plasma fibrinogen, a putative inflammatory marker, to levels similar to lean dogs being fed that diet. The results also found the fatty acid profile of obese dogs, characterized by a lower omega-3 index and serum n-3 PUFA, along with a higher serum n-6:n-3 ratio, puts these dogs at higher risk for inflammation. It was speculated the addition of dietary sPLA2i might decrease inflammation in obese dogs through reduction of plasma fibrinogen and may change the fatty acid profile. Study sponsored by Diana Pet Food.