Researchers Are Taking a New Look at Long-Valued Uses of India’s Neem Tree : Botany: The evergreen has cleansing and insect-repelling properties. Now it is viewed as a pharmaceutical resource.

In its native India, the neem tree has long been believed to have miraculous powers. And scientists around the world are beginning to agree.

For at least 2,000 years, Indians have cleaned their teeth with its twigs, smeared neem-leaf juice on skin blemishes, drunk neem tea as a tonic, and placed neem leaves in their beds, books, grain bins, cupboards and closets to keep out troublesome bugs.

The tree has relieved so many pains, fevers, infections and other ailments it’s known as “the village pharmacy.”

Now, after two decades of research, scientists from several disciplines are beginning to think the Indians may be right. Even cautious researchers are calling the neem “a wonder plant.”

“At least as of today, the vision is certainly an entrancing one,” said Noel D. Vietmeyer, senior program officer and neem study director for the National Research Council’s Board on Science and Technology for International Development at the National Academy of Science in Washington.

“The world should be exploring it,” Vietmeyer said. “Even if we realize just a fraction of the vision, the benefits will be tremendous. It could provide new resources that are gentle on the land and powerful against many of our insects and diseases.”

Earlier this century, people found a way to get the tree from India to West Africa. In Ghana, the fast-growing tree has become the leading producer of firewood for the densely populated Accra Plains. It’s a leading candidate for helping halt the southward spread of the Sahara.

In the Caribbean, the broadleaf evergreen, which can grow to 90 feet tall and more than 7 feet in girth, is being used to reforest several denuded nations and already has become a major species in Haiti.

Although it’s received little publicity, the neem tree also is being looked to as a potential source of cancer prevention, a harmless and temporary contraceptive, and a safe insecticide.

“U.S. Department of Agriculture studies have shown that chemicals in neem tree oil give good to excellent protection against 131 insect pests, and it shows activity against an additional 70 pests,” said Eugene B. Shultz Jr., who recently chaired an international panel to study the tree.

The panel’s conclusions about the tree’s value were reported in February in the National Academy of Science’s publication, “Neem: The Tree That Might Help Everyone.”

“Neem can become a safe, non-toxic replacement for some of the more toxic and polluting synthetic pesticides on the world market,” Schultz said. “Its use as an insecticide can’t come fast enough.”

Shultz, a professor of engineering and applied sciences at Washington University in St. Louis, noted that a recent World Health Organization study estimated that there are about a million pesticide-poisoning incidents reported each year worldwide. Most of the victims are agricultural workers contaminated by toxic chemicals in synthetic pesticides, and about 20,000 of them die, according to the study.

Schultz said companies such as W. R. Grace & Co. already are investing in neem technology and have products ready to market.

“When we do these studies, we are very careful not to overplay the prospects,” he said. “In the case of the neem tree, however, there is honest enthusiasm. This tree could really solve a lot of problems.”

But Vietmeyer said he doesn’t understand why the research and development isn’t getting more support worldwide.

“The most valuable aspect of neem is that it is a tree that can be grown in the back yards of the poorest people in the poorest countries,” Vietmeyer said. “It’s a chance to give them ways to control pests and diseases in their crops, perhaps control some of their own diseases and even avoid unwanted pregnancies.

“All from a tree in their own back yard that at the same time is providing them with shade and a more pleasant environment. All in all, this ancient village dispensary could provide a lot of healing for the modern world.”

Neem extracts have been used to prevent tooth decay and to prevent and heal inflammation of the gums. It’s used as an active ingredient in toothpastes in Germany and India.

Research shows neem leaves also contain an ingredient that disrupts the fungi that produce cancer-causing aflatoxin on moldy peanuts, corn and other foods in storage, said Deepak Bhatnagar, a U.S. Food and Drug Administration researcher in New Orleans.

“I grew up in India, and I can tell you that my people have used the neem for centuries to protect grain stored in barrels and for other things,” Bhatnagar said. “In fact, I use nothing but neem soap myself. I bring back a supply every time I go to visit.”

And there may be even more benefits in the future.

The oil of the neem seed has been effective in reducing the birth rate in laboratory animals, as well as in a recent human test of 20,000 wives of Indian Army officers, Vietmeyer said.

The oil is a strong spermicide, and other neem compounds show promise as bases of a birth-control pill for men, he said.

“This is just an intriguing hint, at present,” Vietmeyer said, “but in exploratory trials, researchers have reduced fertility in male monkeys and other mammals without inhibiting sperm production. Moreover, the effects seemed to be temporary, which would be a