The metabolic syndrome is affecting many people. Patients with metabolic syndrome suffer from both dyslipidemia and diabetes mellitus. Peroxisome proliferator activated receptors influence the carbohydrate and lipid metabolism. Phytochemicals that influence peroxisome proliferator activated receptors can be used to treat dyslipidemia and to restore glycemic balance. Dyslipidemia is a disorder of lipoprotein metabolism, resulting in overproduction or deficiency of lipoproteins. Dyslipidemia may increase total cholesterol, low density lipoprotein cholesterol and the triglyceride concentrations, and decrease the high-density lipoprotein (HDL) cholesterol concentration in the blood. Dyslipidemia is often a result of diabetes patient who suffer from atherogenic lipid abnormalities and insulin resistance. Pioglitazone is a traditional drug to treat diabetes and works by increasing the sensitivity to insulin. However, pioglitazone has many side effects, including obesity and edema. Therefore, there is still a need for less potent but still effective drugs such as phytochemicals from plants or foods.
Other studies have shown that isoflavones from soy have antilipidemic properties and can play a role in controlling diabetes and obesity. However, scientific studies have resulted in mixed results concerning the effect of soy consumption on dyslipidemia. For this study, extracts from Astragalus membranaceus and Pueraria thomsonii, were screened for possible antidiabetic properties. These two herbs are traditionally known as antidiabetic herbs. The researchers found that these extracts significantly activated peroxisome proliferator activated receptors. They found the isoflavones were the active components: daidzein in Pueraria thomsonii and the isoflavones formononetin and calycosin in Astragalus membranaceus. The effects of these three isoflavones (daidzein, formononetin and calycosin), together with two other common isoflavones (genistein and biochanin A), were investigated in vitro for their properties to influence peroxisome proliferator activated receptors. Biochanin A, formononetin and genistein were more active than calycosin and daidzein. At low dosages, only biochanin A and formononetin activated peroxisome proliferator activated receptors. This study showed that although isoflavones have similar structures they have different functions.
The study concluded that isoflavones, mainly biochanin A and plants containing them, may act as antidiabetic agents and could be used to regulate lipid metabolism.
Source: Shen P, Liu MH, Ng TY, Chan YH and Yong EL.. Differential effects of isoflavones, from Astragalus membranaceus and Pueraria thomsonii, on the activation of PPARalpha, PPARgamma, and adipocyte differentiation in vitro.. Journal of Nutrition. 2006 April;136(4):899-905