HPLC analysis of diosgenin in three species of Costus

G Sulakshana, A Sabitha, Rani
2014 unpublished
Medicinal plants form an essential part of indigenous pharmaceutical system. Costus species (Family: Costaceae), commonly called as spiral ginger or crepe ginger are important medicinal plants used in traditional system of medicine in India. These plants are used for their stimulant, carminative, diuretic, digestive and antiseptic properties. Some of the species of Costus are mainly used for treating diabetes. Species of Costus are known to contain a steroidal saponin-diosgenin as a major
more » ... in as a major bioactive component, which is utilized as a precursor for the synthesis of various drugs. The present study is taken up to quantify the amount of diosgenin present in rhizomes and leaves of three species of Costus (C.pictus, C.speciosus and C.igneus) using HPLC analysis. Introduction Higher plants are the source of numerous chemicals of commercial significance. They have impressive biological properties and are employed in various systems of traditional and folk medicine. In recent years, there is a great demand for plant-based products because of broad biological activities, low impact on environment and safety to non-target organisms. During last few decades, many plant species were screened and plants with high bioactive compounds were identified. Species of Costus are important medicinal plants with a source of anti-diabetic and antimicrobial compounds. The genus Costus is a tropical herbaceous plant belonging to the family Costaceae. The species of Costus are widely employed in folk, ayurvedic and homeopathic systems of medicine [1] . Some of the commonly used species in unani and ayurvedic systems of medicine are C. speciosus Koen., C.pictus D.Don. and C.igneus N.E.Br. The C.pictus and C.igneus are referred as insulin plants [2] . Costus species are perennial rhizomatous herbs with erect or spreading stems. Leaves are simple, smooth, persistent, spirally arranged on stems. Hence these plants are often referred as the spiral ginger. The leaves are sub sessile and appear dark green in colour, elliptic or obovate in shape. In case of C.igneus, the leaves have light purple undersides whereas C.speciosus had silky texture beneath. The inflorescence is a spike around 10 cms long with large bracts in sub terminal position. Bracts are ovate or mucronate forming a cone like structure. Bracts are bright red coloured in C.speciosus and flowers are white in colour, 5-6 cm long with a cup-shaped labellum and crest yellow stamens. Bracts are green in colour in C.pictus and C.igneus but flower colour varies. Flowers of C.pictus are yellow with red stripes whereas in C.igneus they are orange in colour. Fruit is an ellipsoidal capsule. Costus is traditionally used as a medicinal herb mainly for its stimulant, carminative, diuretic, digestive and antiseptic properties. The rhizome is used internally in the treatment of abdominal pain, chest pains, liver problems, jaundice, gall bladder pain etc [3] . The rhizomes are the major source of diosgenin, which is anti-diabetic in nature and is used in the treatment of diabetes mellitus [4] [5] . In Ayurveda, Costus speciosus is used to subdue vata and kapha and promotes complexion. It is reported to cure dyspepsia, fever, cough and other respiratory disorders. It is one of the constituent of indigenous drug "amber mezhugu" useful in rheumatism [6] . The rhizome posses antifertility, anticholinestrase, anti-inflammatory and antihelminthic activities [7] . Essential oil from rhizome showed antimicrobial activity [8] . Antifungal activity of steroid saponins and sapogenins from Costus speciosus was analysed by [9] . In siddha medicine system C. igneus root has been used in the form of powder (chooranam), decoction (kudineer) and oil (thylam) [10] . Dasgupta and Pandey (1970) reported diosgenin as the major constituent isolated from rhizomes of Costus speciosus [5] . Other constituents isolated from Costus species are Tigogenin, dioscin, gracillin β-sitosterol glucoside [11] . In the earlier studies, diosgenin was isolated from tubers of Dioscorea zingiberensis cell cultures by microplatespectrophotometry and HPLC analysis [12] . Preliminary screening and qualitative HPTLC separation of secondary metabolites was reported from the rhizome of Costus speciosus [13] . In the present work, diosgenin content was quantified from rhizomes and leaves of three species of Costus using HPLC method.