Development of standardization parameters of Costus speciosus rhizomes with special reference to its pharmacognostical and HPTLC studies

Abstract

ObjectiveTo study sailent diagnostic pharmacognostical characters of the rhizomes of Costus speciosus along with their phytochemical analysis, physicochemical parameters fluorescence characteristics and HPTLC studies. MethodsFresh rhizome and dried powder sample of the rhizomes were studied macro- morphologically and microscopically. Preliminary phytochemical investigation of plant material and WHO recommended parameters for the standardization were also performed. HPTLC method for the quantification of diosgenin in the ethanolic extract of Costus speciosus rhizomes was also established. ResultsThe rhizome shows a special type of periderm called “Storied Cork”. It consists of several, normally oblong, tangentially stretched, thin walled phellom cells. There are numerous vascular bundles scattered throughout the cortical zone. Each bundle has a cluster of four or five narrow angular xylem elements and a smallest of phloem elements. Stelar portion has less distinct endodermis and pericyclic layers and central scattered vascular bundles. Calcium oxalate crystals of rhomboidal, cuboidal and cylindrical in shape are common in the ground parenchyma cells. The prismatic crystals are 10 μm wide and the druses are 20-30 μm wide. The preliminary phytochemical screening of the rhizomes shows the presence of steroids, saponin glycosides and sugars. In HPTLC studies the Rf value of diosgenin was found to be 0.61. Linearity was found to be in the concentration range of 600 to 1800ng/spot and the correlation coefficient value is 0.9934. The results of analysis were validated in terms of accuracy and precision. The LOD and LOQ were found to be 5.69 ng and 17.25 ng/spot respectively. ConclusionsThe pharmacognostical and HPTLC profile of the rhizomes of Costus speciosus will assist in standardization for quality, purity and sample identification.