Phytochemical Screening and Evaluation of Thrombolytic, Analgesic and Antidiarrhoeal Activity of the Leaves of Cucumis sativus Linn. (Cucurbitaceae) of Methanolic Extracts Aklima Akter 1 *, Md. Zamshed Alam Begh 1 , Fahadul Islam 1 , Tahmina Afroz 1 , Md. Shakhawat Hossain 1 , Md. Faysal 1 , Md. Mominur Rahman 1 1 Department of pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Shukrabad, Dhaka-1207, Bangladesh. Abstract Aims: The present study was performed to evaluate the phytochemical screening of compounds, thrombolytic activity, analgesic activity and antidiarrhoeal activity of the methanolic extract of of Cucumis sativus Linn. (Cucurbitaceae) leaves. Background: Cucumis sativus Linn. is generally disseminated all through the world especially in Asia, Africa and South America. Locally the plant is utilized for basic role of cerebral pain, the seed is utilized for diuretic and cooling purposes. The leaf sap is emetic, it is utilized for treating dyspepsia in children. Methods: The thrombolytic activity was evaluated by using clot lysis method. Analgesic activity was investigated using writhing method in mice and anti-diarrhoeal activity test was performed castor oil-induced diarrhoea in mice as well. Result: Significant thrombolytic activity was found for Cucumis sativus Linn 100mg plant leaves extract (29.33%) clot lysis in respect of positive control streptokinase (30000 IU) was shown 65.26% clot lysis. Analgesic activity was investigated using writhing method at the doses of 250/kg and 500 mg/ kg body weight and found 54.72 % and 55.66 % of inhibition respectively compared to standard Diclofenac Na (76.41 %) writhing inhibition. Anti-diarrhoeal activity test was performed at the dose of 500 mg/kg body weight (PO) against castor oil-induced diarrhoea and % of inhibition of feces was found about 62.5% respectively. Conclusion: Cucumis sativus Linn. was shown significant pharmacological potentiality in various study model which will helpful for further studies. Keywords: Cucumis sativus Linn., Phytochemical screening, Streptokinase, Diclofenac sodium BACKGROUND Plants produce wide arrangement of bioactive principles and constitute an abundance source of medicines. Many developing countries traditional medicine are used as primary purpose of their health care systems [1]. Cucumis sativus Linn. is the botanical name of the cucumber which belongs to family of Cucurbitaceae. It is widely distributed throughout the world particularly in Asia, Africa and South America [2]. The cucumber plant is a delicate yearly with a harsh, succulent, trailing stem. The bushy leaves have 3 to 5 pointed flaps just as the stem bears expanded extension by which the plant can be prepared to bolsters [3]. It grows up to two meters tall and five meters long and bald cylindrical fruits are warty, yellow to green as well as up to 50cm long [4]. Locally the plant is used for primary purpose of headache, the seed is used for diuretic and cooling purposes [5]. The leaf sap is emetic, it is used for treating dyspepsia in children. The fruit has special properties such as depurative, diuretic, emollient, purgative, resolvent and fresh and green fruit is used internally for treating of blemished skin, heat rash and a as a cosmetic for softening the skin as well [6]. Cardiovascular disorder was caused by clotting blood that is known as thrombus formation, is one among the most detrimental disorders which are rising at minacious rate in the present times [7]. Thrombolysis may be correlated with an increased risk of complications in patients who are pregnant or at an increased age, and in people with other conditions [8]. The breakdown or lysis of blood clot is named as thrombolysis is caused by tissue plasminogen activator (tPA). Intravenous heparin utilized as the main line treatment though of its security profile as well as activity [9,10]. A lot of medications have been modified with the advancement of current pharmaceutical study like anistreplase, alteplase, urokinase, streptokinase as well as tissue plasminogen (TPA) [11,12]. Analgesics are administrators that explicitly relieving torment by acting in the Central Nervous System (CNS) and periphery torment center individuals without advancing mindfulness. The study of pain in animals raises ethical, philosophical, and technical problems [13]. Analgesics minimize the levels of chemical mediators (prostaglandins) produced by inflammation, relieve pain, swelling as well as redness. Cyclo-oxygenase (COX 2) enzyme is inhibited by them which is integral in the synthesis of prostaglandins [14]. A lot of synthetic analgesic drug such as paracetamol, aspirin, ibuprofen, codeine, morphine etc. which has greater side or adverse effect like reduced concentration or confusion, vomiting, constipation, renal failure, vertigo etc. [15]. Diarrhoea is the prime concern especially developing countries [16]. Looseness of the bowels is recognized by expanded recurrence of defecation, watery stool just as stomach torment. Different national and worldwide associations are attempting to control this ailment yet the rate of rate is still high, roughly 7.1 million every year. A ton of engineered synthetic substances are accessible for the treatment of looseness of the bowels yet they have some significant symptoms [17,18]. Aklima Akter et al /J. Pharm. Sci. & Res. Vol. 12(3), 2020, 448-451 448