Cytoprotective effect of piperine against benzo[a]pyrene induced lung cancer with reference to lipid peroxidation and antioxidant system in Swiss albino mice

The cytoprotective effect of piperine on benzo[a]pyrene (B[a]P) induced experimental lung cancer was investigated in male Swiss albino mice. Oral administration of piperine (100 mg/kg body wt.) effectively suppressed lung cancer initiated with B[a]P as revealed by the decrease in the extent of lipid peroxidation with concomitant increase in the activities of enzymatic antioxidants (superoxide dismutase, catalase and glutathione peroxidase) and non-enzymatic antioxidant (reduced glutathione, vitamin E and vitamin C) levels when compared to lung cancer bearing animals. Our data suggest that piperine may extend its chemopreventive effect by modulating lipid peroxidation and augmenting antioxidant defense system.     

CNS activities of methanolic extract of Moringa oleifera root in mice

Methanolic extract (ME) of the root of Moringa oleifera was tested for possible pharmacological effects on experimental animals. ME potentiated significantly the sleeping time induced by pentobarbitone sodium, diazepam and meprobamate, showed analgesic properties and also potentiated analgesia induced by morphine and pethidine. Pretreatment with ME caused significant protection against strychnine- and leptazol-induced convulsions. The behavioural studies on mice indicate the CNS depressant nature of ME.     

Hepatoprotective effect of Picrorrhiza kurroa on tissue defence system in d-galactosamine-induced hepatitis in rats

In d-galactosamine-induced hepatitis in rats, a significant increase of lipid peroxidation and a decrease in liver antioxidant enzymes levels are observed. Pretreatment with the ethanol extract of Picrorrhiza kurroa prevented these alterations.     

Hepatoprotective effect of Ginkgoselect Phytosome in rifampicin induced liver injury in rats: evidence of antioxidant activity

The protective effects of Ginkgoselect Phytosome((R)) (GBP) on Rifampicin (RMP) induced hepatotoxicity and the probable mechanism(s) involved in this protection were investigated in rats. Liver damage was induced in Wistar rats by administering rifampicin (500 mg/kg, p.o.) daily for 30 days. Simultaneously, GBP at 25 mg/kg and 50 mg/kg, and the reference drug silymarin (100 mg/kg) were administered orally for 30 days/daily to RMP treated rats. Levels of marker enzymes (SGOT, SGPT and SALP), albaumin (Alb) and total proteins (TP) were assessed in serum. The effects of GBP on lipid peroxidation (LPO), reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR) were assayed in liver homogenates to evaluate antioxidant activity. GBP (25 and 50 mg/kg) and silymarin elicited a significant hepatoprotective activity by lowering the levels of serum marker enzymes and lipid peroxidation and elevated the levels of GSH, SOD, CAT, GPX, GR, Alb and TP in a dose dependant manner. The present findings suggest that the hepatoprotective effect of GBP in RMP induced oxidative damage may be related to its antioxidant and free radical scavenging activity.     

Geraniin and amariin,ellagitannins from Phyllanthus amarus, protect liver cells against ethanol induced cytotoxicity

Ethanol mediated free radical generation plays an important role in the pathogenesis of liver injuries and alcoholic liver diseases. In the present study two ellagitannins namely geraniin and amariin isolated from Phyllanthus amarus were examined for their ability to protect mouse liver slices against ethanol induced toxicity and possible mechanism of its protection. Oxidative stress markers such as, lipid peroxidation, protein carbonyl formation, amount of 8-hydroxy-2-deoxyguanosine and antioxidant enzymes levels were measured using specific biochemical assays. Poly (ADP-ribose) polymerase (PARP), Bax and Bcl2 were checked to assess the induction of apoptosis using western blots. The results showed that geraniin and amariin protected mouse liver slices against ethanol induced cytotoxicity. Both compounds inhibited oxidation of lipid, protein and formation of 8-hydroxy-2-deoxyguanosine, all of which were found to be elevated on exposure to ethanol. These compounds restored the antioxidant enzymes altered on ethanol exposure. Compounds also inhibited the cleavage of PARP and bax and restored Bcl2, induced on exposure to ethanol. In summary, both ellagitannins effectively protected mouse liver slices against ethanol induced cytotoxicity and apoptosis by reducing oxidative damage to biological molecules and modulating Bax/Bcl-2 ratio respectively, thus minimizing liver injury.     

