Desenvolvimento de nanogel de Copaifera reticulata (copaíba) e comparação da fonoforese e uso tópico em reparo de lesão muscular esquelética de ratos wistar

Abstract

Medicinal plants are routinely used by traditional populations. Copaiba (Copaifera reticulata Ducke) oleoresin is often used to treat inflammations; however, it is not easily absorbed by the skin in its natural form. The nanoemulsion of copaiba oil, with its hydrophilic properties and nanometric particles, enhances β-Caryophyllene permeation through the transdermal barrier. The low viscosity of the nanoemulsion can be overcome by combining it with hydrogels (Carbopol®) to improve topical use to treat inflammation. The form of presentation of the active ingredient in the formulation determines skin permeation, with nanoemulsions being the most effective form. Low-frequency ultrasound, by means of phonophoresis, is an important resource that enhances skin permeability of therapeutic substances such as oils obtained from plants with anti-inflammatory properties and nanoemulsions. The objective of this study was to analyze the effect of the C. reticulata Ducke oleoresin in its natural form and of its nanoemulsion gel (nanogel), applied topically or combined with phonophoresis, on muscle repair in Wistar rats submitted to traumatic injury. A copaiba nanoemulsion was prepared with 5% copaiba oil, 5% Polysorbate 80, and 90% water. The nanoemulsion obtained in five replications was incorporated into the CarbopolR in concentrations of 20% nanoemulsion and 80% CarbopolR. The study adhered to all ethical principles regarding the experimental use of animals. Twenty-four animals (males, ± 300g, ± 60 days of life) were submitted to injury to the right gastrocnemius muscle by direct impact with a metal cylinder (267g). After this procedure, the animals were randomly divided into the following groups with 4 rats each: G1 (control), G2 (topical oleoresin), G3 (topical nanogel), G4 (ultrasound), G5 (oleoresin with phonophoresis) and G6 (nanogel with phonophoresis). The treated groups were submitted to five sessions. To analyze muscle repair, blood samples were collected for measurement of the plasma enzymes Aspartate Aminotransferase (AST) and Creatine Kinase (CK) on the 2nd and 6th days after muscle injury. Statistical analysis included Student's t test (intragroup) and ANOVA followed by Tukey’s post hoc test (intergroup), both with significance of p≤0.05. The results showed a significant reduction in AST in G2 (p=0.0314), G5 (p=0.0222), and G6 (p=0.0314) and in CK in G2 (p=0.0176) and G6 (p=0.0396). When compared to G1 on the 6th day after injury, G2, G5, and G6 presented greater AST reductions (p=0.0155). Therefore, the topical application of the oleoresin and of the nanogel, combined with phonophoresis, were efficient in repairing skeletal muscle