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Research article - Vol. 25, 2019 |
Effects of copaiba oil on dermonecrosis induced by Loxosceles intermedia venom
1 Laboratory of Pharmacology; Department of Pharmacy and Pharmaceutical Administration; School of Pharmacy; Fluminense Federal University; Niterói - RJ, Brazil.
2 Laboratory for Cellular Proliferation and Differentiation; Institute of Biomedical Sciences; Federal University of Rio de Janeiro; Rio de Janeiro, RJ, Brazil.
3 Laboratory for Veterinary Clinical Pathology; Department of Pathology and Veterinary Clinics; School of Veterinary Medicine; Fluminense Federal University; Niterói - RJ, Brazil.
4 Laboratory of Physiochemical Quality Control; Department of Pharmaceutical Technology; School of Pharmacy; Fluminense Federal University; Niterói - RJ, Brazil.
5 Laboratory of Arthropods; Scientific Directorship; Vital Brazil Institute; Niterói - RJ, Brazil.
6 Biotherium; Scientific Directorship; Vital Brazil Institute; Niterói - RJ, Brazil.
ABSTRACT
Background:
Accidents caused by spiders of the genus Loxosceles constitute an important public health problem in Brazil. The venom of Loxosceles sp induces dermonecrosis at the bite site and systemic disease in severe cases. Traditional medicine based on plant-derived products has been proven to reduce the local effects of envenomation. The present study verified the healing effects of copaiba oil on lesions induced by the venom of L. intermedia.
Methods:
Cutaneous lesions were induced on the backs of rabbits by intradermal injection of L. intermedia venom. Copaiba oil was applied topically 6 hours after injection; the treatment was repeated for 30 days, after which animal skins were removed and processed for histopathological analysis. Blood samples were also collected before and 24 hours after venom inoculation to measure the hematological parameters.
Results:
Compared to the control group, the platelet count was reduced significantly in all groups inoculated with venom, accompanied by a decreased number of heterophils in the blood. The minimum necrotic dose (MND) was defined as 2.4 μg/kg. Topical treatment with copaiba oil demonstrated a differentiated healing profile: large skin lesions were observed 10 days after venom inoculation, whereas formation of a thick crust, without scarring was observed 30 days after venom inoculation. Histopathological analysis showed no significant difference after treatment. Nevertheless, the copaiba oil treatment induced a collagen distribution similar to control skin, in marked contrast to the group that received only the spider venom injection.
Conclusions:
We conclude that copaiba oil may interfere in the healing process and thus propose it as a possible topical treatment for cutaneous lesions induced by L. intermedia venom.
Keywords: Loxosceles intermedia; venom; skin lesion; copaiba oil; topical treatment
Received: August 23, 2018.
Accepted: February 01, 2019.
Correspondence: marafernandesribeiro@gmail.com
Competing interests The authors declare that they have no competing interests.
Authors' contributions MFR carried out the conception and design of the study, the acquisition, analysis and interpretation of the data and the drafting of the manuscript. FLO carried out analysis and interpretation of data and helped to draft the manuscript. PFC, APS and ASN participated in acquisition of data, histological analysis and interpretation of data. AMS and TBM participated in experimental design and helped draft the manuscript. CMVS conceived the study, and participated in its design and coordination. SCE conceived the study, and participated in its design and coordination and helped to draft the manuscript. All authors read and approved the final manuscript.