Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jethpharm Oxidative stress mediated cytotoxicity in leukemia cells induced by active phyto-constituents isolated from traditional herbal drugs of West Bengal Monaj Kumar Sarkar a , Santanu Kar Mahapatra b,** , Vellingiri Vadivel a,* a Chemical Biology Lab (ASK-II-409), School of Chemical and Biotechnology (SCBT), SASTRA Deemed University, Thanjavur, Tamilnadu, India b Medicinal Chemistry and Immunology Lab (ASK-II-406), School of Chemical and Biotechnology (SCBT), SASTRA Deemed University, Thanjavur, Tamil Nadu, India ARTICLE INFO Keywords: Herbal drugs Traditional healers Leukemia Active compounds Anti-proliferative activity Anticancer mechanism ABSTRACT Ethnopharmacological relevance: In search of safe and effective therapeutic agents as alternative to synthetic chemotherapeutics for the treatment of leukemia, the herbal drugs (Leaf of Madhuca longifolia, leaf of Prosopis cineraria and bark of Flacourtia indica) with long traditional use in West Bengal have received our attention. Aim of the study: Present work was conducted to isolate and identify the active compounds of the selected herbal drugs using bio-assay guided fractionation and also to investigate their anticancer mechanism in leukemia cell lines. Materials and methods: Bio-assay guided fractionation was used for the isolation of active constituents such as myricitrin, vitexin and vanillin from the aqueous extracts of M. longifolia, P. cineraria and F. indica, respectively using liquid partitioning and column chromatography and the compounds were characterized by HPLC, MS and NMR. Dose and time-dependent cytotoxicity of isolated compounds were studied against leukemia cells and their anticancer mechanism such as cell wall damage, nuclear damage, ROS and NO generation, SOD level, LDH release and lipid peroxidation were investigated. Results: Aqueous extract of M. longifolia, P. cineraria and F. indica exhibited maximum anti-proliferative activity against HL-60 (Acute myeloid leukemia, AML, 72.06%), K-562 (Chronic myeloid leukemia, CML, 42.14%) and Jurkat (Acute lymphoblastic leukemia, ALL, 51.71%) cells. Myricitrin, vitexin and vanillin exhibited dose-de- pendent (IC-50 values 164.4, 147 & 29.22 μg/ml) and time-dependent activity with maximum cytotoxicity at 48 h. All these three compounds caused apoptosis in leukemia cells by inducing free radicals such as ROS (1.33–2.65 Arbitrary units) and NO (11.17–18.53 μM), cell membrane damage and nuclear condensation which were evidenced by increased release of LDH (1326–1439 U/L), improved lipid peroxidation (10.19–14.41 nM/ mg protein) and reduced SOD level (6.2–9.21 U/mg protein) in leukemia cells. Conclusions: Based on anti-proliferative activity, the isolated phyto-compounds myrcitrin, vitexin and vanillin from M. longifolia, P. cineraria and F. indica could be developed as natural drugs for treating AML, CML and ALL leukemia types, respectively. 1. Introduction Leukemia is a cancer type which caused by proliferation of white blood cells. Leukemia can be categorized into acute and chronic based on age of the patients i.e., childhood and adult, respectively. In case of acute leukemia immature white blood cells or blasts proliferate, whereas leukemia arising from mature cells leads to chronic. Based on blood cell type, leukemia can be further divided into acute lympho- blastic leukemia (ALL), chronic lymphoblastic leukemia (CLL), acute myeloblastic leukemia (AML) and chronic myeloblastic leukemia (CML) (Davis et al., 2014). AML is a disorder which is characterized by chromosomal abnormalities and mutations in tumor protein p53, c-KIT and CCAAT enhancer binding protein in hematopoietic stem cells from bone marrow (Byrd et al., 2002; Saultz and Garzon, 2016). CML de- velops in hematopoietic stem cells due to fusion of BCR-ABL genes, which leads to philadelphia chromosome (O'Hare et al., 2011). In case of ALL, the most common alterations involve Abelson Murine Leu- kemia1 (ABL1), Janus Kinase 2 (JAK2), and FMS like Tyrosine Kinase (FLT3) (Terwilliger and Abdul-Hay, 2017). Deletion in long arm of chromosomes 11 & 13 and short arm of chromosome 17 and trisomy in chromosome 12 leads to CLL (Hallek, 2017). Even though the chemotherapeutic drugs like cyclophosphamide, https://doi.org/10.1016/j.jep.2019.112527 Received 24 August 2019; Received in revised form 11 November 2019; Accepted 25 December 2019 * Corresponding author. ** Corresponding author. E-mail addresses: santanu@scbt.sastra.edu (S.K. Mahapatra), vadivel@carism.sastra.edu (V. Vadivel). Journal of Ethnopharmacology 251 (2020) 112527 Available online 28 December 2019 0378-8741/ © 2019 Elsevier B.V. All rights reserved. T