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http://www.geneticarchaeology.com/Research/African_Black_Plum_Link_To_Baboon_Contraception.asp

African Black Plum Link To Baboon Contraception (7/21/2007)

-Great Britain

Having spent a year in the rainforests of Nigeria, Post-Doctoral Research Fellow James Higham has announced unique findings on the reproductive ecology of female olive baboons and the contraceptive effects of the African black plum.

The former Roehampton University PhD student investigated the reproductive ecology of females at Gashaka-Gumti National Park for his PhD, and used Roehampton's state-of-the-art hormone laboratory to measure female reproductive function non-invasively from faeces.

During this study, an unexpected seasonal pattern of progestogen excretion emerged in all females, regardless of whether they were lactating, pregnant, or undergoing reproductive cycling at the time. A search of detailed feeding data on the animals provided by a previous Roehampton PhD, showed that one plant was the most likely cause of the observed progestogen increases- the African black plum, Vitex doniana.

"Laboratory tests I then conducted at Roehampton showed that this plant contained phyto-progestogens not present in other food items eaten by the animals," said James.

"This plant also happens to be closely related to another species that is widely used in complementary medicine, and sold in health stores worldwide, for treating PMS, menopause, and other hormone-related women's issues. This plant, Vitex agnus castus, is commonly known as Chasteberry, or Monk's Pepper. The relationship of this plant to women's reproductive hormones has been known for thousands of years, and is mentioned in Homer's The Iliad."

The effects of the increased progesterone levels on those baboon females that were undergoing reproductive cycling were dramatic. Because of their high levels of progesterone, females stopped cycling. In addition, progesterone is known to prevent _expression_ of the bright red swellings that the females of baboons and other primate species famously exhibit at certain times of the month.

"These swellings are very important in mediating the social aspects of reproduction in this species, and without these swellings males show little sexual interest in females. The seasonal consumption of this plant therefore appeared to act on females as both a physiological contraceptive (simulating pregnancy), and a social contraceptive (preventing sexual swelling, and therefore reducing interest from males)."

Other issues covered by James's PhD research included an investigation into the relationship between ovulation and sexual swellings. The ‘honesty' of sexual swellings in reliably indicating ovulation to males is a key question in evolutionary signalling theory, and this particular element of James's research won a Primate Society of Great Britain prize at a recent conference. James's is now continuing his research into primate ecology with a Post-Doctoral Research Fellowship in the Centre for Research in Evolutionary Anthropology.

Research students working on non-human primates in the Centre for Research in Evolutionary Anthropology undertake a fascinating range of projects often involving a combination of fieldwork, observing animals in the wild, or in captivity, combined with analyses back in Roehampton laboratories.

Current PhD students are working in Brazil, Puerto Rico and Nigeria as well as on European zoological collections. Species of interest range from mouse lemurs and baboons, to the golden-backed uacari, a previously unstudied Amazonian monkey. Together with others doing a Masters in Research (MRes), who've worked in Uganda, the Democratic Republic of Congo, South Africa, Madagascar, Indonesia and Thailand, as well as nearer to home in Gibraltar and France, our primatology students are very well travelled. They are developing research skills in a wide range of environments aimed at furthering understanding of some of our nearest relations, and working towards improving their conservation or their welfare in captivity.

Note: This story has been adapted from a news release issued by Roehampton University