Garlic and onions: their cancer prevention properties

Pathways of Gastric Carcinogenesis, Helicobacter pylori Virulence and Interactions with Antioxidant Systems, Vitamin C and Phytochemicals

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.

Effects of garlic supplementation on serum inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Previous studies have indicated that garlic consumption may be beneficial in improving inflammation. This systematic review and meta-analysis aimed to examine the effect of garlic supplementation on inflammatory biomarkers.

METHODS

PubMed/Medline, Scopus and ISI web of science were searched up to February 2019. Random effects model was used to calculate the overall effects on C-reactive protein (CRP), Interleukin-6 (IL-6), and Tumor necrosis factor- α (TNF-α).

RESULTS

17 randomized controlled trials (RCTs) were included in the meta-analyses. Garlic supplementation significantly reduced the level of circulating CRP (P < 0.05), whereas it did not have any significant effect on IL-6 level (p > 0.05). Sub-group analysis showed that aged garlic extract (AGE) was able to reduce CRP and TNF-α significantly (P < 0.05).

CONCLUSIONS

This meta-analysis showed that supplementation with garlic could reduce the level of circulating CRP and AGE could reduce the level of TNF-α and CRP, whereas it had no significant effect on the IL-6 level.

A steroidal saponin isolated from Allium chinense simultaneously induces apoptosis and autophagy by modulating the PI3K/Akt/mTOR signaling pathway in human gastric adenocarcinoma

Allium chinense, as a side dish on Asian table, is often used in folk medicine for its health benefits. (25R)-5α-spirostan-3β-yl-3-O-acetyl-O-β-d-glucopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (A-24) is a bioactive steroidal saponin isolated from Allium chinense. Previously, we have shown that A-24 has cytotoxic effects on cancer cells, but not on normal cells. To further explore the underlying mechanisms, in this study, we investigated the anticancer activity of A-24 in human gastric cancer cell lines in terms of cell proliferation, colony formation, cell cycle, induction of apoptosis/autophagy, and PI3K/Akt/mTOR pathway. A-24 showed dose-dependent cytotoxicity in SGC-7901 and AGS cell lines, it induced intrinsic mitochondrial pathway of apoptosis as well as autophagy, G2/M phase arrest and modulation of cyclinB1, p-cdc2, p-wee1 and p-Histone H3 expression. Furthermore, A-24 downregulated the phosphorylation of Akt at Ser473 and mTOR at Ser2448 in PI3K/Akt/mTOR pathway, and its downstream substrates p-p70S6K and p-4EBP1 in a dose-dependent manner. In addition, the pre-treatment of tumor cells with 3-methyladenine (3-MA) and LY294002 increased A-24-induced apoptosis. Collectively, these findings highlight the significance of downregulation of PI3K/Akt/mTOR pathway in A-24-induced apoptosis and autophagy, and the potential application of A-24 as a novel candidate in the treatment of human gastric adenocarcinoma.

Health Benefits of Plant-Derived Sulfur Compounds, Glucosinolates, and Organosulfur Compounds

The broad spectrum of the mechanism of action of immune-boosting natural compounds as well as the complex nature of the food matrices make researching the health benefits of various food products a complicated task. Moreover, many routes are involved in the action of most natural compounds that lead to the inhibition of chronic inflammation, which results in a decrease in the ability to remove a pathogen asymptomatically and is connected to various pathological events, such as cancer. A number of cancers have been associated with inflammatory processes. The current review strives to answer the question of whether plant-derived sulfur compounds could be beneficial in cancer prevention and therapy. This review focuses on the two main sources of natural sulfur compounds: alliaceous and cruciferous vegetables. Through the presentation of scientific data which deal with the study of the chosen compounds in cancer (cell lines, animal models, and human studies), the discussion of food processing’s influence on immune-boosting food content is presented. Additionally, it is demonstrated that there is still a need to precisely demonstrate the bioavailability of sulfur-containing compounds from various types of functional food, since the inappropriate preparation of vegetables can significantly reduce the content of beneficial sulfur compounds. Additionally, there is an urgent need to carry out more epidemiological studies to reveal the benefits of several natural compounds in cancer prevention and therapy.

Genomic relationship and physiochemical properties among raw materials used for Thai black garlic processing

Raw materials used for black garlic (BG) processing were collected from the major garlic production areas in Northern Thailand. Five of those were identified as of Thai origin (accession G1-G5), and accession G6 was of the Chinese variety. They were initially analyzed for varietal differences using morphological characteristics and genetic variation. Fresh materials from each accession were dried to the same moisture content (55%-60%) and BG processed at 75°C, 90% relative humidity (RH) for 15 days. Thereafter, physiochemical and chemical profiles were analyzed and compared. The dendrogram from random amplified polymorphic DNA fingerprints grouped G2, G3, G4, and G5 as closely related while G1 and G6 were out-groups. Prior to BG processing, the pH of fresh garlic was approximately 6.3 and decreased to 3.7, thereafter. The contents of chemical properties were independent with genotypes. BG processing improved phenolic, flavonoid, and antioxidant but the content of thiosulfinate was minimized in all BG samples. Overall, result indicated that garlics grown in Northern Thailand were genotypically variable. BG processing altered physical and chemical appearance, and these changes were independent with the genotypes.

