Journal of Investigational Biochemistry DOI: 10.5455/jib.20160523022233 www.scopemed.org J Invest Biochem ● 2016 ● Vol 5 ● Issue 2 37 Uterine Contractile Efect of Ethanol Extracts of Sida acuta Burm F. Leaves Obioma Benedeth L. Eze 1 , Okwesili Fred C. Nwodo 2 , Victor Nwadiogo Ogugua 2 , Parker Elijah Joshua 2 ABSTRACT Background: The study evaluated the ureotonic potentials ethanol extracts leaves of Sida acuta. Methods: Preliminary phytochemical tests were carried out on the ethanol extract of Sida acuta Burm F. leaves. The presence or absence of phytochemicals such as saponnins, flavonoids, alkaloids, tanninis, terpenoids, steroids, carbohydrates, hydrogen cyanide, cardiac glycosides, phenols and reducing sugars were observed. Two pregnant Wistar albino rats were used for the study. The rats were killed by stunning and abdomens were cut open. The uterus were carefully isolated and transferred into dejalon solution which was continuosly bubbled with air and maintained at 37 o C and 7.0 pH. Result: Phytochemical screening revealed high content of flavonoids mg/100g (6.172 ± 0.003), phenols (4.643 ± 0.006), alkaloids (4.643 ± 0.006), cardiac glycosides mg/100g (3.813 ± 0.003), and moderate contents of hydrogen cyanide (2.695 ± 0.003) while low concentrations were observed in steroids (0.512 ± 0.005), saponins (0.246 ± 0.003) and terpenoids (0.813 ± 0.003). Resins, carbohydrates, reducing sugars, tannins, proteins, fats and oil were not detected. The results of the uterine contractility test showed effects compared with the normal rhythm of the uterus. Atropine did not block the extract-induced contraction. Ergomentrine in doses that blocked adrenaline induced-contraction reduced the extract-induced contraction by half. Indomethacin blocked oxytocin-induced contraction and reduced the extract-induced contraction slightly. Conclusions: These results suggest that ethanol extract of Sida acuta leaves possesses oxytocic effects and this portends danger among pregnant women who might take the leaf infusion. The investigation substantiates its use in hastening of labour. KEY WORDS: Acetylcholine; Adrenaline; Atropine; Contractility; Ergomentrine and Ureotonic. 1 Department of Biochemistry, Micha- el Okpara University of Agriculture, Umudike, Umuahia, Abia State, Nigeria. 2 Department of Biochemistry, University of Nigeria Nsukka, Enugu State, Nigeria. Address for correspondence: Obioma Benedeth L. Eze, Department of Biochemistry, Michael Okpara University of Agriculture, Umudike, Umuahia, Abia State, Nigeria. obiomabenedeth@gmail.com, ofcnwodo@yahoo.com Received: March 16, 2016 Accepted: May 23, 2016 Published: July 11, 2016 Original Research INTRODUCTION Herbal preparations are use in pregnancy problems to induce labour, removed retained placenta and in the management of post-partum bleeding [1]. Some of these preparations have side effects and can lead to the death of the unborn baby and/or uterine rupture, and other long-term effects on the mother or baby [2]. Biological effects generated by these preparations are due to biomolecules that act primarily on the uterus [3]. These actions may be the regulation of uterine contractions during labour, resulting in either stimulation (uterotonic) or inhibition (tocolytic) of myometrial muscle contractions [4]. flavonoids have effect on calcium availability for the contraction of smooth muscle and cardiac muscle while cardiac glycosides have effect on the uterus of animals [5,6]. Uterotonic plants are plants that stimulate uterine contraction. They are use to assist labour, remove retained placenta, treat post-partum bleeding, and as an abortifacient [1]. Substances that are called uterotonics are suggested to have laxative, purgative, diarrheagenic, cathartic, abortifacient, and emmenagogic effects [7]. Oxytocin as an uterotonics agent is biochemically synthesized hormones that act on distant hormone receptors or upstream from other hormones in the body to induce uterine contractions. Labour is facilitated by phasic myometrial contractions that are herd by the development of action potentials across the plasma membrane which result from a transient increase in the cytosolic free Ca 2+ concentration [4]. Calcium-dependent smooth muscle contractions are released from the sarcoplasmic reticulum (SR) and extracellular stores through voltage-gated calcium channels. Smooth muscle contractility by different agonists or by electrical depolarization which results in a rapid increase in [Ca 2+ ]i [8]. When Ca 2+ binds to four binding sites of calmodulin, it causes a conformational change that allows the calmodulin-calcium complex to interact with inactive myosin light chain kinase (MLCK), to activate the enzyme [9]. MLCK phosphorylates the 20kDa myosin light chain (MLC). Phosphorylation of MLC causes the conformational changes in the myosin head that leads to activation of myosin ATPase which results in force generation and/or shortening (contraction) of the muscle fibres [10]. Dephosphorylation of MLC by MLC phosphatase (MLCP) results in smooth muscle relaxation [11]. Other physiological mechanisms that influence myometrial contraction include interactions with cell membrane receptors, peptides, metabolic and neuronal factors and hormones [12]. In Nigeria, the infusion of the leaves of Sida acuta Burm F. are use in folk medicine to induce labour. Therefore this work is aimed at investigation of in-vitro contractility effect of ethanol extract of Sida acuta leaves on isolated rat uterus MATERIALS AND METHODS Plant materials The leaves of Sida acuta Burm F. (Iseketu) were collected from Nsukka in Nsukka Local Government Area of Enugu State, Nigeria. A taxonomist, Mr Alfred Ozioko of