Evidence for the involvement of TNF-α, IL-1ß and IL-10 in the antinociceptive and anti-inflammatory effects of indole-3-guanylhydrazone hydrochloride, an aromatic aminoguanidine, in rodents.

BACKGROUND: Indole-3-guanylhydrazone hydrochloride (LQM01) is a new derivative of aminoguanidine hydrochloride, an aromatic aminoguanidine. METHODS: Mice were treated with LQM01 (5, 10, 25 or 50 mg/kg, i.p.), vehicle (0.9% saline i.p.) or a standard drug. The mice were subjected to carrageenan-induced pleurisy, abdominal writhing induced by acetic acid, the formalin test and the hot-plate test. The model of non-inflammatory chronic muscle pain induced by saline acid was also used. Mice from the chronic protocol were assessed for withdrawal threshold, muscle strength and motor coordination. LQM01 or vehicle treated mice were evaluated for Fos protein. RESULTS: LQM01 inhibits TNF-α and IL-1ß production, as well as leukocyte recruitment during inflammation process. The level of IL-10 in LQM01-treated mice increased in pleural fluid. In addition, LQM01 decreased the nociceptive behavior in the acetic acid induced writhing test, the formalin test (both phases) and increased latency time on the hot-plate. LQM01 treatment also decreased mechanical hyperalgesia in mice with chronic muscle pain, with no changes in muscle strength and motor coordination. LQM01 reduced the number of Fos positive cells in the superficial dorsal horn. This compound exhibited antioxidant properties in in vitro assays. CONCLUSIONS: LQM01 has an outstanding anti-inflammatory and analgesic profile, probably mediated through a reduction in proinflammatory cytokines release, increase in IL-10 production and reduction in neuron activity in the dorsal horn of the spinal cord in mice. GENERAL SIGNIFICANCE: Beneficial effects of LQM01 suggest that it has some important clinical features and can play a role in the management of 'dysfunctional pain' and inflammatory diseases.

New perspectives for chronic pain treatment: a patent review (2010-2016).

INTRODUCTION: Chronic pain is a major problem of public health worldwide and is responsible for the increase in health costs. The therapeutic options available in the market for the treatment of chronic pain are often rather ineffective due to; the high number of adverse reactions, tolerance and dependence, reducing the quality of life, pharmacotherapy adherence and functional capacity. Hence, several studies have been conducted in the search for new treatment alternatives for chronic pain syndromes. Areas covered: This review brings together the therapeutic patents published over the past six years reporting the discovery of new drugs for the treatment of chronic pain, based on the perspective that these compounds are candidates for the management of chronic pain conditions. Expert opinion: Over the past 6 years, several pharmaceutical companies, as well as universities and researchers, have synthesized a series of compounds, which have been shown to be effective in controlling chronic pain in preclinical studies. These findings nurture the hope of discovering new therapeutic options for chronic pain. However, such studies are in early stages and there is a long and hard path to be followed until these compounds can become chemical entities available to the public.