Antihyperglycemic and antioxidant activities of total alkaloids from Catharanthus roseus in streptozotocin-induced diabetic rats

We evaluated the hypoglycemic and antioxidant effects of the total alkaloids of leaves and twigs of Catharanthus roseus Linn.(CTA) in streptozotocin(STZ)-induced diabetic rats. The hypoglycemic effect was measured by blood glucose and plasma insulin level. Oxidative stress was measured in heart, liver and kidney by levels of antioxidant markers, free radical scavengers and lipid peroxides i.e. superoxide dismutase(SOD), catalase(CAT), glutathione(GSH) and thiobarbituric acid reactive substances(TBARS). Biochemical parameters, i.e. aspartate aminotransferase(AST), alanine aminotransferase(ALT), alkaline phosphate(ALP) were observed in diabetic control and treated rats. Oral administration of CTA for30 days was followed by a significant(P \ 0.05) decrease in fasting blood glucose and increase in insulin level as compared with untreated diabetic rats. Also it significantly(P \ 0.05) reduced ALT, AST and ALP. The treatment also resulted in significant(P \ 0.05) reductions in GSH,SOD, CAT, and decrease in TBARS in the heart, liver and kidney of diabetic rats. The results suggest that CTA can effectively normalize the impaired antioxidant status in STZ-induced diabetes in a dose-dependent manner.CTA exerted rapid protective effects against lipid peroxidation by scavenging of free radicals and reducing the risk of diabetic complications.     

Celastrus paniculatus seed water soluble extracts protect cultured rat forebrain neuronal cells from hydrogen peroxide-induced oxidative injury

The effects of aqueous extracts of Celastrus paniculatus (CP) seeds were shown to have antioxidant properties in rats. In the study reported here, we have investigated the free radical scavenging capacity of three aqueous extracts (WSEs) obtained from CP seeds: a room temperature extract (WF); a hot water extract (HF); an acid extract (AF). All the WSEs exhibited a dose-dependent free radical scavenging capacity for 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and also for superoxide-generated assays (in vitro assays). In addition, we used enriched forebrain primary neuronal cell (FBNC) cultures to evaluate the neuroprotective effects of the three CP-WSE extracts on H(2)O(2)-induced toxicity. FBNC were pre-treated with the CP-WSE and then with H(2)O(2) to evaluate the protection afforded against H(2)O(2)-induced toxicity. The criteria for neuroprotection by the WSEs were based on a mitochondrial function test following the H(2)O(2)-induced neurotoxicity. All the WSEs significantly attenuated H(2)O(2)-induced neuronal death, and AF was the most effective in protecting the neuronal cells against oxidative injury caused by H(2)O(2). In 10 day FBNC, cellular superoxide dismutase activity was not affected by the WSEs or H(2)O(2), but catalase activity was decreased and levels of malondialdehyde were increased by H(2)O(2) treatment. When the neuronal cells were treated with WSEs prior to H(2)O(2) exposure, catalase activity was increased and levels of malondialdehyde were decreased significantly. The data presented here suggest that CP seed WSEs protected neuronal cells in part by their free radical scavenging properties, by reducing lipid peroxidation, and also by their ability to induce the antioxidant enzyme catalase. Our results indicate that WSEs might exert neuroprotective effects against increased oxidative stress resulting from free radical damage that is associated with a number of neurodegenerative diseases.     

