Short- and long-term exposure to low levels of pesticide and flavonoid mixtures modify endogenous antioxidants in tissues of rats

Environmental impact of molecularly imprinted polymers used as analyte sorbents in mass spectrometry

The molecularly imprinted polymers (MIPs) with the following herbicides used as templates 2,4-dichlorophenoxyacetic acid (2,4-D) or 4-chloro-2-methylphenoxy- acetic acid (MCPA) were synthesized by precipitation polymerization technique using 4-vinylpyridine (4-VP) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linking agent, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator in methanol solvent. For the flavonoid MIPs, rutin (Ru) and quercetin (Q) were used as templates and synthesized via a similar technique, utilizing acrylamide (AA) as a functional monomer. Analysis of binding in the molecularly imprinted and non-imprinted polymer (NIP) has proved that MIP shows a higher affinity towards the analytes, compared to NIP. MIP was used to determine analytes in water using the Flowing Atmospheric-Pressure Afterglow Mass Spectrometry (FAPA-MS) technique. In this approach, the method limit of detection (MLOD) of 2,4-D, MCPA, Ru, and Q in MIP was 4, 3, 10, and 5 μg in 1 g MIP, respectively. The release kinetics of the analytes from MIP and their stability in water was studied. The cultures of Tetradesmus obliquus (Turpin) M.J. Wynne and Daphnia magna Straus were used for in vivo toxicity studies revealing that only Ru-MIP and Q-MIP had negative effect on the living organisms used in the bioassays.

Behavioral impairment and neurotoxic responses of silver catfish Rhamdia quelen exposed to organophosphate pesticide trichlorfon: Protective effects of diet containing rutin

Trichlorfon is an organophosphate pesticide used extensively for controlling ectoparasites in aquaculture. Studies have found that trichlorfon caused environmental pollution and severe neurotoxic effects in several freshwater species. Feed additives such as flavonoids may reduce or prevent pesticide-induced toxicity in fish. The aim of the present study was to determine whether acute exposure to trichlorfon impairs behavior and causes oxidative damage in brains of silver catfish (Rhamdia quelen). We also sought to determine whether rutin would be capable of preventing or reducing these effects. Silver catfish were divided into four groups: groups A and C received basal feed, while groups B and D received feed containing 3 mg rutin/kg diet for 21 days. After 21 days, groups C and D were exposed for 48 h to a nominal concentration of 11 mg trichlorfon/L water. Fish exposed to trichlorfon showed significantly longer distances travelled and swimming performances than did unexposed fish. Cerebral levels of reactive oxygen species and lipid peroxidation were significantly higher in fish exposed to trichlorfon than in unexposed fish, while cerebral superoxide dismutase, catalase, glutathione peroxidase, and acetylcholinesterase (AChE) activities were significantly lower. Taken together, our findings suggest that dietary supplementation rutin completely prevented all alterations elicited by trichlorfon, except for cerebral AChE activity; the latter remained significantly lower compared to the unexposed group. In summary, rutin prevents trichlorfon-induced neurotoxicity in silver catfish.

Metabonomic analysis of the protective effect of quercetin on the toxicity induced by mixture of organophosphate pesticides in rat urine

The present study aims to investigate the protective effect of quercetin against the joint toxic action induced by the mixture of four organophosphate pesticides (mixture-OPs) (dimethoate, acephate, dichlorvos, and phorate) at their corresponding no observed adverse effect level (NOAEL) using metabonomics. Rats were randomly divided into control, quercetin-treated, mixture-OPs-treated, and quercetin plus mixture-OPs-treated groups. Mixture-OPs and quercetin were given to the rats daily through drinking water and intragastric administration, respectively, for 90 days. The metabonomic profiles of rat urine were analyzed using ultra-performance liquid chromatography–mass spectrometry (UPLC/MS). The 14 metabolites significantly changed in the treatment groups compared with the control group, including the biomarkers of OPs exposure (dimethylphosphate, dimethyldithiophosphate, diethylphosphate) and the metabolites of quercetin (quercetin and isorhamnetina). The intensities of gentisic acid, creatinine, suberic acid, hippuric acid, uric acid, and citric acid significantly decreased, whereas the intensities of 7-methylguanine, estrone sulfate, and cholic acid significantly increased, in the mixture-OPs-treated group compared with the control group ( p < 0.01). The variation tendency of the aforementioned metabolites was significantly ameliorated in the high-dose quercetin (50 mg/(kg bw day)) plus mixture-OPs-treated group compared with the mixture-OPs-treated group ( p < 0.05). However, the intensities of these metabolites in the high-dose quercetin plus mixture-OPs-treated group were still significantly different from those of the control group ( p < 0.05). Results indicated that high dose of quercetin elicits a partial protective effect on the toxicity induced by mixture-OPs, including fatty acid and energy metabolism, antioxidant defense system, DNA damage, and liver and kidney function.

