I don鈥檛 know what a hot flash feels like, but by all accounts it isn鈥檛 pleasant. About three quarters of women going through menopause know all about hot flashes which may occur several times a day for years. From what I鈥檝e been told, the sensation may just mimic standing close to a fireplace, or it may feel as if the gates of hell have been thrown open. The misery is caused by declining levels of estrogen due to a winding down of ovarian activity. This decline is sensed by the hypothalamus, the tiny organ in the brain that controls our body temperature. For some reason, the reduction in circulating estrogen is interpreted by the hypothalamus as a message to cool the body down. The response is to increase sweating and to circulate more blood through the skin so that it can lose heat to the surrounding air. And there you have a hot flash! Treatment would appear to be simple. Don鈥檛 let blood levels of estrogen decline. That isn鈥檛 hard to do since compounds with estrogen-like activity can be readily extracted from the urine of pregnant mares or can be synthesized in the lab. Indeed, in the lab, hormones that are identical to the body鈥檚 own hormones, therefore termed 鈥渂ioidentical鈥� can be prepared. But there鈥檚 a catch. While treatment with estrogen can solve the problem of hot flashes, it introduces other problems. Risk of breast cancer and heart disease increases with estrogen supplementation, although the risk is very small if treatment is only over a few years. And there may even be a solution to this problem.
Estrogen carries out its work by fitting into what are called estrogen receptors located in cells all over the body. The breasts, uterus, brain, bones, lungs, liver and heart all have cells with these receptors. Now for the interesting nuance. There are actually two types of receptors, termed alpha and beta. While activating both receptors can reduce hot flashes, it is the activation of alpha estrogen receptors that are associated with side effects. So the development of estrogen analogues that activate only the beta receptors is an attractive approach. An intriguing possibility is emerging from a mix of conventional and traditional Chinese medicine, prompted by a personal encounter with breast cancer. In 1997 Mary Tagliaferri, already equipped with a masters degree in traditional Chinese medicine was diagnosed with breast cancer. She had successful conventional treatment after which she decided to go to Medical School hoping to learn how to to apply rigorous science to tease out the best herbal treatments. Dr. Tagliaferri went on to found a company, Bionovo, dedicated to studying traditional herbal medicines through proper controlled clinical trials. One of the company鈥檚 targets is a treatment for hot flashes. Looking through the Chinese herbs traditionally used for this, Bionovo scientists combined twenty two herbs into a medication tentatively called Menerba. In clinical trials it has been shown to have only beta estrogen receptor stimulating activity, with the most active ingredient being liquiritigenin, a component of licorice. Standardized doses of Menerba have been shown in preliminary double blind clinical trials with 217 women to significantly reduce hot flashes without side effects. If further trial go well, the drug should be on the market next year. A fascinating combination of modern science and ancient wisdom.
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