Research notes

Garlic zaps migrating cancer cells

For the first time, researchers have shown that aged garlic extract hinders the migration of cancer cells, which is a critical feature of tumor cell movement.

Previous studies have shown that aged garlic extract suppresses cancer growth and enhances the immune system against cancer. Little was known about its ability to inhibit cancer cell migration.

In the lab, the researchers found that the garlic not only killed many of the rat cancer cells but also inhibited their movement, compared to a control group of cells.

Cancer cells will move across a laboratory dish, producing a visual trail, said study author Guang Hu, M.D., a clinical assistant professor of medicine.

The researchers measured the distance of trails left behind by cells that passed through varying amounts of garlic overnight. The average trail distance in the control group was 7.44 mm. But when treated with the highest concentration of extract (20 mg/ml), the distance dropped to 2.48 mm. The more garlic added, the greater its effect.

“The results suggest that garlic, as a natural plant, unlike other cancer treatment methods, may play a role in fighting cancer without significant side effects,” said the study authors.

“This was an interesting, but also intrinsic study,” said Hu. “The method can be adopted for other research.”

A high school student, Xiran Hu, led the research. She conducted the study at Providence College and at Children’s Hospital Boston. At the time, Xiran Hu was a senior at Bay View High School in East Providence. She is also Guang Hu’s daughter. They are two of the study’s six authors.

The findings appeared in the June issue of the International Journal of Molecular Medicine. Xiran Hu is now a sophomore at Wellesley College. – Scott J. Turner

Kicking the habit

More alcoholic smokers die prematurely from smoking than from alcohol use. The two habits are intertwined, often with other existing conditions such as depression.

A new Brown-led study may help improve ways to enhance smoking cessation among alcoholic smokers by shedding light on links among drinking, smoking and depression.

The research appears in the September issue of Psychology of Addictive Behaviors.

The researchers found that the length of time since last alcohol use and the degree of depressive symptoms both influenced an alcoholic smoker’s readiness to quit smoking. High levels of depressive symptoms seem to interfere with an alcoholic’s readiness to quit smoking, they said.

The study involved 253 alcoholic smokers already in outpatient alcohol treatment programs. It compared a behavioral treatment that included a motivational enhancement designed to increase readiness to quit smoking to a standard treatment. Each treatment also included a nicotine patch.

The findings suggest that providers who offer smoking-cessation treatment to alcoholics should “repeatedly assess the smoker’s depression level during treatment and treat the depression when warranted,” said lead author and research fellow Brian Hitsman.

The research was funded in part by the National Institute on Alcohol Abuse and Alcoholism and by the National Institute on Drug Abuse. Abrams also directs the Centers for Behavioral and Preventive Medicine, Brown Medical School and the Miriam Hospital. – Scott J. Turner

Douching, high-risk women and HIV

New findings about douching may throw a wrinkle into the more than 60 trials under way worldwide to test microbicides. Called “chemical condoms,” microbicides are topical gels designed to prevent vaginal transmission of HIV.

The study of 623 women at high risk for HIV infection found that close to three-quarters recently douched. From creating suitable products to monitoring for safety, many issues are considered when designing microbicide trials. But some important sex-related activities, such as the habit of douching, have not been amply examined among women most likely to become infected with HIV.

“Douching can affect a microbicide’s safety and effectiveness,” said Kenneth Mayer, M.D., one of the study authors and a microbicide investigator. “Finding that recent douching was very common may greatly influence the current trials of microbicides to protect against HIV in high-risk women. Given that microbicides act very differently, depending on the product, some products could be less effective than others for women who douche regularly or in connection with sex.”

The study appeared in the July issue of Sexually Transmitted Diseases. Its authors described how most of the subjects had been told at some point that douching was not healthy. This finding suggested that the practice of douching was learned early in life, via self-instruction, or from family members, the study authors said. Among the women, douching was persistent, and it could be difficult to alter through educational messages alone, they said.

“After new products are found to be safe in low-risk women, they (high-risk women) have to be studied in the circumstances in which their unprotected intercourse occurs,” said Mayer, professor of medicine and community health and head of the Brown University AIDS program. “To best evaluate the ultimate safety and effectiveness of each microbicide, high-risk women will have to be allowed to douche during efficacy trials.”

Douching is common in some cultures but most physicians discourage the practice. The vagina is an efficient self-cleaning organ, and douching can trigger a range of complications, say gynecologists.

The National Institute of Allergy and Infectious Diseases and Abt Associates were the primary funding sources for the study. – Scott J. Turner