Asparagus racemosus--ethnopharmacological evaluation and conservation needs

Asparagus racemosus Willd. (Asparagaceae) is an important medicinal plant of tropical and subtropical India. Its medicinal usage has been reported in the Indian and British Pharmacopoeias and in traditional systems of medicine such as Ayurveda, Unani and Siddha. Asparagus racemosus is mainly known for its phytoestrogenic properties. With an increasing realization that hormone replacement therapy with synthetic oestrogens is neither as safe nor as effective as previously envisaged, the interest in plant-derived oestrogens has increased tremendously making Asparagus racemosus particularly important. The plant has been shown to aid in the treatment of neurodegenerative disorders and in alcohol abstinence-induced withdrawal symptoms. In Ayurveda, Asparagus racemosus has been described as a rasayana herb and has been used extensively as an adaptogen to increase the non-specific resistance of organisms against a variety of stresses. Besides use in the treatment of diarrhoea and dysentery, the plant also has potent antioxidant, immunostimulant, anti-dyspepsia and antitussive effects. Due to its multiple uses, the demand for Asparagus racemosus is constantly on the rise; however, the supply is rather erratic and inadequate. Destructive harvesting, combined with habitat destruction in the form of deforestation has aggravated the problem. The plant is now considered 'endangered' in its natural habitat. Therefore, the need for conservation of this plant is crucial. This article aims to evaluate the biological activities, pharmacological applications and clinical studies of Asparagus racemosus in an attempt to provide a direction for further research. Keeping in mind the fact that it is the active principle that imparts medicinal value to a plant; consistency in quality and quantity needs to be maintained to ensure uniform drug efficacy. Also, deliberate or inadvertent adulteration needs to be dealt with at an early stage. To overcome these prevalent problems, the availability of genetically superior and uniform planting material is essential. This can be obtained by a combination of various biotechnological tools involving chemoprofiling, tissue culture and use of molecular markers. Along with the application of these methods, proper agro-techniques and adequate marketing opportunities would encourage cultivation of Asparagus racemosus and thereby contribute to its conservation. There are also several gaps in the existing literature with regard to the pharmacological actions of Asparagus racemosus. These include an incomplete understanding about the interaction/synergy between Asparagus racemosus and other plant constituents in polyherbal formulations; lack of information regarding the mode of action of the various constituents of Asparagus racemosus, etc. Consequently, we have suggested a 'systems biology' approach that includes metabolite profiling, metabolic fingerprinting, metabolite target analysis and metabonomics to enable further research.