Efeito anti-hiperalgésico do (-)-α-bisabolol e do complexo de inclusão (-)-α-bisabolol/β-ciclodextrina em modelos de dor crônica

• Ano de defesa: 2018
• Autor(a) principal: Fontinele, Laíza Lima
• Orientador(a): Quintans, Jullyana de Souza Siqueira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Ciências da Saúde
• Palavras-chave em Português: Ciências da saúde; Terpenos; Dor; Dor crônica; Inflamação; Citocinas; Dor neuropática; Microgliose
• Palavras-chave em Inglês: Terpenes; Neuropathic pain; Inflammation; Cytokines; Microgliosis
• Área do conhecimento CNPq: CIENCIAS DA SAUDE
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/8559

Chronic pain is a continuous or recurring pain, which exceeds the normal course of recovery to an injury or disease. According to the chronic pain origin it can be classified as inflammatory or neuropathic. The neuropathic pain is a type of chronic pain, characterized by abnormalities such as dysesthesia, hyperalgesia and allodynia, interfering the patient's quality of life and is difficult to treatment. In view of this, and considering that (-)-α-bisabolol (BIS) presents several promising pharmacological properties for the relief of this type of pain, this study aimed to evaluate the antinociceptive and anti-inflammatory effect of pure BIS and its complex of inclusion in β-cyclodextrin (β-CD) in preclinical models of chronic pain. Thus, the complexing efficiency of BIS and β-CD was investigated by means of High Performance Liquid Chromatography (HPLC). The Chronic pain models were induced by injection of CFA (25 μl; i.pl.) and partial lesion of the sciatic nerve (PNSL). The animals were evaluated for behavioral parameters: mechanical hyperalgesia, thermal hyperalgesia, muscle strength and motor coordination. In addition, we assessed the concentrations the cytokines of TNF-α and IL-10, the expression of the ionized calcium-binding adapter protein (IBA-1). Animals were treated with BIS and BIS/β-CD (50 mg/kg, p.o) or vehicle. The complexation efficiency (EE%) of BIS in inclusion complexes with β-CD is equal to 50% ± 0.19. From this result, it is inferred that the amount of BIS included in the β-CD cavity is less than 50 mg/kg. Then, by means of HPLC analysis and calculation of dose concentration, it was possible to determine that the amount of BIS in β-CD was about 5 mg/kg. Despite this difference in doses between BIS and BIS/β-CD, a significant reduction (p <0.001) in mechanical hyperalgesia was observed in both pain models studied, and a significant reduction (p <0.001) in thermal hyperalgesia in the model of DN. No alterations were found in muscle strength and motor coordination. In addition, both compounds inhibit (p <0.05) TNF-α production in the sciatic nerve and spinal cord and stimulate (p <0.05) the release of IL-10 in the spinal cord in PNSL induced-mice. Further, BIS and BIS/β-CD reduce IBA-1 immunostaining compared to vehicle treated-mice. Therefore, BIS and BIS/β-CD attenuates the hyperalgesia, misregulated the cytokines release and inhibit IBA-1expression in spinal cord in PNSL model. Therefore, the results show that BIS and BIS/β-CD have an antihyperalgesic effect in chronic inflammatory pain model and DN model and that this effect may be associated to the modulation of pro and anti-inflammatory cytokines and inhibition of microgliosis, which leads to decreased release of cytokines and hypersensitivity to noxious stimuli. These facts are currently considered as important therapeutic strategies for the treatment of DN. Thus, we can suggest that BIS and BIS/β-CD are promising molecules for the treatment of chronic pain such as neuropathic pain.