Supplementation of garlic lowers lipids and increases antioxidant capacity in plasma of rats

Effect of Heat-Treated Garlic (Allium sativum L.) on Growth Parameters, Plasma Lipid Profile and Histological Changes in the Ileum of Atherogenic Rats

Dietary supplementation with raw garlic has a preventive and healing effect in cardiovascular diseases, but it could also damage the intestinal mucosa, resulting in impairment of nutrient absorption. Garlic processing, including heat treatment, changes the content and biological activity of garlic, so it is crucial to find food-processing methods that will preserve the health-promoting properties of garlic while minimizing its negative impact on the digestive system. Therefore, in this study, the effect of garlic (Allium sativum L.) on growth parameters, plasma lipid profile, and morphological parameters in the ileum of Wistar rats subjected to various types of heat treatment (90 s blanching garlic, 10 min boiling in water, 10 min pan frying without fat, microwave heating fresh garlic, 90 s blanching and microwave heating garlic, 10 min boiling in water and microwave heating garlic, and 10 min pan frying without fat and microwave heating garlic) was determined in an atherogenic diet (containing 1% addition of cholesterol). In the conducted research, it was found that the diet supplemented with heat-treated garlic used in the atherogenic diet improved the consumption and growth parameters of rats, depending on the type and time of its use. The highest consumption was recorded in atherogenic groups supplemented with garlic subjected to a longer (10 min) heat treatment and was then heated in a microwave oven. Garlic subjected to the shortest heat treatment proved to be most effective, and a significant improvement in the lipid profiles of rats' plasma with atherogenic was observed. Extending the time of heat treatment of garlic and, additionally, its microwaving significantly weakened the action of garlic in the body, but still retained its hypolipidemic effect. The greatest influence on the structural changes in the mucosa of the rats' iliac intestine, manifested by degeneration of the mucosa, shortening the length of the intestinal villi, damage to the brush border, and thus impairment of the intestinal absorption, was exerted by supplementing the atherogenic diet with garlic subjected to short-term heat treatment. Among the processes used, blanching was the least favorable, and the long-lasting thermal processes (cooking, frying for 10 min) had a positive effect on the mucosa of the rats' intestines. The results obtained in this study confirm that the selection of an appropriate method of thermal processing of garlic may allow for the maintenance of preventive and therapeutic efficacy of garlic in cardiovascular diseases, while ensuring the safety of its long-term use in the context of degenerative changes in the gastrointestinal tract.

Studying the effect of garlic consumption and endurance training on serum levels of some pro-and anti-inflammatory cytokines in female mice with breast cancer - A randomized trial

Background:

This study aimed to determine the effect of garlic consumption and endurance training on the serum levels of some pro-inflammatory and anti-inflammatory cytokines in female mice with breast cancer.

Methods:

This study is an experimental research randomly conducted on 32 female BALB/c mice divided into 4 equal groups (N = 8), including: Cancer Control (CC), Garlic Supplementation (GS), Endurance Training (ET), Endurance Training + Garlic Supplementation (ET + GS). One million cancerous cells were injected to all mice's upper right thigh using the subcutaneous injection method. Exercise groups performed endurance training for 8 weeks (5 days a week.(Garlic supplement groups received 1 ml of the garlic extract orally per kilogram of body weight. The control groups -were not given any task, activity or exercise during the research. At the end of the research, all the mice were anesthetized, and their blood samples were collected.

Results:

The period of 8-week simultaneous endurance exercise and consumption of garlic supplement significantly decreased the serum level of interleukin-6 (F = 75 P = 0.00), interleukin-8 (F = 97.9 P = 0.00), and interleukin-17 (F = 95.7 P = 0.00), and increased the serum level of interleukin-10 (F = 50.4 P = 0.00).

Conclusions:

Along with other existing methods, reduction of inflammatory factors, endurance exercises and consumption of garlic supplement have been proved to be an extremely effective treatment for breast cancer patients.

