Effect of Thunbergia laurifolia Extract on Cerebral Blood Flow in Rats

Abstract

Background: Thunbergia laurifolia Linn. (TL) is a herbal medicine which has been used as an antidote for several poisonous agents including insecticides and as a component of a mixture of crude extracts to treat drug addicted patients. The previous study using Functional Magnetic Resonance Imaging (fMRI) technique found that oxyhemoglobin: deoxyhemoglobin increased in amygdala, caudate and nucleus accumbens by TL. These areas represent reward and addiction behavior. Objective: The present study aim to investigate the direct effect of TL (100, 200 and 300 mg/kg) on cerebral blood flow, mean arterial blood pressure, partial pressures of oxygen and carbondioxide in normal rats. Material and Method: Methanol extract of TL (100, 200 and 300 mg/kg, n = 12 in all groups) was administered intraperitoneally to rats. Cerebral blood flow, mean arterial pressure, pH, PO2 and PCO2 were measured at 5 min before, 5, 10, 20 and 30 min after injection. Results: The results showed a significant increase in cerebral blood flow and mean arterial blood pressure in a dose-related manner, but partial pressures of oxygen and carbondioxide were not affected. Conclusion: The finding explains that TL cause the increase in oxyhemiglobin: deoxyhemoglobin by increasing cerebral blood flow and mean arterial blood pressure. © 2017 Medical Association of Thailand. All rights reserved.