Formononetin inhibits osteosarcoma cell proliferation and promotes apoptosis by regulating the miR-214-3p/phosphatase and tensin homolog pathway

BACKGROUND

Phytoestrogens have a similar molecular structure to estrogens which can produce either estrogenic or anti-estrogenic effects. It is generally believed that phytoestrogens combine with the estrogen receptor of osteosarcoma cells, affecting a variety of signal transduction pathways and cell metabolism, resulting in altered cell proliferation, differentiation, apoptosis, invasion and migration ability. Formononetin (FN) is the active ingredient of traditional Chinese medicine astragalus, angelica, and Pueraria lobate. Our study aims to detect the role of FN on MG-63 cell viability and apoptosis through regulating phosphatase and tensin homolog (PTEN) expression via MicroRNA-214-3p (miR-214-3p).

METHODS

3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Caspase 3 assay evaluated cell viability and apoptosis, respectively. Real-time quantitative polymerase chain reaction (qRT-PCR) and western blot evaluated the mRNA and protein expressions, respectively. The binding site of miR-214-3p/PTEN was detected via dual luciferase assay.

RESULTS

FN suppressed cell viability and induced apoptosis, and decreased miR-214-3p level and promoted PTEN expression. PTEN was then regarded as a target of miR-214-3p, and FN improved PTEN level via inhibiting miR-214-3p. Further analysis showed that overexpressed miR-214-3p improved cell viability and suppressed apoptosis of MG-63 cells by inhibiting PTEN expression.

CONCLUSIONS

Finally, our results revealed that FN inhibited cell viability and induced apoptosis by regulating miR-214-3p. FN acted as a new treatment for MG-63 cells via increasing PTEN level by inhibiting the miR-214-3p level.

Nutraceuticals in Neurological Disorders

Neurological diseases are one of the major healthcare issues worldwide. Posed lifestyle changes are associated with drastically increased risk of chronic illness and diseases, posing a substantial healthcare and financial burden to society globally. Researchers aim to provide fine treatment for ailing disorders with minimal exposed side effects. In recent decades, several studies on functional foods have been initiated to obtain foods that have fewer side effects and increased therapeutic activity. Hence, an attempt has been made to unravel several extraction techniques to acquire essential bioactive compounds or phytochemicals from therapeutically active food products. This has led to the conception of the term functional foods being meddled with other similar terms like "pharmafoods," "medifoods", "vitafoods", or "medicinal foods". With a dire need to adhere towards healthy options, the demand of nutraceuticals is widely increasing to combat neurological interventions. An association between food habits and the individual lifestyle with neurodegeneration has been manifested, thereby proposing the role of nutraceuticals as prophylactic treatment for neurological interventions. The current review covers some of the major neurological disorders and nutraceutical therapy in the prevention of disease.

Genoprotective activities of plant natural substances in cancer and chemopreventive strategies in the context of 3P medicine

Severe durable changes may occur to the DNA structure caused by exogenous and endogenous risk factors initiating the process of carcinogenesis. By evidence, a large portion of malignancies have been demonstrated as being preventable. Moreover, the targeted prevention of cancer onset is possible, due to unique properties of plant bioactive compounds. Although genoprotective effects of phytochemicals have been well documented, there is an evident lack of articles which would systematically present the spectrum of anticancer effects by phytochemicals, plant extracts, and plant-derived diet applicable to stratified patient groups at the level of targeted primary (cancer development) and secondary (cancer progression and metastatic disease) prevention. Consequently, clinical implementation of knowledge accumulated in the area is still highly restricted. To stimulate coherent co-development of the dedicated plant bioactive compound investigation on one hand and comprehensive cancer preventive strategies on the other hand, the current paper highlights and deeply analyses relevant evidence available in the area. Key molecular mechanisms are presented to detail genoprotective and anticancer activities of plants and phytochemicals. Clinical implementation is discussed. Based on the presented evidence, advanced chemopreventive strategies in the context of 3P medicine are considered.

Assessment of Genetic Diversity of the "Acquaviva Red Onion" (Allium cepa L.) Apulian Landrace

Onion (Allium cepa L.) is the second most important vegetable crop worldwide and is widely appreciated for its health benefits. Despite its significant economic importance and its value as functional food, onion has been poorly investigated with respect to its genetic diversity. Herein, we surveyed the genetic variation in the “Acquaviva red onion” (ARO), a landrace with a century-old history of cultivation in a small town in the province of Bari (Apulia, Southern of Italy). A set of 11 microsatellite markers were used to explore the genetic variation in a germplasm collection consisting of 13 ARO populations and three common commercial types. Analyses of genetic structure with parametric and non-parametric methods highlighted that the ARO represents a well-defined gene pool, clearly distinct from the Tropea and Montoro landraces with which it is often mistaken. In order to provide a description of bulbs, usually used for fresh consumption, soluble solid content and pungency were evaluated, showing higher sweetness in the ARO with respect to the two above mentioned landraces. Overall, the present study is useful for the future valorization of the ARO, which could be promoted through quality labels which could contribute to limit commercial frauds and improve the income of smallholders.

Sulfur bentonite-organic-based fertilizers as tool for improving bio-compounds with antioxidant activities in red onion

BACKGROUND

Red onion is popular in cuisines worldwide and is valued for its potential medicinal properties. Red onion is an important source of several phytonutrients such as flavonoids, thiosulfinates and other sulfur compounds, recognized as important elements of the diet. Nowadays, there is the need of producing food enriched in health benefit compounds. In this study, pads of sulfur bentonite (SB) with the addition of orange residue (OR) or olive pomace (OP) were used to improve the quality of red onion. The experiment was conducted for 3 months in the field to evaluate the phytochemicals of differently amended red onion.

