Dietary Flavonoids as Potential Natural Biological Response Modifiers Affecting the Autoimmune System

Can apricot kernels fatty acids delay the atrophied hepatocytes from progression to fibrosis in dimethylnitrosamine (DMN)-induced liver injury in rats?

Background and aims

The present study was aimed to analyze the chemical composition of ground apricot kernel (GAK) and examine its effect on hepatic fibrosis in vivo induced by dimethylnitrosamine (DMN) in rats.

Methods and results

Hepatic fibrosis was induced by intraperitoneal injections of 10 mg/kg DMN for 3 consecutive days each week over a period of 4 wk. The rats were randomly assigned to five groups of nine rats each: the negative control group (NC), the hepatic fibrosis group (PC), hepatic fibrosis supplemented with GAK (0.5 mg/kg/BW/rat), hepatic fibrosis supplemented with GAK (1 mg/kg/BW/rat) and hepatic fibrosis supplemented with GAK (1.5 mg/kg/BW/rat). Rats were killed, blood was collected and livers were excised for biochemical measurements and histological examination. Results indicate that the diet supplemented with GAK led to improving liver function, lipid peroxides, and liver CAT, SOD and GSH. These results were confirmed by liver histology. Hierarchically high levels f GAK (1.5 mg/kg/BW/rat) gave the best results compared to other tested levels.

Conclusion

This study demonstrates that GAK administration specifically (1.5 mg/kg/BW/rat) can effectively improve liver fibrosis caused by DMN, and may be used as a therapeutic option and preventive measure against hepatic fibrosis. Furthermore, a human trial would be applied specially GAK is a part of Egyptian diet. The act of why high amounts of GAK was improved biochemical values compared to low or moderate levels tested in this study may be due to increase levels of oleic acid and other polyphenols in apricot kernels

Chemical investigation of different crude extracts from Teucrium ramosissimum leaves. Correlation with their antigenotoxic and antioxidant properties

The effect of extracts obtained from Teucrium ramosissimum leaves on genotoxicity and SOS response induced by aflatoxin B(1) (0.5 μg/assay) as well as nitrofurantoin (5 μg/assay) was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The T. ramosissimum tested extracts exhibited no genotoxicity either with or without the external S9 activation mixture. However, all the extracts, particularly the total oligomers flavonoids (TOF) extract significantly decreased the genotoxicity induced by aflatoxin B(1) and nitrofurantoin. Antioxidant capacity of the tested extracts was evaluated using the enzymatic (xanthine/xanthine oxidase assay) (X/XOD) and the non-enzymatic (NBT/Riboflavine assay) systems. TOF extract was the most effective one in inhibiting both xanthine oxidase activity and NBT reduction. Our findings emphasize the potential of T. ramosissimum to prevent mutations and also its antioxidant effect.

Antioxidant activity and total phenolic content of aqueous and methanolic extracts of Jordanian plants: an ICBG project

As part of an International Cooperative Biodiversity Groups (ICBG) program to study Jordan's biodiversity, the relative levels of antioxidant activity and the total phenolic content of aqueous and methanolic extracts of a total of 95 plant species, all of Jordanian origin and those collected at random, have been measured. The total phenolic content of aqueous and methanolic extracts of the investigated plant species ranged from 4.4 to 78.3 mg and from 2.1 to 52.8 mg gallic acid equivalents g(-1) dry weight, respectively, while the total antioxidant capacity ranged from 20.0 to 916.7 and from 15.1 to 915.6 micromol Trolox equivalents g(-1) dry weight, respectively. Based on this collection, approximately 5% of assayed plants showed high levels of antioxidant activity. There was a significant linear correlation between antioxidant activity and total phenolic content for aqueous and methanolic extracts, suggesting that phenolic compounds were the predominant antioxidant components in the investigated plant species. Interestingly, a few of the collected plants had high-antioxidant activity yet "low" phenolic content includes Ceratonia siliqua and Viscum cruciatum. These plants may serve as sources of antioxidants with new chemotypes.

Factors influencing the relation between alcohol and cardiovascular disease

PURPOSE OF REVIEW

Light-to-moderate alcohol intake is known to have cardioprotective properties in some subsets of the population. This review focuses on factors that modify the relation between alcohol and cardiovascular disease.

