Momordica Charantia and Diabetes Mellitus
Momordica charantia is a vine that belongs to Family Cucurbitaceae, and it is a relative of cucumber and squash. It is called bitter gourd or bitter melon in English speaking countries, kerala in India and Pakistan, and ampalaya in the Philippines, and it grows in damp and wet places. Upon reaching its reproductive stage, it produces a cucumber shaped fruit with wrinkled skin. It is known for its bitter taste, which makes some people uncomfortable eating it. Its taste, though, is overshadowed by the health benefits it offers.
It has been used as traditional medicine in India and China for thousands of years. People used it to treat various diseases, including diabetes mellitus. It is consumed as a salad, as an ingredient for other food recipes, or as a tea. It is a very popular herbal medicine to poor and diabetic people who cannot afford expensive drugs to treat their diseases, and they have found it to be very effective. In fact, wealthy people are now also taking bitter gourd supplements (in capsule form) because of its anti-diabetic effect.
Diabetes mellitus is caused by the failure of cells to absorb glucose., the main energy source of the cell. It must go inside the cell to be transformed into the energy rich chemical compound Adenosine Triphosphate (ATP). The hormone insulin helps the cell to absorb glucose by initiating the necessary biochemical pathways in the cell membrane. When glucose molecules are not absorbed by the cells, glucose will concentrate in the blood – a condition called hyperglycemia. If there is not enough insulin produced by the Islet of Langerhans (specialized cells in the pancreas), Type 1 diabetes mellitus occurs. On the other hand, if the cells became resistant to insulin, Type 2 diabetes mellitus occurs.
Hyperglycemia is the major symptom of diabetes, but it is not the direct cause of death in diabetic patients. Body tissues are destroyed when cells produce too many toxic by-products through the metabolism of fats as an energy source. These toxic by-products are not produced if glucose molecules are used instead of fats. Unfortunately, cells have no choice but to metabolize fats, in the absence of glucose inside the cell. Too much of these toxic compounds can shut down vital organs, leading to death.
The hypoglycemic effect (lowering blood glucose level) of Momordica charantia has been investigated by biochemists, medical researchers, and pharmaceutical companies for decades. These studies broaden our knowledge of the positive effects of bitter gourd in treating diabetes mellitus.
The Hypoglycemic Effect of Bitter Gourd
Welihinda et al. (1982) investigated the effect of bitter gourd extract in stimulating the cells of the Islet of Langerhans to produce insulin. They found that the extract significantly affected the cells to produce insulin. This experimental result tells us that bitter gourd can be an alternative treatment for Type 1 diabetes mellitus. Further research is needed to investigate the effect of bitter gourd extract for patients with Type 1 diabetes.
Another study found that an active compound in bitter gourd is able to inhibit the absorption of glucose in the intestinal lining. If glucose uptake in the intestine is decreased, there would be a lower glucose concentration in the blood. This study, however, was performed on laboratory rats. More studies are needed to know if bitter gourd effectively inhibits glucose absorption in the intestinal tract of humans (Meir and Yanib 1985).
Khanna et al. (1981) investigated the hypoglycemic effect of a polypeptide-p isolated from bitter gourd. They claimed that polypeptide-p is an insulinomimetic agent – an agent that mimics the biochemical activity of insulin in the plasma membrane. It helps the cell to absorb glucose just as natural insulin does.
Sridhar et al. (2008) investigated the effect of bitter gourd extract in stimulating the sensitivity of insulin in the muscle cells of laboratory mice. Muscle cells need a continuous supply of glucose. If the muscle cells are resistant to insulin, glucose molecules cannot enter. The animal would then experience weakness or fatigue. In the experiment of Sridhar and colleagues, insulin sensitivity in mice was induced by giving them high fat diet. After injecting the mice with bitter gourd extract, the researchers measured increased insulin sensitivity in muscle cells. The result of their experiment is in agreement with the findings of other studies. The exact biochemical mechanism of the effects of bitter gourd in enhancing insulin sensitivity are still unknown, but scientists are working to unravel this mystery. Nevertheless,these experimental findings imply that bitter gourd can help patients with Type 2 diabetes, because it helps the cells to absorb glucose.
Bitter gourd is highly recommended as an alternative treatment for diabetes mellitus. There are now bitter gourd supplements available in capsule form for people living in the temperate region. If raw bitter gourd is available, diabetic people can eat it raw, blend it into a juice, or add it to their favorite salads and soups. It is, however, important for diabetic people to consult their doctors before they take bitter gourd.
Welihinda, J., Gylfe, E., Karlsson, E. & Hellman, B. 1982. “Effect of a hypoglycemic plant extract (Momordica charantia) on isolated pancreatic islets rich in ß-cells.” Acta Endocrinol. 100:S247.
Meir, P. & Yaniv, Z. 1985. “An in vitro study on the effects of Momordica charantia on glucose uptake and glucose metabolism in rats.” Planta Med. 51:12-16.
Sridhar MG, Vinayagamoorthi V, Suyambunathan VA, Bobby Z, & Selvaraj N. 2008. “Bitter gourd (Momordica charantia) improves insulin sensitivity by increasing skeletal muscle insulin- stimulated IRS-1 tyrosine phosphorylation in high-fat-fed rats”. British Journal of Nutrition 99: 806-812.
Khana P, Jains SC, Paragariya A, Dixit VP. 1981. Hypoglycemic activity of polypeptide-p from a plant source. J nat Prod (Lloydia) 44: 648-655.