Pharmacology STUDY OF THE ANTI-IINFLAMMATORY ACTIVITY OF SOME MEDICINAL EDIBLE PLANTS GROWING IN EGYPT N. M. AMMAR* S. Y. AL OKBI** D. A. MOHAMED** SUMMARY: Several edible plants are used in traditional medicine for the treatment of inflammatory condi- tions. The anti-inflammatory activity of some bioactive fractions isolated from the seeds of Trigonella foenum groecum, L., the roots of Glycyrrhiza glabra, L. and the fruits of Coriandrum sativum, L. were determined using the carragenan induced oedema method in comparison with two reference synthetic anti-inflammatory drugs. The petroleum ether and the aqueous methanolic extract of fenugreek and liquorice as well as the whole pow- dered fruit of coriander in a dose of 200 mg/kg exhibited a significant reduction in the volume of inflammation with variable degreeses. The same active dose from the three plants also inhibited prostaglandins E2 levels in a range of 55-64%. Chromatographic fractionation of the bioactive components revealed the isolation of unsatu- rated fatty acids and flavonoids in the three plants, while saponins were only present in fenugreek and liquorice. The anti-inflammatory activity may be attributed to the presence of the forementioned bioactive compounds. Key Words: Anti-inflammatory, medicinal, edible plants. INTRODUCTION The severe side effects of steroidal and nons- L., family Leguminosae, (Fenugreek) and the fruits of teroidal anti-inflammatory drugs evoked us to search Coriandrum sativum L., family Umbelliferae (Coriander). for new anti-inflammatory agents from natural botanical The anti-inflammatory activity of liquorice has been sources which may have minimal drawbacks. studied and still current research is being carried out by Our review of 'folk medicine' indicated that many some authors (1-2). The majority of literature deals plants possessing an anti-inflammatory activity were only with the activity of the the aqueous extract and its sometimes consumed by humans. These were the roots main component, glycyrrhizin. The anti-inflammatory of Glycyrrhiza glabra, L., family Leguminosae activity of fenugreek seeds have been reported (3), the (Liquorice), the seeds of Trigonella foenum groecum, authors noticed only the topical anti-inflammatory activ- ity of the aqueous alcoholic extract on treating Aphthus *From Department of Pharmaceutical Sciences, National Research ulcers and attributed its activity to the presence of Center, Dokki, Cairo, Egypt. **From Department of Nutrition, National Research Center Dokki, triterpenoid saponins. Scanty literature concerning the Cairo, Egypt. anti-inflammatory effect of coriander fruits were avail- Journal of Islamic Academy of Sciences 10:4, 113-122, 1997 113 ANTI-INFLAMMATORY ACTIVITY OF SOME PLANTS AMMAR, AL OKBI, MOHAMED able, only the topical anti-inflammatory activity of glyc- 5. Chemicals Used for Induction of Inflammation erol-ethanol extract of coriander fruits was studied and λ-Carrageenan, type IV (Sigma, USA) Carrageenan is a polysaccharide isolated from two species Girgartina aciculaire proved to be successful (4). So we decided to extend and G. pistillata, which grow together in the sea. Carrageenan our study to include the systemic anti-inflammatory is prepared by dissolving 0.05 gm in 5ml distilled water. activity of several bioactive fractions isolated from the three aforementioned plants in comparison with two METHODS reference synthetic anti-inflammatory drugs. The aim of 1. Preparation of Plants for Phytochemical Studies the present work is to evaluate their anti-inflammatory The three plants were separately air dried, reduced to No. activity on the induced acute inflammation using car- 36 powder and kept in tightly closed containers. 500 g of the dried powder of each plant under investigation were placed in rageenan model in experimental rats, in addition, the a continuous extraction apparatus and subjected to succes- measurement of PGE will be carried out. 2 sive extraction using petroleum ether (60°-80°C) then 50% aqueous methyl alcohol. For each organic solvent the extrac- MATERIALS tion was continued till no residue was obtained when small 1. Plant Materials aliquot colourless extract was evaporated to dryness in a The plant materials used in this investigation consisted of: small glass watch. For each extract the solvent was com- The seeds of Trigonella foenum groecum, L., family Legumi- pletely removed by distillation under reduced pressure at a nosae, (Fenugreek), the roots of Glycyrrhiza glabra, L., family temperature not exceeding 40°C and dried to a constant Leguminosae (Liquorice), and the fruits of Coriandrum weight in a vacuum dessicator over anhydrous calcium chlo- sativum L., family Umbelliferae (Coriander), which were col- ride. lected from Egyptian markets. All samples were authenticated by Miss Badia Hassan Diwan, Consultant of Taxonomy 2. Phytochemical Study of the Biologically Active Department of Systematic and Egyptian Flora, El-Orman Extracts Garden-Giza, Egypt. The solvent free petroleum ether and alcoholic extracts of each of the three plants were subjected to phytochemical 2. Materials for Chromatography examination using chemical and chromatographic methods. 