Structural characterization and antioxidant activity of a low-molecular polysaccharide from Dendrobium huoshanense

The present study aimed at investigating the structural features and antioxidant activities of a polysaccharide fraction (DHP1A) obtained from Dendrobium huoshanense, a precious herb medicine in China. DHP1A mainly consisted of mannose (Man), glucose (Glc) and a trace of galactose (Gal), with a molecular weight of 6700 Da. Its backbone contained (1 → 4)-linked α-D-Glcp, (1 → 6)-linked α-D-Glcp and (1 → 4)-linked β-D-Manp, with a branch of terminal β-D-Galp. The in vitro antioxidant evaluation revealed that DHP1A had a remarkable inhibition effect on the FeCl₂-induced lipid peroxidation. Furthermore, DHP1A pretreatment decreased the production of malondialdehyde (MDA), and restored the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), as well as the level of glutathione (GSH) in the livers of CCl₄-treated mice. These results suggested that DHP1A was a potential antioxidant component in D. huoshanense.     

Thyroid inhibitory,antiperoxidative and hypoglycemic effects of stigmasterol isolated from Butea monosperma

Stigmasterol, isolated from the bark of Butea monosperma was evaluated for its thyroid hormone and glucose regulatory efficacy in mice. Its administration at 2.6 mg/kg/d for 20 days reduced serum triiodothyronine (T₃), thyroxin (T₄) and glucose concentrations as well as the activity of hepatic glucose-6-phophatase (G-6-Pase) with a concomitant increase in insulin indicating its thyroid inhibiting and hypoglycemic properties. A decrease in the hepatic lipid peroxidation (LPO) and an increase in the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) suggested its antioxidative potential. The highest concentration tested (5.2 mg/kg) evoked pro-oxidative activity.     

Protective effect of Codium fragile against UVB-induced pro-inflammatory and oxidative damages in HaCaT cells and BALB/c mice

Acute exposure to ultraviolet (UV) radiation causes pro-inflammatory responses via diverse mechanisms including oxidative stress. Codium fragile is a green alga of Codiales family and has been reported to exhibit anti-edema, anti-allergic, anti-protozoal and anti-mycobacterial activities. In this study, we have investigated a novel anti-inflammatory potential of C. fragile using in vitro cell culture as well as in vivo animal models. In HaCaT cells, buthanol and ethylacetate fractions of 80% methanol C. fragile extract (CFB or CFE) and a single compound, clerosterol (CLS) isolated from CFE attenuated UVB (60 mJ/cm²)-induced cytotoxicity and reduced expression of pro-inflammatory proteins including cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and tumor necrosis factor-α (TNF- α). Moreover, CFB, CFE and CLS effectively suppressed UVB-induced production of pro-inflammatory mediators such as prostaglandin E₂ (PGE₂) and nitric oxide (NO). In another experiment, topical application of CFB, CFE or CLS prior to UVB irradiation (200 mJ/cm²) on BALB/c mice, inhibited the UVB-elevated protein levels of COX-2, iNOS, and TNF-α. Furthermore, CFB, CFE and CLS suppressed oxidative damages caused by UVB irradiation for example lipid peroxidation and/or protein carbonylation, which seemed to be mediated by up-regulation of antioxidant defense enzymes. These results suggest that C. fragile could be an effective therapeutic agent providing protection against UVB-induced inflammatory and oxidative skin damages.     

Germination,osmotic adjustment,and antioxidant enzyme activities of gibberellin-pretreated <Emphasis Type="Italic">Picea asperata</Emphasis> seeds under water stress

Germination of dragon spruce (Picea asperata Mast.) seeds pretreated with gibberellin (GA) in response to water stress and changes in the levels of osmotic adjustments as well as in activities of antioxidant enzymes were investigated. With decreasing water potential caused by increasing concentrations of PEG 6000, germination percentage and germination index decreased gradually; the decrease was especially prominent under the serious water stress from PEG −0.6 MPa. In contrast, osmotic regulation substances (free proline and soluble sugar contents), lipid peroxidation (MDA), and activities of antioxidant enzyme (ascorbate peroxidase, catalase, and peroxidase) increased markedly with decreased water potential. Similarly, the values in all parameters under −0.6 MPa PEG treatment were markedly higher than the control and −0.2 MPa PEG treatment. These results suggested that P. asperata seed germination was insensitive to water stress. In addition, seeds pretreated with GA had increased tolerance to water stress as measured by germination percentage and germination index, osmotic regulation substance, and antioxidant enzyme activities.     