The Influence of Plants from the Alliaceae Family on Morphological Parameters of the Intestine in Atherogenic Rats

Bulbs from the Alliaceae family have been well-known and valued spices for thousands of years, not only for their unique flavor and aroma features, but also for their high nutritional and health-promoting values. Long-term or excessive consumption of these vegetables, especially raw garlic, can have side effects in the body (including in the digestive tract), causing a number of pathological changes in the intestinal wall; these changes lead, in turn, to its damage, dysfunction, and disorder development. Therefore, the aim of this study was to investigate the effect of the addition of freeze-dried vegetables from the Alliaceae family, i.e., garlic (Allium sativum L.), white onion, and red onion (Allium cepa L.) on the morphometric parameters (intestinal villi length, crypt depth, thickness of tunica mucosa, and the thickness of tunica muscle) of the jejunum of rats fed a semi-synthetic atherogenic diet (1% dietary cholesterol). In freeze-dried vegetables administered to rats, the contents of selected bioactive ingredients and their antioxidant potentials were determined. The effect of the onion vegetable supplements on growth parameters, serum lipid profile, plasma antioxidant potential, and the intestinal morphological parameters of rats loaded with cholesterol was determined. In an animal experiment, 30 male Wistar rats were divided into 5 diet groups, diet consumption and FER were studied. Supplementation of the atherogenic diet with vegetables improved the blood plasma lipid profiles and atherogenic indices, in a manner that was dependent on the type of supplementation used, with the best hypolipidemic and anti-atherosclerotic effects found in garlic use. The atherogenic diet, as well as the supplementation of this diet with the tested vegetables from the Alliaceae family, influenced the histological changes in the epithelium of the jejunum of rats. The damage to the intestinal mucosa was the greatest in animals fed an atherogenic diet supplemented with garlic. Bearing in mind that the desired beneficial therapeutic or prophylactic effects of onion vegetables (in particular garlic) in the course of various metabolic ailments (including atherosclerosis) are achieved during long-term supplementation, it is important to remember their possible cytotoxic effects (e.g., on the digestive tract) in order to achieve real benefits related to the supplementation with vegetables from the Alliaceae family.

Natural Products Counteracting Cardiotoxicity during Cancer Chemotherapy: The Special Case of Doxorubicin, a Comprehensive Review

Cardiotoxicity is a frequent undesirable phenomenon observed during oncological treatment that limits the therapeutic dose of antitumor drugs and thus may decrease the effectiveness of cancer eradication. Almost all antitumor drugs exhibit toxic properties towards cardiac muscle. One of the underlying causes of cardiotoxicity is the stimulation of oxidative stress by chemotherapy. This suggests that an appropriately designed diet or dietary supplements based on edible plants rich in antioxidants could decrease the toxicity of antitumor drugs and diminish the risk of cardiac failure. This comprehensive review compares the cardioprotective efficacy of edible plant extracts and foodborne phytochemicals whose beneficial activity was demonstrated in various models in vivo and in vitro. The studies selected for this review concentrated on a therapy frequently applied in cancer, anthracycline antibiotic-doxorubicin-as the oxidative stress- and cardiotoxicity-inducing agent.

Analytical Methods Used in Determining Antioxidant Activity: A Review

The study of antioxidants and their implications in various fields, from food engineering to medicine and pharmacy, is of major interest to the scientific community. The present paper is a critical presentation of the most important tests used to determine the antioxidant activity, detection mechanism, applicability, advantages and disadvantages of these methods. Out of the tests based on the transfer of a hydrogen atom, the following were presented: the Oxygen Radical Absorption Capacity (ORAC) test, the Hydroxyl Radical Antioxidant Capacity (HORAC) test, the Total Peroxyl Radical Trapping Antioxidant Parameter (TRAP) test, and the Total Oxyradical Scavenging Capacity (TOSC) test. The tests based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin-Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl] (DPPH) test. All these assays are based on chemical reactions and assessing the kinetics or reaching the equilibrium state relies on spectrophotometry, presupposing the occurrence of characteristic colours or the discolouration of the solutions to be analysed, which are processes monitored by specific wavelength adsorption. These assays were successfully applied in antioxidant analysis or the determination of the antioxidant capacity of complex samples. As a complementary method in such studies, one may use methods based on electrochemical (bio)sensors, requiring stages of calibration and validation. The use of chemical methods together with electrochemical methods may result in clarification of the operating mechanisms and kinetics of the processes involving several antioxidants.

