Phytochemical and Pharmacological Studies on some Cyperus plants

Abstract

Cyperus belongs to family Cyperaceae which comprises about 700 specieswidely used in traditional medicine. The rhizomes and tubers of C. rotundus were used as a herbal remedy to treat bowel and stomach disorders in several countries including China, India, Iran, and Japan.Also they were used in perfumes, spices, and ayurvedic remedies in Arab countries, Africa, China, and India. The tubers of Egyptian C. esculentuswere used as pectoral and emollient for the inflamed breasts of suckling mothers and the ash of Egyptian C. papyrus wasused in healing wounds and preventing the malignant ulcers from spreading in the mouth or elsewhere. The preliminary phytochemical screening of Cyperuslaevigatusaerial parts showed the presence of flavonoids, carbohydrates and / or glycosides, sterols and /or triterpens, tannins, saponins and volatile oils. The assessment of total phenolic and total flavonoid contents confirmed that the aerial parts of C. laevigatus L. are rich with phenolic compounds and flavonoids with a value 288.91 ± 5.77 GAE/g and 117 ± 9.63 quercitinequivelant/g respectively. The methanol fraction was fractionated on polyamide column chromatography using H2O:EtOH in order of decreasing polarities to give eight major fractions which were purified on Sephadex LH-20 eluted with aqueous ethanol of different polarities to give a new flavonoid,chrysoeriol 7-O-6'''-O-acetyl-β-D-glucopyranosyl-(1→4) glucopyranoside along with other six known compounds: luteolin7-O-β-glucopyranoside, apigenin 7-O-β-glucopyranoside, chrysoeriol 7-O-β-glucopyranoside, luteolin, apigenin and chrysoeriol. The analysis of the essential oil by chromatography/mass spectrometry (GC-MS) led to the identification of sixty five compounds where terpenesrepresent the major constituents (77.78%), including monoterpenes (59.14%), sesquiterpenes (10.5%), and diterpenes (8.14%). The lipoidal matter of Cyperuslaevigatusaerial parts was analysed bygas chromatography where the major components of unsaponifiable matter were heneicosane (25.5%), nonadecene (18.2%), eicosene (10.7%), nonadecane (9.0%), eicosane (8.9%) and docosane (5.0%). While the major constituents of the saponifiable matter were E-octadec-8-enoic acid (31.8%), nonadecanoic acid (18.9%), heptadecanoic acid (11.2%), E-hexadeca-8-enoic acid (10.2%), docosanoic acid (3.3%), linoleic acid (2.6%) and eicosatetraenoic acid (2.5%). The DPPH radical scavenging assay showed that the total extract and methanol fraction had moderate anti-oxidant activities. The total extract, methanol fraction and ethyl acetate fraction showedanti-inflammatory activitywhere the NO% accumulation decreased with increasing sample concentration (12.5, 25, 50, 100 µg/ml) with values ranging from 76 – 66%, 84 – 67% and 77 – 66% respectively. The histopathological study of the pancreas, liver and kidney of diabetic rats treated with intragastricC. laevigatusmethanol showed dramatic decrease in all abnormal histological changes as compared to the diabetic group. The diabetic groups treated with C. laevigatus methanol fraction showed decrease in serum levels of glucose, glucagon and nitric oxide while the serum levels of insulin and the serum paraoxonase activity were increased. The EtOAc and CH2Cl2 fractions showed a significant anti-microbial activities against Gram positive bacteria Staphylococcus aureus, Bacillus subtilisand the yeast, Candida albicansranging between 10-20 μg/disc and a weak anti-microbial activity against the Gram negative bacteria Escherichia coli and Pseudomonas aeruginosain comparison with the positive controls thiamphenicol and nystatin