Effects of mechanical damage and herbivore wounding on H2O2 metabolism and antioxidant enzyme activities in hybrid poplar leaves

The changes of hydrogen peroxide (H₂O₂) metabolism and antioxidant enzyme activities in a hybrid poplar (Populus simonii × P. pyramidalis ‘Opera 8277’) in response to mechanical damage (MD) and herbivore wounding (HW) were investigated to determine whether H₂O₂ could function as the secondary messenger in the signaling of systemic resistance. Results show that H₂O₂ was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves. The activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were also enhanced. However, the H₂O₂ accumulation and antioxidant enzyme activities were inhibited in MD leaves through the pretreatment with DPI (which is a specific inhibitor of NADPH oxidase). The results of this study suggest that H₂O₂ could be systemically induced by MD and HW treatments, and H₂O₂ metabolism was closely related to the change in SOD, APX and CAT activities. A high level of antioxidant enzymes could decrease membrane lipid peroxidation levels and effectively induce plant defense responses. Foundation project: This research is supported by the Key Science Program of the Sate Forestry Administration of China (2006–59), and the National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science & Technology of China (2006BAD01A15; 2006BAD24B04). Biography: AN Yu (1982–), female, Postgraduate in College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P. R. China.     

Hepatoprotective effect of curcumin in lipopolysaccharide/-galactosamine model of liver injury in rats: relationship to HO-1/CO antioxidant system

This work studied a relationship between HO-1/CO system and lipid peroxidation with consequent effects on liver functions and NOS-2. We focused on curcumin pretreatment in rat toxic model of d-galactosamine and lipopolysaccharide. Hepatocyte viability, lipid peroxidation, antioxidant status, ALT and AST were evaluated. HO-1 and NOS-2 expressions and respective enzyme activity were determined. Curcumin caused decreases in ALT and AST levels as well as in lipid peroxidation. Furthermore, curcumin pretreatment increased liver HO-1 (2.4-fold, p = 0.001), but reduced NOS-2 (4.1-fold, p = 0.01) expressions. In conclusion, the tuning of CO/NO pathways is important in shedding light on curcumin's cytoprotective effects in this model.     

Protective effects of Picrorrhiza kurroa against HCl/ethanol-induced ulceration in rats

The antiulcerogenic effects of the ethanol extract of Picrorrhiza kurroa rhizomes and roots (PK) on HCl/ethanol-induced ulceration in rats with respect to acid/pepsin, lipid peroxidation, antioxidant status, proteins and glycoproteins in the gastric mucosa have been investigated. Oral pre-treatment with PK (100 mg/kg/day for 10 days) significantly prevented the induced ulceration and maintained the rats at near normal status.     

Effects of mechanical damage and herbivore wounding on H_2O_2 metabolism and antioxidant enzyme activities in hybrid poplar leaves

The changes of hydrogen peroxide(H2O2) metabolism and antioxidant enzyme activities in a hybrid poplar(Populus simonii ×P.pyramidalis ‘Opera 8277') in response to mechanical damage(MD) and herbivore wounding(HW) were investigated to determine whether H2O2 could function as the secondary messenger in the signaling of systemic resistance.Results show that H2O2 was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves.The activities of antioxida...     