RESULTS

Treated plants were better in quality than controls. Antioxidant activity, detected as DPPH, ORAC and ABTS, was highest in plants grown in the presence of SB enriched with agricultural wastes, particularly SB-OR. Polyphenols increased in all treated plants. The volatile fraction was clearly dominated by sulfur compounds that are strictly related to the concentration of the aroma precursors S-alkenyl cysteine sulfoxides. The greater amount of thiosulfinates in treated compared with untreated onion evidenced that SB pelletized with agricultural wastes can represent a new formulation of organic fertilizer able to improve the beneficial properties of onion. The results highlighted that the best red onion quality was obtained using SB-OR pads.

CONCLUSION

The use of SB bound with agricultural wastes represents a novel strategy to increase bio-compounds with beneficial effects on human health, to enhance the medical and economic values of sulfur-loving crops, with important consequences on the bio and green economy. © 2019 Society of Chemical Industry.

Protocol and Preliminary Results of the Nutritarian Women's Health Study: A Longitudinal Effectiveness-Implementation Hybrid Study Assessing Dietary Intake and Health Outcomes

Whole-food plant-rich dietary patterns have been shown to be associated with significant health benefits and disease-risk reduction. One such program, which has been gaining popularity, is the micronutrient-dense plant-rich (mNDPR) "Nutritarian" diet. The goal of this study is to determine the feasibility of implementing an online mNDPR "Nutritarian" intervention program and to determine the effectiveness of this program in reducing risk of chronic disease in women. The Nutritarian Women's Health Study is a long-term online longitudinal hybrid effectiveness-implementation study. Participants are recruited through social media, medical professionals/offices, and nutrition-related events and conferences. Participants receive online nutrition education and complete regular self-reported questionnaires regarding lifestyle, nutrition practices, and health. The online intervention program appears to be feasible and effective. Some decline in dietary adherence, particularly for certain food types, was observed during the study. For groups at risk, based on body mass index or waist-to-height ratio, there were initial decreases in body mass index and waist-to-height that leveled off over time, in some cases returning to baseline measures. The study suggests the implementation of the Nutritarian dietary pattern, through an online intervention component, may be effective in reducing the risk of chronic disease, with implications for clinical and public health practice.

Comparison of Organosulfur and Amino Acid Composition between Triploid Onion Allium cornutum Clementi ex Visiani, 1842, and Common Onion Allium cepa L., and Evidences for Antiproliferative Activity of Their Extracts

Species that belong to the genus Allium have been widely used for human food and traditional medicine. Their beneficial health effects, as well as the specific aroma, are associated with their bioactive chemical compounds, such as sulfur compounds and flavonoids. Gas chromatography and mass spectrometry (GC-MS) and reverse-phase high-performance liquid chromatography (reverse-phase HPLC) were used to identify organosulfur and amino acid content of triploid hybrid onion, Allium cornutum Clement ex Visiani, 1842, and common onion, Allium cepa L. Allium extracts were tested for their antiproliferative activity in three human cancer cell lines (HeLa, HCT116, and U2OS). DNA fragmentation and DAPI staining analysis were performed on HeLa cells to evaluate the effect of extracts on DNA damage and cell morphology. The mRNA expression of p53, Bax, and Caspase-3 genes involved in apoptosis were analyzed by real-time PCR. Using GC-MS, 27 compounds were found in two Allium species headspaces. Differences were noted among the main compound abundance in the headspace (although the major thiols and disulfides were qualitatively identic in both Allium species) and dipropyl disulfide, diisopropyl trisulfide, and (Z)-prop-1-enyl propyl trisulfide were predominant sulfides. Identification of amino acids and their quantities were determined by reverse-phase HPLC. Most abundant amino acids in both onions were arginine (Arg) and glutamic acid (Glu). The results of cytotoxicity testing confirmed antiproliferative effects of both species. The DNA fragmentation assay, DAPI staining and real time PCR analysis confirmed that A. cornutum and A. cepa extracts induced apoptosis in HeLa cells. This study presents the evidence for possible therapeutic use of A. cornutum and A. cepa extracts against human cervical carcinoma cell line.

Genome size analysis of field grown and somatic embryo regenerated plants in Allium sativum L

In the present study, an efficient in vitro propagation protocol has been developed from clove explants of Allium sativum L., one of the oldest vegetable and medicinal plant used worldwide. Garlic is propagated vegetatively as cross-fertilization is strictly precluded due to sterile flowers. Due to a low rate of multiplication, limited genetic improvement possibility and increased germplasm degradation, plant tissue culture becomes an efficient and preferred tool for quality and rapid propagation of garlic. Here, the clove explants were cultured on Murashige and Skoog basal medium amended with different concentrations of Plant Growth Regulators (PGRs) namely 2,4-dichlorophenoxy acetic acid (2,4-D), 6-benzyl amino purine (BAP), and 1-naphthalene acetic acid (NAA). Within 2 weeks of inoculation, white compact callus was formed, maximum callus induction frequency (85.99%) was on 1.5 mg l^-1 2, 4-D added MS medium. Induced callus transformed into an embryogenic callus on 2, 4-D and BAP amended MS medium with highest embryogenic frequency (77.7%) was noted on 0.25 mg l^-1 2, 4-D and 1.0 mg l^-1 BAP added medium. Embryogenic callus differentiated into progressive stages of somatic embryos starting from globular, scutellar, and finally to coleoptilar stage of the embryo. Histological and scanning electron microscopic study of embryogenic callus was conducted, showing different stages of embryos, their origin and development, re-confirming somatic embryogenesis incidence in A. sativum. Green and mature somatic embryos were germinated and converted into plantlets on 0.5 mg l^-1 BAP amended MS medium. The in vitro regenerated plants were cultured separately in IBA and NAA supplemented media for root induction. The MS medium amended with 1.0 mg l^-1 IBA proved to be the best PGR treatment in inducing roots. The rooted plants were acclimatized and transferred ex vitro with about 87% survival rate. Cytological and flow cytometric analyses were performed to assess the genetic stability of in vitro regenerated plants. Cytological studies of in vitro regenerated plants showed 2n = 16 chromosome number and did not reveal any numerical variation in chromosomes. Flow cytometry was employed to measure the 2C DNA content of somatic embryo regenerated A. sativum plants and compared with in vivo grown garlic. The histogram peaks of relative 2C DNA content of in vitro regenerated plantlets were similar to the corresponding 2C DNA peak of in vivo grown plants. Flow cytometric 2C DNA content of embryo regenerated and field-grown A. sativum plants were the same, i.e., 33.45 pg and 33.56 pg, respectively, confirming genetic similarity. In conclusion, the present cytological and flow cytometric study suggest that the in vitro culture conditions are quite safe, did not encourage genetic alterations, and regenerants were "true to type."

