Modulating Effects of Oil Palm Phenolics in Uncontrolled Insulin-treated Type 2 Diabetes Mellitus

Recent studies suggest the potential of polyphenols as a supplementary treatment for diabetes mellitus owing to their biological properties. Polyphenols are natural phytochemical compounds found in fruits and vegetables. The most common group of phenolic compounds in our diet are phenolic acids and flavonoids. The two main classes are hydroxybenzoic acid derivatives and hydroxycinnamic acid derivatives. The potential efficacy of polyphenols on glucose homeostasis and carbohydrate metabolism is being aggressively investigated in in vitro, animal models and clinical trials. The anti-hyperglycemic property of polyphenols is mainly contributed by the reduction of dietary carbohydrate absorption through intestines, improvement of β-cell function and insulin action, stimulation of insulin secretion, modulation of the enzymes involved in glucose metabolism, anti-oxidative and anti-inflammatory effects. The key enzymes responsible for the digestion of dietary carbohydrates to glucose are α-glucosidase and α-amylase. One of the most well-known properties of polyphenols especially phenolic acids on carbohydrate metabolism is the inhibition of these enzymes. Some investigations have shown that polyphenols are also able to regulate postprandial glycemia and inhibit the development of glucose intolerance by a facilitated insulin response and increased secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagonlike polypeptide-1 (GLP-1). The current study focuses on the glucose-controlling properties of phenolic compounds extracted from oil palm (Elaeis guineensis), a high oil-producing tropical plant that also rich in phytochemicals. The major phenolic components in OPP are identified as caffeoylshikimic acid, protocatechuic acid and p-hydroxybenzoic acid. OPP has been found to exert various positive health effects parallel to the well-established physiological benefits of polyphenols. It has been shown that OPP protects against early type 2 diabetes and encouraging results suggest its role in modulating the development of diabetes. The current study aims to investigate and determine the effects of oil palm phenolics (OPP) on the blood glucose control in patients with uncontrolled insulin treated type 2 diabetes mellitus.