Sajan et al. World Journal of Pharmaceutical Research www.wjpr.net Vol 9, Issue 01, 2020 1220 INVESTIGATION OF ANTI-BACTERIAL ACTIVITY OF CUPRESSUS TORULOSA LEAF EXTRACT Ramesh Raj Padhaya 1 , Suvechha Bhandari 2 , Mribha Manandhar 3 , Amrit Khanal 4 , Sajan Maharjan 5* 1 National Aurveda and Research Centre, Kirtipur, Kathmandu, Nepal. 2 JF Institute of Health Sciences/LACHS Affiliated to Institute of Medicine, Tribhuvan University. 3 Ohm Pharmaceuticals Pvt. Ltd, Tathali, Bhaktapur. 4 Ohm Hospital and Research Centre, Chabahil, Kathmandu, Nepal. 5 Central Institute of Science and Technology, New Baneshwor, Kathmandu, Nepal. ABSTRACT The aim of present study was to investigate antibacterial activity of Cupressus torulosa leaf extract. The dried material was extracted by using 3 different solvents namely methanol, hexane and ethyl actetate. Plant extracts were subjected to phytochemical screening which showed the presence of Alkaloid, Glycoside, tannins, carbohydrate and amino acids. In test for antibacterial activity against four microorganisms (Streptococcus pyogens, Acinetobacter calcoaceticus, Escherechia coli, Staphylococcus aureus), methanol extracts showed highest antibacterial activity whereas hexane extracts showed less activity. This activity was assessed by measuring the diameter of ZOI of four concentrations used. ZOI was larger in 200ug/ml and least in 25ug/ml concentration of extracts. The largest zone of inhibition (15mm) was obtained with S.pyogens in methanol extract. When hexane extract was used, largest ZOI was 10mm against acinetobacter calcoaceticus. When ethyl acetate extracts was used, largest ZOI was 12mm against staphylococcus aureus. Among four pathogenic bacteria used all were found susceptible (ZOI<10) to plant extracts at different concentrations in methanol extracts. In ethyl acetate extracts, S.aureus and E. coli were found less susceptible whereas in hexane extracts, Acinetobacter calcoaceticus was found less susceptible. World Journal of Pharmaceutical Research SJIF impact Factor 8.084 Volume 9, Issue 1, 1220-1231. Research Article ISSN 2277– 7105 Article Received on 23 Oct. 2019, Revised on 13 Nov. 2019, Accepted on 03 Dec. 2019, DOI: 10.20959/wjpr20201-16397 *Corresponding Author Sajan Maharjan Central Institute of Science and Technology, New Baneshwor, Kathmandu, Nepal.