Bitter melon juice may prevent pancreatic cancer

A new study shows that bitter melon juice restricts the ability of pancreatic cancer cells to metabolize glucose, thus cutting the cells' energy source and eventually killing them.

Bitter melon

Bitter melon is not the standard melon of the bitter taste. Bitter melon (Momordica charantia) is a fruit, widely cultivated and eaten across Southeast Asia, Africa, China, Japan, Oceania and in the Caribbean. It is especially popular among Japanese living in Okinawa, which may help to explain their exceptionally long lifespans. Although eaten for centuries, bitter melon's many health benefits (anti-viral, antioxidant, anti-diabetes) have only recently come to light in Western medicine, with research on its anti-cancer potential sharply accelerating in just the last four years. Bitter melon has now shown activity against cancers of the breast, prostate, colon, liver, stomach and naso-pharynx, as well as leukemia and neuroblastoma. But not until this latest study has it been shown that bitter melon is also cytotoxic to pancreatic cancer - and potently so.

Potent cytotoxicity against all four pancreatic cancer cell lines tested

Researchers at University of Colorado Cancer Center prepared bitter melon juice by simply purchasing the melons (Chinese variety) from a local grocery store, removing pulp and seeds, then using a household juicer. Solids were removed, and the remaining juice was either tested directly on cell cultures, or freeze dried and ground into a fine powder to be used later for feeding to mice.

When tested against cancer cell cultures, bitter melon juice (diluted to just five percent in water) showed remarkable potency in reducing the viability of all four pancreatic cancer cell lines tested. The viability of AsPC-1and Capan-2 cancer cell lines was reduced by 90 percent, while BxPC-3 and MiaPaCa-2 viability was reduced by 98 percent, after 72 hours treatment. The juice was seen to induce programmed cell death (apoptosis) along several different pathways. More importantly, it also activated AMPK, which indicates that it disrupts the cancer cells' metabolism of glucose, literally starving them of the sugar they need to survive.

Bitter melon inhibits pancreatic tumor growth by 64 percent in mice - at doses achievable in humans

To test the effectiveness of the juice in vivo, researchers implanted mice with MiaPaCa-2 human pancreatic cancer cells, and then fed half of them five milligrams daily of the freeze dried juice powder for six weeks. Remarkably, mice fed on the juice powder showed pancreatic tumors 64 percent smaller than the untreated mice, and showed no visible side effects. This level of efficacy is similar to that of the chemo drug most often used for pancreatic cancer, which reduced tumor growth by 52 percent in a different study using the same type of mice and cancer cell line (but after 18 days).

It's worth noting that the five milligram dose of powder given to the mice (which weigh about 13 grams each) translates to about six grams of powder for a 75 kg adult. This is quite close to the 4.8 grams of freeze dried bitter melon powder given to adults daily for three months in a recent study on ameliorating metabolic syndrome (it worked), and this dose was "generally well tolerated" according to the study's researchers.

The discovery that bitter melon starves cancer cells of glucose comes at an interesting time. The disruption of cancer cells' glucose metabolism happens to be Big Pharma's hot new target for chemo drug development. This new study has shown us that nature has already supplied us with a safe and cheap natural medicine that does exactly that.

"Three years ago researchers showed the effect of bitter melon extract on breast cancer cells only in a Petri dish. This study goes much, much farther. We used the juice -- people especially in Asian countries are already consuming it in quantity. We show that it affects the glucose metabolism pathway to restrict energy and kill pancreatic cancer cells," says Rajesh Agarwal, PhD, co-program leader of Cancer Prevention and Control at the CU Cancer Center and professor at the Skaggs School of Pharmacy and Pharmaceutical Sciences.

Agarwal's interest came from connecting the dots of existing research in a novel way. Diabetes tends to presage pancreatic cancer and bitter melon has been shown to effect type-II diabetes, and has been used for centuries against diabetes in the folk medicines of China and India. Following this line of thinking, Agarwal and colleagues wondered what would happen if they closed out the middle man of diabetes and directly explored the link between bitter melon and pancreatic cancer.

The result, Agarwal says, is, "Alteration in metabolic events in pancreatic cancer cells and an activation of the AMP-activated protein kinase, an enzyme that indicates low energy levels in the cells."

"It's a very exciting finding," Agarwal says. "Many researchers are engineering new drugs to target cancer cells' ability to supply themselves with energy, and here we have a naturally-occurring compound that may do just that."

The Agarwal Lab is now applying for grants that will allow them to move the study of bitter melon into further chemoprevention trials in mouse models of pancreatic cancer.

Other health benefits

Like most bitter-tasting foods, bitter melon stimulates digestion. While this can be helpful in people with sluggish digestion, dyspepsia, and constipation, it can sometimes make heartburn and ulcers worse. The fact that bitter melon is only a mild inflammation modulator, however, means that it rarely does have these negative effects, based on clinical experience and traditional reports.

The healing properties of Bitter Melon are becoming more widely accepted in the United States among natural health practitioners and even some allopathic medical doctors. Some particularly exciting research, appropriate to our contemporary moment, reflects the powerful insulin-lowering effects of Bitter Melon – it can be a very powerful anti-diabetic! Other studies on Bitter Melon have shown it to also be an effective treatment for HIV/AIDS. Other uses include treatment for viruses, the cold and flu, cancer and tumors, high cholesterol, and psoriasis. The main preparation methods for medicinal doses of bitter melon include capsules and tables, leaf and vine powders, tinctures, and even enemas.

At least 32 active chemicals have been identified in Bitter Melon so far, beta-sitosterol-d-glucoside, citrulline, GABA, lutein, lycopene and zeaxanthin. As for vitamins, Bitter Melon is chock full of them! Bitter Melons are rich in iron. They have twice the beta carotene of broccoli, twice the calcium of spinach, twice the potassium of bananas, and contain Vitamins A, C, B1 to B3, Phosphorus and good dietary fiber. Many claim that Bitter Melon’s bitterness comes from the high concentration of quinine it contains, however little documented evidence has supported this claim. Despite the lack of documentation, it is still regarded by Asians, as well as Panamanians and Columbians, as a valuable agent for preventing and treating malaria.

For those with a taste or tolerance for bitter flavor, a small melon can be eaten as food or up to 50 ml of fresh juice can be drunk per day. An option for those who do not care for the bitter taste are bitter melon tinctures, of which 5 ml is generally taken two to three times per day.

Precautions and side effects

Excessively high doses of bitter melon juice can cause abdominal pain and diarrhea. Small children or anyone with hypoglycemia should not take bitter melon because this herb could theoretically trigger or worsen low blood sugar (hypoglycemia). Furthermore, diabetics taking hypoglycemic drugs (such as chlorpropamide, glyburide, or phenformin) or insulin should use bitter melon only under medical supervision, as it may potentiate the effectiveness of the drugs and lead to severe hypoglycemia. Bitter Melon has also been found to have abortative properties; pregnant women should use consult a doctor before consuming it in excessive amounts.

Consumption tips

Here are some consumption recommendations:

1. Always wash Bitter Melon thoroughly under running water.

2. Use fresh Bitter Melon for best results.

3. Always choose bitter gourds that are fresh, bright, deep green in colour.

4. Don’t consume more than 2 bitter melons a day

4. The Bitter Melon leaves should be kept in a cool, dry, dark place. They stay fresh in refrigerator up to a week.

5. Marinade with salt to reduce bitterness.