Pakistani researchers tested a methanolic extract from the nootropic plant Bacopa monnieri (waterhyssop) for prospective antinociceptive effects. They showed that the B. monnieri extract could serve as a complementary therapy for cases of neuropathic pain that are complicated by allodynia and hyperalgesia.
The University of Peshawar supported this study. The findings were published in the scientific journal BMC Complementary and Alternative Medicine.
A chronic constriction injury (CCI) model was created using rats as test animals. Treated animals received 40 and 80 milligrams per kilogram (mg/kg) of B. monnieri extract every day. The positive control group received 75 mg/kg of the prescription drug gabapentin for comparison.
During the third, seventh, 14th, and 21st day, the rat behaviors of static- and dynamic-allodynia, cold allodynia, heat-hyperalgesia, and punctated-hyperalgesia were assessed.
Both doses of B. monnieri extract greatly reduced the effects allodynia and hyperalgesia in rats. The animals demonstrated higher paw withdrawal thresholds, paw withdrawal latency, and heat. They also showed lower paw withdrawal duration when stimulated by pinpricks and cold.
The extract also corrected the changes caused by CCI in the nociceptive behaviors of the rats. The B. monnieri treatment restored the animals' pain threshold to the normal levels before CCI.
The positive control group that received gabapentin showed greater levels of the same effects.
The researchers conclude that B. monnieri merits further studies in order to find out its precise means of blocking pain as well as to test its effectiveness on other neuropathic pain models. Likewise, its primary bioactive compound – bacoside-A – requires additional testing to determine its role and importance in alleviating neuropathic pain.
Shahid M, Subhan F, Ahmad N, Ullah I. A BACOSIDES CONTAINING BACOPA MONNIERI EXTRACT ALLEVIATES ALLODYNIA AND HYPERALGESIA IN THE CHRONIC CONSTRICTION INJURY MODEL OF NEUROPATHIC PAIN IN RATS. BMC Complementary and Alternative Medicine. 2017;17(1). DOI: 10.1186/s12906-017-1807-z.