This study is an initial investigation into the traditional (folk) medicine practice of using Solenace plants for pain relief. Solenace plants that will be investigated include: Atropa belladonna, Datura Stramonium, Mandragoras officinarum, Hyoscyamos niger and Solanum nigrum; each have documented use for pain relief in folk medicine. The psychoactive properties of these plants are largely attributed to concentrations of anticholinergic tropane alkaloids such as atropine, scopolamine, hyoscyamine, hyoscine and atroscine. In order to investigate the application of extracts from Solenace plants for pain relief, rat pain models will be employed, which will allow for assessment of the efficacy of these plants for pain relief beyond folk applications. Solenace plant extracts will be produced and analyzed to identify and quantify alkaloids and to determine dose-response characteristics of any alkaloid derived pain alterations. In addition to systemic, the effects of intrathecal extract administrations will be tested in three pain paradigms: hot-plate, tail-flick, and formalin tests, as spinal cholinergic circuitry has been implicated in pain responsivity. Extract and alkaloid induced alterations in pain responsivity will also be tested in animals receiving lesions of the rostral ventrpmedial medulla, a key supraspinal pain locus featuring dense muscarinic cholinergic innervation. This study will also examine the pain alterations caused by non-cholinergic hallucinogens, to determine whether changes in pain responsivity seen caused by extracts and alkaloids result from their hallucinogenic properties. Based on the results of these studies, a further investigation will focus on the development of new assays that test aspects of pain responsivity that may not be assessed by current paradigms. Together, the proposed studies will provide specific information regarding the viability, effects, and routes of action of extracts from Solenace plants in analgesic applications, and may contribute to the development of novel treatments for pain relief in humans.
