Evaluation of the Effects of Chronic Administration of Citrus aurantium Essential Oil on the Development of Tolerance and Dependence to Morphine

Background: Long-term exposure to opioids may lead to physical dependence and tolerance. The purpose of this study was to investigate the effects of Citrus aurantium essential oil (CEO) on the morphine-induced tolerance and dependence. Methods: To evaluate morphine tolerance, the experiments were carried out in 6 rat groups (n=8) in the weight range of 225-275 g. The control group received morphine (10 mg/kg/day) and the test groups received morphine with the different doses of essential oil (CEO 20, 40 and 80 mg/kg/day) or 4 mL/kg of essential oil vehicle (KolliphorÒ HS15 30% in normal saline that adjusted in pH=7.4 with phosphate buffer) intraperitoneally. The hot-plate test was carried out every other day, 90 minutes after the injections. To examine morphine withdrawal, male Wistar rats were divided into seven groups (n=8) randomly, including: morphine sulphate, CEO (20, 40 and 80 mg/kg) + morphine, vehicle of CEO + morphine. The rats were rendered morphine-dependent by injection of additive doses of morphine subcutaneously for 9 days. The procedure of the morphine administration was as following protocol: day1: 5 mg/kg/12h, day 2 and 3: 10 mg/kg/12h, day 4 and 5: 15 mg/kg/12h, day 6 and 7: 20 mg/kg/12h and day 8 and 9: 25 mg/kg/12h. In the 9th day, 2 hours after the last dose of morphine, naloxone (4 mg/kg) was injected intraperitoneally. Some withdrawal behaviors were counted for 60 minutes. Results: Morphine tolerance was completed after 5 days in the control group. The vehicle group showed tolerance on the 9th day (p-value=0.991), 20mg group in the 13th day (p-value to control=0.010, to vehicle=0.049), 40 mg group on the 15th day (p-value to control and vehicle<0.001) and 80 mg group on the 13th day (p-value to control= 0.001, to vehicle= 0.007). The results showed that CEO could reduce the morphine withdrawal syndrome and total withdrawal score (TWS). Intraperitoneally injection of CEO in two doses (40 mg/kg with p<0.001 and 80 mg/kg with p<0.01) significantly reduced the TWS in comparison to the morphine+vehicle treated group. Conclusion: The results indicated that chronic administration of C. aurantium essential oil extracted had beneficial effects in reducing morphine withdrawal syndrome and could significantly delay tolerance to morphine

Determination of triamterene in human plasma and urine after its cloud point extraction

A new analytical approach was developed involving cloud point extraction (CPE) and spectrofluorimetric determination of triamterene (TM) in biological fluids. A urine or plasma sample was prepared and adjusted to pH 7, then TM was quickly extracted using CPE, using 0.05% (w/v) of Triton X-114 as the extractant. The main factors that affected the extraction efficiency (the pH of the sample, the Triton X-114 concentration, the addition of salt, the extraction time and temperature, and the centrifugation time and speed) were studied and optimized. The method gave calibration curves for TM with good linearities and correlation coefficients (r) higher than 0.99. The method showed good precision and accuracy, with intra- and inter-assay precisions of less than 8.50% at all concentrations. Standard addition recovery tests were carried out, and the recoveries ranged from 94.7% to 114%. The limits of detection and quantification were 3.90 and 11.7 µg L-1, respectively, for urine and 5.80 and 18.0 µg L-1, respectively, for plasma. The newly developed, environmentally friendly method was successfully used to extract and determine TM in human urine samples