Bitter Melon Extract (Charantin)とは？用途・使用量・代替品・規格

Bitter Melon Extract, also known as Bitter Gourd Extract or Charantin, is a natural plant extract processed from the fruit of bitter melon (Momordica charantia L.), a plant of the Cucurbitaceae family, through extraction, separation, concentration, and drying processes. It is a functional ingredient with multiple biological activities. Bitter melon, also known as balsam pear or karela, is native to tropical regions of Asia and is widely distributed in tropical, subtropical, and temperate regions. It has a long cultivation history in India, Japan, Southeast Asia, and China (approximately 600 years). Bitter melon has a bitter and cold nature and has been used for centuries in traditional medicine for its effects of clearing heat, removing toxins, reducing blood lipids and blood glucose, and beautifying the skin. Bitter melon is both a traditional vegetable and an important medicinal and edible plant, used as both food and medicine in Asia, Africa, and South America. The main active components of bitter melon extract include charantin (also known as momordicin), polypeptide-P (insulin-like peptide), bitter melon saponins, bitter melon polysaccharides, flavonoids, and various trace elements. These components endow bitter melon extract with multiple effects including lowering blood glucose, antioxidant activity, anti-inflammatory activity, lowering blood lipids, anti-tumor activity, and immunomodulation. Bitter melon contains steroidal saponins such as charantin, insulin-like peptides, and alkaloids, which confer its blood glucose-lowering activity. Charantin stimulates insulin release and inhibits glucose formation in the bloodstream, which may play a significant role in the treatment of diabetes, especially non-insulin-dependent diabetes mellitus. This blood glucose-lowering function is attributed to two substances: (1) charantin – a crystalline substance obtained from ethanol extract of bitter melon fruit; and (2) P-insulin (or plant insulin, so named because it is derived from plants), which has a macromolecular polypeptide structure pharmacologically similar to bovine insulin. Bitter melon extract products are available in various forms, including ratio extracts (4:1, 10:1, 20:1, etc.), charantin extracts (content 5%–30%), bitter melon polysaccharide extracts (30%), bitter melon saponin extracts, bitter melon peptide extracts, and whole fruit extracts.

The main active components of bitter melon extract are shown in the table below: Component Category

Charantin (also known as Momordicin) : Charantin is composed of an equal mixture of two steroidal saponins: β-sitosteryl glucoside (C35H60O6) and 5,25-stigmasteryl glucoside (C35H58O6), with a molecular weight of 1287.43. Animal studies have shown that charantin reduced blood glucose levels in experimental rabbits by 42% at a controlled dose of 50 mg/kg. The blood glucose-lowering effect of charantin may surpass that of conventional hypoglycemic drugs, exhibiting both pancreatic and extrapancreatic effects, with mild antispasmodic and anticholinergic activities. Polypeptide-P (Plant Insulin) : Polypeptide-P is an insulin-like polypeptide with a molecular weight of approximately 11,000. It has a macromolecular polypeptide structure composed of two polypeptide chains linked by disulfide bonds and is pharmacologically similar to bovine insulin. Subcutaneous and intramuscular administration of polypeptide-P in diabetic patients has a blood glucose-lowering effect, with the peak effect occurring 4–8 hours after administration (compared to 2 hours for bovine insulin). Polypeptide-P has a structure very similar to human insulin and can even mimic many of insulin‘s reaction mechanisms, potentially helping type 1 diabetes patients with insufficient insulin secretion to lower blood glucose.