RECENT FINDINGS

Several large American studies have shown that the J-shaped relation is influenced by age and coronary heart disease risk-factor status since only middle-aged and elderly and those already at risk of developing coronary heart disease seem protected by drinking alcohol. It has also been suggested that only those who have a steady - in contrast to a binge - intake of alcohol have benefits with regard to cardiovascular disease. Prospective studies from the UK, Sweden and Denmark have further suggested that wine drinkers have a lower mortality than beer and spirits drinkers.

SUMMARY

The J-shaped relation between alcohol intake and cardiovascular disease seems to be influenced by age, gender, drinking pattern and type of alcohol.

Epidemiologic evidence for the cardioprotective effects associated with consumption of alcoholic beverages

The impact of alcohol intake on mortality from all causes has been described in a large number of prospective population studies from many countries. Most have shown a J-shaped relation between alcohol intake and subsequent mortality, indicating that there are both beneficial and harmful effects of ethanol on health. The risk of death from ischemic heart disease is seen to be significantly increased, and highest among abstainers, but not significantly increased among heavy drinkers. Some studies have found plausible mechanisms for the beneficial effect of light to moderate drinking. Subjects with a moderate alcohol intake have a higher level of high density lipoprotein than abstainers. Further, moderate drinkers are seen to have a lower low density lipoprotein. Also, alcohol has a beneficial effect on platelet aggregation, and thrombin level in blood is higher among drinkers than among non-drinkers. In the other end of the range of intake, the ascending leg of the U-shaped curve has been explained by the increased risk of cirrhosis, pancreatitis, and development oropharynx, oesophagus, and breast cancer. In exploring the French paradox, it has been suggested that wine may have beneficial effects additional to that of ethanol. Recently, several prospective population studies have supported this idea. It is, however, also likely that the apparent additional beneficial effect of wine on health in addition to the effect of ethanol itself is a consequence of confounding.

Contribution of beverages to the intake of lipophilic and hydrophilic antioxidants in the Spanish diet

OBJECTIVE

To investigate the contribution of beverages to the intake of lipophilic and hydrophilic antioxidants in the Spanish diet.

DESIGN

This includes the following (i) estimation of the daily intakes of beverages in Spain, from national food consumption data obtained from annual surveys of 5400 households, 700 hotels and restaurants and 200 institutions; (ii) determination of total antioxidant capacity in the selected beverages using two complementary procedures: ferric reducing ability of plasma (FRAP), which measures the ferric reduction capacity, and ABTS, which measures the radical scavenging capacity; (iii) determination of the antioxidant capacity in both lipophilic and hydrophilic extracts of the beverages; (iv) determination of the antioxidant efficiency of the lipophilic and hydrophilic phase of the beverages; and (v) estimation of the intake of dietary antioxidants from beverages in comparison with the daily requirements of antioxidant vitamins C and E.

RESULTS

The contribution of beverages to the antioxidant intake in the Spanish diet is estimated at 1623 mg of vitamin E and 598 mg of vitamin C by FRAP, and 1521 mg of vitamin E and 556 mg of vitamin C by ABTS. Coffee is the main contributor (66 and 61% by FRAP and ABTS, respectively), followed by red wine (16 and 22%), fruit juices (6 and 5%), beer (4 and 5%), tea (3 and 5%) and milk (4 and 1%).

CONCLUSIONS

Beverages account for a very high proportion of dietary antioxidant intake as compared to intake of antioxidant vitamins C and E. Although their metabolic effect must be affected by the bioavailability of the antioxidants, the significance of this intake for antioxidant status and health should be considered.

Alcohol, type of alcohol, and all-cause and coronary heart disease mortality

Many studies from a variety of countries have shown a U- or J-shaped relation between alcohol intake and mortality from all causes. It is now quite well documented from epidemiologic as well as clinical and experimental studies that the descending leg of the curve results from a decreased risk of cardiovascular disease among those with light-to-moderate alcohol consumption. The findings that wine drinkers are at a decreased risk of mortality from cardiovascular disease compared to non-wine drinkers suggest that substances present in wine are responsible for a beneficial effect on the outcome, in addition to that from a light intake of ethanol. Several potential confounding factors still remain to be excluded, however.