Therapeutic Effects of Garlic on Hepatic Steatosis in Nonalcoholic Fatty Liver Disease Patients: A Randomized Clinical Trial

BACKGROUND AND AIMS

Emerging evidence suggests that garlic (Allium sativum L.) and its bioactive components can mitigate hepatic steatosis by the modulation of hepatic lipid metabolism. We aimed to assess the efficacy of the garlic administration on hepatic steatosis in patients with NAFLD.

PATIENTS AND METHODS

This clinical trial was conducted on adult patients with ultrasound-diagnosed NAFLD. Eligible participants were randomly assigned, with the use of the stratified blocked procedure, to receive 800 mg garlic or placebo for 15 weeks. The primary outcome was the improvement in the hepatic steatosis diagnosed by ultrasound technique after 15 weeks of intervention.

RESULTS

A total of 110 patients underwent randomization, and 98 patients completed the trial. Twenty-four (51.1%) patients in the garlic group achieved improvement in the hepatic steatosis compared to eight (15.7%) patients in the placebo group with the relative risk of 5.6 (95% CI: 2.17 to 14.5; P=0.001), which remained significant after adjusting for baseline value of hepatic steatosis. There were significant reductions in weight and serum ALT, AST, FBS, Hb A1C, total cholesterol, LDL-cholesterol, and TG concentration with the garlic intake compared to placebo (P<0.05). The results were also significant after adjusting for weight change, energy intake, and physical activity. No serious adverse effects were observed with the garlic intake.

CONCLUSION

The intake of garlic powder was accompanied by a significant improvement in the hepatic steatosis and comorbidity related to this condition among subjects with NAFLD.

Contemporary Formulations for Drug Delivery of Anticancer Bioactive Compounds

BACKGROUND

The immense development in the field of anticancer research has led to an increase in the research of bioactive compounds with anticancer potential. It has been known that many bioactive natural compounds have low solubility (and low bioavailability) as their main drawback when it comes to the formulation and drug delivery to specific sites.

OBJECTIVE

As many attempts have been made to overcome this issue, this review gives a summary of the current accomplishments regarding the development of new Drug Delivery Systems (DDSs) represented by nanoparticles (NPs) and exosomes.

METHODS

We analyzed the published data concerning selected compounds that present the most prominent plant secondary metabolites with anticancer potential, specifically flavone (quercetin), isoflavone (genistein and curcumin) and stilbene (resveratrol) groups that have been formulated as NPs and exosomes. In addition, we summarized the patent literature published from 2015-2018 that address these formulations.

RESULTS

Although the exact mechanism of action for the selected natural compounds still remains unclear, the anticancer effect is evident and the main research efforts are directed to finding the most suitable delivery systems. Recent patents in this field serve as evidence that these newly designed natural compound delivery systems could be powerful new anticancer agents in the very near future if the noted difficulties are overcome.

CONCLUSION

The focus of recent research is not only to clarify the exact mechanisms of action and therapeutic effects, but also to answer the issue of suitable delivery systems that can transport sufficient doses of bioactive compounds to the desired target.

Comparative Study of Onion (Allium cepa) and Leek (Allium ampeloprasum): Identification of Organosulphur Compounds by UPLC-QTOF/MS and Anticancer Effect on MCF-7 Cells

Onion (Allium cepa) and leek (Allium ampeloprasum var. porrum) are common herbs and vegetables found in our daily life. It belongs to the genus Allium, which is usually known for their high antioxidant and anticancer properties. Medical researchers highly recommend the exploitation of herbs and plants as alternative ways in the treatment of cancer. This research was designed to study the anticancer effects of onion and leek extracts on MCF-7 human breast cancer cell. Crude extracts of ethanol, methanol, and water of onion and leek were obtained by maceration. MCF-7 cells were cultured in complete media at 37 °C and subjected to different treatments that involved varying concentrations (10, 50, and 100 μg/mL) of onion and leek extracts for 24, 48, and 72 h of incubation. The percentage of cell viability and the concentration of extracts on MCF-7 cells were determined using MTT assay. The water leek extract proved to be the most effective extract at 50 μg/mL, whereby it showed a significant inhibition ability due to the presence of entadamide A-β-D-glucopyranoside as identified by ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF/MS). Further studies about the mechanism of both extracts in causing cell death and the determination of the presence of other bioactive compounds in the extracts are needed.

