Effect of Thunbergia laurifolia Extract on Cerebral Blood Flow in Rats
Watchareewan Thongsaard PhD*, Amporn Jariyapongskul PhD*, Chonticha Areebambud MSc**
Affiliation : * Department of Physiology, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand ** Biomedical Science Program, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand
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.
Keywords : Cerebral blood flow, Mean arterial blood pressure, Thunbergia laurifolia
