www.wjpr.net Vol 4, Issue 06, 2015. 445 Usama et al. World Journal of Pharmaceutical Research EFFECT OF THIRST STRESS ON THE PRODUCTION OF PHYTOCHEMICAL CONSTITUENTS OF RHAZYA STRICTA PLANT AND ANALGESIC ACTIVITY OF ITS BIOACTIVE FRACTIONS Usama Shaheen 1*,2 and Muhammad Ahmed 3 1 Department of Pharmacognosy, Faculty of Pharmacy, Umm Al-Qura University, Makkah, 21955, Saudi Arabia. 2 Department of Pharmacognosy, Faculty of Pharmacy, Al Azhar University, Cairo, Egypt. 3 Department of Pharmacology, Faculty of Pharmacy, Umm Al-Qura University, Makkah, 1355, Saudi Arabia. ABSTRACT Rhazya stricta Decne is an important folkloric medicinal plant used in Saudi Arabia and other countries of Arabian Peninsula to relieve various diseases. Alkaloids and flavonoids represent the most active secondary metabolites of this plant. Rain is the only source of water for desert wild plants. This search includes the estimation of total phenol, flavonoids, and alkaloids in two plant samples. Describing the effect of prolonged thirst on the production of these constituents in the plant and assessment of the analgesic activity of its different extracts. The total phenol and flavonoid contents were estimated using spectrophotometer assay by Folin-Ciocalteau and AlCl 3 reagents respectively. While the concentration of its alkaloids was determined spectrophotometrically through the formation of ion-pair complex with acidic dye (methyl orange), followed by measuring the absorbance of produced color at λmax 530 nm. Also, the analgesic activity of ethanol extract, alkaloid fraction, and phenol rich fraction were determined by hot plate test. The result of these assays found that the alkaloid content was decreased in the absence of rain while the phenol and flavonoid contents were increased by thirst in a long period of no rain. The ethanol extract (20 mg/kg) and Phenol fractions (10 and 20 mg/kg) were found to exhibit significant analgesic activity in comparison with the stranded. World Journal of Pharmaceutical Research SJIF Impact Factor 5.990 Volume 4, Issue 6, 445-455. Research Article ISSN 2277– 7105 *Correspondence for Author Usama Shaheen Department of Pharmacognosy, Faculty of Pharmacy, Umm Al- Qura University, Makkah, 21955, Saudi Arabia. Article Received on 04 April 2015, Revised on 24 April 2015, Accepted on 20 May 2015