International Journal of Ayurvedic Medicine, Vol 12 (1), 73-83 Published online in http://ijam.co.in ISSN No: 0976-5921 Research Article Key Words: Breast cancer, MCF-7, MDA-MB-231, Salicin, In Silico. Introduction Cancer is an evolving threat to humankind and it worsens the socio-economy and psychological health of the suffering patients. Breast cancer is maintaining its position with no reduction in risk of occurrence, recurrence and mortality. According to the breast cancer facts and figures 2019-2020 (American cancer society) (1), an estimated 268,600 new cases of invasive breast cancer will be diagnosed and approximately 41,760 women are expected to die from breast cancer in 2019-2020. According to WHO in 2018 (2), 627,000 women died from breast cancer – that holds 15% of all cancer deaths among women. Though, breast cancer rates are higher among women in more developed regions. However it is spanning in nearly every region globally from rural to urban. Now the cancer scenario in India is 1,392,179 for the year 2020. The common 5 leading sites are breast, lung, mouth, cervix, uteri, and tongue. Around 57% of the patients are diagnosed at advanced stage for breast cancer (3). Several, therapeutics have tried to make their way towards breast cancer treatment. Among them a few are partially successful and most treatments are failures due to resistivity. Breast cancers are treatable only if diagnosed early or at the initial stages. Thus, strategies to treat, manage or prevent the risk of breast cancer are always a need for the global population. In this regard we attempted to find the therapeutic effect of salicin on breast cancer. Salicin is obtained from the bark of Salix species of plants (willow bark). It has been traditionally consumed in China and Europe, throughout centuries for its anti-ache and anti-inflammatory nature. Salicin, also known as salicoside or delta-salicin, is an aryl beta-D-glucoside (salicyl alcohol) in which the phenolic hydrogen is replaced by a beta-D-glucosyl residue. Salicin acts as a prodrug, an antipyretic, a non- narcotic analgesic, a non-steroidal anti-inflammatory drug (4). However, salicin has been extensively studied as a potent anti-inflammatory agent. The potential medicinal value of salicin as anti-tumorigenic, antiproliferative and antiangiogenic effects still remain unexplored. Salicin is metabolized to salicylic acid in vivo and then plays a major role, in clinical studies, willow bark extract (source of salicin) has been reported to be effective in pain management and anti-inflammation (5, Salicin a promising ER, PR and HER 2 binding molecule proving lethal against Hormone + and triple negative breast cancer cells Mrudul Pravinbhai Vekaria 1* , Pravin Tirgar 1 1. R.K University, School of pharmacy, Bhavnagar Highway, Tramba, Gujarat 360020, India. Abstract Therapeutics against breast cancer is a major research field, due to inefficiency or partial efficiency of existing therapeutics. An urge to discover better therapeutics always persists. Our objective is to study salicin against breast cancer cells, in order to find its therapeutic properties. To study the effect of salicin on breast cancer cells, we performed MTT assay on MCF-7 (hormone positive) and MDA-MB-231 (triple negative) breast cancer cell lines, we did brine shrimp lethality test (BSLT) assay to see the lethal effects of salicin. By the help of bioinformatics we tried to locate the targets that delineate salicin activity. Salicin was docked with estrogen receptor (ER), progesterone receptor (PR) and Human epidermal growth factor receptor 2 (HER2) to study its binding efficiency and possible targets of salicin. Salicin remarkably reduces cell viability both in MCF-7 and MDA-MB-231, along with being lethal to brine shrimps. These results together opine that salicin can be an effective therapeutics against breast cancer cells. The mechanism of action of salicin is probably through ER, PR and HER2 receptors because it can efficiently bind these receptors with minimum energy required for binding. This explains that salicin can easily bind to these receptors. These results together opine that salicin can be an effective therapeutics against breast cancer cells. The mechanism of action of salicin is probably through ER, PR and HER2 receptors because it can efficiently bind these receptors with minimum binding energy. ER, PR and HER2 are major reasons behind the disease pathogenicity depending on the type of breast cancer. According to our results salicin may either induce apoptosis or reduce cellular mitosis both via P53 dependent and independent pathway, which makes salicin a good choice of both hormone positive and negative breast cancer cells. 73 * Corresponding Author: Mrudual Pravinbai Vekaria R.K University, School of Pharmacy, Bhavnagar Highway, Tramba, Gujarat 360020, India. Email Id: vekaria_mrudul@yahoo.com