Anti-Obesity Effects of Matoa (Pometia pinnata) Fruit Peel Powder in High-Fat Diet-Fed Rats

Fruit peels, pericarps, or rinds are rich in phenolic/polyphenolic compounds with antioxidant properties and potentially beneficial effects against obesity and obesity-related non-communicable diseases. This study investigated the anti-obesity effects of matoa (Pometia pinnata) and salak (Salacca zalacca) fruit peel. Neither matoa peel powder (MPP) nor salak peel powder (SPP) affected the body weight, visceral fat weight, or serum glucose or lipid levels of Sprague–Dawley rats when included as 1% (w/w) of a high-fat diet (HFD). However, MPP significantly decreased the hepatic lipid level. MPP at a dose of 3% (w/w) of the HFD decreased body weight, visceral fat, and serum triglyceride levels as well as the hepatic lipid content. The inhibitory effect of MPP on hepatic lipid accumulation was not enhanced when its concentration was increased from 1% to 3% of the HFD. The anti-obesity effect of matoa was partly explained by the inhibitory effect of the matoa peel extract on fatty acid-induced secretion of ApoB-48 protein, a marker of intestinal chylomicrons, in differentiated Caco-2 cell monolayers. We identified hederagenin saponins that are abundant in MPP as potential anti-obesity substances. These results will contribute towards the development of functional foods with anti-obesity effects using the matoa fruit peel.