An Appraisal of Developments in Allium Sulfur Chemistry: Expanding the Pharmacopeia of Garlic

Alliums and allied plant species are rich sources of sulfur compounds that have effects on vascular homeostasis and the control of metabolic systems linked to nutrient metabolism in mammals. In view of the multiple biological effects ascribed to these sulfur molecules, researchers are now using these compounds as inspiration for the synthesis and development of novel sulfur-based therapeutics. This research has led to the chemical synthesis and biological assessment of a diverse array of sulfur compounds representative of derivatives of S-alkenyl-l-cysteine sulfoxides, thiosulfinates, ajoene molecules, sulfides, and S-allylcysteine. Many of these synthetic derivatives have potent antimicrobial and anticancer properties when tested in preclinical models of disease. Therefore, the current review provides an overview of advances in the development and biological assessment of synthetic analogs of allium-derived sulfur compounds.

S-1-propenylmercaptocysteine protects murine hepatocytes against oxidative stress via persulfidation of Keap1 and activation of Nrf2

The onion-derived metabolite, S-1-propenylmercaptocysteine (CySSPe), protects against oxidative stress and exhibits anti-inflammatory effects by modulating cellular redox homeostasis. We sought to establish whether CySSPe activates nuclear factor erythroid 2-related factor 2 (Nrf2) and whether activation of Nrf2 by CySSPe involves modification of the Kelch-like ECH-associated protein-1 (Keap1) to manifest these effects. We found that CySSPe stabilized Nrf2 protein and facilitated nuclear translocation to induce expression of antioxidant enzymes, including NQO1, HO-1, and GCL. Moreover, CySSPe attenuated tert-butyl hydroperoxide-induced cytotoxicity and dose-dependently inhibited reactive oxygen species production. Silencing experiments using Nrf2-siRNA confirmed that CySSPe conferred protection against oxidative stress by activating Nrf2. CySSPe enhanced cellular pool of reduced glutathione (GSH) and improved GSH:GSSG ratio. Pretreatment of cells with l-buthionine-S,R-sulfoximine (BSO) confirmed that CySSPe increases de novo synthesis of GSH by upregulating expression of the GSH-synthesizing enzyme GCL. Treatment of cells with CySSPe elevated hydrogen sulfide (H₂S) production. Inhibition of H₂S-synthesizing enzymes, cystathionine-gamma-lyase (CSE) and cystathionine-beta-synthase (CBS), by pretreating cells with propargylglycine (PAG) and oxyaminoacetic acid (AOAA) revealed that H₂S production was partially dependent on a CSE/CBS-catalyzed β-elimination reaction with CySSPe that likely produced 1-propenyl persulfide (RSSH). Depleting cells of their GSH pool by exposure to BSO and diethylmaleate attenuated H₂S production, suggesting a GSH-dependent formation of H₂S, likely via the reduction of RSSH by GSH. Finally, treatment of cells with CySSPe persulfidated Keap1, which may be the mechanism involved for the stabilization of Nrf2 by CySSPe. Taken together, our results showed that attenuation of oxidative stress by CySSPe is associated with its ability to produce H₂S or RSSH, which persulfidates Keap1 and activates Nrf2 signaling. This study provides insights on the potential of CySSPe as an onion-derived dietary agent that modulates redox homeostasis and combats oxidative stress.

Effects of Helicobacter pylori treatment and vitamin and garlic supplementation on gastric cancer incidence and mortality: follow-up of a randomized intervention trial

OBJECTIVE

To assess the effects of Helicobacter pylori treatment, vitamin supplementation, and garlic supplementation in the prevention of gastric cancer.

DESIGN

Blinded randomized placebo controlled trial.

SETTING

Linqu County, Shandong province, China.

PARTICIPANTS

3365 residents of a high risk region for gastric cancer. 2258 participants seropositive for antibodies to H pylori were randomly assigned to H pylori treatment, vitamin supplementation, garlic supplementation, or their placebos in a 2×2×2 factorial design, and 1107 H pylori seronegative participants were randomly assigned to vitamin supplementation, garlic supplementation, or their placebos in a 2×2 factorial design.

INTERVENTIONS

H pylori treatment with amoxicillin and omeprazole for two weeks; vitamin (C, E, and selenium) and garlic (extract and oil) supplementation for 7.3 years (1995-2003).

MAIN OUTCOME MEASURES

Primary outcomes were cumulative incidence of gastric cancer identified through scheduled gastroscopies and active clinical follow-up through 2017, and deaths due to gastric cancer ascertained from death certificates and hospital records. Secondary outcomes were associations with other cause specific deaths, including cancers or cardiovascular disease.

RESULTS

151 incident cases of gastric cancer and 94 deaths from gastric cancer were identified during 1995-2017. A protective effect of H pylori treatment on gastric cancer incidence persisted 22 years post-intervention (odds ratio 0.48, 95% confidence interval 0.32 to 0.71). Incidence decreased significantly with vitamin supplementation but not with garlic supplementation (0.64, 0.46 to 0.91 and 0.81, 0.57 to 1.13, respectively). All three interventions showed significant reductions in gastric cancer mortality: fully adjusted hazard ratio for H pylori treatment was 0.62 (95% confidence interval 0.39 to 0.99), for vitamin supplementation was 0.48 (0.31 to 0.75), and for garlic supplementation was 0.66 (0.43 to 1.00). Effects of H pylori treatment on both gastric cancer incidence and mortality and of vitamin supplementation on gastric cancer mortality appeared early, but the effects of vitamin supplementation on gastric cancer incidence and of garlic supplementation only appeared later. No statistically significant associations were found between interventions and other cancers or cardiovascular disease.

CONCLUSIONS

H pylori treatment for two weeks and vitamin or garlic supplementation for seven years were associated with a statistically significant reduced risk of death due to gastric cancer for more than 22 years. H pylori treatment and vitamin supplementation were also associated with a statistically significantly reduced incidence of gastric cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00339768.

