ABSTRACT
-004, a lipid extract of Roystonea regia fruits that contains oleic, lauric and myristic acids as major components inhibits α1-adrenoreceptors-mediated contractile responses in isolated rat vas deferens and prostate trips; no study has demonstrated a similar effect for oleic, lauric or myristic acids individually. Therefore, the effects of D-004 (250 g/ml), oleic (100 g/ml), lauric (50 g/ml) or myristic (25 g/mL) acids and their combined effects on phenylephrine (PHE: 10-7- 10-4 mol/L) induced contractions has been studied. No treatment changed the basal tone of the preparations, but all inhibited PHE-induced contractions. D-004 produced the highest inhibition, followed by lauric acid, which was more effective than myristic and oleic acids against PHE-induced contractions of control group. D-004 and the mixture of the three acids produced similar inhibitions.
ABSTRACT
Policosanol is a mixture of higher aliphatic alcohols purified from sugar cane wax, with cholesterol-lowering effects demonstrable in experimental models and in patients with type II hypercholesterolemia. The protective effects of policosanol on atherosclerotic lesions experimentally induced by lipofundin in rabbits and rats and spontaneously developed in stumptail monkeys have been described. The present study was conducted to determine whether policosanol administered orally to rabbits with exogenous hypercholesterolemia also protects against the development of atherosclerotic lesions. Male New Zealand rabbits weighing 1.5 to 2 kg were randomly divided into three experimental groups which received 25 or 200 mg/kg policosanol (N = 7) orally for 60 days with acacia gum as vehicle or acacia gum alone (control group, N = 9). All animals received a cholesterol-rich diet (0.5 percent) during the entire period. Control animals developed marked hypercholesterolemia, macroscopic lesions and arterial intimal thickening. Intima thickness was significantly less (32.5 +/- 7 and 25.4 +/- 4 µm) in hypercholesterolemic rabbits treated with policosanol than in controls (57.6 +/- 9 µm). In most policosanol-treated animals, atherosclerotic lesions were not present, and in others, thickness of fatty streaks had less foam cell layers than in controls. We conclude that policosanol has a protective effect on the atherosclerotic lesions occurring in this experimental model.
Subject(s)
Male , Animals , Anticholesteremic Agents/pharmacology , Atherosclerosis/prevention & control , Cholesterol, Dietary/administration & dosage , Fatty Alcohols/pharmacology , Hypercholesterolemia , Administration, Oral , Aorta/pathology , Case-Control Studies , Cholesterol/biosynthesis , Cholesterol/blood , Disease Models, Animal , Hypercholesterolemia/etiology , RabbitsABSTRACT
Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane wax, whose main component is octacosanol. An inhibitory effect of policosanol on platelet aggregation and cerebral ischemia in animal models has been reported. Thus, the objective of the present study was to evaluate the effect of policosanol on cerebral ischemia induced by unilateral carotid ligation and bilateral clamping and recirculation in Mongolian gerbils. Policosanol (200 mg/kg) administered immediately after unilateral carotid ligation and at 12- or 24-h intervals for 48 h significantly inhibited mortality and clinical symptoms when compared with controls, whereas lower doses (100 mg/kg) were not effective. Control animals showed swelling (tissue vacuolization) and necrosis of neurons in all areas of the brain studied (frontal cortex, hippocampus, striatum and olfactory tubercle), showing a similar injury profile. In the group treated with 200 mg/kg policosanol swelling and necrosis were significantly reduced when compared with the control group. In another experimental model, comparison between groups showed that the brain water content of control gerbils (N = 15) was significantly higher after 15 min of clamping and 4 h of recirculation than in sham-operated animals (N = 13), whereas policosanol (200 mg/kg) (N = 19) significantly reduced the edema compared with the control group, with a cerebral water content identical to that of the sham-operated animals. cAMP levels in the brain of control-ligated Mongolian gerbils (N = 8) were significantly lower than those of sham-operated animals (N = 10). The policosanol-treated group (N = 10) showed significantly higher cAMP levels (2.68 pmol/g of tissue) than the positive control (1.91 pmol/g of tissue) and similar to those of non-ligated gerbils (2.97 pmol/g of tissue). In conclusion, our results show an anti-ischemic effect of policosanol administered after induction of cerebral ischemia, in two different experimental models in Mongolian gerbils, suggesting a possible therapeutic effect in cerebral vascular disorders
Subject(s)
Animals , Female , Brain Ischemia/therapy , Cyclic AMP/analysis , Fatty Alcohols/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Brain Ischemia/pathology , Constriction , Disease Models, Animal , GerbillinaeABSTRACT
Thromboxane A* release by guinea pig lungs stimulated by AA and ionophore A 23187 was inhibited by levamisole (40 and 120 *g/ml), whereas leukotrienes, Pgl* or PgE* generation were unaffected. Since levamisole (1,5-25 *M) also inhibited plateled aggregation induced by collagen, which is markedly T x A* dependent, we suggest that levamisole acts as a thromboxane synthetase inhibitors