Factors influencing the relation between alcohol and mortality--with focus on wine

The impact of alcohol intake on mortality has been described in a large number of prospective population studies from many countries. Most have shown a J-shaped relation between alcohol intake and subsequent mortality, indicating that there are both beneficial and harmful effects of ethanol on health. In exploring the French paradox, it has been suggested that wine may have beneficial effects additional to that of ethanol. Recently, several prospective population studies have supported this idea. However, it is also likely that the apparent additional beneficial effect of wine on health is confounding.

In vitro and ex vivo anti- and prooxidant components of Cichorium intybus

The water soluble antioxidant properties of Cichorium intybus var. Silvestre, whose production zone is around Chioggia, Italy, were investigated. Vegetable juices were obtained by centrifugation, and (1) filtration at 2 degrees C; (2) filtration at 25 degrees C, and stored for 3 h; (3) boiled for 30 min at 102 degrees C, and then analysed. The antioxidant properties were evaluated in vitro as antioxidant activity (AA) (model system beta-carotene-linoleic acid) and ex vivo as protective activity (PA) against rat liver cell microsome lipid peroxidation measured as 2-thiobarbituric acid-reactive substances (TBA-RS) generated by peroxide degradation. All the vegetable juices showed high but very variable AA (> 83%) and PA (> 64%). After dialysis and analysis of fractions it was shown that the vegetable contained both biological antioxidant and prooxidant compounds. The prooxidants had MW < 3000, conversely the very active antioxidants (PA = 100%) had MW > 15,000. Electrophoretic analysis revealed that the most active fraction was a complex mixture of brown components at MW > 300,000.

Prune suppresses ovariectomy-induced hypercholesterolemia in rats

Elevated cholesterol among women who have experienced natural or surgical menopause has been linked to ovarian hormone deficiency. The purpose of this study was to investigate the efficacy of prune, a good source of dietary fiber and phytochemicals, on lowering cholesterol in an ovariectomized (ovx) rat model. Forty-eight 90-day-old female Sprague-Dawley rats were randomly assigned to four groups: sham-operated (sham) + control diet, ovx + control diet, ovx + low-dose (LD; 5%) prune, and ovx + high-dose (HD; 25%) prune. After 45 days of treatment, rats were euthanized and tissues were collected for analyses. Ovariectomy elevated serum total cholesterol by 22% compared with sham, and HD prune diet prevented this increase without affecting high density lipoprotein cholesterol concentrations. Animals fed the HD prune diet had 13% lower liver total lipids compared with ovx animals. The findings of this study showed that prune exhibits hypocholesterolemic properties in ovarian hormone deficiency. Dose-response studies should be conducted to establish the effectiveness of prune in prevention of hypercholesterolemia in postmenopausal women who are not on estrogen replacement therapy and seek dietary alternatives. Mechanistic studies also are needed to establish its mode of action.

Accumulation of (-)-epicatechin metabolites in rat plasma after oral administration and distribution of conjugation enzymes in rat tissues

Absorption of orally administered (-)-epicatechin (EC) in rats was studied to obtain plasma pharmacokinetic profiles of EC metabolites. Rats were administered 172 micromol/kg body weight of EC, and blood was collected from the tail for 8 h after administration. Seven groups of compounds possessing the basic structure of EC were identified by using a combination of enzymatic hydrolysis, HPLC and electron impact mass spectrometry. Metabolites were quantified with a new, simple and sensitive method using HPLC with electrochemical detection. Ingested EC was absorbed from the alimentary tract and was present in the rat common blood circulation in the form of glucuronide and/or sulfate conjugates. The activity of conjugative enzymes in rat tissues was studied. The highest activity of glucuronosyltransferase was found in the intestinal mucosa of both of the small and large intestine; the highest activity of phenolsulfotransferase occurred in the liver, and that of catechol-O-methyl transferase was found in the liver and kidney. It has been proposed that the first detoxification step of dietary EC, namely, glucuronidation, occurs at the level of the intestinal mucosa in rats, and EC enters the common blood circulation exclusively in the glucuronized form. The compound is then sulfated in the liver and methylated in the liver and kidney. Because ingested EC undergoes extensive conjugation, its biological activities previously demonstrated in vitro may not be occurring in in vivo systems.