Evaluation of Bioactive and Physicochemical Properties of White and Black Garlic (Allium sativum L.) from Conventional and Organic Cultivation

The aim of this study was to evaluate the bioactive and physicochemical properties of white and black garlic (Allium sativum L.) from conventional and organic cultivation. Both white conventional (G) and organic (EG) garlic were processed during 45 days heat treatment at 70 °C temperature and 80% relative humidity. In black garlic (BG) samples the content of soluble solids, total reducing sugars, total polyphenol as well as antioxidant activity significantly (p < 0.05) increased (by about 33.5%, 60.5%, 118.4%, 125.8%, respectively), while a pH significantly (p < 0.05) decreased (by about 41.1%) as compared to white garlic samples. The study showed significant differences between colour of white and black garlic, both in the L*a*b* and RGB colour space, especially in the case of the L* parameter, indicating that the colour of garlic changed from white to dark brown or black during the thermal processing. All organic garlic samples had improved bioactive ingredients and antioxidant activity compared to conventional garlic for both fresh (unprocessed) and heat-treated black garlic. The production of black garlic, especially organic (EBG), allows one to obtain a product with higher amount of bioactive compounds, which can be widely used in the design of health-promoting functional food.

Influence of Thermal Processing on the Bioactive, Antioxidant, and Physicochemical Properties of Conventional and Organic Agriculture Black Garlic (Allium sativum L.)

This study examines the effect of fermentation processes (70 °C temperature; 80% humidity; 45 days) on the content of bioactive compounds (total polyphenols, selected phenolic acids, and flavonoids), antioxidant activity and physicochemical properties of conventional and organic garlic (Allium sativum L.). Raw garlic from conventional cultivation (GR) showed significantly lower content of phenolic components and antioxidant activity compared to raw garlic from organic cultivation (GREcol) (by 22.8% and 25.1%, respectively). The fermentation processes of the garlic from both the conventional (BG) and organic (BGEcol) cultivation significantly increased the content of total polyphenols (more than two times), phenolic acids (more than 1.5 times) and flavonoids (1.5 and 1.3 times, respectively). The garlic fermentation process also significantly increased antioxidant potential: two times for BG and three times for BGEcol. The content of bioactive compounds (total polyphenols, phenolic acids, and flavonoids) was significantly (p < 0.05) higher in organic black garlic (BGEcol) compared to conventional black garlic (BG). Heat treatment leading to changes in both the physicochemical, organoleptic and health-promoting properties allowed to obtain a new product gaining in sensory attractiveness and enabling a wide range of applications.

Study of Antioxidant Properties of Agents from the Perspective of Their Action Mechanisms

The creation and analysis of a large variety of existing methods for the evaluation of integrated antioxidant properties are quite relevant in connection with a range of biological mechanisms of the antioxidants (AO) action. In this work, the existing methods are correlated with mechanisms of antioxidant action. It is shown that the results obtained by various methods are mainly incomparable. This can be connected with the implementation of various mechanisms of antioxidant action in methods. The analysis of the literature data presented in this review indicates the difficulty of creating a universal method and the feasibility of using integrated approaches based on the use of several methods that implement and combine various mechanisms of the chemical conversion of antioxidants. This review describes methods for studying the chelating ability of antioxidants, except for methods based on electron and hydrogen atom transfer reactions, which are currently not widely covered in modern literature. With the description of each mechanism, special attention is paid to electrochemical methods, as the interaction of active oxygen metabolites of radical and non-radical nature with antioxidants has an electron/proton/donor-acceptor nature, which corresponds to the nature of electrochemical methods and suggests that they can be used to study the interaction.

Effect of Alliaceae Extract Supplementation on Performance and Intestinal Microbiota of Growing-Finishing Pig

Simple Summary

The increasing interest in phytogenics for use with livestock, especially swine and poultry, is mainly due to their antimicrobial, antioxidant, growth-promoting, and gut microbiome modulation properties, which makes them ideal candidates to mitigate the negative effects of the ban on antibiotic growth promoters in the European Union. We tested the ability of Allium spp. extract (containing garlic and onion), one of the best-known phytogenics, used in pig feed, to improve growth performance through modulation of the microbiome and changes in the metabolism of short-chain fatty acids in the gut tract. The promising results obtained in the present study suggested that Allium spp. extracts had the potential to be used in feeding pigs to improve growth performances by modulating the microbiota and metabolism of short-chain fatty acids.