S-Alk(en)ylcysteine sulfoxides in the genus Allium: proposed biosynthesis, chemical conversion, and bioactivities

S-Alk(en)ylcysteine sulfoxides are sulfur-containing natural products characteristic of the genus Allium. Both the flavor and medicinal properties of Allium plants are attributed to a wide variety of sulfur-containing compounds that are generated from S-alk(en)ylcysteine sulfoxides. Previous radiotracer experiments proposed that S-alk(en)ylcysteine sulfoxides are biosynthesized from glutathione. The recent identification of γ-glutamyl transpeptidases and a flavin-containing S-oxygenase involved in the biosynthesis of S-allylcysteine sulfoxide (alliin) in garlic (Allium sativum) provided insights into the reaction order of deglutamylation and S-oxygenation together with the localization of the biosynthesis, although the rest of the enzymes in the pathway still await discovery. In intact plants, S-alk(en)ylcysteine sulfoxides are stored in the cytosol of storage mesophyll cells. During tissue damage, the vacuolar enzyme alliinase contacts and hydrolyzes S-alk(en)ylcysteine sulfoxides to produce the corresponding sulfenic acids, which are further converted into various sulfur-containing bioactive compounds mainly via spontaneous reactions. The formed sulfur-containing compounds exhibit bioactivities related to pathogen defense, the prevention and alleviation of cancer and cardiovascular diseases, and neuroprotection. This review summarizes the current understanding of the occurrence, biosynthesis, and alliinase-triggered chemical conversion of S-alk(en)ylcysteine sulfoxides in Allium plants as well as the impact of S-alk(en)ylcysteine sulfoxides and their derivatives on medicinal, food, and agricultural sciences.

Onion and Garlic Intake and Breast Cancer, a Case-Control Study in Puerto Rico

Studies show an inverse association between onion and garlic intake and risk of cancers of the lung, prostate, and stomach. There is limited evidence on the association between onion and garlic intake and breast cancer. We assessed this association in a population-based, case-control study in Puerto Rico. Incident, primary breast cancer cases (n = 314) were identified among women aged 30-79 from hospital and clinic records. Controls (n = 346) were women with no history of cancer other than nonmelanoma skin cancer, residents of the same area. Dietary intake was estimated using a food frequency questionnaire. Total onion and garlic intake included sofrito (a popular garlic- and onion-based condiment) intake frequency. Unconditional logistic regression assessed the association between onion and garlic consumption and breast cancer adjusting for age, education, parity, family history, body mass index, age at menarche, total energy, and smoking. Inverse associations with breast cancer were observed for moderate (OR (odds ratio) = 0.59, 95% CI (confidence interval): 0.35, 1.01) and high consumption (OR = 0.51, 95% CI: 0.30, 0.87) compared to low consumption of onion and garlic (P_trend = 0.02). Results were similar when stratified by menopausal status. Study results suggest that high onion and garlic consumption is protective against breast cancer in this population.

Association of p38MAPK-p53-Fas aggregation in S-allyl cysteine mediated regulation of hepatocarcinoma

Bioactive components of dietary phytochemicals have been reported to possess antitumor activities. Evidences suggested key role of stress responsive p38MAPK in the induction of nutraceuticals mediated apoptosis in hepatocellular carcinoma (HCC). Current study demonstrated detailed molecular bagatelle associated with p38 MAPK mediated effective suppression of cell growth both in HepG2 and chemically induced liver carcinoma after S-allyl cysteine (SAC) treatment. SAC promoted p38MAPK activity responsible for p53 phosphorylation, its stabilization followed by nuclear translocation leading to induction in expression and oligomerization of Fas protein. Distinctive p38MAPK-p53 axis dependent Fas-FasL-FADD mediated caspase activities along with perturbed cell cycling became normalized with continuation of SAC treatment for another month to diethylnitrosamine induced liver carcinoma. Co-treatment with SB203580, the p38MAPK inhibitor, prevented pro-apoptotic effect of SAC by altering p53 phosphorylation and death inducing signaling complex conformation in HepG2 and induced HCC. Collectively study suggested significant contribution of p38MAPK-p53-DISC-Caspase pathway in the regulation of anti-neoplastic activity of SAC against HCC.

Anti-cancer activities of S-allylmercaptocysteine from aged garlic

While most types of malignancies remain recalcitrant to treatment, application of natural products or their analogs in daily life has offered some hopes as an effective prophylaxis against cancer onset and progression in the past decades. Emerging evidence supports a link between garlic consumption and decreased cancer incidence. Notably, aged garlic extract (AGE) exhibits stronger anti-cancer activities than that of fresh garlic, by virtue of enrichment of several AGE-specific organosulfur compounds, including S-allylmercaptocysteine (SAMC). In this review, we summarize the up-to-date mechanistic pathways associated with the anti-proliferative, anti-metastatic and pro-apoptotic effects of SAMC in various cancer models. Based upon the proven safety and improved understanding on its anti-neoplastic properties, SAMC has gained recognition as a promising daily food supplement for cancer prevention or management.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.

