β-Caryophyllene ameliorates the development of experimental autoimmune encephalomyelitis in C57BL/6 mice

Abstract

Multiple sclerosis is the most common autoimmune inflammatory and demyelinating disease of the central nervous system. The experimental autoimmune encephalomyelitis (EAE) is an appropriate and a well-establish model for studying the pathogenesis of MS. β-caryophyllene (BCP), a natural sesquiterpene found in many plant species, is a potent anti-inflammatory compound. Herein we investigated the in vitro and in vivo immunomodulatory effects of BCP on C57BL/6 mice induced with EAE. BCP was in vitro evaluated (4, 20, and 40μM) on splenocytes obtained from EAE-induced C57BL/6 mice, and in vivo (25 or 50mg/kg/day) orally administered on EAE-mice. The clinical course, body weight, cytokines and oxygen radicals production were investigated in C57BL/6 EAE-mice. In vitro and in vivo immunological responses were evaluated by ELISA, and CNS sections were stained by hematoxylin and eosin methods The in vitro production of H₂O₂, NO, IFN-γ, and TNF- α was inhibited by BCP (20 and 40μM) in cultured cells from EAE-mice. BCP (25 and 50mg/kg/day) reduced clinical score and severity of EAE and inhibited H₂O₂, NO, TNF-α, IFN-γ and, IL-17 production. EAE-mice, orally treated with BCP (mainly at 50mg/kg/day), displayed levels of cytokines and clinical signs similar to animals with no EAE disease, demonstrating the therapeutic action of BCP on EAE animals. Histopathological and histomorphometric analysis confirmed that BCP treatment significantly reduced the numbers of inflammatory infiltrates and attenuated neurological damages in the CNS of EAE-mice.

Keywords: Citokines; Experimental autoimmune encephalomyelitis; Multiple sclerosis; Natural products; β-Caryophyllene.