Catechin, an active constituent of green tea, preserves skeletal muscle activity in dexamethasone induced cachexia by increasing acetylcholine sensitivity in muscles of Wistar rats

Chronic administration of glucocorticoids produces cachexia like symptoms such as muscular dystrophy, weight loss and skeletal muscle dysfunction. However, only limited options are available for treatment of this disease. One of the tea catechins, epigallocatechin-3-gallate attenuated skeletal muscle atrophy in cancer cachexia. In this context, we explored here (+)-catechin hydrate (catechin) for of its anticachectic activity in dexamethasone induced muscle dystrophy. Dosing of catechin at 100 mg/kg p.o. was continued for 5 days along with a daily dosing of dexamethasone at 0.6 mg/kg i.p. On the 6th day, animals were assessed for cachectic condition using changes in body weight, functional aspect of skeletal muscle such as muscle integrity, locomotor activity, handgrip strength, glucose uptake, responsiveness of skeletal muscle to acetylcholine, by estimating inflammatory parameters such as nitrite, myeloperoxidase in the gastrocnemius muscle and by evaluating plasma biochemical parameters such as triglycerides, total protein, albumin, creatinine, urea and IL-6 levels. Except for a few parameters, such as body weight, glucose uptake by hemi-diaphragm and triglyceride level, remaining parameters were significantly reversed by catechin treatment. The underlying mechanism of the myoprotective action of catechin has been postulated by the increased sensitivity of muscle to acetylcholine as demonstrated in this study, which might be responsible for prevention of muscle inflammation.

Antidiarrheal effect of fractions from stem bark of Thespesia populnea in rodents: Possible antimotility and antisecretory mechanisms

OBJECTIVE@#To evaluate antidiarrheal activity of the fractions of aqueous extract from stem barks of Thespesia populnea (Malvaceae).@*METHODS@#From the aqueous extract three fractions namely ethyl acetate fraction (EAF), methanolic fraction (MF) and residue fraction (RF) were made and studied for antidiarrheal activity. Antidiarrheal activity of the fractions were evaluated in castor oil induced diarrhea, prostaglandin E(2) (PG-E(2)) induced diarrhea and charcoal meal test as in vivo models and the most potent fraction was further evaluated with in vitro models to determine the possible antimotility effect.@*RESULTS@#In castor oil induced diarrhea model, the RF (10, 25, 50 and 100 mg/kg, po.) and MF (100 mg/kg, po.) has significantly reduced the cumulative wet faecal mass, where as the EAF have not shown any significant antidiarrheal activity, RF was found to be more potent than MF. Based on these results and percentage yield, only RF was evaluated in PG-E(2) induced enteropooling and charcoal meal test. RF (10, 25 and 50 mg/kg) had shown significant inhibition of PG-E(2) induced secretions (antisecretory) and decreased the movement of charcoal in charcoal meal test indicating its antimotility activity. Furthermore, RF has showed significant inhibition of acetylcholine, histamine and BaCl(2) induced contractions on rat colon, guinea pig ileum and rabbit jejunum with EC(50) values of 241.7, 303.1 and 286.1 μg/mL, respectively indicating the antimotility effect of RF. The phytochemical analysis of RF showed presence of gums and mucilages and the possible mechanism may be the combination inhibition of elevated prostaglandin biosynthesis and reduced propulsive movement of the intestine.@*CONCLUSIONS@#RF possesses good antidiarrheal activity comparing with other two fractions and the possible mechanism thought to be associated with combination of antisecretory and antimolity.