Abstract

The aim of the present study was to ascertain whether an Allium spp. extract rich in organosulfur compounds, such as propyl thiosulfonate (PTSO), added to the feed of growing-finishing pigs at 5 g/kg enhances growth performance or affects the fecal microbiome, the levels of short-chain fatty acids, or the antioxidant capacity of the animals. Fifty male growing pigs (large white) of 23.07 ± 2.87 kg average body weight were randomly allotted to two treatments in a 103-day trial. The trial was divided into two periods, an initial growing phase (56-days) and a finishing phase (47-days). Two dietary treatments for each phase (growing and finishing) were used: a control diet (CON) and an experimental diet consisting of the control diet to which 5 g/kg of Allium spp. extract was added to substitute sepiolite (GAR). Throughout the study, body weight, average daily gain (kg/day, ADG), feed intake (kg/day), and feed conversion ratio (kg/kg) were measured, while the backfat thickness and muscle depth were determined at the end of the study. Besides, feces samples were taken for bacterial counts by means of real-time PCR and short-chain fatty acid (SCFA) profile determination, and the antioxidant capacity was assessed in serum and saliva. In the animals receiving Allium spp. extract (5 g/kg) in the feed, ADG increased (p < 0.05) throughout the trial, Salmonella spp. and Clostridium spp. counts in feces had decreased (p < 0.05) when measured on day 56, and, by day 103, Salmonella spp., Clostridium spp., and Enterobacteriaceae counts had decreased (p < 0.05) and Lactobacillus spp. counts had increased (p < 0.01) in feces. Regarding the SCFA profile in feces and antioxidant capacity measured in serum and saliva, supplementation with Allium spp. extract significantly increased the levels of propionic, isobutyric, and isovaleric acids and the percentage of total branched fatty acids, while the c2/c3 and (c2 + c4)/c3 ratios were lower (p < 0.05) in feces; the Trolox equivalent antioxidant capacity and the cupric reducing antioxidant capacity levels in serum were significantly higher in the same pigs on day 103 than on day 0. Consequently, based on the current results, Allium spp. extract rich in organosulfur compounds, added to the diet at 5 g/kg, had a beneficial effect on the microbiota and would seem to be a possible alternative for increasing the growth performance of growing-finishing pigs. However, further studies on the effects of Allium spp. supplementation on carcass quality are necessary.

Impact of steaming pretreatment process on characteristics and antioxidant activities of black garlic (Allium sativum L.)

Impact of steaming pretreatment processes on physical properties, bioactive compounds and antioxidant activities, of black garlics (Allium sativum L.) was studied. Steaming pretreatment at different times (0, 4 and 6 min) was conducted before incubating in 60 °C-incubator at different incubation times (0, 9 and 18 days). Different steaming pretreatment processes affected the color and hardness of black garlic differently, while total polyphenol content (TPC) and total flavonoid content (TFC) were also determined by the steaming pretreatment time used. TPC and TFC increased with increasing of incubating time, where the highest those bioactive compounds was observed from 18-day incubation, especially with 4 min of steaming pretreatment (p ≤ 0.05). Increase of those bioactive compounds was in accordance with increasing of DPPH radical scavenging activity (DPPH) and ferric reducing antioxidant power (FRAP) of black garlic during incubation. In addition, black garlic obtained from 18-day incubation with steaming pretreated for 4 min revealed the optimum condition providing the black garlic with high in both DPPH and FRAP, compared with others (p ≤ 0.05). Therefore, steaming pretreatment could effectively improve the efficiency of black garlic production process by increase the generation rate of bioactive compounds as well as induce antioxidant properties of black garlic with shorten process time.

