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Exposure of rats to acrylamide (ACR) caused hind limb paralysis in 58% of the animals on day 10 and decreased behavioural parameters, namely distance travelled, ambulatory time, stereotypic time and basal stereotypic movements compared with the control group. These rats also had a decrease in the reduced glutathione (GSH) content and glutathione-S-transferase (GST) activity in the corpus striatum and an increase in striatal dopamine receptors, as evident by an increase in the binding of 3H-spiperone to striatal membranes. Treatment with the ethanol:water (1:1) extract of the rhizomes of Acorus calamus (AC-002) increased the GSH content and GST activity in the corpus striatum while insignificant changes were observed in other parameters. Rats treated with ACR and AC-002 in combination had a lower incidence of paralysis (18%) compared with those treated with ACR alone on day 10 of the experiment. The rats also showed a partial recovery in other behavioural parameters. The levels of GSH content and GST activity increased in the corpus striatum, while the dopamine receptors decreased compared with the ACR treated rats. The results suggest that the neurobehavioural changes produced by ACR may be prevented following treatment with Acorus calamus rhizomes.

In an attempt to locate the biologically active fraction(s) of the plant Verbena officinalis Linn. (Verbenaceae), a preliminary screening of successive petroleum ether, chloroform and methanol extracts of aerial parts for antiinflammatory activity using carrageenan paw oedema model was carried out. All three extracts were found to exhibit antiinflammatory activity with the chloroform extract being the most active. Chemical investigations of petroleum ether and chloroform extracts led to the isolation of beta-sitosterol, ursolic acid, oleanolic acid, 3-epiursolic acid, 3-epioleanolic acid, and minor triterpenoids of derivatives of ursolic acid and oleanolic acids. Chromatographic purification of the methanol extract yielded two iridoid glucosides, verbenalin and hastatoside, a phenylpropanoid glycoside, verbascoside and beta-sitosterol-D-glucoside., (Copyright 2000 John Wiley & Sons, Ltd.)

The extracts of Swertia chirata were evaluated for antihepatotoxic activity using paracetamol and galactosamine models. The methanol extract of the whole plant was found active at a dose of 100 mg/kg i.p. On fractionating this extract into chloroform soluble and butanol soluble fractions, the activity was retained in the chloroform soluble fraction which was most active at a dose level of 25 mg/kg i.p. with overall protection of 81% and 78% against paracetamol and galactosamine, respectively. The butanol soluble fraction, rich in bitter secoiridoids, was devoid of significant activity. The protective effect observed against these two hepatotoxins which are different in their mechanisms of inducing hepatotoxicity, suggests broader and non-specific protection of the liver against these two toxins by non-bitter components of Swertia chirata.

The methanol extract of Swertia chirata was evaluated for antihepatotoxic activity against carbon tetrachloride induced liver toxicity in experimental rats. The extract was found to be active and on fractionation into butanol soluble and chloroform soluble fractions, the activity was traced and found more profound in the chloroform soluble fraction. The butanol soluble bitter rich fraction showed marginal activity. The results based on biochemical estimations have been expressed statistically and are additionally supported by histopathological examination of the liver of experimental rats and pentobarbitone induced sleep time studies in mice.

Two antileukemic daphnane esters, Pimelea factor P2 (I) and the new compound dircin (II), were isolated from the twigs and flowers of Dirca occidentalis A. Gray (Thymelaeaceae). Three lignans, (-)-medioresinol (III), (+)-syringaresinol (IV), and (-)-lariciresinol (V), as well as the coumarin daphnoretin (VI), were found to be additional cytotoxic constitents of this taxon.