Pakistan Journal of Pharmacology Vol.21, No.2, July 2004, pp.19-22 DOSE-RESPONSE CURVE OF SOMINA (HERBAL PREPARATION): A STUDY ON FROG HEART MUHAMMAD AHMED + , AISHA AZMAT, MOHAMMAD ABDUL AZEEM*, NAVAID-UL-ZAFAR**AND SYED IQBAL AHMAD Dr. Hafiz Muhammad Ilyas Institute of Pharmacology and Herbal Sciences Hamdard University, Karachi-74600, Pakistan *Neuro-Muscular Unit, Department of Physiology University of Karachi, Karachi-75270, Pakistan **Hamdard Laboratories (Waqf) Pakistan, Karachi, Pakistan ABSTRACT Dose response relation is important with respect to pharmacological efficacy of drug substances and must be known for herbal preparation. Herbal preparations Somina (Hamdard Patent), having five ingredients is not yet screened for its dose response relation. In the present study Somina is used for the determination of dose response on exposed Frog’s heart preparation. U’s shape dose response curve was obtained which shows maximum response at 20mg/ml while it was found to reduce at low and higher doses. The dose response curve is discussed on the basis of properties of ingredients available in this herbal preparation. INTRODUCTION Many herbal formulated preparations are traditionally used in folk medicine as remedies for the treatment of a variety of human ailments from time immemorial. However, pharmacological data is not available for all of them. In addition, Dose response relationship is also not known for such medicines. This relation is very important in therapeutic decisions and in experimental pharmacology. Rossum (1963) stresses the importance of studying dose-response curves for the analysis of the mechanism of action. Further, Dose- response theory is also important with respect to toxicology. Vom Saal (1997) has discovered a series of Non-Monotic Dose-Response Curves. He suggested that in a Non-Monotonic Dose-Response Curve (NMDRC), the shape of the dose response curve reverses as the level of contamination goes up. Some NMDRC are shaped like U’s, with high responses at low and at high levels of contamination. Others are shaped like inverted U’s with the greatest response in intermediate ranges. He also suggested that observable fact is that low doses may actually cause greater impact than high doses for a specific response. The same effect has been found by Gupta (2000). In view of the above information in the literature, the study for the determination of Dose response relation is carried out on one of the traditional medicine “Somina” formulated by Hamdard laboratories (Waqf) Pakistan. Somina is composed of five ingredients that belong to five different medicinal plants. Sesamum indicum (14%), Prunus amygdalus (12%), Papaver somniferum (10%), Lactuca scariola (5%) and Lagenaria vulgaris (12%). It is claimed that Somina is a cephalic tonic having sedative, hypnotic, anxiolytic activities. It is also effective in weakness of brain and memory. i) Sesamum indicum belongs to family Pedaliaceae. Aftab (1995) reported that Sesamum indicum, reduces the blood pressure and heart rate in anaesthetized normotensive rats. ii) Prunus amygdalus belongs to family Rosaceae, has been found to exhibit hypotensive and antisclerotic actions (Vulpe, 2002). iii) Papaver somniferum belongs to family + Correspondence