Curry Leaves Could Cure Prostate Cancer

Curry leaves don’t just satiate the taste buds, as scientists have discovered. There’s a new aspect to these leaves — the possibility of curing prostate cancer. Researchers from the Santiniketan-based Visva-Bharati University, Kolkata’s Indian Institute of Chemical Biology and Georgetown University Medical Centre in Washington, USA, have isolated mahanine — a plant-derived carbazole alkaloid from curry leaves — which has caused the mass death of prostate cancer cells through apoptosis, a type of controlled cell death mechanism.

“Mahanine did not cause death of liver cells, heart or skeletal muscle cells, indicating that this alkaloid selectively kills prostate cancer cells,” says Samir Bhattacharya, the lead researcher. “Mahanine promises a new chemotherapeutic option for prostate cancer treatment,” says Bikas C Paul, a co-researcher. Their findings were published in the journal The Prostate (Vol 66, No 12).

The research team exposed LNCaP and PC3, two types of cultured human prostate cancer cells, to mahanine-extracted and purified from curry leaves. The cancer cells were treated with one mg/ml, two mg/ml and three mg/ml mahanine for one, two and three days. And over 72 hours, at two mg/ml dose, mahanine reduced the viability of both types of cancer cells by 50 per cent. At three mg/ml dose, mahanine destroyed almost all the cancer cells within 48 hours. Studying the effects of mahanine on PC3 cancer cells, the team found that it inhibited the activity of AKT — a protein that fuels the growth of prostate cancer cells. It also blocked the generation of Bcl-xL — a type of protein that helps cancer cells survive.

“At 60 hours, mahanine completely abolished Bcl- xL,” says Bhattacharya. Reduction in the levels of Bcl-xL releases cytochrome c, a protein of mitochondria. Cytochrome C activates caspase, an enzyme that further accelerates the death of cancer cells without damaging any neighbouring healthy cells.

Mahanine has also been shown to cause the death of human leukaemic cells. “But the concentration of mahanine we used was well below the concentration used to kill leukaemic cells,” says Bhattacharya. “This suggests that prostate cancer cells are more sensitive to mahanine-induced cell death compared to leukaemic cells.”

Prostate cancer has been found to be one of the 10 leading male cancer cases in India. According to the population-based cancer registry, prostate cancer is on the rise in cities like Pune, Delhi, Chennai, Bangalore and Kolkata. In the US, prostate cancer is the second leading cause of death in men.

The above article was originally published in the science and technology section of Down To Earth, a science and environment fortnightly published from New Delhi, on December 31 2006 issue and written by this blogger.

Healthy Diet of Mothers Helps Prevent Child Leukaemia

A TEAM from the US-based University of California has found that women eating more vegetables, fruits and other foodstuff rich in proteins have less chances of giving birth to children suffering from leukaemia. Among the fruits and vegetables, carrots, string beans and cantaloupe reduce the risk the most, the researchers point out in their paper, published in a recent issue of journal Cancer Causes and Control (Vol 15, No 6).

To hunt down the anti-cancer agents, the team led by Christopher Jensen studied the diet pattern of 276 women. Of them, 138 had given birth to children suffering from acute lymphoblastic leukaemia (ALL). Rest had healthy children (in other words, they were part of the control group). After meticulously monitoring the women’s food habits before pregnancy, the team identified levels of glutathione and carotenoids — two anti-cancer agents — in their diet. These agents mainly consist of proteins.

Glutathione, a molecule comprising amino acids, acts as an antioxidant (in other words it prevents oxidative damage to healthy cells). Even carotenoids are a molecule having the same function. Both mop up compounds that have carcinogenic effects.

