Antioxidant activity of oak (Quercus) leaves infusions against free radicals and their cardioprotective potential

Investigation of phytotherapeutic potential of herbal mixtures and their effects on salbutamol induced cardiotoxicity and hyperlipidemia in rabbits

BACKGROUND

Cardiovascular diseases (CVDs) are the major cause of deaths all over the world. The high level of blood cholesterol and oxidative stress are major risk factors for heart diseases. The phytotherapeutics have attracted attention as potential agents for preventing and treating oxidative stress associated diseases. The objective of present study was to evaluate the synergetic cardio-protective and antilipidemic potential of medicinal plants viz. Coriandrum sativum, Piper nigrum and Cactus grandiflorus. Cardio-protective and anti-lipidemic potential of herbal mixture was evaluated against salbutamol induced cardiotoxicity in rabbits. For this purpose, rabbits were divided into six groups as normal control, salbutamol control, curative and standard drug curative.

RESULTS

Salbutamol significantly (p < 0.05) increased the level of serum cardiac biomarkers (ALT, CK-MB, AST and LDH) and lipids (LDL, triglycerides, cholesterol) in rabbits. The prior and post administration of herbal mixture significantly (p < 0.05) lowered the elevated level of serum cardiac biomarkers and lipids equal to normal control. Gross pathological examination revealed that heart of salbutamol control animals became hardened, congested and were enlarged than preventive and curative groups. The phytotherapeutic analysis of medicinal plants revealed the presence of phenols, tannins, alkaloids and steroids.

CONCLUSION

The results showed that this herbal mixture has strong cardio-protective and anti-lipidemic potential.

Therapeutic Efficacy of Aerobic Exercise Training along with Oak Husk Hydroalcoholic Extract for Amelioration of Inflammation in Obese Elderly Male Mice

BACKGROUND

Fibrinogen and interleukin-1β as a proinflammatory cytokine and interleukin-10 and nesfatin-1 as an anti-inflammatory cytokine have an important role in the development and prevention of systemic inflammation and incidence of obesity-induced diseases. Thus, this study is aimed at the interaction effects of aerobic training and oak husk hydroalcoholic extract consumption on plasma levels of fibrinogen, interleukin-1β, nesfatin-1, and interleukin-10 in obese elderly male mice.

MATERIALS AND METHODS

In this experimental study, 40 fat male mice were fed a high-fat diet for 4 weeks to induce obesity, and subsequently, they were divided randomly into four groups: control, supplement, exercise-placebo, and exercise-supplement. The training groups performed aerobic exercise 5 days a week for 6 weeks (approximately 80-75% VOmax 2). The supplement groups received a solution of oak husk hydroalcoholic extract at a dose of 20 milligram per kilogram of body weight for 6 weeks. Blood samples were taken 48 h after the last training session, and the levels of IL-10, fibrinogen, IL-1β, and nesfatin-1 were measured. Data were analyzed using one-way ANOVA and LSD post hoc tests.

RESULTS

The results showed that six-week training and oak husk hydroalcoholic extract consumption significantly increased the levels of IL-10 and nesfatin-1 in experimental groups (P < 0.001). Also, the levels of fibrinogen and IL-1β decreased significantly in training groups. Averages between group variations of all indicators were statistically significant, and they were more meaningfully pronounced in the exercise-supplement group than other groups (P ≤ 0.05).

CONCLUSIONS

Considering the results of the present study, the use of moderate aerobic exercise and oak husk hydroalcoholic extract is recommended to reduce the risk of obesity; it may also have a positive effect on inflammatory factors.

