Int. J. Pharm. Sci. Rev. Res., 39(2), July – August 2016; Article No. 17, Pages: 93-99 ISSN 0976 – 044X International Journal of Pharmaceutical Sciences Review and Research Available online at www.globalresearchonline.net © Copyright protected. Unauthorised republication, reproduction, distribution, dissemination and copying of this document in whole or in part is strictly prohibited. 93 Eman A. Ibrahim 1 , Doha H. Abou Baker 2 , Farouk K. El-Baz 1 * 1 Plant Biochemistry Department, National Research Centre (NRC), 33 EL Bohouth St. (Former EL Tahrir st.), Dokki, Giza, Egypt. 2 Medicinal and Aromatic Plant Department, National Research Centre (NRC), 33 El Bohouth St. (former El Tahrir st.), Dokki, Giza, Egypt. *Corresponding author’s E-mail: fa_elbaz@hotmail.com Accepted on: 02-06-2016; Finalized on: 31-07-2016. ABSTRACT Rhubarb (Rheum rhaponticum L.) is considered one of the commonly used edible and medicinal plant. This work was carried out to investigate the anti-inflammatory and antioxidant activities of Rhubarb roots extract. Total tannin, total phenolic and total flavonoid contents of ethanolic and water extracts as well as phenolic and flavonoid compounds were also determined in Rhubarb roots. The highest content of total tannin, phenolic and flavonoid were found in ethanolic extract. The major phenolic acids were benzoic and ferulic acids followed by vanillic acid, while the major flavonoid was narengine. The results indicated that the highest antioxidant and anti-inflammatory activities were found in ethanolic extract and highly correlated with phenolic content. The results of the current work indicated that ethanolic extract has the potential to be used as a natural anti- inflammatory and antioxidant. Keywords: Rhubarb roots, anti-inflammatory, antioxidant. INTRODUCTION hubarb is a perennial plant belonging to Polygonaceae. It also, considers a common vegetable known as sibiric Rhubarb. 1 This herbis a storehouse of a large number of important crude drugs. 2 Phytochemical investigation on Rhubarb has proved major bioactive ingredients arephenolic compounds in six skeletal type including anthraquinones (physcion, chrysophanol, emodin, aloe-emodin and rhein and their glucosides), anthocyanins (cyanidin 3-rutinoside and cyanidin 3-glucoside), flavonoids (catechin, quercetin 3-O- rhamnoside, quercetin3-O-galactoside, and quercetin 3- O-rutinoside), stilbene (trans-rhapontigenin and desoxyrhapontigenin (cis-rhapontigenin, resveratrol and piceatannol). 3 Rhubarb is well-known for its strong biological activities such ascathartic, anticancer, hepatoprotective, anti- inflammatory, anti-diabetic, analgesic, antiplatelet, antibacterial, anti-oxidative, and antimutagenic effects. 4- 11 Rhubarb roots are used as oriental laxative medicine and an antipsoriatic drug, also used against diarrhea, as well as stomachic, antiemetic, hemorrhoids, measles, smallpox and cholagogue. 12,13 Rhubarb also showed the protective effect against liver injury and fatty liver. 14-15 The purpose of the current work was to investigate the anti-inflammatory and antioxidant activities of Rhubarb roots extract. MATERIALS AND METHODS Preparation of Plant Extracts Rhubarb was purchased from local market in Egypt. The Rhubarb roots were extracted, briefly, 10 g of the dried powder were soaked with 100 ml water and 80% ethanol and shacked for 24 h at room temperature. The extraction was repeated twice and then filtered. The resulting of different extracts was used for the determination of total tannin, phenolic, flavonoid, as well as their anti-inflammatory and antioxidant activities. Quantitative Analysis Total Tannin Content Total tannin content was determined using the Folin- Ciocalteu reagent assay according to Tambe and Bhambar. 16 About 0.1 ml of Rhubarb roots extract or standard solutions of (tannic 20-120 mg/l) was added to 7.5 ml distilled water then 0.5 ml of Folin reagent and 1 ml of 35% sodium carbonate solution were added. The volume was made up for 10 ml with distilled water and the absorbance was measured against blank at 725 nm by using spectrophotometer. Total Phenolic Content Total phenolic in Rhubarb roots ethanolic and water extracts were determined by using Folin-Ciocalteu’s reagent. 17 The reaction mixture was prepared from mixing 0.5 ml of Rhubarb ethanol extract, 2.5 ml of 10% Folin-Ciocalteu’s reagent dissolved in water and 2.5 ml 7.5% NaHCO 3 . The mixtures were incubated in a thermostat at 45 o C for 45 min. The absorbance was spectrophotometrically recorded at 760 nm. Standard series concentrations of Gallic acid were prepared in ranges 2-12 µg/ml and treated as the samples. Total Flavonoid Content Total flavonoid content of Rhubarb roots extract was determined by the aluminum chloride method using quercetin as a standard. 18 0.2 ml of the extracts or standard solutions (quercetin, 20–120 mg/l) was mixed with 0.3 ml 5 % NaNO 2 . After 5 min, 0.3 mL of 10% AlCl 3 Anti-Inflammatory and Antioxidant Activities of Rhubarb Roots Extract R Research Article