Comparative Evaluation of the Analgesic Effects of Pistacia atlantica Leaves, Gum, and Fruit Extracts in Rats

Background: Pistacia atlantica (PA) trees grow in all areas of Iran. Pistacia atlantica fruit is edible and mostly consumed by residents. Also, PA leaves, gum, and fruit are considered to have medicinal value in traditional medicine. Objectives: This study was designed to evaluate the analgesic effects of the hydroalcoholic extract of PA leaves, gum, and fruit. Methods: Seventy-two adult male Sprague-Dawley rats were divided into 12 groups, including control and test groups. In the positive control group, the rats received the standard drug paracetamol at a dose of 100 mg/kg, IP. In the test groups, the rats received leaves, gum, and fruit extracts at the doses of 25, 50, and 100 mg/kg, IP. Then, the rats were assessed for antinociception by the tail-flick and formalin tests. In this study, the ethical guidelines approved by the Ethics Committee of Shiraz University of Medical Sciences regarding the use of animals in experimental studies were followed. Results: The results showed that the leaves extract at the doses of 25 and 50 mg/kg and the gum extract at the dose of 100 mg/kg had a substantial analgesic effect, as demonstrated by the increase in the latency time in the tail-flick test and the decrease in the pain sensitivity in the formalin test (P < 0.05). The fruit extract, compared with the other parts of the plant, had no analgesic effect. Conclusions: The stronger analgesic effects of PA leaves extract, compared to those observed for the extracts of other parts of PA, might be due to the higher concentration of components with analgesic properties in PA leaves.