Ginkgo extract delivered by mouth significantly reduces 'post-surgical type' pain sensitivity and inflammation, according to animal trials. And now a trial to investigate the pain pathways involved has found that the standardized extract (EGb 761) reduces inflammation and sensitivity to all but mechanical pain equally – whether injected locally into a sore paw or into the spinal canal.
In both cases, the ginkgo extract appears as effective as a commonly used nonsteroidal anti-inflammatory drug (NSAID) in reducing post-injury heat pain hypersensitivity (thermal hyperalgesia) and acute inflammation, say study leader Sharron Dolan, PhD, and colleagues at Glasgow Caledonian University, UK.
Their findings are reported in the May issue of Anesthesia & Analgesia.
The researchers used a standard technique to induce pain and inflammation in the paws of rats. They then compared the effects of treatment with EGb 761 and diclofenac - an NSAID commonly used to treat arthritis and other painful conditions.
These treatments were given in two different ways:
• Local injection into the painful, swollen paw
• And central (intrathecal) injection into the spinal canal.
At both injection sites, EGb 761 had significant pain-reducing effects.
• In reducing thermal hyperalgesia, it was just as effective as diclofenac.
• The ginkgo extract effectively reduced swelling in the paw, even when injected into the spinal canal.
However, EGb 761 had no effect on abnormal responses to mechanical stimuli, such as a pinprick (mechanical hyperalgesia). Diclofenac did reduce mechanical hyperalgesia.
The study also adds to the evidence suggesting that gingko extracts could play a useful role in treating some types of inflammatory pain.
More study is needed to further clarify how EGb 761 works, and to demonstrate the full range of its treatment and adverse effects.
Source: International Anesthesia Research Society news release, Apr 27, 2011