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Neem oil as a male contraceptive, invented by Gursaran P. Talwar, Shakti N. Upadhyay, and Suman Dhawan (J.N.U. Complex, Shahid Jeet Singh Marg, New Delhi 110 067, IN), no assignee. U.S. Patent 5,501,855, issued Mar. 26, 1996.

Use of an intra-vas application of neem oil (Azadirachta indica A. Juss., Meliaceae) as an alternate approach to vasectomy for long-term contraception in male rats. The immunomodulatory properties of the plant appear to block spermatogenesis without affecting testosterone production. Although reduced in diameter, the seminiferous tubules appeared normal and contained mostly early spermatogenic cells. No antisperm antibody could be detected in the serum. Unilateral administration of neem oil in the vas resulted in a significant reduction of testicular size and spermatogenic block only on the side of application. The draining lymph node cells of the treated side also showed enhanced proliferative response to in vitro mitogen challenge. Neem oil and other neem plant extracts have long found varied applications in Ayurvedic and traditional Indian herbal practice. This patent describes one such use, along with the experimental data supporting that use.


Invented by Ezio Bombardelli, Paolo Morazzoni, and Giuseppe Mustich and assigned to Indena S.p.A., Milan, Italy. U.S. Patent 5,653,185, issued June 3, 1997.

Patent covers novel extracts of Piliostigma thonningii (Schumach.) Milne-Redh., Fabaceae, that have antiviral action, protecting the processes for preparing and formulating the extracts, and the use of the extracts to treat the viral infections that cause such diseases as herpes, influenza, broncho-pulmonary infections and HIV.


Invented by Alfred Jann (Marin-Thonon, France), Rolv Lundheim (Trondheim, Norway), Peter Niederberger (Epalinges, Switzerland), and Michel Richard (Peney-Le-Jorat, Switzerland). No assignees. U.S. Patent 5,637,301, issued June 10, 1997.

Sea buckthorn (Hippophae rhamnoides L., Elaeagnaceae) berries and leaf tissues yield juice and aqueous extracts containing an ice-nucleating agent that has a number of potential industrial applications. An ice-nucleating agent elevates the freezing temperature of a liquid in which it is dissolved. This type of compound occurs throughout nature, and plays a critical role in the annual cycle of deciduous tree leaf changes. As ambient temperature drop during the autumn, certain types of bacteria that grow on leaves and stems of deciduous trees produce elevated levels of ice-nucleating compounds. When the organisms freeze at a temperature several degrees above the freezing temperature of pure water, the resulting ice crystals sustain the damage that causes the leaves to discolor and fall off. Species of ice-nucleating bacteria are the key to the commercial "snow-making" process at ski resorts, and have applications in the processing of frozen food products. This patent cites several previous patents on ice-nucleating microorganisms, but this appears to be the first patent on ice-nucleating compounds from a plant.


Invented by Sylvia Lee-Huang and others, and assigned to New York University (New York, NY), American Biosciences, Inc. (Boston, MA), and the United States of America as represented by the Secretary of the Department of Health and Human Services, Washington, D.C. U.S. Patent 5,484,889, issued January 16, 1996.

A Single Chain Ribosome Inactivating Protein (SCRIP) that occurs naturally in high concentrations in the fruit and seed of Chinese bitter melon plant (Momordica charantia L., Curcubitaceae) has shown dramatic anti-tumor and anti-HIV activity in laboratory tests. SCRIPs occur naturally in many different plants, where they serve as an important component of a plant's immune response to invading bacteria and viruses. SCRIPs that have been identified in studies include pokeweed antiviral protein (from Phytolacca spp.), wheat germ protein, gelonin, dianthins, momorcharins, and trichosanthin. The M. charantia proteins (the momorcharins) selectively inactivate the ribosomes of tumor cells and HIV-infected cells, without damaging healthy cells. The ribosomes are the structures inside the cell where ribonucleic acid (RNA) executes the protein assembly orders from the DNA in the nucleus of the cell. When protein assembly stops, the cell dies.

The patent covers not only the anti-tumor and anti-HIV capabilities of momorcharins, but also the method of extracting them from the Momordica charantia plant, the method of purifying them, and a method of producing the proteins recombinantly in other organisms. The importance to this patent of the processing and purification steps points to a significant feature of modern plant patenting strategy: it's not enough to simply identify a botanical lead. A plant-product developer must go considerably beyond the plant itself, to make it into a patentable product.

Article copyright American Botanical Council.


By Karen Dean