LAUSR

Kappaphycus alvarezii is edible red seaweed from the phylum Rhodophyta. In recent studies, K. alvarezii has demonstrated its beneficial therapeutic properties such as antioxidant, wound-healing, and anticancer properties. This study aimed to investigate the effect of 100 and 200 mg kg−1K. alvarezii extracts on streptozotocin-induced type II diabetic ICR mice. Changes in plasma glucose level and body weight in mice treated with extracts before and after treatments were evaluated. Stomach tissue and epididymal white adipose tissue (WAT) were excised and ground into fine powder before RNA extraction. The messenger RNA (mRNA) expressions of ghrelin from stomach and resistin from epididymal WAT were measured by quantitative RT-qPCR. Multiplexed immunoassays were performed to analyze protein serum level of diabetic-related biomarkers relative to negative control mice. Kappaphycus alvarezii-treated diabetic mice did not experience significant changes in plasma glucose level and body weight. Interestingly, RT-qPCR analysis reported an opposing effect of 100 and 200 mg kg−1K. alvarezii on both ghrelin and resistin mRNA expression. The 100 mg kg−1 seaweed extracts upregulated ghrelin mRNA expression while reducing resistin mRNA expression. On the contrary, 200 mg kg−1 seaweed extracts demonstrated opposing action whereby it downregulated ghrelin and upregulated resistin expression levels. Multiplexing analysis of K. alvarezii treatments did not give significant upregulation or downregulation of the diabetic-related biomarkers relative to diabetic control mice. Instead, results from tolbutamide-treated mice have consistently demonstrated its effective antidiabetic activity in each experiment mentioned above. In conclusion, there was insufficient strong evidence to prove that 100 and 200 mg kg−1K. alvarezii extracts are effective in treating streptozotocin-induced diabetic mice.