Indian Journal of Experimental Biology Vol.53, January 2015, pp. 36-43 Phytochemical and antimicrobial activities of Himalayan Cordyceps sinensis (Berk.) Sacc. Mamta 1 , Shubhi Mehrotra 2 , Amitabh 1 , Vandana Kirar 1 , Praveen Vats 1 , Shoma Paul Nandi 2 , PS Negi 3 & Kshipra Misra 1 * 1 Defense Institute of Physiology and Allied Science, Timarpur, Delhi, 110 054, India 2 Amity Institute of Biotechnology, Amity University, Sector 125, Noida, 201 303, India 3 Defence Institute of Bio-energy Research, Haldwani, Nanital (Uttarakhand), 263 139, India Received 07 March 2014; revised 09 December 2014 This study evaluated the phytochemical and antimicrobial activities and also quantified bioactive nucleoside using high performance thin layer chromatography (HPTLC) of five extracts of Indian Himalayan Cordyceps sinensis prepared with different solvents employing accelerated solvent extraction (ASE) technique. The phytochemical potential of these extracts was quantified in terms of total phenolic and total flavonoid content while antioxidant activities were determined by 1,1-diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric-reducing antioxidant power (FRAP) assays. Total reducing power (TRP) was determined by converting iron (III) into iron (II) reduction assay. CS 50%Alc (15.1+ 0.67mg/g of dry extract) and CS 100%Alc (19.3 + 0.33mg/g of dry extract) showed highest phenolic and flavonoid content, respectively while CS Aq extract showed maximum antioxidant activity and the highest concentration of the three nucleosides (adenine 12.8±0.49 mg/g, adenosine 0.36±0.28 mg/g and uracil 0.14±0.36 mg/g of dry extract) determined by HPTLC. The evaluation of extracts for antimicrobial activity against gram-negative and gram-positive bacterial strains showed CS 25%Alc, CS 75%Alc and CS 100%Alc extract to be more effective against E. coli, P. aerugenosa and B. subtilis giving 9, 7 and 6.5 mm of zone of inhibition (ZOI) in 93.75, 93.75 and 45 µg concentration, respectively, whereas CS Aq extract showed minimal inhibition against these. Keywords: Antimicrobial activity, Antioxidant, Bioactive nucleoside, Caterpillar fungus, Herbal Oxidative stress is associated with increased production of oxidizing species or significant decrease of antioxidants and is involved in various human diseases such as in cellular necrosis, cardiovascular disease, cancer, neurological disorder and even aging 1 . Non-toxic antioxidants from natural sources, especially medicinal plants are known to prevent oxidative damage caused by free radical and are rich in polyphenolics and bioactive compounds 2 . Phenolic compounds are one of the most widely available groups of phytochemicals found in plants and possess antioxidant and several health promoting activities. There are studies which have clearly shown that medicinal plants can protect the human body against both oxidative stress and pathogenic bacteria due to their inherent antioxidant and antimicrobial properties 3 . Hence, it is important to characterize and evaluate the medicinal herbs responsible for antioxidant and antimicrobial potential. Medicinal mushrooms or mushroom extracts have been traditionally used for centuries in China and Japan as herbal medicines because they possess large amount of essential amino acid, nucleotides, important minerals, vitamins and large contingent of enzymes etc. Cordyceps sinensis is one of such medicinal fungi, belongs to clavipitaceae family and genus ascomycete. It is an entomogenous fungus that parasitizes the larva of the moth and this entire fungus and larva combination results in unique profile of secondary metabolites which is used for medicinal purposes 4 . C. sinensis is found in the alpine region of the Himalayan at an altitude of more than 3500 meters 5 in India, China, Tibet, and Yunnan. The known pharmacological and biological actions of C. sinensis are mainly due to its bioactive polysaccharides, modified nucleosides —————— *Correspondence: Tel.: +91-11-23883303; Fax: +91-11-23914790 E-mail: kmisra99@yahoo.com Abbreviations: ABTS, 2,2’-azino-bis (3-ethylbenzothiazoline-6- sulphonic acid); ASE, Accelerated Solvent Extraction; CSE, Cordyceps sinensis extracts; CS Aq , C. sinensis aqueous extract; DPPH, 1,1-diphenyl-2-pycryl-hydrazyl; FRAP, ferric reducing antioxidant power; TE, trolox equivalent; TPTZ, 2,4,6-tripyridy-s- triazine; TRP, Total reducing power; ZOI, zone of inhibition.