The Star Ingredient of Japan's Blood Sugar-Lowering Products Is "Natural Insulin" From Ayurveda
Complementary and alternative therapeutic systems have rapidly gained popularity in the fight against diabetes over the past few years. More than 1,200 plants have been claimed to have antidiabetic effects, and to date, approximately 400 plants and compounds have been studied in detail. Salacia reticulata has been extensively studied in animal models and humans for its putative hypoglycemic and anti-obesity effects.
1. Active ingredientsof Salacia reticulata
Salacia reticulata is a woody climbing shrub with green-brown bark, native to northern Sri Lanka and southern India, also known as Kothara himbutu in Sri Lanka, and other species such as S. chinensis and S. oblonga are also found in Asia and other parts of the world. The safety of S. reticulata and other Salacia species on rats and mice showed that the extracts are extremely safe.
It has been recognized that the key antidiabetic compounds in Salacia, such as salacinol and kotalanol, are mainly derived from the roots and stems; mangiferin is mainly derived from the roots. In addition, the roots of the plant contain a variety of other chemical components such as 1,3-diketone, 26-hydroxy-1,3-fridela-dione, 30-hydroxy-20(30)dihydroisoigestrin, dulcerative colchicine, epicatechin, glycoside tannins, hydroxyferric alcohol, igestrin, 16-acetoxy-kotalaginin, lambic acid, hedyotisin, rutin, and triterpenes.
2. Mechanism of action for blood sugar control
Suppress postprandial blood sugar
Bioassays of the isolated active fractions of Salacia revealed that inhibition of α-glucosidase is the main mechanism of its hypoglycemic effect.
The intestinal enzymes, α-glucosidase and α-amylase, break down starch, dextrin, maltose, and sucrose in the small intestine into easily absorbed monosaccharides. Inhibition of these enzymes delays glucose absorption and helps alleviate postprandial blood glucose surges in diabetic patients. Salacia extracts are expected to reduce postprandial hyperglycemia and hyperinsulinemia by inhibiting polysaccharide and oligosaccharide digestion. Methanol and/or 80% aqueous methanol extracts of Salacia have been shown to suppress blood glucose levels in maltose- and sucrose-loaded rats.
Shimoda et al. demonstrated in 1998 that Salacia water extract dose-dependently inhibited serum glucose levels induced by sucrose, maltose, and α-starch, but had no inhibitory effect on serum glucose levels induced by glucose and lactose. The same study also investigated the effects of Salacia extract on various glucosidases and α-amylases prepared from rat jejunum and concluded that Salacia extract strongly inhibited the effects of α-glucosidase and α-amylase, but not β-glucosidase.
Similarly, Yoshikawa et al. demonstrated in 2002 that Salacia extract was able to suppress postprandial blood glucose levels in male Wistar rats subjected to sucrose and maltose loading, reaching statistically significant levels at 0.5 and 2 hours. No suppression of blood glucose was observed in rats subjected to glucose loading. The hypoglycemic effects of these studies were attributed to salixanol and gaudalanol.
In 2008, another compound, thiocyclanol, was isolated from Salacia salacia. They measured the sucrase and maltase inhibitory activities of the aqueous extract in vitro using maltose and sucrose as substrates. The study demonstrated that this new compound had a more potent α-glucosidase inhibitory effect than salixanol.
3. Anti-obesity effect of Salaciareticulata
1) Pancreatic lipase
In addition to this, the anti-obesity effects of Salacia have been extensively studied. Pancreatic lipase activity is a key enzyme in the digestion of dietary fat and is therefore thought to aid in weight loss. In 2006, a study demonstrated that Salacia root extracts inhibited olive oil-induced hypertriglyceridemia in rats. Similarly, hot water extracts of Salacia also inhibited pancreatic lipase activity. Therefore, inhibition of pancreatic lipase activity in the small intestine is thought to be the primary mechanism by which Salacia root reduces postprandial hyperlipidemia.
2) Inhibits the differentiation of adipocytes
For a long time, the main role of adipocytes was considered to be the storage of excess energy. Recent evidence suggests that adipocytes have endocrine functions and regulate glucose and lipid metabolism by actively secreting various adipocytokines. Adipocytes are divided into immature adipocytes, mature adipocytes, and hypertrophic adipocytes, and adipocytes at each stage secrete different types of adipocytokines. Adipocyte hypertrophy is the basis of various metabolic diseases, including insulin resistance, ischemic cardiovascular and cerebrovascular diseases, and non-alcoholic fatty liver disease (NAFLD). Therefore, the regulation of these adipocytes may play a role in fat accumulation and its subsequent effects on cardiovascular and cerebrovascular diseases.
In 2011, scholars studied the differentiation of mouse-derived 3T3-L1 adipocyte precursors in the presence or absence of Salacia extract. They demonstrated that in the presence of Salacia, the differentiation of precursor cells into mature adipocytes was significantly inhibited. The same study also showed that Salacia had an inhibitory effect on peroxisome proliferator-activated receptor γ (PPAR) expression and reduced the concentration of adiponectin. Previous studies have shown that Salacia acts directly on adipocytes to prevent obesity.