Laura Cabarga1,2, Gerard Batallé1,2, Olga Pol1,2. 1. Grup de Neurofarmacologia Molecular, Institut d'Investigació Biomèdica Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Catalunya, Spain. 2. Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Catalunya, Spain.
Abstract
BACKGROUND: Therapies to treat chronic neuropathic pain and its associated comorbidities are limited. Recent studies demonstrated that the administration of slow-releasing hydrogen sulfide (H2S) donors inhibited chemotherapy-induced neuropathic pain. However, the antidepressant or anxiolytic effects of these compounds and their mechanisms of action during chronic neuropathic pain have not been evaluated. AIMS: To determine whether the administration of two slow-releasing H2S donors, allyl isothiocyanate (A-ITC) and phenyl isothiocyanate (P-ITC), inhibits the nociceptive and emotional disorders associated with chronic neuropathic pain. METHODS: In C57BL/6 male mice with neuropathic pain caused by the chronic constriction of the sciatic nerve, we assessed the effects of intraperitoneal administration of A-ITC and P-ITC in (a) the mechanical allodynia, thermal hyperalgesia and thermal allodynia induced by nerve ligation; (b) the anxiety- and depressive-like behaviours linked with neuropathic pain; (c) glial activation and mitogen-activated protein kinases phosphorylation, and (d) expression of the antioxidant enzymes, heme oxygenase 1 (HO-1), NADPH quinone oxidoreductase1, and glutathione S-transferase mu-1 (GSTM1), and alpha-1 (GSTA1), in hippocampus and prefrontal cortex (PFC). RESULTS: Both treatments inhibited the allodynia and hyperalgesia, depressive-like behaviours, astroglial activation, and the extracellular signal-regulated kinase 1/2 phosphorylation but were unable to abolish the anxiety-like behaviours accompanying neuropathic pain. A-ITC and P-ITC also augmented the expression of HO-1, GSTM1, and GSTA1 in the hippocampus and/or PFC. CONCLUSIONS: The administration of slow-releasing H2S donors might be a promising treatment for the management of chronic neuropathic pain and some associated comorbidities via inhibiting the inflammatory and plasticity changes, and activating the endogenous antioxidant responses.
BACKGROUND: Therapies to treat chronic neuropathic pain and its associated comorbidities are limited. Recent studies demonstrated that the administration of slow-releasing hydrogen sulfide (H2S) donors inhibited chemotherapy-induced neuropathic pain. However, the antidepressant or anxiolytic effects of these compounds and their mechanisms of action during chronic neuropathic pain have not been evaluated. AIMS: To determine whether the administration of two slow-releasing H2S donors, allyl isothiocyanate (A-ITC) and phenyl isothiocyanate (P-ITC), inhibits the nociceptive and emotional disorders associated with chronic neuropathic pain. METHODS: In C57BL/6 male mice with neuropathic pain caused by the chronic constriction of the sciatic nerve, we assessed the effects of intraperitoneal administration of A-ITC and P-ITC in (a) the mechanical allodynia, thermal hyperalgesia and thermal allodynia induced by nerve ligation; (b) the anxiety- and depressive-like behaviours linked with neuropathic pain; (c) glial activation and mitogen-activated protein kinases phosphorylation, and (d) expression of the antioxidant enzymes, heme oxygenase 1 (HO-1), NADPH quinone oxidoreductase1, and glutathione S-transferase mu-1 (GSTM1), and alpha-1 (GSTA1), in hippocampus and prefrontal cortex (PFC). RESULTS: Both treatments inhibited the allodynia and hyperalgesia, depressive-like behaviours, astroglial activation, and the extracellular signal-regulated kinase 1/2 phosphorylation but were unable to abolish the anxiety-like behaviours accompanying neuropathic pain. A-ITC and P-ITC also augmented the expression of HO-1, GSTM1, and GSTA1 in the hippocampus and/or PFC. CONCLUSIONS: The administration of slow-releasing H2S donors might be a promising treatment for the management of chronic neuropathic pain and some associated comorbidities via inhibiting the inflammatory and plasticity changes, and activating the endogenous antioxidant responses.