The findings have significant implications for countries like India, as leukaemia is the most common form of childhood cancer in the country. “On an average, six out of every 100,000 Indian newborns fall prey to the disease,” informs Kanjaksha Ghosh, deputy director of the Institute of Immunohaematology, Mumbai. “The study reinforces traditional knowledge that healthy eating during pregnancy is good,” Ghosh adds. “It also shows that eating fruits could be a cost-effective antidote to childhood leukaemia in India where most people are unable to afford the high cost of treatment,” says Prantar Chakrabarti, assistant professor at the Institute of Haematology and Transfusion Medicine, Kolkata.

The above article was written by this blogger and originally published in ‘Down To Earth’, a science and environment fortnightly published from New Delhi on October 15, 2004.

Curcumin Halts Breast Cancer

Curcumin, the main ingredient of turmeric and the compound that gives curry its mustard-yellow colour, checks the spread of cancer cells to lungs in mice with breast cancer, claim researchers from the US-based University of Texas M. D. Anderson Cancer Centre. The study published in October 15 2005 issue of the journal Clinical Cancer Research reveals that the spice possibly shuts down the activity of a protein that plays key role in spreading breast cancer cells.

The research team found that besides stemming the migration of cancer cells, curcumin reduced the toxic effects of paclitaxel (TaxolTM), a commonly prescribed drug for chemotherapy. This drug if used for long time could trigger spread of breast cancer cells.

It is known that Taxol is toxic. It activates a protein that produces a protein that initiates inflammation causing unbridled cell growth. In other words, cancer cells attack the body at a global scale. Curcumin stops such inflammatory response, blocking cancer cells’ unabated growth. Curcumin makes the chemotherapy with paclitaxel less toxic. At the same time, it increases paclitaxel’s efficacy.

“We are excited about the results of the study and the possible implications for taking the findings into the clinic in the next several years,” says Bharat Aggarwal, professor of cancer medicine in M. D. Anderson's Department of Experimental Therapeutics. “At this time, advanced breast cancer is a difficult foe to fight with few proven treatments available after surgery, chemotherapy and radiation therapy.”

Taxol is currently used as the front-line chemotherapeutic agent in breast cancers, but because the drug frequently induces drug resistance after prolonged use, it is not effective in treating metastatic breast cancer, says Aggarwal.

Researchers studied 60 mice with breast cancer, which were randomly assigned to one of four groups: control group, Taxol only, curcumin only and the combination of Taxol and curcumin. After the tumors grew to 10 mm (about the size of a pea), they were surgically removed, and the mice were fed a powdered curcumin diet.

Lungs lined with visible cancer cells were seen in 96 per cent of mice in the control group. The group that only received Taxol modestly reduced the migration of cancer cells to lungs. The group with only curcumin and the group with curcumin plus Taxol showed significant reduction in number of visible cancer cells in lungs.

Microscopic metastasis (metastasis means migration of cancer cells from one organ to another), or metastasis that is visible only when using a microscope, was found in the lungs of 28 per cent of mice treated with the combination of curcumin and Taxol, and there was no macroscopic disease present. The micrometastases present consisted of only a few cells, suggesting that the combination inhibited the growth of breast cancer tumor cells that were in the lung before the tumors were removed.

In a previous study published in the August 15 issue of the journal Cancer, the same researchers found that cancer cells commit suicide when the activity of nuclear factor-kappa B (NF-kB) is shut down. The curcumin works the same way. Taxol plays the role of miscreant by activating NF-kB in breast cancer cells. Curcumin comes to the rescue by silencing “IKK”, a protein that turns on the NF-kB.

Curcumin’s ability to cripple NF-KB could be very useful as a therapeutic agent. Because this protein has been linked to cancer cell growth in many cell types. Turmeric has also been found to inhibit growth of 19 clinical strains of Helicobacter pylori, a cancer-causing bacterium linked to the increased risk of stomach and colon cancers. Studies have also shown that turmeric could destroy blood cancer cells. In Indian medicine, curcumin has long been in use. As it also increases the delicacy of Indian cuisine as spice, it could be a cost-effective arsenal for battling a host of cancers.