Sericin has been implicated in lower cholesterolemic effect due to its properties with several mechanisms. Mitochondria are one of the most important targets to be affected in high blood cholesterol and glucose conditions. The protective role of sericin on mitochondria remains doubtful. To examine this role, electron microscopic, histopathologic, immunohistochemical, and biochemical studies were performed in a high-cholesterol diet/streptozotocin rat model. The results demonstrated that sericin reduced blood cholesterol without hypoglycemic effect. Sericin alleviated dysmorphic mitochondria in heart and liver but not in kidney and also decreased peculiar endoplasmic reticulum in the exocrine pancreas. In addition, sericin decreased hepatic steatosis and preserved zymogen granule referable to the decline of reactive oxygen species production in hepatic mitochondrial extraction and down-regulation of malondialdehyde expression in the liver and exocrine pancreas however irrelevant to lipase activity. This study suggests that sericin has antioxidative property to reduce blood cholesterol by means of diminishing fat deposit in hepatocyte and improves mitochondria and endoplasmic reticulum integrities.
Impact statement
The present work provides new insights regarding the antioxidative effect of sericin in (i) reducing blood cholesterol, (ii) improving liver and heart mitochondrial structures, (iii) maintaining endoplasmic reticulum integrity in exocrine pancreatic glands, and (iv) inhibiting fat deposition in the liver. Electron microscopic, histopathologic, immunohistochemical, and biochemical studies were performed. All of the results demonstrate the efficacy of sericin as a candidate for development of a functional food or adjunctive therapeutic agent against non-communicable diseases such as hypercholesterolemia.
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