Phenolic Compounds from An Algerian Endemic Species of Hypochaeris laevigata var. hipponensis and Investigation of Antioxidant Activities

: Hypochaeris laevigata var. hipponensis (Asteraceae) is an endemic plant from Algeria. In the current study, we analyzed for the first time its chemical composition, especially phenolic constituents of dichloromethane (DCM), ethyl acetate (EA), and n-butanol (BuOH) fractionsof the aerial parts of Hypochaeris laevigata var. hipponensis by liquid chromatography-mass spectrometry (LC-MS/MS). The number of phenolic compounds detected in DCM, EA, and BuOH fractions were found to be 9, 20, and 15, respectively. More specifically, 12 phenolic acids were detected. Among them, quinic acid, chlorogenic acid, and caffeic acid were the most abundant ones. Meanwhile, only seven flavonoids were detected. Among them, rutin, apigetrin, and isoquercitrin were the major ones. We also determined the total phenolic and flavonoid contents, and fraction EA showed the highest values, followed by BuOH, and DCM fractions. Furthermore, the antioxidant action was dictated by five methods and the tested plant fractions demonstrated a noteworthy antioxidant action.

An integrated approach to the investigation of antioxidant properties by potentiometry

An analytical methodology is proposed for a comprehensive study of antioxidant properties of various objects based on the implementation of various mechanisms of antioxidant action. In order to interpret results regarding the action of antioxidants in living organisms it is proposed to adhere to certain requirements for research methods of antioxidant properties, for oxidizing agents of a radical and non-radical nature. The developed integrated approach consists in using the potentiometry method and is based on the antioxidant capacity determination which is founded on the interaction of antioxidants with the К₃[Fe(CN)₆] by the ET-mechanism and the conjugation mechanism and the antiradical capacity determination based on the interaction of antioxidants with peroxyl radicals by the HAT-mechanism. Individual antioxidants of natural origin, plant materials extracts as well as synthesized 6-nitro-1,2,4-triazoloazin containing polyphenols fragments, which are complex conjugated structures, have been investigated. It has been shown that in the antioxidants study it is advisable to use the integrated approach that will allow to evaluate antioxidant properties from the point of view of various antioxidants action mechanisms.

Alliin, an Allium sativum Nutraceutical, ReducesMetaflammation Markers in DIO Mice

Obesity generates a chronic low-grade inflammatory state which promotes oxidative stress and triggers comorbidities. Alliin is the main organosulfur compound in garlic and has been shown to induce a decrease in the expression of proinflammatory cytokines; its systemic effect on metabolic parameters and adipose tissue is not yet known, however. After nine weeks of HFD and with obesity established in C57BL/6 mice, we observed that a daily treatment with alliin for 3.5 weeks (15 mg/kg) did not affect body weight, but significantly improved insulin sensitivity and glucose tolerance, both evaluated through a blood glucose monitoring system. Once alliin treatment was completed, serum, adipose tissue, and organs of interest related to metabolism were removed for further analysis. We observed that alliin significantly decreased the size of adipocytes from epididymal adipose tissue, evaluated via microscopy. A decrease in gene expression and serum protein levels of the adipocytokines leptin and resistin, as well as decreased serum IL-6 concentration, were detected by qRT-PCR and ELISA, respectively. It did not, however, affect mRNA expression of antioxidant enzymes in the liver. Taken altogether, these results indicate that treatment with alliin reduces metaflammation markers in DIO mice and improves some metabolic parameters without affecting others.

Antimicrobial resistance of three common molecularly identified pathogenic bacteria to Allium aqueous extracts

The aim of this work was to evaluate the in vitro bacterial inhibition of different types of garlic on Escherichia coli ATCC 25922, Listeria monocytogenes and Staphylococcus aureus. The bacterial strains were molecularly identified using gen 16S rDNA molecular identification. Four different types of garlics were used: 1) white, 2) Japanese, 3) elephant and 3) black, and these were evaluated at two different concentrations (0.25 and 0.125 g/mL) per garlic type. Bioactive compounds present in the garlics were identified using high-performance liquid chromatography coupled to ultraviolet detector (HPLC-UV), and total polyphenols were quantified by the Folin-Ciocalteu technique. The Kirby-Bauber method was used for the bacterial evaluation. Aqueous extract of black garlic had the highest amount of polyphenols 6.26 ± 0.21 mg GAE/mL. The area of inhibition was measured and classified as sensitive, intermediate or resistant. Using the disc diffusion assay, higher concentration (0.25 g/mL) of aqueous extract of white garlic had the highest antibacterial activity area, with 21.46 ± 3.94 mm for L. monocytogenes, 20.61 ± 2.47 mm for S. aureus and 17.83 ± 2.21 mm for E. coli. White garlic had comparable antimicrobial activity as the control (tetracycline at 30 μg) as indicated by the size of the inhibition halos. Based on your results, white garlic can be used as an alternative to synthetic antimicrobials.