Development and optimization of a high-throughput HPLC-MS/MS method for the simultaneous determination of naringenin and its valine carbamate prodrug in rat plasma

A valine carbamate prodrug of naringenin (NAR) called 4'V was synthesized to enhance its oral bioavailability because of low water solubility and poor membrane permeability of NAR. This study developed and fully validated a sensitive, rapid, and robust HPLC-MS/MS method for the simultaneous determination of NAR and 4'V in plasma. The analytes were treated using liquid-liquid extraction, separated on a Phenomenex Kinetex XB-C₁₈ column, and detected using a triple-quadrupole tandem mass spectrometer equipped with an electrospray ionization interface. The analytes were eluted within only 4 min by gradient procedure. The excellent linear correlations were validated over the range of 4-400 ng/mL (r = 0.9990) for NAR and 2-2000 ng/mL (r = 0.9951) for 4'V, with lower limits of quantification of 4 and 2 ng/mL, respectively. For all quality control samples, the intra-day and inter-day precision and accuracy were within ±15%. The validated method was economical, high throughput, and reliable and was first successfully applied to a pharmacokinetic study of NAR and 4'V after oral administration to Sprague-Dawley rats. The results of the pharmacokinetic study demonstrated that the idea of amino acid carbamate prodrug is a promising strategy to improve the bioavailability of NAR.

Protection of natural antioxidants against low-density lipoprotein oxidation

This chapter reports essential information about the protective action of antioxidants against LDL oxidation. The activity of individual compounds (tocopherols, vitamin C, phenolic compounds) as well as extracts obtained from plant material (cereals, fruits, legumes, nuts, mushrooms, by-products of food industry) is reported. The structure-antioxidant activity relationship of phenolic compounds is discussed. This article summarizes the findings to date of both in vitro and in vivo studies using foods or phenolic extracts isolated from foodstuffs at inhibiting the incidence of LDL oxidation. This chapter summarizes also the reportings to date of in vivo studies using foods or beverages at inhibiting the incidence of LDL oxidation.

The Potential Protective Effects of Phenolic Compounds against Low-density Lipoprotein Oxidation

BACKGROUND

The exact mechanism(s) of atherosclerosis in humans remains elusive, but one theory hypothesizes that this deleterious process results from the oxidative modification of low-density lipoprotein (LDL). Research suggests that foods rich in dietary phenolic compounds with antioxidant activity can mitigate the extent of LDL oxidation in vivo. With regard to the different classes of flavonoids, there appears to be a structurefunction relationship between the various moieties/constituents attached to the flavonoids' three ring system and their impact at retarding LDL oxidation.

METHODS

This article summarizes the findings to date of both in vitro and in vivo studies using foods or phenolic extracts isolated from foodstuffs at inhibiting the incidence of LDL oxidation. Three bases: SCOPUS, Web Science, and PubMed were used for search.

RESULTS

An often used method for the determination of antioxidant properties of natural phenolic compounds is the LDL oxidation assay. LDLs are isolated from human plasma and their oxidation is induced by Cu2+ ions or 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH). The sample is incubated with a phenolic extract or individual/isolated phenolic compounds. LDL oxidation is then monitored by various chemical methods (e.g., measurement of the generation of conjugated dienes and trienes). This technique confirmed the antioxidant properties of several extracts as obtained from plant material (e.g., grapes, berries, orange, grapefruit, coffee, tea, chocolate, olives, nuts) as well as the individual phenolic compounds (e.g., luteolinidin, apigenidin, caffeic acid, chlorogenic acid, catechin, quercetin, rutin). Several studies in vivo confirmed protective effects of phenolic compounds against LDL oxidation. They covered the healthy subjects with hyperlipidaemia, overweight, obesity, metabolic syndrome, heavy smokers, patients receiving haemodialysis, patients with peripheral vascular disease, and subjects at high cardiovascular risk. The studies comprise individuals of all ages, and the number of participants in the different experiments varied widely.

CONCLUSION

Properly designed double-blind, placebo-controlled randomised clinical trials offer stronger evidence as to the impact of dietary phenolics consumption at retarding LDL oxidation. More such clinical trials are needed to strengthen the hypothesis that foods rich in dietary phenolic compounds with antioxidant activity can mitigate the extent of LDL oxidation in vivo.

