Neem plant compound may treat prostate cancer: study

Oral administration of a bioactive compound from neem - a medicinal plant native to the Indian subcontinent - may significantly suppress development of prostate cancer, a new study led by an Indian origin scientist has claimed.
Consumption of nimbolide, a bioactive terpenoid compound derived from Azadirachta indica or more commonly known as the neem plant over 12 weeks shows reduction of prostate tumour size by up to 70 per cent and decrease in tumour metastasis by up to 50 per cent, researchers said.
Prostate cancer is one of the most commonly diagnosed cancers worldwide, said researchers led by Associate Professor Gautam Sethi from the National University of Singapore (NUS).

However, currently available therapies for metastatic prostate cancer are only marginally effective. Hence, there is a need for more novel treatment alternatives and options.
"Although the diverse anti-cancer effects of nimbolide have been reported in different cancer types, its potential effects on prostate cancer initiation and progression have not been demonstrated in scientific studies," said Sethi.
"In this research, we have demonstrated that nimbolide can inhibit tumour cell viability - a cellular process that directly affects the ability of a cell to proliferate, grow, divide, or repair damaged cell components - and induce programmed cell death in prostate cancer cells," he said.

Cell invasion and migration are key steps during tumour metastasis. The study showed that nimbolide can significantly suppress cell invasion and migration of prostate cancer cells, suggesting its ability to reduce tumour metastasis.

The researchers observed that upon the 12 weeks of administering nimbolide, the size of prostate cancer tumour was reduced by as much as 70 per cent and its metastasis decreased by about 50 per cent, without exhibiting any significant adverse effects.
"This is possible because a direct target of nimbolide in prostate cancer is glutathione reductase, an enzyme which is responsible for maintaining the antioxidant system that regulates the STAT3 gene in the body," said Sethi.

"The activation of the STAT3 gene has been reported to contribute to prostate tumour growth and metastasis.
"We have found that nimbolide can substantially inhibit STAT3 activation and thereby abrogating the growth and metastasis of prostate tumour," he added.
The findings were published in the journal Antioxidants & Redox Signaling.