Changes in antioxidant status of porcine ovarian granulosa cells after quercetin and T-2 toxin treatment

The aim of this study was to determine the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), production of reactive oxygen species (ROS), and total antioxidant status (TAS) in porcine ovarian granulosa cells after quercetin and T-2 toxin exposure in vitro. Porcine ovarian granulosa cells were incubated with quercetin and T-2 toxin separately or in mutual combination at the doses of 1 ng/mL, 10 ng/mL, 100 ng/mL, and the control group without any additions for 24 h. In this study T-2 toxin developed stress reaction in porcine ovarian granulosa cells and increased generation of ROS. Quercetin had no effect in elimination of ROS generation induced by T-2 toxin, but was effective in maintaining and increasing of TAS, activities of SOD and GPx in porcine granulosa cells in vitro. These results contribute towards the understanding of cellular stress and its response.

Onion extract (Allium cepa L.), quercetin and catechin up-regulate paraoxonase 1 activity with concomitant protection against low-density lipoprotein oxidation in male Wistar rats subjected to oxidative stress

BACKGROUND

Paraoxonase 1 (PON1) protects the oxidative modification of low-density lipoprotein (LDL) and is a major anti-atherosclerotic protein component of high-density lipoprotein. We explored the effect of onion extract and flavonoids (quercetin and catechin) in the regulation of PON1 expression and correlating with oxidised LDL levels in male Wistar rats subjected to mercuric chloride (HgCl₂) induced oxidative insult. Rats were divided into eight groups: Control, Experimental (HgCl₂), Experimental + onion/catechin/quercetin, Positive control (Normal + onion/catechin/quercetin). Treatment continued for 4 weeks.

RESULTS

PON1 activity and radical scavenging activity decreased in the Experimental group (P < 0.001) with increased susceptibility of LDL for oxidation and plasma malondialdehyde levels (P < 0.001). Onion extract significantly attenuated the adverse effects of HgCl₂ by up-regulating PON1 activity (P < 0.05), radical scavenging activity (P < 0.01), and protected against LDL oxidation (P < 0.001) and lipid peroxidation (P < 0.01). Similar effects were observed with quercetin and to a lesser extent with catechin.

CONCLUSIONS

The findings may explain the anti-atherosclerotic effect of onion and also foods containing quercetin and catechins.

Alleviation of podophyllotoxin toxicity using coexisting flavonoids from Dysosma versipellis

Podophyllotoxin (POD) is a lignan-type toxin existing in many herbs used in folk medicine. Until now, no effective strategy is available for the management of POD intoxication. This study aims to determine the protective effects of flavonoids (quercetin and kaempferol) on POD-induced toxicity. In Vero cells, both flavonoids protected POD-induced cytotoxicity by recovering alleviating G2/M arrest, decreasing ROS generation and changes of membrane potential, and recovering microtubule structure. In Swiss mice, the group given both POD and flavonoids group had significantly lower mortality rate and showed less damages in the liver and kidney than the group given POD alone. As compared to the POD group, the POD plus flavonoids group exhibited decreases in plasma transaminases, alkaline phosphatase, lactate dehydrogenase, plasma urea, creatinine and malondialdehyde levels, and increases in superoxide dismutase and glutathione levels. Histological examination of the liver and kidney showed less pathological changes in the treatment of POD plus flavonoids group. The protective mechanisms were due to the antioxidant activity of flavonoids against the oxidative stress induced by POD and the competitive binding of flavonoids against POD for the same colchicines-binding sites. The latter binding was confirmed by the tubulin assembly assay in combination with molecular docking analyses. In conclusion, this study for the first time demonstrated that the coexisting flavonoids have great protective effects against the POD toxicity, and results of this study highlighted the great potential of searching for effective antidotes against toxins based on the pharmacological clues.

Investigation of STW 5 (Iberogast®) preventive effects in experimental sepsis

CONTEXT

STW 5 (Iberogast(®)) is a well known herbal combination drug containing glycosides and flavonoids for which multiple pharmacological properties have been shown.

OBJECTIVE

In this study, attempts were made to assess whether STW 5, an aqueous ethanol solution, has a preventive effect against liver and lung pathological damage in rats after experimental induction of sepsis [cecal ligation and puncture (CLP)].

MATERIALS AND METHODS

Experimental sepsis was induced in rats using CLP operation. The rats (n = 36) were divided into six groups (six/group): Sham-operated (SOP); CLP; CLP + STW 5 (2.5, 5 and 10 mg/kg) and CLP + indomethacin. The drugs were injected intraperitoneally immediately after sepsis induction.

RESULTS

It was found that induction of sepsis 24 h after CLP was associated with significant liver and lung damage, also remaining after STW 5 administration.

DISCUSSION AND CONCLUSION

It appears that STW 5, which has a pronounced efficacy in functional gastro-intestinal diseases, has no effect on septic liver and lung damage in the CLP rat model.