Oak kombucha protects against oxidative stress and inflammatory processes

Black tea infusion is the common substrate for preparing kombucha; however other sources such as oak leaves infusions can be used for the same purpose. Almost any white oak species have been used for medicinal applications by some ethnic groups in Mexico and could be also suitable for preparing kombucha analogues from oak (KAO). The objective of this research was to investigate the antioxidant activity and anti-inflammatory effects of KAO by examining its modulation ability on macrophage-derived TNF-alpha and IL-6. Herbal infusions from oak and black tea were fermented by kombucha consortium during seven days at 28 °C. Chemical composition was determined by LC-ESI-MS/MS. The antioxidant activity of samples against oxidative damage caused by H₂O₂ in monocytes activated (macrophages) was explored. Additionally, it was determined the anti-inflammatory activity using lipopolysaccharide (LPS) - stimulated macrophages; in particular, the nitric oxide (NO), TNF-alpha, and IL-6 production was assessed. Levels of pro-inflammatory cytokines IL-6 and TNF-alpha were significantly reduced by the sample treatment. Likewise, NO production was lower in treatment with kombucha and KAO compared with LPS-stimulated macrophages. Fermented beverages of oak effectively down-regulated the production of NO, while pro-inflammatory cytokines (TNF-alpha and IL-6) in macrophages were stimulated with LPS. Additionally, phytochemical compounds present in KAO decrease oxidative stress.

Evaluation of Hypoglycemic and Genotoxic Effect of Polyphenolic Bark Extract from Quercus sideroxyla

Quercus sideroxyla is a wood species whose bark has phenolic compound and should be considered to be bioactive; the hypoglycemic and genotoxic properties of Q. sideroxyla bark were evaluated in this study. Total phenolic compound was determined in crude extract (CE) and organic extract (OE). The OE has the highest amount of phenols (724.1 ± 12.0 GAE/g). Besides, both CE and OE demonstrated effect over the inhibition of α-amylase in vitro. Hypoglycemic activity was assessed by glucose tolerance curve and the area under curve (UAC); OE showed the highest hypoglycemic activity. In addition, diabetes was induced by streptozotocin (65 mg/kg) and the extracts (50 mg/kg) were administered for 10 days; OE showed hypoglycemic effect compared with diabetic control and decreased hepatic lipid peroxidation. Acute toxicity and genotoxicity were evaluated in CE; results of acute toxicity did not show any mortality. Besides, the comet assay showed that CE at a dose of 100 mg/kg did not show any genotoxic effect when evaluated at 24 h, whereas it induced slight damage at 200 mg/kg, with the formation of type 1 comets.

Cell Systems to Investigate the Impact of Polyphenols on Cardiovascular Health

Polyphenols are a diverse group of micronutrients from plant origin that may serve as antioxidants and that contribute to human health in general. More specifically, many research groups have investigated their protective effect against cardiovascular diseases in several animal studies and human trials. Yet, because of the excessive processing of the polyphenol structure by human cells and the residing intestinal microbial community, which results in a large variability between the test subjects, the exact mechanisms of their protective effects are still under investigation. To this end, simplified cell culture systems have been used to decrease the inter-individual variability in mechanistic studies. In this review, we will discuss the different cell culture models that have been used so far for polyphenol research in the context of cardiovascular diseases. We will also review the current trends in cell culture research, including co-culture methodologies. Finally, we will discuss the potential of these advanced models to screen for cardiovascular effects of the large pool of bioactive polyphenols present in foods and their metabolites.

Antioxidant, anti-inflammatory and anticarcinogenic activities of edible red oak (Quercus spp.) infusions in rat colon carcinogenesis induced by 1,2-dimethylhydrazine

