e n v i r o n m e n t a l t o x i c o l o g y a n d p h a r m a c o l o g y 3 9 ( 2 0 1 5 ) 307–312 Available online at www.sciencedirect.com ScienceDirect jo ur nal homepage: www.elsevier.com/locate/etap Growth inhibition and apoptosis induction by Scutellaria pinnatifida A. Ham. on HL-60 and K562 leukemic cell lines Motahareh Boozari a , Ameneh Mohammadi b , Javad Asili a , Seyed Ahmad Emami a , Zahra Tayarani-Najaran c,∗ a Department of Pharmacognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran b Research Center of Natural Products Safety and Medicinal Plants, North Khorasan University of Medical Sciences, Bojnurd, 01830-49504, Iran c Department of Pharmacodynamics and Toxicology, School of Pharmacy; Mashhad University of Medical Sciences, P.O. Box: 9188617871, Mashhad, Iran a r t i c l e i n f o Article history: Received 20 August 2014 Received in revised form 1 December 2014 Accepted 8 December 2014 Available online 16 December 2014 Keywords: Scutellaria pinnatifida Lamiaceae Cytotoxicity Wogonin Neobaicalein a b s t r a c t A rich flavonoid plant extensively used in traditional medicine is Scutellaria (Lamiaceae). In this study the cytotoxic effects of different extracts of Scutellaria pinnatifida were explored on two different cancer cell lines including K562 and HL-60 and a normal cell line. Also, the role of apoptosis on this toxicity was explored. The cell viability was quantitated by alamarBlue ® assay. S. pinnatifida could effectively decrease the viability of malignant cells and the CH 2 Cl 2 extract of S. pinnatifida had showed the most cytotoxic effects among other extracts. Apoptosis was confirmed after propidium iodide staining of DNA fragments and detection of the sub-G1 peak in the related flow cytometry histogram of cells. The results of western blot assay showed that CH 2 Cl 2 extract has been able to increase the amount of Bax and cleavage of PARP protein after a 48 h contact with cells. Neobaicalein (skullcapflavone II) and wogonin were identified in the extract of S. pinnatifida as the active components. The result of the present study confirmed the putative role of neobaicalein (skullcapflavone II) and wogonin as cytotoxic components in the CH 2 Cl 2 extract of S. pinnatifida. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Some species of the genus Scutellaria have long been used in traditional medicine in various countries like China, Korea, North America, and some of the European countries as valuable remedies. New researches have also vali- dated the traditional applications of the plant. Furthermore, ∗ Corresponding author. Tel.: +98 511 8823255. E-mail addresses: tayaraninz@mums.ac.ir, tayaraniz@gmail.com (Z. Tayarani-Najaran). biological studies on newly identified chemicals such as baicalin, baicalein, neobaicalein (skullcapflavone II), and wogonin have further shown the putative value of Scutel- laria genus. Shang et al. reviewed biological properties of the Scutellaria genus and the active components of the plant and reported antioxidative, hepatoprotective, anticonvulsive, antibacterial, antitumor, antiviral, and anti-inflammatory effects (Shang et al., 2010). http://dx.doi.org/10.1016/j.etap.2014.12.002 1382-6689/© 2014 Elsevier B.V. All rights reserved.