Pharmacognostical phytochemical and biological screening of dendrobium ochreatum

Abstract

The present thesis entitled Pharmacognostical, Phytochemical and Biological screening of newlineDendrobium ochreatum. orchids are generally used ornamentally throughout the world. Despite newlineof its folk medicinal use it has drawn less attentions to the researchers regarding their medicinal newlineproperties yet here an attempt has been made by focusing on the medicinal properties of the newlineDendrobium orchids. The Pharmacognostical and Phytochemical evaluation of different parts of newlineDendrobium ochreatum plant were performed in this work. The root is a typical root and in newlinetransverse section shows the features of an adventitious root i.e-Epidermis, Phloem and Xylem. newlineDifferent parts of the plants like root, stem and leaves were taken and were extracted with three newlinedifferent solvents i,e-Hexane, Chloroform and Ethanol in gradient elution techniques. Nine newlineextracts obtained this way were subjected for further studies. Different codes were assigned for newlinethose extracts eg-LHDO, LCDO, LEDO, SHDO, SCDO, SEDO,RHDO, RCDO, REDO (where newlineL stand for leaves S stands for stem, R stand for root, H stand for hexane, C stand for newlinechloroform, E stand for ethanol and DO means Dendrobium ochreatum). The plant extracts were newlinefree from microbial contamination. The preliminary phytochemical screenings of all nine newlineextracts were performed. The presence of alkaloids, flavonoids, terpenoids and tannins in various newlineextracts were observed. Only the chloroform extracts of stem showed presence of steroids. All newlinethe extracts were subjected to antioxidant study, From the DPPH assay, it was observed that newlineSCDO and REDO showed moderate free radical scavenging activity (IC50 172.27 and#956;g/ml) and newline(IC50 132.43 and#956;g/ml) respectively compared to standard ascorbic acid (22.89 and#956;g/ml) in newlinecomparison to other extracts. LHDO and RHDO showed very poor free radical scavenging newlineactivity. From ABTS assay same extracts (SCDO and REDO) showed moderate free radical newlinescavenging activity (IC50 140.06 and#956;g/ml) and (IC50 123.21 and#956;g/ml) respectively compared to newlinestandard ascorbic acid