Anti-hyperalgesic effect of (-)-α-bisabolol and (-)-α-bisabolol/ß-Cyclodextrin complex in a chronic inflammatory pain model is associated with reduced reactive gliosis and cytokine modulation.

Chronic pain is a continuous or recurring pain which exceeds the normal course of recovery to an injury or disease. According to the origin of the chronic pain, it can be classified as inflammatory or neuropathic. This study aimed to evaluate the antinociceptive and anti-inflammatory effect of (-)-α-bisabolol (BIS) alone and complexed with ß-cyclodextrin (ßCD) in preclinical models of chronic pain. Chronic pain was induced by Freund's Complete Adjuvant (FCA) or partial lesion of the sciatic nerve (PLSN). Swiss mice were treated with BIS, BIS-ßCD (50 mg/kg, p.o) or vehicle (control) and mechanical hyperalgesia, thermal hyperalgesia, muscle strength and motor coordination were evaluated. In addition, levels of TNF-α and IL-10 and expression of the ionized calcium-binding adapter protein (IBA-1) were assessed in the spinal cord of the mice. The complexation efficiency of BIS in ßCD was evaluated by High-Performance Liquid Chromatography. BIS and BIS-ßCD reduced (p < 0.001) mechanical and thermal hyperalgesia. No alterations were found in force and motor coordination. In addition, BIS and BIS-ßCD inhibited (p < 0.05) TNF-α production in the spinal cord and stimulated (p < 0.05) the release of IL-10 in the spinal cord in PLSN-mice. Further, BIS and BIS-ßCD reduced IBA-1 immunostaining. Therefore, BIS and BIS-ßCD attenuated hyperalgesia, deregulated cytokine release and inhibited IBA-1 expression in the spinal cord in the PLSN model. Moreover, our results show that the complexation of BIS in ßCD reduced the therapeutic dose of BIS. We conclude that BIS is a promising molecule for the treatment of chronic pain.

Actividad in vitro anti-Leishmania (Trypanosomatidae) del epóxido trans-Z-&-bisaboleno y del Safrol, en frutos de Piper auritum (Piperaceae) / Anti-Leishmania (Trypanosomatidae) activity of trans-Z-&-bisabolene epoxide and isolation of safrole, in fruits of Piper auritum (Piperaceae)

Resumen La leishmaniasis es una enfermedad con una alta incidencia en el ser humano, que puede ser controlada, pero como los tratamientos tienen efectos secundarios importantes se han realizado estudios de diversas plantas con el fin de encontrar compuestos con actividad antileishmaniásica que presenten pocos efectos nocivos para el ser humano. El presente estudio consistió en realizar un tamizaje fitoquímico de la planta, para identificar la presencia de cumarinas, terpenos, triterpenos y azúcares reductores. El objetivo fue encontrar componentes químicos puros con actividad contra el parásito Leishmania sp. Por tal razón se purificaron los compuestos: trans-Z-alfabisaboleno y el Safrol, a los que se les realizaron pruebas del efecto anti parasitario que presentaron un CI50 de 50.0 µg/mL y 0.0 µg/mL, respectivamente. Además, se discute la importancia de estos nuevos hallazgos. El compuesto mayoritario presente en los aceites esenciales (Safrol) no es el componente que presentó la actividad. Es importante realizar estudios sobre su proyección en el tratamiento de la leishmaniasis.

Abstract The leishmaniosis disease incidence is high in tropical regions, and its current treatment has shown severe secondary effects. Considering this problem, many studies have focused on plants, looking for chemical components that have anti-leishmanial activity, and are free of adverse effects for human beings. The purpose of this work was to find a chemical component with this kind of activity in Piper auritum. In a phytochemical screening of this plant, we found some cumarins, terpens, triterpens and reducing sugars; and later, we identified the components trans-Z-α-bisabolene epoxide and Safrol. The first component presented a CI50 of 50.0 µg/mL of anti-Leishmania activity. The Safrol, which is the major component of the essential oils of this plant, did not show antiparasitic activity. These results are discussed considering treatment of leishmaniasis. Rev. Biol. Trop. 66(2): 826-835. Epub 2018 June 01.