Protective effects of catechin and quercetin on antioxidant status, lipid peroxidation and testis-histoarchitecture induced by chlorpyrifos in male rats

Mature male Wistar rats were given chlorpyrifos (5.4 mg/kg, 1/25 of the oral LD(50)), catechin (20 mg/kg),quercetin (20 mg/kg), catechin plus chlorpyrifos, and quercetin plus chlorpyrifos daily via gavage for four weeks. No statistical differences were found in the catechin-only and quercetin-only groups compared with the control group. By the end of the fourth week, chlorpyrifos alone increased the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), while decreased glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities compared with the control group in rat testis tissues. In the catechin-plus-chlorpyrifos and quercetin-plus-chlorpyrifos groups, there were statistically significantly decreased MDA levels, SOD and CAT activities, while increased GPx and GST activities compared with the chlorpyrifos-only group. Light microscopic analyses revealed that chlorpyrifos-only induced numerous histopathological changes in the testis tissues. Milder pathological alterations were observed in rats catechin-plus-chlorpyrifos, and quercetin-plus-chlorpyrifos. Thus, it appears that catechin and quercetin ameliorate chlorpyrifos induced toxicity except histopathological changes in rat testis tissues.

Influence of flavonoid extracts from celery on oxidative stress induced by dichlorvos in rats

The present work was to investigate the effects of flavonoid extracts from celery on oxidative stress induced by dichlorvos (DIC) in male Wistar rats maintained on a normal diet. The rats were given DIC through intragastric administration by the dose of 7.2 mg/kg·body weight (bw)/day and additionally added 5% flavonoid extracts to the diet for 4 weeks continuously. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST) and the content of malondialdehyde (MDA) in livers of rats were measured at the end of the experiment. Under the influence of DIC, there were significant decrease in the activities of SOD, CAT and GST and significant increase in GPx activity and MDA content. The results also showed that the activities of SOD, GST and CAT in the DIC-treated group declined significantly when compared with the flavonoid extracts group and the DIC + flavonoid extracts group, respectively. With regard to GPx activity and MDA content, significant increase were showed in the DIC-treated group in comparison to those in the flavonoid extracts group and the DIC + flavonoid extracts group, respectively. The observations presented lead us to conclude the harmful effects of DIC during the exposure and the protective role of flavonoids in minimizing these effects.

Heart and kidney oxidative stress status in septic rats treated with caraway extracts

CONTEXT

Carum carvi L., (Umbelliferae) known as caraway, is a famous traditional herbal plant supposed to contain active components with pharmacological properties.

OBJECTIVE

In this study, the effects of caraway extracts on preventing sepsis induced by oxidative tissue injuries have been investigated by measuring heart and kidney oxidative stress parameters.

MATERIALS AND METHODS

 Sepsis was induced in rats (n = 6) by experimental cecal ligation and puncture (CLP) model. Then, either hydroalcoholic extract or essential oils (50 and 100 mg/kg body weight) were injected intraperitonially immediately after CLP operation. Twenty-four hours after CLP, the rats were anesthetized when kidney and heart tissues were removed to analyze the tissue oxidative stress parameters, that is, glutathione (GSH) and lipid peroxidation (LP).

RESULTS

Sepsis induction caused a significant increase in kidney but not heart LP, indicating that kidney was more affected by sepsis induction than heart. Kidney LP and plasma urea/creatinine ratio levels were readily reversed in rats treated with essential oils but not in those treated with hydroalcoholic extract. Unlike LP, the heart and kidney GSH levels were not affected in all treated groups.

DISCUSSION AND CONCLUSION

Our data imply that caraway oils probably have a protective role in kidney tissue against oxidative injury in advanced stages of sepsis.

Antioxidant status and selected biochemical parameters of porcine ovarian granulosa cells exposed to lead in vitro

The objective of this study was to determine the activity of superoxide dismutase (SOD), total antioxidant status (TAS) and release of calcium, phosphorus, magnesium, sodium, potassium, total lipids, totals proteins, glucose, cholesterol and triglycerides by porcine ovarian granulosa cells cultured in vitro after lead acetate administration. The parameters were analyzed using semi-automated clinical chemistry analyzer Microlab 300, microprocessor-controlled analyzer EasyLite and spectrophotometer Genesys 10. Cells were cultured with lead acetate trihydrate [Pb(CH(3)COO)(2).3H(2)O] as follows: group Max (5 mg Pb(CH(3)COO)(2).3H(2)O/10 mL), group A (2.5 mg/10 mL), group B (0.83 mg/10 mL), group C (0.625 mg/10 mL), group D (0.455 mg/10 mL) and the control group without lead exposure for 18 hrs. The highest TAS was estimated in the control group without lead treatment in comparison with other groups (MAX, A, B, C, D). Statistical analyses showed significantly lower value (P < 0.05) in group B. The activity of SOD was the lowest in the control group in comparison to those exposed to in vitro lead culture. A significant decrease (P < 0.05) of calcium content in group MAX in comparison with control group was determined. Release of phosphorus by ovarian granulosa cells was significantly lower (P < 0.05; 0.01; 0.001) in all the treated groups in comparison with control group. Lead was found to stimulate the release of magnesium and potassium by granulosa cells, but the increase remained statistically insignificant. The highest concentration of glucose was noted in control group, but the differences were not significant either. No significant differences (P > 0.05) were detected in concentration of other studied parameters among observed groups, too.