Insights on the neuromodulatory propensity of Selaginella (Sanjeevani) and its potential pharmacological applications.

Exploiting the potential of natural compounds to attenuate endogenous redox status to achieve neuroprotection is a novel concept in human disease therapy. This has necessitated a need to identify newer efficient phytochemicals possessing propensity to act on various biochemical therapeutic targets with low or no toxicity. Selaginella is a lithophytic pteridophyte which grows on constantly irrigated rocks in high altitude zones in different parts of the world. It is appraised to be "Sanjeevani" (the resurrection herb) based on its mythological reference in the Indian epic "Ramayana". Due to the presence of a unique disaccharide, trehalose, most species of Selaginella can survive severe drought conditions, maintaining the plant's structural stability and resurrect during rains. Several species of the genus are used in ethnic medicine for the therapy of jaundice, chronic trachitis, lung cancer, labor pain and wound healing. The major natural compounds in the genus Selaginella are characteristic flavonoid-dimers, called 'biflavonoids'. Although various biological effects of Selaginella have been documented in vitro, studies on its neuromodulatory properties are nonexisting despite the presence of potentially therapeutic biflavonoids. We have reviewed the existing literature on the possible pharmacological properties of Selaginella. Further, recent evidence gathered from our laboratory on the neuromodulatory propensity of S. delicatula employing in vivo models of chemically induced neurodegenerative diseases in rodents and Drosophila are discussed. Our findings point to a mechanism which modulates redox status and mitochondrial dysfunction suggesting their possible therapeutic use in oxidative stress-mediated neurodegenerative diseases including Parkinson's disease.