Overview of Phytochemistry and Pharmacology of Nilakanthi (Ajuga bracteosa Wall. ex Benth.)

Human beings from prehistoric period are mainly dependent on mother nature for the fulfilment of their elementary needs, such as medicines, foodstuffs, shelters, clothing, flavors and fragrances, etc. From ancient times, medicinal plants are known to act as a source of a variety therapeutic agents which are widely used in traditional medicine system to cure the various deteriorative diseases and ailments. The wide range of therapeutic applications of various medicinal plants is largely attributed to the presence of a variety of bioactive secondary metabolites (SMs), such as alkaloids, terpenoids, steroids, flavonoids, polyphenolic acids, saponins, tannins, glycosides and essential oils etc. Apart from a variety of traditional uses, medicinal plants are also well known for their notable pharmacological potential like anticancer, antiperiodic, antimicrobial, analgesic, antiemetic, antitumor, antioxidant, antiinflammatory, antiarthritic, etc. Ajuga bracteosa Wall. ex Benth (A. bracteosa), commonly known as Nilakanthi in Ayurveda belongs to the family Lamiaceae, is an important endangered medicinal plant of Himalayan origin. A. bracteosa is a good source of flavanol, glycosides, ergosterol, neo-clerodane diterpenoids, iridoid glycosides, 8-endoperoxide and phyto-ecdysones, which shows numerous biological and pharmacological activities viz. antiviral, antitumor, antimicrobial, antiplasmodial, anti-inflammatory, antiarthritic, antioxidant, etc. Further, variety of A. bracteosa leaves uses had been elaborately described in Ayurveda, Unani and Chinese medicine text, for the treatment of numerous ailments like agues, dysentery, vomiting etc. The plant is also known for its antivenom potential against snake bite. A. bracteosa is an endangered and medicinally high valued Himalayan species that why it is very significant to reveal its full potency. Therefore, the present article mainly focuses on the distribution, cultivation, traditional uses, phytochemistry, pharmacological potential and future prospective of this versatile Himalayan plant.

Keywords: Ajuga bracteosa, Himalayas, Medicinal plant, Pharmacology, Phytochemistry, Secondary metabolites, Traditional uses.