An LC-MS/MS Method to Measure S-Methyl-l-Cysteine and S-Methyl-l-Cysteine Sulfoxide in Human Specimens Using Isotope Labelled Internal Standards

This is the first report describing an analytical method for quantitative analysis of two naturally occurring sulphur compounds, S-methyl-l-cysteine (SMC) and S-methyl-l-cysteine sulfoxide (SMCSO), in human body fluids using isotope-labelled internal standards and liquid chromatography-mass spectrometry (LC-MS)/MS techniques. This method was validated according to the guideline of the Royal Society of Chemistry Analytical Methods Committee. It offers significant advantages including simple and fast preparation of human biological samples. The limits of detection of SMC were 0.08 µM for urine and 0.04 µM for plasma. The limits of detection of SMCSO were 0.03 µM for urine and 0.02 µM for plasma. The calibration curves of all matrices showed linearity with correlation coefficients r² > 0.9987. The intra and inter day precisions in three levels of known concentrations were >10% and >20%, respectively. The quantification accuracy was 98.28 ± 5.66%. The proposed method would be beneficial for the rapid and accurate determination of the SMC and SMCSO in human plasma and urine samples using by isotope labelled internal standards.

Consumption of garlic and its interactions with tobacco smoking and alcohol drinking on esophageal cancer in a Chinese population

Garlic consumption has been associated inversely with esophageal cancer (EC); however, its interactions with tobacco smoking and alcohol consumption have never been evaluated in an epidemiological study. We evaluated the potential interactions between garlic intake and tobacco smoking as well as alcohol consumption in a population-based case-control study with 2969 incident EC cases and 8019 healthy controls. Epidemiologic data were collected by face-to-face interviews using a questionnaire. The adjusted odds ratio (OR) and 95% confidence interval (CI) were estimated and additive and multiplicative interactions were evaluated using unconditional logistic regression models, adjusting for potential confounding factors. Semi-Bayes (SB) adjustments were used to reduce potential false-positive findings. EC was associated inversely with raw garlic intake [SB-adjusted OR for more than once a week=0.68, 95% CI: 0.57-0.80], with a strong dose-response pattern in the overall analysis and in the stratified analyses by smoking and drinking. EC was associated positively with smoking and alcohol drinking, with SB-adjusted OR of 1.73 (95% CI: 1.62-1.85) and 1.37 (95% CI: 1.28-1.46) in dose-response effects of increased intensity and longer duration of smoking/drinking. Moreover, garlic intake interacts with smoking [synergy index (S)=0.83, 95% CI: 0.67-1.02; ratio of OR=0.88, 95% CI: 0.80-0.98] and alcohol drinking (S=0.73, 95% CI: 0.57-0.93; ratio of OR=0.86, 95% CI: 0.77-0.95) both multiplicatively and additively. Our findings suggested that high intake of raw garlic may reduce EC risk and may interact with tobacco smoking and alcohol consumption, which might shed a light on the development of EC as well as a potential dietary intervention among high-risk smokers and drinkers for EC prevention in the Chinese population.

The beneficial effects of subcutaneous Allium cepa injection on random flap survival in rats

Random flaps are frequently used in the practice of reconstructive surgery. The aim of this experimental study was to investigate the effects of Allium cepa on random flap survival in rats. Fourteen Wistar rats were used for this experimental study. The subjects were divided into experiment and control groups. Rats in the experiment group received daily injections of A. cepa extract for 7 d before the elevation of the flaps. Following the treatment period, elevation and reinsertion of the dorsal flaps were performed. Necrotic and total flaps areas were marked and calculated 7 d after the flap elevation. Histological examinations and microangiography were performed to evaluate the results. The mean value of the proportion of necrotic flap areas to the total flap area was 25.06 and 50.6% in the A. cepa and control group, respectively (p = .0079). In the histological examination, number of vessels identified in the dermis were 23.75 ± 0.7 and 33.75 ± 9 in the A. cepa and control group, respectively (p = .7457). In angiographic images, vessels formations were more noticeable in the A. cepa group. We conclude that preoperative subcutaneous A. cepa injection increases dorsal flap survival in rats.

The mechanisms of pharmacokinetic food-drug interactions - A perspective from the UNGAP group

The simultaneous intake of food and drugs can have a strong impact on drug release, absorption, distribution, metabolism and/or elimination and consequently, on the efficacy and safety of pharmacotherapy. As such, food-drug interactions are one of the main challenges in oral drug administration. Whereas pharmacokinetic (PK) food-drug interactions can have a variety of causes, pharmacodynamic (PD) food-drug interactions occur due to specific pharmacological interactions between a drug and particular drinks or food. In recent years, extensive efforts were made to elucidate the mechanisms that drive pharmacokinetic food-drug interactions. Their occurrence depends mainly on the properties of the drug substance, the formulation and a multitude of physiological factors. Every intake of food or drink changes the physiological conditions in the human gastrointestinal tract. Therefore, a precise understanding of how different foods and drinks affect the processes of drug absorption, distribution, metabolism and/or elimination as well as formulation performance is important in order to be able to predict and avoid such interactions. Furthermore, it must be considered that beverages such as milk, grapefruit juice and alcohol can also lead to specific food-drug interactions. In this regard, the growing use of food supplements and functional food requires urgent attention in oral pharmacotherapy. Recently, a new consortium in Understanding Gastrointestinal Absorption-related Processes (UNGAP) was established through COST, a funding organisation of the European Union supporting translational research across Europe. In this review of the UNGAP Working group "Food-Drug Interface", the different mechanisms that can lead to pharmacokinetic food-drug interactions are discussed and summarised from different expert perspectives.

The garlic compound ajoene covalently binds vimentin, disrupts the vimentin network and exerts anti-metastatic activity in cancer cells

BACKGROUND

Garlic has been used for centuries for its flavour and health promoting properties that include protection against cancer. The vinyl disulfide-sulfoxide ajoene is one of the phytochemicals found in crushed cloves, hypothesised to act by S-thiolating reactive cysteines in target proteins.

