Gabriela Becker1, Indiara Brusco2, Rosana Casoti3, Marila Crivellaro Lay Marchiori4, Letícia Cruz4, Gabriela Trevisan5, Sara Marchesan Oliveira6. 1. Neurotoxicity and Psychopharmacology Laboratory, Graduate Program in Biological Sciences: Biochemistry Toxicology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, RS, Brazil. Electronic address: saramarchesan@ufsm.br. 2. Neurotoxicity and Psychopharmacology Laboratory, Graduate Program in Biological Sciences: Biochemistry Toxicology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, RS, Brazil. 3. School of Pharmaceutical Sciences of Ribeirão Preto - University of São Paulo (FCFRP-USP), Ribeirão Preto, SP, Brazil. 4. Laboratory of Pharmaceutical Technology, Graduate Program in Pharmaceutical Sciences, Health Sciences Center, Federal University of Santa Maria, Santa Maria, RS, Brazil. 5. Graduate Program in Pharmacology, Health Sciences Center, Federal University of Santa Maria, Santa Maria, RS, Brazil. 6. Neurotoxicity and Psychopharmacology Laboratory, Graduate Program in Biological Sciences: Biochemistry Toxicology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, RS, Brazil. Electronic address: saramarchesan@hotmail.com.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Copaiba oleoresin, extracted from Copaifera L., is used as a wound healing, analgesic, antimicrobial and, mainly, anti-inflammatory agent. Thus, in this study we investigated the antinociceptive and anti-inflammatory effects of a topical formulation containing Copaiba oleoresin (3%) in a UVB radiation-induced skin burn model (0.75 J/cm2) in mice and performed a cream-formulation stability study. MATERIALS AND METHODS: The chemical composition of Copaiba oleoresin was analyzed using gas chromatography (GC-MS). The topical antinociceptive (evaluated through mechanical allodynia and thermal hyperalgesia) and the anti-inflammatory (dermal thickness and inflammatory cell infiltration) effects of treatments were assessed. The cream-formulation stability study was performed after two months, and organoleptic characteristics, pH, spreadability and rheological characteristics were analyzed. RESULTS: Copaiba oleoresin cream was able to prevent UVB radiation-induced mechanical allodynia on the 2nd, 3rd and 4th day after UVB radiation exposure with a maximum inhibition (Imax) of 64.6 ± 7% observed on the 2nd day; it also reduced the thermal hyperalgesia on the 1st and 2nd days post UVB radiation, with a Imax of 100% observed on the 2nd day. Moreover, topical treatment with Copaiba oleoresin cream inhibited the inflammatory cell infiltration, but did not reduce the dermal thickness. Such effects can be attributed, at least in part, to the presence of biological components, such as β-caryophyllene and other sesquiterpenes identified by GC-MS. CONCLUSION: Our results demonstrate that the topical formulation containing Copaiba oleoresin presented antinociceptive and anti-inflammatory effects in mice subjected to a UVB radiation and that the cream-formulation was stable for two months. Thus, use of Copaiba oleoresin is a promising strategy for the treatment of inflammatory pain associated with sunburn.
ETHNOPHARMACOLOGICAL RELEVANCE: Copaiba oleoresin, extracted from Copaifera L., is used as a wound healing, analgesic, antimicrobial and, mainly, anti-inflammatory agent. Thus, in this study we investigated the antinociceptive and anti-inflammatory effects of a topical formulation containing Copaiba oleoresin (3%) in a UVB radiation-induced skin burn model (0.75 J/cm2) in mice and performed a cream-formulation stability study. MATERIALS AND METHODS: The chemical composition of Copaiba oleoresin was analyzed using gas chromatography (GC-MS). The topical antinociceptive (evaluated through mechanical allodynia and thermal hyperalgesia) and the anti-inflammatory (dermal thickness and inflammatory cell infiltration) effects of treatments were assessed. The cream-formulation stability study was performed after two months, and organoleptic characteristics, pH, spreadability and rheological characteristics were analyzed. RESULTS:Copaiba oleoresin cream was able to prevent UVB radiation-induced mechanical allodynia on the 2nd, 3rd and 4th day after UVB radiation exposure with a maximum inhibition (Imax) of 64.6 ± 7% observed on the 2nd day; it also reduced the thermal hyperalgesia on the 1st and 2nd days post UVB radiation, with a Imax of 100% observed on the 2nd day. Moreover, topical treatment with Copaiba oleoresin cream inhibited the inflammatory cell infiltration, but did not reduce the dermal thickness. Such effects can be attributed, at least in part, to the presence of biological components, such as β-caryophyllene and other sesquiterpenes identified by GC-MS. CONCLUSION: Our results demonstrate that the topical formulation containing Copaiba oleoresin presented antinociceptive and anti-inflammatory effects in mice subjected to a UVB radiation and that the cream-formulation was stable for two months. Thus, use of Copaiba oleoresin is a promising strategy for the treatment of inflammatory pain associated with sunburn.