Picroliv prevents oxidation in serum lipoprotein lipids of Mastomys coucha infected with Plasmodium berghei.

Picroliv, an iridoid glycoside mixture from the root and rhizome of Picrorhiza kurrooa, at the dose of 6 mg/kg p.o. for two weeks provided significant protection against the generation of lipid peroxidation products in serum beta-lipoproteins of P. berghei infected M. coucha. Incubation of normal rat hepatocytes with very low density lipoprotein or low density lipoprotein isolated from infected animals caused significant generation of lipid peroxides followed by a decrease in the viability of these cells, however these effects were partially reversed with the lipoproteins from infected and picroliv treated groups. High density lipoprotein from infected animals was not toxic to hepatocytes in vitro.

Picroliv protects against alcohol-induced chronic hepatotoxicity in rats.

Daily administration of ethyl alcohol (3.76 g/kg, p.o.) for 45 days resulted in significant changes in several biochemical parameters of the liver and serum of albino rats. After exposure to alcohol for 30 days when Picroliv (12 mg/kg, p.o.), an iridoid glycoside fraction of Picrorhiza kurroa, was administered for 15 days along with alcohol, the degree of change in most of the parameters was reduced.

Picroliv affects gamma-glutamyl cycle in liver and brain of Mastomys natalensis infected with Plasmodium berghei.

Picroliv, the standardized preparation of iridoid glycosides from Picrorhiza kurrooa, at the dose of 6 mg/kg, po for two weeks provided significant protection against depletion of reduced glutathione levels in liver and brain of Plasmodium berghei infected Mastomys natalensis. The activation of gamma-glutamyl transpeptidase enzyme and decreased levels of cysteine, sulphydryl groups as well as glutathione synthesis in both tissues due to P. berghei infection were reversed by picroliv. Enzymatic and non enzymatic lipid peroxidation in microsomes in vitro was significantly reduced by picroliv along with the recovery of reduced glutathione.

Effect of picroliv on low density lipoprotein receptor binding of rat hepatocytes in hepatic damage induced by paracetamol.

Picroliv from root and rhizome of Picrorhiza kurroa showed reversal of low density lipoprotein (LDL) binding to paracetamol-induced damaged hepatocytes of rats. Changes in levels of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, alkaline phosphatase, conjugated dienes and lipids of hepatocytes were significantly prevented by picroliv at different doses. The effect of picroliv on enzyme levels, LDL receptor binding and lipids in damaged hepatocytes was found to be comparable to silymarin, a known hepatoprotective agent.

Effect of picroliv on glutathione metabolism in liver and brain of Mastomys natalensis infected with Plasmodium berghei.

Administration of picroliv, the active principle from Picrorhiza kurrooa, at a dose of 6 mg/kg, po for two weeks showed significant protection against changes in liver and brain glutathione metabolism of Plasmodium berghei infected Mastomys natalensis. The depletion of reduced glutathione level and inhibition of glutathione-S-transferase, glutathione reductase and glutathione peroxidase activities due to P. berghei infection were markedly recovered by picroliv. The increased levels of lipid peroxidation products in damaged tissues were also reduced along with the recovery of glutathione metabolism.

Picroliv, picroside-I and kutkoside from Picrorhiza kurrooa are scavengers of superoxide anions.

Picroliv, the active principle of Picrorhiza kurrooa, and its main components which are a mixture of the iridoid glycosides, picroside-I and kutkoside, were studied in vitro as potential scavengers of oxygen free radicals. The superoxide (O2-) anions generated in a xanthine-xanthine oxidase system, as measured in terms of uric acid formed and the reduction of nitroblue tetrazolium were shown to be suppressed by picroliv, picroside-I and kutkoside. Picroliv as well as both glycosides inhibited the non-enzymic generation of O2- anions in a phenazine methosulphate NADH system. Malonaldehyde (MDA) generation in rat liver microsomes as stimulated by both the ascorbate-Fe2+ and NADPH-ADP-Fe2+ systems was shown to be inhibited by the Picroliv glycosides. Known antioxidants tocopherol (vitamin E) and butylated hydroxyanisole (BHA) were also compared with regard to their antioxidant actions in the above system. It was found that BHA afforded protection against ascorbate-Fe(2+)-induced MDA formation in microsomes but did not interfere with enzymic or non-enzymic O2- anion generation; and tocopherol inhibited lipid peroxidation in microsomes by both prooxidant systems and the generation of O2- anions in the non-enzymic system but did not interfere with xanthine oxidase activity. The present study shows that picroliv, picroside-I and kutkoside possess the properties of antioxidants which appear to be mediated through activity like that of superoxide dismutase, metal ion chelators and xanthine oxidase inhibitors.