Physicochemical Characterization and Biological Activities of Black and White Garlic: In Vivo and In Vitro Assays

White and three types of black garlic (13, 32, and 45 days of aging, named 0C1, 1C2, and 2C1, respectively) were selected to study possible differences in their nutraceutic potential. For this purpose, garlic were physicochemically characterized (Brix, pH, aW, L, polyphenol, and antioxidant capacity), and both in vivo and in vitro assays were carried out. Black garlic samples showed higher polyphenol content and antioxidant capacity than the white ones. The biological assays showed that none of the samples (neither raw nor black garlic) produced toxic effects in the Drosophila melanogaster animal genetic model, nor exerted protective effects against H₂O₂, with the exception of the 0C1 black garlic. Moreover, only white garlic was genotoxic at the highest concentration. On the other hand, 0C1 black garlic was the most antigenotoxic substance. The in vivo longevity assays showed significant extension of lifespan at some concentrations of white and 0C1and 1C2 black garlic. The in vitro experiments showed that all of the garlic samples induced a decrease in leukemia cell growth. However, no type of garlic was able to induce proapoptotic internucleosomal DNA fragmentation. Taking into account the physicochemical and biological data, black garlic could be considered a potential functional food and used in the preventive treatment of age-related diseases. In addition, our findings could be relevant for black-garlic-processing agrifood companies, as the economical and timing costs can significantly be shortened from 45 to 13 days of aging.

Physicochemical Characteristics of Black Garlic after Different Thermal Processing Steps

This study investigated the physicochemical characteristics of black garlic (BG) after different thermal processing steps. Compared with fresh garlic (FG), the moisture content and pH in BG decreased significantly, while the ash content and browning intensity increased during thermal processing. The total mineral and the free sugar contents were significantly higher than that of the BG2 and BG4 samples, respectively. The free sugar content increased by 16-fold in the BG cloves compared with that of FG, while the amino acid content increased during the first stage of thermal processing, and subsequently decreased. The thiosulfinate content in all samples decreased to during thermal processing. The pyruvic acid content initially increased and then decreased during thermal processing. These results contribute to our understanding of the role of thermal processing in the quality formation of BG.

Antioxidant Activity/Capacity Measurement. 1. Classification, Physicochemical Principles, Mechanisms, and Electron Transfer (ET)-Based Assays

Because there is no widely adopted "total antioxidant parameter" as a nutritional index for labeling food and biological fluids, it is desirable to establish and standardize methods that can measure the total antioxidant capacity (TAC) level directly from plant-based food extracts and biological fluids. In this review, we (i) present and classify the widely used analytical approaches (e.g., in vitro and in vivo, enzymatic and nonenzymatic, electron transfer (ET)- and hydrogen atom transfer (HAT)-based, direct and indirect assays) for evaluating antioxidant capacity/activity; (ii) discuss total antioxidant capacity/activity assays in terms of chemical kinetics and thermodynamics, reaction mechanisms, and analytical performance characteristics, together with advantages and drawbacks; and (iii) critically evaluate ET-based methods for analytical, food chemical, biomedical/clinical, and environmental scientific communities so that they can effectively use these assays in the correct places to meet their needs.

Immunomodulation and anti-inflammatory effects of garlic compounds

The benefits of garlic to health have been proclaimed for centuries; however, only recently have Allium sativum and its derivatives been proposed as promising candidates for maintaining the homeostasis of the immune system. The complex biochemistry of garlic makes it possible for variations in processing to yield different preparations with differences in final composition and compound proportion. In this review, we assess the most recent experimental results, which indicate that garlic appears to enhance the functioning of the immune system by stimulating certain cell types, such as macrophages, lymphocytes, natural killer (NK) cells, dendritic cells, and eosinophils, by mechanisms including modulation of cytokine secretion, immunoglobulin production, phagocytosis, and macrophage activation. Finally, because immune dysfunction plays an important role in the development and progress of several diseases, we critically examined immunoregulation by garlic extracts and compounds isolated, which can contribute to the treatment and prevention of pathologies such as obesity, metabolic syndrome, cardiovascular disorders, gastric ulcer, and even cancer. We concluded that A. sativum modulates cytokine secretion and that such modulation may provide a mechanism of action for many of their therapeutic effects.

