Carrageenan-induced Rat Hind Paw Edema Research Articles

Pharmacological Study ofCuscuta campestris Yuncker

The dried ethanol extract of the whole plant of Cuscuta campestris Yuncker was studied for its analgesic, antipyretic, antiinflammatory as well as CNS-depressant activities. The extract was given orally at doses of 50 and 100 mg/kg. A significant protection against the p-benzoquinone-induced writhing response in mice was observed. A marked lowering of the body temperature of both hyperthermic as well as normothermic mice was produced. Therefore, the extract possesses a hypothermic rather than an antipyretic effect. A marked inhibition of the carrageenan-induced rat hind paw oedema was also obtained. Regarding its CNS action, the extract produced a decrease in the motor activity of mice placed on a rotarod. In the conditioned avoidance reaction test the percentage of failure to avoid electric shock was shown to be increased after administration of the extract without any effect on the escape behaviour of the trained rats. Therefore, the CNS-depressant activity of the extract seems to be due to a tranquillizing effect. It could be concluded that the extract possesses analgesic, hypothermic, antiinflammatory as well as CNS-depressant activities.

The influence of carbon tetrachloride-induced liver damage on the inflammatory reaction elicited by carrageenan and its treatment with diclofenac

The effect of impaired hepatic function on the development of the inflammatory process as well as on treatment with diclofenac was investigated. Carbon tetrachloride was used to induce liver injury and the elevation of serum transaminases was taken as evidence for impaired hepatic function. The carrageenan-induced rat hind paw oedema and the granuloma pouch were chosen as models of inflammation. The results of the study revealed that: (1) The intensity of inflammation in both models was markedly attenuated in CCl4-treated animals. (2) Serum total proteins were decreased in liver-injured animals particularly in acute experiments. (3) In liver-injured groups diclofenac showed more pronounced anti-inflammatory activity in chronic experiments, but not in acute ones. (4) Neither CCl4 nor diclofenac affected the levels of histamine and serotonin in the granuloma pouch exudate. The level of prostaglandins was decreased in CCl4 and in diclofenac-treated animals. At the same time, the leukotriene content was elevated. The mechanism by which CCl4 induced liver injury attenuates inflammatory response to carrageenan is not entirely understood. Its effect on protein metabolism and extravasation as well as on PG synthesis could play a possible role. Decreased drug metabolism may be, at least in part, responsible for the enhanced response of diclofenac in the cases of liver-injured animals. Dose adjustment of the drug in case of hepatic impairment might be necessary.

L-652,469 - a dual receptor antagonist of platelet activating factor and dihydropyridines from Tussilago farfara L

L-652,469, 14-acetoxy-7β-(3′-ethylcrotonoyloxy)-notonipetranone, isolated from the methylene chloride extracts of the buds of Tussilago farfara L, was found to inhibit both platelet activating factor (PAF) and Ca 2+ entry blocker binding to membrane vesicles. It inhibits the [ 3H]PAF specific binding to rabbit platelet membranes with equilibrium inhibition constants (K i) of 3.2 and 4.0 μM in the presence of 150 mM NaCl and 10 mM MgCl 2 respectively. It is a competitive PAF receptor antagonist with an equilibrium dissociation constant (K B) of 5.16 μM. It also competitively inhibits the specific binding of Ca 2+ channel blockers (e.g. [ 3H]nitrendipine; K i = 1.2 μM) in cardiac sarcolemmal vesicles. At 10 −5 M, L-652,469 causes a 60% relaxation of Ca 2+-induced contraction of rat thoracic aorta strips. Due to its dual antagonistic activities, L-652,469 potently inhibits the gel-filtered rabbit platelet aggregation with a pA 2 of 5.79. It was also found to be orally active with a beneficial effect to inhibit the PAF-induced rat foot edema and the first phase of carrageenan-induced rat hindpaw edema.