Hypolipidemic activity of Achyranthus aspera Linn in normal and triton induced hyperlipemic rats.

The alcoholic extract of A. aspera, at 100 mg/kg dose lowered serum cholesterol (TC), phospholipid (PL). triglyceride (TG) and total lipids (TL) levels by 60, 51, 33 and 53% respectively in triton induced hyperlipidemic rats. The chronic administration of this drug at the same doses to normal rats for 30 days, lowered serum TC, PL, TG and TL by 56, 62, 68 and 67% respectively followed by significant reduction in the levels of hepatic lipids. The faecal excretion of cholic acid and deoxycholic acid increased by 24 and 40% respectively under the action of this drug. The possible mechanism of action of cholesterol lowering activity of A. aspera may be due to rapid excretion of bile acids causing low absorption of cholesterol.

Effect of picroliv on protein and nucleic acid synthesis.

Oral administration of picroliv, a standardised fraction of roots and rhizomes of Picrorhiza kurroa, showed stimulation of nucleic acid and protein synthesis in rat liver. Results are comparable with a standard hepatoprotective agent, silymarin.

Hepatoprotective activity of picroliv against carbon tetrachloride-induced liver damage in rats.

Administration of carbon tetrachloride to normal rats increased activities of hepatic 5(1)-nucleotidase, acid phosphatase, acid ribonuclease while the activities of succinate dehydrogenase, glucose 6-phosphatase, superoxide dismutase and cytochrome P450 were decreased. Levels of lipid peroxides, total lipids and cholesterol of liver were also increased. The activities of serum glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and alkaline phosphatase were increased. Other serum parameters showing changes after carbon tetrachloride were: bilirubin, proteins, cholesterol, triglycerides and lipoprotein-X. Picroliv (from the plant Picrorhiza kurroa) in doses of 6 and 12 mg/kg provided a significant protection against most of the biochemical alterations produced by carbon tetrachloride. The degree of protection afforded by picroliv, when administered simultaneously or as a pretreatment was almost equal.

Evaluation of hepatoprotective activity of picroliv (from Picrorhiza kurroa) in Mastomys natalensis infected with Plasmodium berghei.

Administration of picroliv, a standardized fraction of alcoholic extent of Picrorhiza kurroa (3-12 mg/kg/day for two weeks) simultaneously with P. berghei infection showed significant protection against hepatic damage in Mastomys natalensis. The increased levels of serum glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase, lipoprotein-X (LP-X) and bilirubin in the infected animals were marked reduced by different doses of picroliv. In the liver, picroliv decreased the levels of lipid peroxides and hydroperoxides and facilitated the recovery of superoxide dismutase and glycogen. Picroliv had no effect on the degree of parasitaemia.

Stimulation of low density lipoprotein receptor activity in liver membrane of guggulsterone treated rats.

Chronic feeding of guggulsterone to rats showed hypolipidaemic activity in blood serum and liver membrane lipids. The decrease in serum cholesterol is associated with enhanced uptake of LDL by the liver through receptor mediated endocytosis, located on the surface of the cell membrane. In the present communication it has been shown that membranes prepared from liver of guggulsterone treated rats exhibit up to 87% increase in binding sites for human 125I-LDL. Significant decrease in lipid levels of serum as well as of membrane were observed. Lipid lowering activity of the drug in relation to LDL catabolism and other possible mechanisms have been explained.

Hepatoprotective activity of silymarin against hepatic damage in Mastomys natalensis infected with Plasmodium berghei.

Silymarin, a flavolignan from the seeds of Silybum marianum, showed significant hepatoprotective activity in P. berghei-induced hepatic damage in M. natalensis, as assessed by changes in several serum and liver biochemical parameters. Changes in lipoprotein-X, GOT, GPT, alkaline phosphatase and bilirubin were found to be protected by silymarin at different doses. Maximum activity was observed at a dose of 5 mg/kg bw, po. Silymarin had no effect on parasitaemia.