Biologic Pathways Affected by Acupuncture in Rats Also Targeted by Drugs in Humans

JULY 25, 2015—New research on acupuncture in animal models suggests that the ancient Chinese therapy stimulates the same biologic pathways activated by pain and stress, similar to the way drugs work in humans. This new study from researchers at Georgetown University Medical Center (GUMC), published July 21 in the journal Endocrinology, offers the strongest evidence to date on the relationship between acupuncture and chronic stress.

“The benefits of acupuncture are well known by those who use it, but such proof is anecdotal. This research, the culmination of a number of studies, demonstrates how acupuncture might work in the human body to reduce stress and pain, and, potentially, depression,” said the study’s senior investigator, Ladan Eshkevari, PhD, CRNA, LAc, associate professor in the department of nursing and the department of pharmacology and physiology.

Eshkevari and her team found that applying a specific technique with electroacupuncture (ensuring equitable and consistent distribution of electro stimulation) to a single but powerful acupuncture point — stomach meridian point 36 (St36) — blunts activity in the hypothalamus pituitary adrenal (HPA) axis. As the chronic stress pathway also associated with chronic pain, the immune system, mood and emotions, dialing HPA down via acupuncture reduced production of stress hormones that are involved in the chronic stress response.

“Some antidepressants and anti-anxiety drugs exert their therapeutic effects on these same mechanisms,” Eshkevari said. The study was co-authored by Susan E. Mulroney, PhD, and Rupert Egan, both from GUMC, and Lixing Lao, PhD, from the University of Hong Kong.

In previous research where Eshkevari mimicked the benefit experienced by individuals who have acupuncture regularly, she found that treating rats with acupuncture before subjecting them to cold-induced painful stress reduced the amount of HPA hormones they produced. In her new study, Eshkevari looked at the benefit of receiving acupuncture during a stressful event — “which is how acupuncture is most often utilized clinically.” She found that electroacupuncture administered at St36 minutes after painful cold exposure was as effective in minimizing the production of stress hormones as receiving acupuncture ahead of time.

The study, which was supported in part by the American Association of Nurses Anesthetists (AANA) doctoral fellowship award to Eshkevari, focused on four different groups of rats. In addition to a control group that was not exposed to stress or acupuncture, there were three stress groups that received either acupuncture through electroacupuncture; sham acupuncture (delivered in an area that is not an acupuncture point); and a placebo group that did not receive any acupuncture. As part of the study, Eshkevari used a drug to block acupuncture’s manipulation of the HPA system, and found that production of stress hormones equalized in all treatment groups, confirming that electroacupuncture affects the HPA system.

Behavioral and protein analyses indicated that acupuncture appears to prevent stress induced release of hormones, as well as decrease depression and anxiety-like behavior in the rats. “This is the first report linking the effects of electroacupuncture at St36 to chronic stress induced depressive and anxious behavior in animals,” Eshkevari said.

“We have now found a potential mechanism, and at this point in our research, we need to test human participants in a blinded, placebo controlled clinical study — the same technique we used to study the behavioral effects of acupuncture in rats,” Eshkevari said. “This work provides a framework for future clinical studies on the benefit of acupuncture, both before or during chronic stressful events.”

Renee Twombly and Kat Zambon 
GUMC Communications