Antidepressant-like Activity of Andrographis paniculata in Type-2

Andrographis paniculata (Burm. F.) Wall. Ex Nees (Family: Acanthaceae), commonly known as Kalmegh or ‘‘King of Bitters”, is one of the many traditionally known medicinal plants listed in WHO herbal Monograph [1]. It is a rich natural source of bioactive labdane diterpinoids like andrographolide, neoandrographolide, isoandrographanolide, andrograpanin, etc. Amongst them andrographolide is quantitatively the major easily extractable secondary metabolite of the plant [2]. Diverse types of andrographolide containing Andrographis paniculata extracts have been reported to possess broad spectrums of pharmacological activity profiles potentially useful for treatments of diabetes and obesity [3-5], liver disorders [6], inflammatory diseases [7] etc. Beneficial effects of some such extracts for symptomatic relief of upper respiratory tract infections [8] and other disorders have also been observed in clinical trials. Reports revealing brain functions modulating, immunostimulating, and nootropics like efficacies of such extracts suggest that Andrographis paniculata could as well be another adaptogenic herb potentially useful for combating mental health problems commonly associated with chronic diseases. In a very first report indicating such possibilities sedative and some other unspecific brain function altering activities of fairly high acute intra-peritoneal doses of an extract of the plant in rodent models were described [9], and in another more recent report appearing after more than a decade the effects of daily doses of another such extracts as immunostimulant, cerebroprotective and nootropic agents in normal and type-2 diabetic rats was described [10]. However, no analytical data or standardization protocols for the extracts used for the studies were mentioned in both these reports, and no attempts were made to detect their potential antidepressants or anxiolytics like therapeutic potentials. Similar, or analogous, have also been the cases for numerous other reports describing diverse therapeutic potentials of different types of extracts obtained from this traditionally known medicinal plant. More recent efforts made in our laboratories to define the psychopharmacological activity profile of an analytically well standardizes and therapeutically used Andrographis paniculata extract (AP), highly enriched in andrographolide (>30% w/w), were the very first ones revealing its therapeutic potentials for treatments of depression, anxiety, and other psychopathologies characterized by exaggerated symptoms of both anxiety and depression [11,12].