Cytotoxic, cytoprotective and antioxidant effects of isolated phenolic compounds from fresh ginger

Twenty-nine phenolic compounds were isolated from the root bark of fresh (Yunnan) ginger and their structures fully characterized. Selected compounds were divided into structural categories and twelve compounds subjected to in-vitro assays including DPPH radical scavenging, xanthine-oxidase inhibition, monoamine oxidase inhibition, rat-brain homogenate lipid peroxidation, and rat pheochromocytoma PC12 cell and primary liver cell viability to determine their antioxidant and cytoprotective properties. Isolated compounds were also tested against nine human tumor cell lines to characterize anticancer potency. Several diarylheptanoids and epoxidic diarylheptanoids were effective DPPH radical scavengers and moderately effective at inhibiting xanthine oxidase. An enone–dione analog of 6-shogaol (compound 2) was isolated and identified to be most effective at protecting PC12 cells from H₂O₂-induced damage. Almost all tested compounds inhibited lipid peroxidation. Three compounds, 6-shogaol, 10-gingerol and an enone-diarylheptanoid analog of curcumin (compound 6) were identified to be cytotoxic in cell lines tested, with KB and HL60 cells most susceptible to 6-shogaol and the curcumin analog with IC₅₀ < 10 μM. QSAR analysis revealed cytotoxicity was related to compound lipophilicity and chemical reactivity. In conclusion, we observed distinct compounds in fresh ginger to have biological activities relevant in diseases associated with reactive oxygen species.     

Antiinflammatory, analgesic and antioxidant activities of the fruit of Foeniculum vulgare

Oral administration (200 mg/kg) of Foeniculum vulgare fruit methanolic extract exhibited inhibitory effects against acute and subacute inflammatory diseases and type IV allergic reactions and showed a central analgesic effect. Moreover, it significantly increased the plasma superoxide dismutase (SOD) and catalase activities and the high density lipoprotein-cholesterol level. On the contrary, the malondialdehyde (MDA) (as a measure of lipid peroxidation) level was significantly decreased in F. vulgare fruit methanolic extract group compared to the control group (P<0.05). These results seems to support the use of F. vulgare fruit methanolic extract in relieving inflammation.     

Monitoring the antioxidant activity of extracts originated from various Serratula species and isolation of flavonoids from Serratula coronata

The antioxidant effect of aqueous methanolic herb extracts of Serratula coronata, S. wolffii and S. tinctoria was investigated using both enzyme-dependent and enzyme-independent systems. The extracts displayed concentration-dependent inhibition of lipid peroxidation. Flavonoids and ecdysteroids present in the extracts were evaluated as antioxidant components. The flavonoid-containing fraction of the herb extract of S. coronata was more effective in lipid peroxidation than the ecdysteroid-containing fraction. This paper also reports the isolation of quercetin 3-O-methyl ether, apigenin, luteolin, quercetin, luteolin 4'beta-D-glucoside and quercetin 4'beta-D-glucoside from S. coronata.     

Antioxidant activity of heartwood extracts of Papua New Guinean woods

Antioxidant effects of methanol extracts from the heartwood of 23 Papua New Guinea (PNG) wood species were examined. The extract ofAmoora sp. (Meliaceae) showed the strongest antioxidant activity against lipid peroxidation in rabbit erythrocyte membrane and linoleic acid autoxidation. Also, the extract ofAmoora sp. showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicalscavenging activity. These results showed that the heartwood ofAmoora sp. is a possible source of antioxidative agents. The result of antioxidant activity-guided fractionation suggested that gallic acid, protocatechuic acid, and hydrolyzable tannins in the extract ofAmoora sp. caused the potent antioxidant activity.Part of this report was presented at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, 2001     

Antioxidant activity of banana flavonoids

The antioxidant activity of flavonoids from banana (Musa paradisiaca) was studied in rats fed normal as well as high fat diets. Concentrations of peroxidation products namely malondialdehyde, hydroperoxides and conjugated diens were significantly decreased whereas the activities of catalase and superoxide dismutase were enhanced significantly. Concentrations of glutathione were also elevated in the treated animals.