An antimalarial drug used in ancient Chinese medicine may be an effective treatment for polycystic ovary syndrome (PCOS), a groundbreaking study suggests.
The herbal extract artemisinin appears to stop the ovaries from producing too much testosterone, and women who took the drug for 12 weeks had more regular periods. The findings from the small trial by a Chinese team were hailed as a potential breakthrough that could lead to an entirely new approach to treating the condition, which affects around one in 10 women.
“It’s very rare that you get a brand new development in a very important condition, so this is huge,” said Dr Channa Jayasena, a clinical senior lecturer at Imperial College London, who was not involved in the research. “This is a tremendous potential breakthrough and really welcome, as women’s health problems have traditionally not received the attention that heart disease and cancer have.”
PCOS occurs when the ovaries produce too much testosterone. The hormonal imbalance hinders ovulation, which can lead to irregular periods and affect fertility. There are other wide-ranging health impacts, with many patients developing insulin resistance, which increases the risk of obesity, heart disease and diabetes. Higher testosterone levels can also cause excess facial hair and acne.
“The name [of the syndrome] makes it sound like it only affects the ovaries, which does a disservice to women,” Jayasena said. “It is a body-wide disease. You are more likely to have obesity, heart disease, excess hair, acne, as well as irregular periods and fertility problems.”
Current treatments include the birth control pill, which suppresses testosterone production and thus helps manage irregular periods and the cosmetic symptoms of PCOS. Fertility drugs or surgery can also help stimulate ovulation for women with PCOS who are unable to conceive. However, these treatments are not fully effective and are not suitable for everyone.
The latest study, published in Science, suggests that artemisinin blocks an enzyme called CYP11A1 that is essential for testosterone production in the ovaries. In a series of detailed experiments in mice and rats with a PCOS-like condition, scientists have shown that the drug reduces testosterone and restores fertility. “This is an excellent tour de force … the results are quite dramatic,” Jayasena said.
In patients, PCOS disrupts the ovulation cycle, which normally involves follicles in the ovary maturing in a conveyor belt fashion, with one follicle selected each month to fully mature and release an egg. In PCOS, follicles are overactive, meaning that many small follicles are maturing at the same time.
Prof Richard Anderson, the head of obstetrics and gynecology at the University of Edinburgh, said: “They get stuck in a traffic jam and instead of one going on to ovulate, they all stay in this state of partial development.” He said the results of the study looked “remarkably positive”.
In a pilot trial, 19 women with PCOS were given the artemisinin for 12 weeks. They had a significant reduction in hormone levels, an ultrasound scan showed a reduction in follicle activity, and regular periods were restored in 12 of the participants (63%), with no reported negative side effects.
Prof Qi-qun Tang, who led the research at Fudan University in Shanghai, said: “Based on our findings, artemisinins are promising candidates for the treatment of PCOS because they strongly inhibit ovarian androgen synthesis, reduce immature follicles and the [menstrual] cycle.”
The women’s periods remained regular in an extended 12-week follow-up after they stopped using the drug. “We are now extending this observation period to determine if there is a relapse after a longer period without the drug,” Tang said, adding that the team was fine-tuning the dose and timing of the medication with the aim on conducting a larger clinical trial.
Anderson said: “It looks very exciting and what’s interesting is that it’s a repurposing of a drug that’s been used for a long time. It has a great track record as a drug that people can take safely, so that’s a fantastic hurdle to overcome already.”
A larger trial would still be needed to determine any potential risks of using the drug for a long period of time. There is also a question as to whether the drug restores fertility. This can be a potential benefit, but there can also be serious risks to using a hormone-suppressing drug during pregnancy. “It can be a double-edged sword if it helps you get pregnant,” Jayasena said. “Then you have to show that it is safe during pregnancy.”
