Sistema de Eventos Acadêmicos da UFMT, XI Mostra da Pós-Graduação

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EFFECT OF NANOESTRUTURED COPAÍBA OIL IN THE ANTINOCICEPTION
Mariane Costa Silva, Stela Regina Ferrarini, Karoline Paiva da Silva, Norberto Cysne Coimbra, Ricardo De Oliveira

Última alteração: 09-10-19

Resumo


Copaíba (Copaifera Langsdorffii) is a native tree of South America and easily found in the region of the Amazonic rainforest. The oil extracted from that tree is widely used by the general population and several studies report that copaíba oil has anti-inflammatory, antiseptic, antimicrobial properties and also promotes antinociception. Thus, we hypothesised that copaíba oil causes an antinociceptive effect and that its nanostructured form may be more effective even at lower doses. The aim of the present work was to investigate the antinociceptive effect caused by nanostructured copaíba oil (COnano). Male Wistar rats (250grs) from the Central Laboratory of the Federal University of Mato Grosso were used. The copaibeira, from which the oil was extracted is located in the city of Itaúba, Mato Grosso, Brazil. Nociceptive thresholds were measured using the tail-flick test. Each animal was placed in a holding device and its tail was inserted into the heating sensor of an analgesimeter apparatus. The heating sensor operates in such a way that the progressive calorimetric elevation is automatically interrupted when the animal withdraws its tail from the apparatus. A small adjustment of current intensity could be performed at the beginning of the experiment to obtain three consecutive tail withdrawal latencies (TWL) between 2.5 and 3.5 seconds. The animals received COnano (0.5, 1 and 2 mg/kg) and copaíba oil (200mg/kg) by gavage, intraperitoneal injections of morphine (1mg / kg) or vehicle, and the TWL were recorded at 20,30,40,50,60 and 80 minutes after intragastric or intraperitoneal administration of drugs. The experiments were carried out according to the Ethics Committee for the use of Experimental Animals (CEUA23108.993820/2018-73). Data were submitted to  a two-way analysis of variance (MANOVA), followed by the Newman-Keuls post hoc test and significant differences were considered at p<0.05. Administration of COnano (2mg/kg - more effective dose) significantly increased the nociceptive thresholds at all times when compared to control [F(4,38) varying from 7.44 to 17.28; p<0.0001] and there was no significant effect at intermediate and low doses (Newman-Keuls, P>0.05 in all cases). According to MANOVA, there was a significant effect of treatment [F(4,31) = 7.437; p<0.001], of  time [F(8.248) = 23.93; p <0.0001] and of the interaction between treatment versus time [F(32.248) = 1.758; p<0.05]. There was a significant effect of copaiba oil (200mg/kg) in the time of 50 minutes [F(4,31) = - 0.9232; p <0.0001] after gavage. Morphine caused a significant antinociceptive effect, considering that there was an increase in nociceptive thresholds at all times [F(4,31) varying from 1,758 to 23,93; p <0.0001]. The data demonstrated that COnano at the dose of 2mg/kg increased the nociceptive thresholds significantly at all times, while free copaiba oil at the dosage of 200 mg/kg caused an increase only in the time of 20, 30 and 40 minutes after intragastric ingestion. These findings suggest that nanostructured copaíba oil are more suitable for phytotherapy with analgesic properties.


Palavras-chave


copaíba oil; antinociception; nanostructured