Pak. J. Pharm. Sci., Vol.28, No.3, May 2015, pp.945-949 945 Antimicrobial, antitumor and brine shrimp lethality assay of Ranunculus arvensis L. extracts Muhammad Zeeshan Bhatti 1,2* , Amjad Ali 2 , Asma Saeed 3 , Ahmad Saeed 4 and Salman Akbar Malik 1 1 Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan 2 Institute of Biomedical Sciences, School of Life Science, East China Normal University, Dongchuan Road, Shanghai, China 3 Department of Biological Sciences, Gomal University, Dera Ismail Khan, Pakistan 4 Department of Chemistry, University of Science & Technology, Bannu, Pakistan Abstract: To investigate the antitumor activity, brine shrimp lethality assay, antibacterial and antifungal activity of Methanol Extract (ME), Water Extract (WE), Acetone Extract (AE), Chloroform Extract (CE), Methanol-Water Extract (MWE), Methanol-Acetone Extract (MAE), Methanol-Chloroform Extract (MCE) of Ranunculus arvensis (L.). Antitumor activity was evaluated with Agrobacterium tumefaciens (At10) induced potato disc assay. Cytotoxicity was evaluated with brine shrimp lethality assay. Antibacterial activity was evaluated with six bacterial strains including Escherichia coli, Enterobacter aerogenes, Bordetella bronchiseptica, Klebsiella pneumoniae, Micrococcus luteus and Streptococcus anginosus and antifungal screening was done against five fungal strains including Aspergillus niger, A. flavus, A. fumigates, Fusarium solani and Mucor species by using disc diffusion method. Best antitumor activity was obtained with ME and WE, having highest IC 50 values 20.27±1.62 and 93.01±1.33μg/disc. Brine shrimp lethality assay showed LC 50 values of AE, MAE and ME were obtained as 384.66±9.42μg/ml, 724.11±8.01μg/ml and 978.7±8.01μg/ml respectively. WE of R. arvensis revealed weak antimicrobial result against the tested microorganisms. On the other hand, the antifungal activity of the plant extracts was found to be insignificant. These findings demonstrate that extracts of R. arvensis possesses significant antitumor activity. Further extensive study is necessary to assess the therapeutic potential of the plant. Keywords: Ranunculus arvensis; antitumor activity; potato disc assay; brine shrimp lethality assay; antimicrobial. INTRODUCTION Plant materials remain a vital source to conflict serious diseases in the world. In developing countries, people use traditional medicine when they suffering from diseases (Yildirim et al., 2013). The medicinal values of the plants occur due to the presence of chemical active substances, which produce a specific physiological action on the body of human being (Shihabudeen et al., 2010). They are helpful to cure many infectious diseases, use of synthetic antimicrobial compounds contain side effects that are associated with these synthetic drugs (Islam et al., 2011). To cope with these challenges, the demand of better results oriented new antimicrobial agents has increased (Karakas et al., 2012). Plants have host bioactive molecules, which most likely developed as chemical resistance against infections (Pierangeli et al., 2011). Natural products obtain from these plants have potential for the treatment of cancer (Conforti et al., 2008). The mortality rate of cancer increased 22% up until 1990, and ten million new cases were reported in 2000, over six million deaths were occur worldwide (Karaskas et al., 2012; Parkin et al., 2001). To promote the use of plants as a source of antitumor and antimicrobial drugs, it is necessary to examine the activity, composition and also confirm their way of use (Nair and Chanda, 2007). Thus, plants are considered as most important and interesting candidate for the development of new and safe drugs for aliments (Parkin et al., 2000). In many cases, the bio- active compounds of these plants extracts remain anonymous, and their occurrence is only detected by biological assays (Karaskas et al., 2012). These bioassays are use for screening and evaluation of plant extracts possesses antitumor, antimicrobial activity, cytotoxicity etc. (Dzhambazov et al., 2002). Ranunculus arvensis (L.), commonly known as corn buttercup, belong to family Ranunculaceae. It is native to Europe, but mostly found in high mountains of the Mediterranean Region, Southeastern, Eastern Regions of Anatolia and also in Pakistan (Sayhan et al., 2009; Kosa et al., 2008). Ranunculaceae is a large family comprising around 2500 species distributed all over the world (Fostok et al., 2009). R. arvensis is folk remedy for asthma, gout, arthritis, high fever and psoriasis in the Far East (Akbulut et al., 2011). Since this plant has important medicinal properties the present study has been undertaken and we herein, report the antitumor activity, brine shrimp lethality assay and antimicrobial activity of various crude extracts of R. arvensis for the first time. *Corresponding author: e-mail: zeshan34@yahoo.com