ABSTRACT
Rice bran (RB) is one of the nutrient-rich agricultural byproducts. It is a composite of carbohydrates, lipids, proteins, fibers, minerals, and trace elements such as phosphorus, potassium, magnesium, calcium and manganese. The extraction and purification process influences the quality and quantity of rice bran oil, which is rich in tocopherols, tocotrienols, γ-oryzanol, and unsaturated fatty acids. The bioactive components of RB have been reported for exhibiting antioxidant, anti-inflammatory, hypocholesterolemic, anti-cancer, anti-colitis, and antidiabetic properties. In vitro and in vivo studies, and clinical trials in human volunteers revealed the anti-hyperglycemic activity of RB derived compounds. An updated comprehensive review on the antidiabetic property of RB and its derivative is required to appraise the current knowledge in the particular field. Thus, the present paper covered the composition and bioactivities of RB, and influence of extraction methods on the biological property of rice bran oil and rice bran extract. And the current review also focused on the reported anti-hyperglycemia activity of rice bran derivatives, and its probable mechanism.
ABSTRACT
Anthocyanins (ACN) are water-soluble pigments, belonging to flavonoids, and are present in almost all fruits, and vegetables at varying concentration. About 635 ACN were distinguished based on the position and number of methoxyl and hydroxyl moieties in the basic structure of ACN. Pelargonidin, cyanidin, delphinidin, malvidin, peonidin, and petunidin are extensively studied anthocyanidins. The absorption, bioavailability, metabolism, pharmacokinetics, molecular mechanism, and analytical techniques of several phytochemicals were described. The biological benefits (antidiabetic, anti-neuro-disorder, anti-cardiovascular diseases, antigastrointestinal diseases, and disorders) of flavonoids and ACN have been reported. Several in vitro, and in vivo reports demonstrated that ACN-rich plant extracts ameliorate the diabetes-associated consequences by reducing the glucose absorption, ROS production, oxidative stress, glomerular angiogenesis, lipid synthesis, and FoxO1 and adipose triglyceride lipase expressions, and improve the insulin secretion, insulin sensitivity, glucose tolerance, glucose uptake, glucose consumption, antioxidant activity. The literature search was made in Scopus, Google Scholar, PubMed using the keywords 'anthocyanin' and 'diabetes'. The documents were carefully checked for the relevance to the current manuscript and the selection was made without any chronological restriction. The present manuscript summarizes the updated reports on antihyperglycemic properties of ACN.