Antioxidant effect of garlic (Allium sativum) and black seeds (Nigella sativa) in healthy postmenopausal women

Objectives:

The objective of this study is to investigate the antioxidant effects of garlic extract and crude black seeds’ consumption on blood oxidant/antioxidant levels in healthy postmenopausal women.

Methods:

In total, 30 healthy postmenopausal women (mean age = 50.31 ± 4.23 years) participated. They ingested two garlic soft gels per day (each is equivalent to 1000 mg of fresh garlic bulb) and crude black seed grounded to powder in a dose of 3 g/day for 8 weeks. Oxidant (malondialdehyde) activity in plasma and antioxidants superoxide dismutase and glutathione peroxidase activities in erythrocytes were studied.

Results:

Significant low levels of plasma malondialdehyde with increased erythrocyte glutathione peroxidase and superoxide dismutase activities.

Discussion:

Menopause is associated with an increase in oxidative stress and a decrease in some antioxidant parameters. Consumption of garlic extracts and crude black seeds may have a beneficial effect on improved balance between blood oxidants and antioxidants in healthy postmenopausal women.

Methods of measurement and evaluation of natural antioxidant capacity/activity (IUPAC Technical Report)

The chemical diversity of natural antioxidants (AOXs) makes it difficult to separate, detect, and quantify individual antioxidants from a complex food/biological matrix. Moreover, the total antioxidant power is often more meaningful to evaluate health beneficial effects because of the cooperative action of individual antioxidant species. Currently, there is no single antioxidant assay for food labeling because of the lack of standard quantification methods. Antioxidant assays may be broadly classified as the electron transfer (ET)- and hydrogen atom transfer (HAT)-based assays. The results obtained are hardly comparable because of the different mechanisms, redox potentials, pH and solvent dependencies, etc. of various assays. This project will aid the identification and quantification of properties and mutual effects of antioxidants, bring a more rational basis to the classification of antioxidant assays with their constraints and challenges, and make the results more comparable and understandable. In this regard, the task group members convey their own experiences in various methods of antioxidants measurement.

Protective effect of polyphenols extract of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) on hypercholesterolemia-induced oxidative stress in rats

The present study examines the effect of polyphenols extract of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) (APE) on high cholesterol diet fed rats (HCD). APE was orally administrated by gavage at doses of 10, 40 and 200 mg total phenolics/kg body weight of rats once a day for 28 days. At the end of four weeks, serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C), and markers of oxidative stress viz., malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the serum and liver of HCD and normal rats were assessed and compared. The results showed that administration of APE was significantly effective in decreasing the serum levels of TC, LDL-C and MDA, increasing the serum level of HDL-C and antioxidant capacity. In addition, oral gavage of APE could also increase the antioxidant capacity, CAT and GSH-Px activities in liver. These results suggested that APE exerted a high hypocholesterolemic and antioxidant activities, which might be characterized by a protective effect on cardiovascular health in vivo.

Differences in responsivity of original cupric reducing antioxidant capacity and cupric-bathocuproine sulfonate assays to antioxidant compounds

The cupric reducing antioxidant capacity (CUPRAC) method using bathocuproine sulfonate (BCS) as cuprous-chelating ligand claims to be an efficient substitute for the conventional CUPRAC assay using neocuproine; however, differences in their physical chemistry give rise to significantly varying responsivities to antioxidant compounds. The antioxidant capacity due to β-carotene (in acetone or dichloromethane) was fully measurable by conventional CUPRAC but not at all by cupric-BCS assay. Furthermore, CUPRAC exhibits distinctly stronger responses than cupric-BCS to naringenin, α-tocopherol, and bilirubin.