1) Plates of silica gel 60 GF254 [0.25 mm. thickness, E. The extracts of the three plants were separately screened for Merk, Dermastadt, Germany] for TLC. the following constituents, carbohydrates and (glycosides, 2) Sheets of Whatmann filter paper No. 1 for Pc. tannins, flavonoids alkaloids and/or nitrogenous bases, 3) Sheets of Whatmann filter paper (3MM) for PPc. saponins unsaturated sterols and/ triterpenes, coumarins and volatile oils (5). 3. Animals White female albino rats of Sprague-Dawely strain of 150g 3. Chromatographic Investigation average body weight were used. The animals were kept indi- The bioactive extracts of the three plants were subjected vidually in wire bottomed cages at room temperature of to chromatographic identification using thin layer, paper, as 25±2°C and a relative humidity of about 55%. well as preparative layer chromatography. Sterols and triter- penes (5) were detected using the bioactive petroleum ether 4. Drugs (Synthetic anti-inflammatory agents) extract of the three plants separately by spotting an aliquot of Two reference anti-inflammatory drugs were used in our each sample on silica gel G plates using (benzene:ethanol) study. (19:1) as solvent system and detection was carried out by 1) Commercial name: Indomethacin, Chemical name: 1- vanillin sulphuric acid reagent followed by heating at 100°C for (4. Chlorobenzoyl)-(-methoxy-2-methylindol-3-yl) acetic acid 5 minutes. Saponins were isolated from the remaining aque- obtained from Pharco Pharmaceuticals Company. ous concentrate of liquorice and fenugreek after evaporation 2) Commercial name: Urbason retard, Chemical name of the bioactive hydromethanolic extract under vacuum at Methyl Prednisolon-6 α- methyl predinosolone 11 β, 17 α, 21- 60°C (6). The isolated saponin compounds from each plant Trihydroxy-6 α- methyl pregna-1,4-diene-3,20-dione, obtained were investigated by TLC on silica gel 'G' plates developed from Hochest Orient Company. with (n-butanol:acetic acid:water) (4:1:1) or (chloroform: 114 Journal of Islamic Academy of Sciences 10:4, 113-122, 1997 ANTI-INFLAMMATORY ACTIVITY OF SOME PLANTS AMMAR, AL OKBI, MOHAMED methanol:water) (65:40:10). The spots were visualized by volume meter immediately before the injection of carrageenan spraying with Modified Khagi Mishner reagent (7). Acid hydrol- and after 30 minutes, 1, 1.5, 2, 3 and 4 hours of carrageenan ysis of each saponin was carried out with 2N sulphuric acid. injection. The volume of inflammation in the hind paw volume The sapogenins isolated were detected by spotting on silical of rats given different anti-inflammatory agents was compared gel 'G' plates using [petroleum ether:benzene:ethyl with that of the control inflammed rats. acetate:acetic acid] [10:20:6:0.5] as solvent system and detected by spraying with Khagi Mishner reagent. Flavonoids 2) Determination of Prostaglandin E2 in Plasma of were detected and isolated in the three plants by spotting an Inflammed Rats: aliquot of the bioactive aqueous methanolic extract of each Plasma prostaglandin levels were determined nearly at the time of the best anti-inflammatory effect of the natural and separately on thin layer chromatography using silica gel GF254 as adsorbant development was carried out using (methanol: synthetic agent proved to have an anti-inflammatory activity chloroform) (8:2) or on paper chromatography using (n from the previous experiment. butanol-acetic acid-water) (4:1:5) as solvent system. The The same experiment of induction of inflammation was fluroescent spots were detected with aluminium chloride repeated using another rats of the same sex and body weight reagent under UV. The flavonoid glycosides were hydrolysed which were given only the low dose of the plant extract to their respective aglycones and sugars with 2N HCL. All the (200mg/kg). In this experiment the control inflammed groups isolated compounds were identified by physical and spectral contain twelve rats. A normal control group of 6 rats was analysis as well as co-chromatography with authentic samples added (where no injection of carrageenan or oral medication and comparison with reported literature. Sugars in all cases was given). Concerning reference drugs; only two groups of were detected by using Kieselguhr impregnated with Phos- rats were run where rats received one oral dose of 5 mg of phate buffer (pH 5) as adsorbant