Red oak (Quercus spp.) leaves are traditionally used as food in Mexico, and some of their infusions have potential anticarcinogenic and anti-inflammatory effects; however, these properties have not yet been scientifically tested. The aim of this work was to explore the anti-inflammatory activity in HT-29 cells and anticarcinogenic effect in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis of red oak infusions. Quercus infusions were prepared and administered as the sole source of drink to male Sprague-Dawley rats (1% w/v) for the entire 26-week experimental period. On week 4, rats received 8 subcutaneous injections of DMH (21 mg/kg body weight) once a week. The results showed that mean tumor (0.9 ± 0.2 vs. 2.6 ± 0.3) and multiplicity (1.2 ± 0.1 vs. 2.0 ± 0.23), and β-catenin protein level (2.2-fold) in adenocarcinomas were significantly lower in Quercus  sideroxyla-treated group compared with DMH group. By contrast, Quercus  durifolia and Quercus  eduardii infusions had no protective effect. Additionally, the experiments in HT-29 cells confirmed that Q. sideroxyla infusion effectively decreased the levels of the inflammatory markers COX-2 and IL-8 by modulating the expression of NF-κB. These results highlight some of the molecular mechanisms related to the chemopreventive effect of Q. sideroxyla infusion and its potential value as a source of bioactive compounds.

A Review on Pharmacological and Analytical Aspects of Naringenin

Flavonoids are a widely distributed group of phytochemicals having benzo-pyrone nucleus, and more than 4,000 different flavonoids have been described and categorized into flavonols, flavones, flavanones, isoflavones, catechins and anthocyanidins. Flavonoids occurs naturally in fruits, vegetables, nuts, and beverages such as coffee, tea, and red wine, as well as in medical herbs. Flavonoids are responsible for the different colors of plant parts and are important constituents of the human diet. Flavanoids have different pharmacological activities, such as antioxidant, anti-allergic, antibacterial, anti-inflammatory, antimutagenic and anticancer activity. Naringenin belongs to the flavanones and is mainly found in fruits (grapefruit and oranges) and vegetables. Pharmacologically, it has anticancer, antimutagenic, anti-inflammatory, antioxidant, antiproliferative and antiatherogenic activities. Naringenin is used for the treatments of osteoporosis, cancer and cardiovascular diseases, and showed lipid-lowering and insulin-like properties. In the present review, detailed pharmacological and analytical aspects of naringenin have been presented, which revealed the impressive pharmacological profile and the possible usefulness in the treatment of different types of diseases in the future. The information provided in this communication will act as an important source for development of effective medicines for the treatment of various disorders.

Efficacy of a local-drug delivery gel containing extracts of Quercus brantii and Coriandrum sativum as an adjunct to scaling and root planing in moderate chronic periodontitis patients

Objective:

Recent advances in the field of alternative medicine introduced various herbal products for the treatment of periodontitis. The purpose of this study was to evaluate the effects of combined extracts from Quercus brantii and Coriandrum sativum on periodontal indices in adult periodontitis patients.

Methods:

In this randomized, double-blinded clinical trial, performed in Isfahan Dental School in 2012, a new herbal medicament containing combined extracts from Q. brantii and C. sativum was formulated in the gel form for subgingival application. Following scaling and root planing (SRP), both herbal and placebo gels were delivered at the experimental and control sites, respectively. Periodontal pocket depth, clinical attachment level, papilla bleeding index, and plaque index were measured at baseline, 1 month and 3 months later. Both intra-and inter-groups changes were registered. The obtained data were analyzed by SPSS software, using repeated measure analysis of variance, paired t-test, Mann-Whitney, Friedman, and Wilcoxon tests. Differences with P < 0.05 were considered to be significant.

Findings:

Both groups indicated statistically significant improvements in the periodontal indices (P < 0.05), but there were no significant differences between two study groups with this regard.

Conclusion:

The herbal gel does not have considerable advantages over SRP alone as an adjunct in periodontal treatment.

Antioxidant characterization of oak extracts combining spectrophotometric assays and chemometrics

Antioxidant characteristics of leaves, twigs, and acorns from two Serbian oak species Quercus robur L. and Quercus petraea L. from Vojvodina province (northern Serbia) were investigated. 80% ethanol (in water) extracts were used for antiradical power (ARP) determinations against DPPH(•), (•)NO, and O2 (•-) radicals, ferric reducing antioxidant power (FRAP), total phenol, tannin, flavonoid, and proanthocyanidin contents. Permanganate reducing antioxidant capacity (PRAC) was determined using water extracts. Beside, mentioned parameters, soluble proteins, lipid peroxidation (LP), pigments and proline contents were also determined. The data of different procedures were compared and analyzed by multivariate techniques (correlation matrix calculation and principal component analysis (PCA)). PCA found that investigated organs of two different oak tree species possess similar antioxidant characteristics. The superior antioxidant characteristics showed oak leaves over twigs and acorns and seem to be promising source of antioxidants with possible use in industry and pharmacy.

