euscaphic-acid and Pain

The Rubus species has been used in folk medicine to treat several ailments, including infectious and dolorous diseases. In this work we evaluate the phytochemical and analgesic activity of hydroalcoholic extract (HE), some fractions (hexane, dichloromethane, ethyl acetate and butanolic), as well as a pure compound denoted as 28-methoxytormentic acid (1) obtained from aerial parts of R. rosaefolius. The compounds were isolated and identified by chromatographic and spectroscopic analysis. The antinociceptive action was evaluated by two well know models of pain in mice: writhing and formalin induced-pain. The results showed that the HE, fractions and compound (1), exhibits potent and dose-related analgesic activity when evaluated in both models of pain. Compound (1), which seems to be the main active principle, showed promising analgesic effects, being several times more potent than aspirin and paracetamol, two well-known analgesic and antiinflammatory drugs used as reference. In the writhing test, it showed an ID(50) of 5.10 (3.64-7.14) mg kg(-1) and maximum inhibition (MI) of 64.22%. When analyzed by formalin induced-pain test, this compound showed ID(50) values of 9.98 (8.08-12.31) and 6.31 (5.07-7.98) mg kg(-1) and MI of 59.37 and 90.37% for the first and second phases, respectively. The results justify, at least partially the popular use of this plant for the treatment of dolorous processes, suggesting that 1 is one of the active principles of this plant.

Topics: Analgesics, Non-Narcotic; Animals; Male; Mice; Pain; Pain Measurement; Plant Components, Aerial; Plant Extracts; Rosaceae; Triterpenes

Experiments were designed to address whether the pentacyclic triterpene tormentic acid isolated from the stem bark of the plant Vochysia divergens exerts oral anti-allodynic properties in two models of chronic pain in mice: neuropathic pain caused by partial ligation of the sciatic nerve and inflammatory pain produced by intraplantar injection of Complete Freund's Adjuvant. Oral administration of tormentic acid (30 mg/kg) twice a day for several consecutive days produced time-dependent and pronounced anti-allodynia effect in both ispsilateral and contralateral paws after plantar injection of Complete Freund's Adjuvant. The inhibition observed was 82+/-9% and 100+/-11%, respectively. Interestingly, tormentic acid did not inhibit paw oedema formation following Complete Freund's Adjuvant plantar injection. Tormentic acid (30 mg/kg, p.o.) and gabapentin (70 mg/kg, p.o.), given twice a day, inhibited markedly the neuropathic allodynia induced by partial ligation of the sciatic nerve, with inhibition of 91+/-19% and 71+/-16%, respectively. The anti-allodynic action of tormentic acid was not associated with impairment of the motor activity of the animals. Together, the present results indicate that tormentic acid or its derivatives might be of potential interest in the development of new clinically relevant drugs for the management of persistent neuropathic and inflammatory allodynia.

Topics: Acetates; Amines; Analgesics; Animals; Chronic Disease; Cyclohexanecarboxylic Acids; Female; Freund's Adjuvant; Gabapentin; gamma-Aminobutyric Acid; Inflammation; Ligation; Male; Mice; Motor Activity; Pain; Peripheral Nervous System Diseases; Phytotherapy; Plant Bark; Plant Extracts; Sciatic Nerve; Time Factors; Touch; Triterpenes