ABSTRACT
Desmodium pulchellum has been reported to be a traditional remedy of schistosomiasis. Our previous pharmacological studies demonstrated a decreased locomotion, an increased blood pressure, and an increased respiration n rats treated with aqueous extracts from various parts of the herb, especially the root bark. This prompted us to isolate the active principles responsible for such activities. In this experiment, the root bark was extracted by maceration using a series of solvents. Dried methanolic extract was found to possess the above mentioned effects. At a dose of 30 mg/kg (p.o) induced stereotyped behaviors (paw padding, tail-flick, hind-limb extension) in rats. Higher doses caused convulsion and death within an hour. These similar behaviors induced by tryptophan, were potentiated by the extract. This potentiation was antagonized by cyproheptadine, a serotonin antagonist. This evidence of action mediated-through serotonergic system indicates that the extract may become a useful antidepressant. The speculation was tested on behavioral despaired-mice which was forced to swim. A weak antide-pressant effect compared to an antidepressant, imipramine, was observed.
ABSTRACT
Desmodium pulchellum is a medicinal herb which has been reported to possess anthelminthic effects against the liver fluke (O. viverrini) in hamsters. This report shows pharmacological effects of the herb extracts in concious rats. Locomotion associated with muscle relaxation was obserbed. Meanwhile, rats received the extracts had rapid respiration and became red at ears, nose and feet compared to control rats. These results suggest that the herb has major effects on motor, respiratory and cardiovascular system. Both gripping of mice on inclined plane and locomotion of rats were decreased by the herb extracts. The extract from bark of the root exhibited the most potent effect compared to wooden part of the root, leaves and stem. Intravenous injection of these extracts into anaesthetized rats increased respiratory volume (both expired and inspired air), blood pressure and amplitude of QRS-complex. These results indicate that bark of the root exhibits all of these major pharmacological effects and is the most potent part of the herb.
ABSTRACT
This report is the preliminary study on effects of the extract from Desmodium pulchellum’s root on the fluke “Opisthorchis viverrini” in hamsters. After 45 days of infection with metacercariae of this liver fluke, all six groups of 5 hamsters had similar number of eggs in feces (p\>0.7). The treatment effects of water extract from this herb (10 g root/1 kg b.w) given for 1,2,3,4 or 5 days on the number of eggs in feces and the number of adult fluke in the liver were compared with those of controls. The results show that the number of eggs in feces from hamsters treated with the herb-extract is significantly decreased from controls (p 0.1). These results suggest that the extract from this herb may have anthelminthic effect on this fluke, at least , on the egg production.