Carotenoid accumulation and characterization of cDNAs encoding phytoene synthase and phytoene desaturase in garlic (Allium sativum)

Phytoene synthase (PSY) and phytoene desaturase (PDS), which catalyze the first and second steps of the carotenoid biosynthetic pathway, respectively, are key enzymes for the accumulation of carotenoids in many plants. We isolated 2 partial cDNAs encoding PSY (AsPSY-1 and AsPSY-2) and a partial cDNA encoding PDS (AsPDS) from Allium sativum. They shared high sequence identity and conserved motifs with other orthologous genes. Quantitative real-time PCR analysis was used to determine the expression levels of AsPSY1, AsPSY2, and AsPDS in the bulbils, scapes, leaves, stems, bulbs, and roots of garlic. High-performance liquid chromatography demonstrated that carotenoids were not biosynthesized in the underground organs (roots and bulbs), but were very abundant in the photosynthetic organs (leaves) of A. sativum. A significantly higher amount of β-carotene (73.44 μg·g(-1)) was detected in the leaves of A. sativum than in the other organs.

Influence of steeping solution and storage temperature on the color change of garlic

The objective of this study was to investigate the browning of garlic under different steeping conditions and storage temperatures. The brown indices of steeped garlics showed lowest values (7.3 and 7) in 25% and 50% EtOH at 7 d of storage. The degree of browning of steeped garlics was lowest (10.2 in 25% EtOH and 10.4 in 50% EtOH) in the samples soaked for 8 h at 13 d of storage. As the storage temperature was increased from 10 to 40 degrees C, the brown indices of garlics revealed an increasing trend relative to storage time regardless of steeping treatment. Overall, the kinetic parameters showed relatively low R(2) and irregular reaction constants, but the k(o) values showed an increasing trend with temperature under a zero-order model. The highest polyphenol content within the garlic bulbs was seen in controls (without steeping treatment, 588.9 microg/g), than 0% EtOH (water, 392.5 microg/g), than 25% EtOH (211.3 microg/g), and finally 50% EtOH (155.6 microg/g). The polyphenol oxidase activity of garlic showed a similar trend to that of polyphenol content. However, the texture properties of garlics steeped with 25% and 50% did not change.

PRACTICAL APPLICATION

The garlic color preferred by consumers is a creamy-white, but this is susceptible to enzymatic browning when pre-peeled and chopped. When garlic was steeped in the 25% and 50% alcohol, the browning of garlic was prevented during storage.

Comparative evaluation of various total antioxidant capacity assays applied to phenolic compounds with the CUPRAC assay

It would be desirable to establish and standardize methods that can measure the total antioxidant capacity level directly from vegetable extracts containing phenolics. Antioxidant capacity assays may be broadly classified as electron transfer (ET)- and hydrogen atom transfer (HAT)-based assays. The majority of HAT assays are kinetics-based, and involve a competitive reaction scheme in which antioxidant and substrate compete for peroxyl radicals thermally generated through the decomposition of azo compounds. ET-based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes colour when reduced. ET assays include the ABTS/TEAC, CUPRAC, DPPH, Folin-Ciocalteu and FRAP methods, each using different chromogenic redox reagents with different standard potentials. This review intends to offer a critical evaluation of existing antioxidant assays applied to phenolics, and reports the development by our research group of a simple and low-cost antioxidant capacity assay for dietary polyphenols, vitamins C and E, and human serum antioxidants, utilizing the copper(II)-neocuproine reagent as the chromogenic oxidizing agent, which we haved named the CUPRAC (cupric ion reducing antioxidant capacity) method. This method offers distinct advantages over other ET-based assays, namely the selection of working pH at physiological pH (as opposed to the Folin and FRAP methods, which work at alkaline and acidic pHs, respectively), applicability to both hydrophilic and lipophilic antioxidants (unlike Folin and DPPH), completion of the redox reactions for most common flavonoids (unlike FRAP), selective oxidation of antioxidant compounds without affecting sugars and citric acid commonly contained in foodstuffs and the capability to assay -SH bearing antioxidants (unlike FRAP). Other similar ET-based antioxidant assays that we have developed or modified for phenolics are the Fe(III)- and Ce(IV)-reducing capacity methods.