As the applicant notes, herbal medicines are part of folk medicine in developing and developed countries and have been used extensively to reduce pain and discomfort. Unfortunately, very little controlled research has been conducted to determine whether these agents actually produce analgesia, their possible sites and mechanisms of action, and their efficacy and potency relative to known classes of analgesic agents. The major hypothesis of this proposal is that purified components of herbal medicines have potential as analgesic and antihyperalgesic agents and their efficacy and potency can be evaluated using animal models of inflammatory persistent pain.
The first aim i s to characterize the efficacy of systemic administration of active components of some herbal medicines in a rat model of inflammatory pain and hyperalgesia. The investigators will use their well-characterized model if inflammation to examine the effects of these active components on pain and hyperalgesia that persists for hours or days. This model will also distinguish between analgesic and antihyperalgesic activity.
The second aim i s to investigate the possible sites of action of agents that have analgesic efficacy by administering these agents to the site of inflammation or to localized sites in the central nervous system. In this instance the investigators will be examining whether these agents have actions in the periphery at the zone of injury, or in the control nervous system at sites of hyperexcitability and sensitization.
The third aim will be to compare the efficacy and potency of active components of herbal medicines with known antihyperalgesic and analgesic agents. The principal investigator and his collaborators will compare the relative potency of active components of herbal medicines to known opioids, excitatory amino acid antagonists, neurokinin receptor antagonists and nonsteroidal antiinflammatory agents. The investigators will also administer herbal-derived agents in combination with specific antagonists of analgesia (e.g., naloxone) to reveal possible mechanisms of action.
| Wei, F; Zou, S; Young, A et al. (1999) Effects of four herbal extracts on adjuvant-induced inflammation and hyperalgesia in rats. J Altern Complement Med 5:429-36 |
