Amelioration of obesity-related metabolic disorders via supplementation of Caulerpa lentillifera in rats fed with a high-fat and high-cholesterol diet

Abstract

Dietary modification, including functional foods, could reduce comorbidities due to obesity. An increase in serum glucose and lipids is often seen in obesity. Furthermore, obesity is also characterized by a decrease in antioxidant capacity (i.e., decrease in superoxide dismutase/SOD) and downregulation of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). It has been well established that PGC-1α is important to regulate mitochondrial biogenesis. Sea grapes (Caulerpa lentillifera) are known as a traditional food in many Asia-Pacific countries. Recent evidence suggests that sea grapes have many beneficial properties as functional foods and may have potential therapeutic functions. We investigated the effect of sea grapes (C. lentillifera) on serum glucose, lipids, PGC-1α, and protein levels of SOD in the liver of Rattus norvegicus, which is induced with a high-fat and high-cholesterol diet. A total of four groups were made, each containing ten male Rattus norvegicus; group A received a standard dry pellet diet as control, group B received cholesterol- and fat-enriched diets (CFED), groups C and D received CFED and 150 and 450 mg/kg body weight (BW) of sea grape extract, respectively, for 4 weeks. Serum glucose and cholesterol were assessed using a blood auto-analyzer. Serum PGC-1α was measured using ELISA. SOD levels were calculated using the superoxide dismutase assay kit by Sigma-Aldrich with blood taken from liver tissue. In this study, sea grape extracts improved total cholesterol levels better than the CFED and normal groups. The efficacy of total cholesterol improvement was similar between the two doses of sea grape extract. Furthermore, sea grape extract increased PCG-1α levels, especially with the dose of 150 mg/kg BW. Blood glucose was also lower in the groups of sea grape extract. Interestingly, the groups treated with sea grapes extract exhibited higher levels of liver SOD compared to the normal and CFED groups. To conclude, sea grapes (C. lentillifera) have promising potential for anti-hyperglycemia and anti-hypercholesterolemia, and for reducing oxidative stress, and providing various health benefits for metabolic disorders.