Anti-Obesity and Hypolipidemic Effects
of Black Soybean Anthocyanins

Journal of Medicinal Food
http://www.liebertonline.com/doi/abs/10.1089/jmf.2006.147

The effect of anthocyanins extracted from black soybean (Glycine max L.) seed coats on body weight, adipose tissue weight, and serum lipids was evaluated in rats fed a high fat diet (HFD).

Rats were raised on a normal diet (ND) (based on the AIN-93M diet), HFD (ND supplemented with 16% lard oil), HFD containing 10% black soybean, and HFD containing 0.037% black soybean anthocyanins (equivalent to that in the 10% black soybean diet).

Weight gain was significantly lowered in the rats fed HFD plus black soybean anthocyanins compared with the rats fed HFD alone (P < .05) and reversed to the level of the rats fed ND.

The black soybean diet also decreased body weight gain compared with the HFD (P < .05). The black soybean anthocyanins-added diet suppressed the HFD-induced weight gain in liver intermediately and tended to decrease the weights of epididymal and perirenal fat pads.

The black soybean anthocyanins were also effective in improving the lipid profile. They significantly reduced the levels of serum triglyceride and cholesterol (P < .05), while they markedly increased the high-density lipoprotein-cholesterol concentration, which was decreased in the rats fed HFD (P < .05).

These results indicate that the anthocyanins in black soybean seed coats have an anti-obesity effect, which can reverse the effects of HFD on body weight, adipose tissue weight, and serum lipid contents.

. . . . . . . . . .

Soybean is an increasingly important source of human food. It contains bioactive phytochemicals such as dietary fiber, isoflavones, tocopherol, phytic acid, saponins, and trypsin inhibitor, which exibit antioxidant and anticancer properties and lower serum cholesterol levels.

Soy protein is reported to decrease lipid levels and body weight. Soybean seed shows diversity in color, including yellow, brown, green, and black seed coat.

In the black soybean seed coat, there is a considerable amount of dietary fiber (80%) and functional ingredients such as anthocyanins. The black pigmentation is due to an accumulation of anthocyanins in the epidermis palisade layer of the seed coat.

The seed coat of black soybeans contain 0.87-23.52 mg/g anthocyanins, with the most prevalent being cyaniding-3 glucoside (80.9% of total content).

Anthocyanins, a group of flavonoids, are water-soluble pigments responsible for most of the red, purple, and blue colors exhibited by flowers, fruits, and other plant tissues.

Although they are highly unstable in the aglycone form (anthocyanidins), they become resistant to light conditions. pH, and oxidation through glycosylation and esterification with various organic acids (citric and malic acids) and phenolic acids.

“Anthocyanins” play an important role as dietary antioxidants in the prevention of oxidative damage. They also have several biological activities, such as anticonvulsant, anticareinogenic, anti-atherosclerotic, and anti-inflammatory actions, and reduce the risk of coronary heart disease.

Recently, some studies have reported that anthocyanins have an anti-obesity effect, Tsuda et al. demonstrated that dietary cyaniding 3-glucoside-rich purple-colored corn pigments significantly suppressed the high fat diet (HFD)-induced increase in body weight, and also suppressed the increase in adipose tissue weights. Anthocyanins from the cornelian cherry are also reported to ameliorate obesity and glucose intolerance in high-fed mice.

Anthocyanins have been found to have an "antihyperglycemic effect because they inhibit the digestion of carbohydrates via a-glucosidase inhibition.”

To Top, To Main soy-beans.org
Read more soy healing articles from Anti-obesity Black Soybean Anthocyanins