ABSTRACT
Introduction: Arteether TM, a derivative of artemisinin, is among the recent drugs that have given renewed hope for combating malarial menace. The present study investigated the effects of arteetherTM on the histology of the retina and cerebellum of Wistar rats. Materials and Methods: Twenty adult albino Wistar rats weighing 150-200 g, were randomly divided into four groups (A, B, C and D) of five animals each and used for this study. Group A rats were given intramuscular (i.m.) arteetherTM (3 mg/kg b.w.) daily for 3 days. Group B rats were given i.m. arteetherTM (6 mg/kg b.w.) daily for 3 days. Group C rats were also given i. m. of arteetherTM (3 mg/kg b. w.) daily for 3 days, and the same dose was repeated at two-weekly intervals for 4 further weeks; while Group D rats which received normal saline (0.9 % w/v, 3 ml/kg b.w.), served as controls. At the end of the experiment, the rats were sacrificed by cervical dislocation. The retina and cerebellum were excised and processed routinely for histopathology changes, using haematoxylin and eosin stain (H & E), as well as Nissl stain. Results: Results obtained showed normal cellular components of the retina and cerebellum in all groups, and no cyto-pathological changes were observed. Conclusion: Thus, this study showed that under light microscopic examination, therapeutic doses of arteetherTM caused no significant cyto-pathologic changes in the retina and cerebellum of Wistar rats.(AU)
Subject(s)
Animals , Rats , Retina/anatomy & histology , Cerebellum/anatomy & histology , Artemisinins/pharmacology , Malaria/prevention & control , Histological Techniques , Rats, WistarABSTRACT
The aim of this study was to examine some in vivo and in vitro cardiovascular effects of Helichrysum ceres leaf ethanolic extract (HCE) in experimental animal paradigms. The acute effects of HCE on blood pressure were studied in anaesthetised normotensive male Wistar rats challenged with intravenous hypotonic saline infusion after a 3.5-hour equilibration for four hours of one-hour control; 1.5-hour treatment and 1.5-hour recovery periods. HCE was added to the infusate during the treatment period. Sub-chronic hypotensive effects of HCE were examined in weanling Dahl Salt-sensitive (DSS) genetically hypertensive rats; which progressively develop hypertension with age; treated with HCE (80 mg / kg) every third consecutive day for seven weeks. isolated atrial muscle strips; portal veins and descending thoracic aortic rings of healthy normotensive Wistar rats were used to investigate the vascular effects of HCE. Acute HCE administration caused a significant (p 0.05) fall in blood pressure in the normotensive anaesthetised Wistar rats. DSS hypertensive rats treated with HCE displayed low arterial blood pressure and heart rate values from weeks five to seven. HCE produced concentration-dependent negative inotropic and chronotropic effects on rat isolated electrically driven left; and spontaneously beating right atrial muscle preparations; respectively. HCE also evoked concentration-dependent relaxation responses of endothelium-intact aortic rings and portal veins isolated from healthy normotensive Wistar rats. The vasorelaxant effects of HCE in intact aortic rings were significantly reduced; but not completely abolished by adding endothelial-derived factor (EDRF) inhibitor; L-NAME; suggesting that the vasorelaxant effect of the extract is mediated via EDRF-dependent and independent mechanisms. The results of the study suggest that the hypotensive action of HCE is elicited; in part; directly by decreasing myocardial contractile performance and total peripheral vascular resistance due to its negative inotropic and chronotropic effects on rat isolated atrial muscle strips; and vasorelaxant effects on isolated vascular smooth muscles. The observed cardiovascular effects of HCE partly support the basis for its use in the management of high blood pressure in folkloric medicine