Design, formulation and evaluation of a mucoadhesive gel from Quercus brantii L. and coriandrum sativum L. as periodontal drug delivery

Background:

Periodontitis is inflammation of the supporting tissues of the teeth caused by specific microorganisms. Intra-periodontal pocket, mucoadhesive drug delivery systems have been shown to be clinically effective in the treatment of periodontitis. The aim of this study was to formulate a mucoadhesive gel from the seed hull of Quercus brantii and fruits of Coriandrum sativum for the treatment of periodontitis.

Materials and Methods:

The semisolid concentrated extracts were incorporated in gel base. Mucoadhesive gels were prepared using carbopol 940, sodium carboxymethylcellulose (sodium CMC) and hydroxypropyl methylcellulose K4M (HPMC) as bioadhesive polymers. Physicochemical tests, mucoadhesive strength measurement and in vitro drug release study were carried out on two formulations containing carbopol 940 and sodium CMC polymers (Formulations F₄ and F₅). We investigated the antibacterial activity of formulation F₅ against Porphyromonas gingivalis using the disk diffusion method on supplemented Brucella agar.

Results:

Eight gel formulations were prepared. Physical appearance, homogeneity and consistency of F₄ and F₅ were good. Mucoadhesion and viscosity of F₅ (1% carbopol 940 and 3% sodium CMC) was more than F₄ (0.5% carbopol 940 and 3% sodium CMC). Drug release from F₅ was slower. Both of formulations were syringeable through 21 G needle. In the disk diffusion method, F₅ produced significant growth inhibition zones against P. gingivalis.

Conclusion:

The ideal formulation for the treatment of periodontitis should exhibit high value of mucoadhesion, show controlled release of drug and be easily delivered into the periodontal pocket preferably using a syringe. Based on in vitro release and mucoadhesion studies, F₅ was selected as the best formulation.

Thymoquinone improves aging-related endothelial dysfunction in the rat mesenteric artery

Aging-related endothelial dysfunction is characterized by blunted nitric oxide (NO)- and endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxations in arteries, which may be due, at least in part, to increased oxidative stress. Endothelial dysfunction will promote the initiation and development of major cardiovascular diseases such as atherosclerosis and hypertension. Thymoquinone (TQ) is the most active constituent of the volatile oil of Nigella sativa seeds with well-documented antioxidative properties and vasodilator effects. This study determined whether TQ improves the endothelial function in middle-aged rats. Control young rats (16 weeks) received solvent (ethanol, 3% v/v), and middle-aged rats (46 weeks) either solvent or TQ (10 mg/kg/day) in the drinking water. Mesenteric artery reactivity was determined in organ chambers, vascular oxidative stress by dihydroethidine and MitoSOX staining, and expression of target proteins by immunohistochemical staining. Aging-related blunted NO- and EDHF-mediated responses were associated with downregulation of endothelial NO synthase (eNOS) and calcium-activated potassium channels (SK(Ca) and IK(Ca)) expression. Endothelial dysfunction was also associated with oxidative stress and an upregulation of angiotensin II and AT1 receptor expressions. Intake of TQ for 14 days restored NO- and EDHF-mediated relaxations, normalized oxidative stress, the expression level of eNOS, SK(Ca), IK(Ca), and the components of the angiotensin system in the mesenteric artery of middle-aged rats. Thus, TQ improves endothelial function in aging, at least in part, through inhibition of oxidative stress and normalization of the angiotensin system. TQ may represent a novel therapeutic approach for aging-associated vascular diseases.