METHODS

Using our fluorescently labelled ajoene analogue called dansyl-ajoene, ajoene's protein targets in MDA-MB-231 breast cancer cells were tagged and separated by 2D electrophoresis. A predominant band was identified by MALDI-TOF MS/MS to be vimentin. Target validation experiments were performed using pure recombinant vimentin protein. Computational modelling of vimentin bound to ajoene was performed using Schrödinger and pKa calculations by Epik software. Cytotoxicity of ajoene in MDA-MB-231 and HeLa cells was measured by the MTT assay. The vimentin filament network was visualised in ajoene-treated and non-treated cells by immunofluorescence and vimentin protein expression was determined by immunoblot. The invasion and migration activity was measured by wound healing and transwell assays using wildtype cells and cells in which the vimentin protein had been transiently knocked down by siRNA or overexpressed.

RESULTS

The dominant protein tagged by dansyl-ajoene was identified to be the 57 kDa protein vimentin. The vimentin target was validated to reveal that ajoene and dansyl-ajoene covalently bind to recombinant vimentin via a disulfide linkage at Cys-328. Computational modelling showed Cys-328 to be exposed at the termini of the vimentin tetramer. Treatment of MDA-MB-231 or HeLa cells with a non-cytotoxic concentration of ajoene caused the vimentin filament network to condense; and to increase vimentin protein expression. Ajoene inhibited the invasion and migration of both cancer cell lines which was found to be dependent on the presence of vimentin. Vimentin overexpression caused cells to become more migratory, an effect that was completely rescued by ajoene.

CONCLUSIONS

The garlic-derived phytochemical ajoene targets and covalently modifies vimentin in cancer cells by S-thiolating Cys-328. This interaction results in the disruption of the vimentin filament network and contributes to the anti-metastatic activity of ajoene in cancer cells.

Characterization of γ-glutamyltranspeptidases from dormant garlic and onion bulbs

This study investigated the characteristics of γ-glutamyltranspeptidases (GGTs) isolated from dormant garlic (Allium sativum L.) and onion (Allium cepa L. var. agrogatum Don) bulbs. GGTs were isolated using (NH 4)2 SO 4 precipitation and hydrophobic interaction chromatography (phenyl-Sepharose column). The optimal temperature, optimal pH of extraction, and the effects of metal ions and organic compounds on the activity of GGTs were investigated. The optimal pH of the GGTs of garlic and onion was 5 and 7, respectively; the optimal temperatures were 70 and 50°C, respectively. Garlic's GGT had a major band at 53 kDa, whereas onion's GGT had two bands at 55 and 22 kDa. Cu2+, Mn2+, Fe2+, Mg2+, glucose, aspartic acid, and cysteine significantly enhanced the activity of garlic's GGT. Lysine and proline remarkably promoted the activity of onion's GGT, whereas Cu2+, glucose, and aspartic acid repress its activity. These results may deepen our understanding of allium GGTs and promote the commercial production of bioactive allium compounds.

Hydrogen Sulfide as a Novel Regulatory Factor in Liver Health and Disease

Hydrogen sulfide (H₂S), a colorless gas smelling of rotten egg, has long been recognized as a toxic gas and environment pollutant. However, increasing evidence suggests that H₂S acts as a novel gasotransmitter and plays important roles in a variety of physiological and pathological processes in mammals. H₂S is involved in many hepatic functions, including the regulation of oxidative stress, glucose and lipid metabolism, vasculature, mitochondrial function, differentiation, and circadian rhythm. In addition, H₂S contributes to the pathogenesis and treatment of a number of liver diseases, such as hepatic fibrosis, liver cirrhosis, liver cancer, hepatic ischemia/reperfusion injury, nonalcoholic fatty liver disease/nonalcoholic steatohepatitis, hepatotoxicity, and acute liver failure. In this review, the biosynthesis and metabolism of H₂S in the liver are summarized and the role and mechanism of H₂S in liver health and disease are further discussed.

Nutraceuticals Inspiring the Current Therapy for Lifestyle Diseases

Nutraceuticals are the pharmaceutically blended products that possess both nutritional as well as the medicinal value. Such a product is designed to improve the physical health, fight against day-to-day challenges such as stress, increase longevity, etc. Nowadays, emphasis is given to those herbs which are used as food and medicine due to its greater acceptance. Due to dynamic action, the popularity of nutraceuticals among people as well as healthcare providers has been increased over medicines and health supplements. This review documents herbs with a wide variety of therapeutic values such as immunity booster, antidiabetic, anticancer, antimicrobial, and gastroprotective. These herbs could be better options to formulate as nutraceuticals. Several nutraceuticals are described based on their availability as food, chemical nature, and mechanism of action.

A novel therapeutic anticancer property of raw garlic extract via injection but not ingestion

Prior studies suggest a possibility that the anticancer property of garlic is more effective only when exposed directly to cancer cells than absorbed first by the normal epithelial cells of the gastrointestinal tract wall. We tested this possibility in two mouse models of highly aggressive malignancies that cannot yet be cured by conventional therapies: sarcoma 180- and EL4-induced lethal ascites. Daily oral gavages of raw garlic extract (RGE; equivalent to 100 mg wet weight) for 21 days failed to offer any meaningful effect in the mice with malignancies. However, the daily injection of the same amounts of the same materials for 21 days completely cured all the mice of cancer. This novel anticancer activity of RGE was present entirely in the size fraction of the molecules smaller than 3000 Dalton rather than the larger molecules and was completely partitioned into the organic phase rather than into the aqueous phase. One half of the anticancer activity was inactivated by heating at 100 °C for 10 min, suggesting that multiple components were concertedly involved. In a direct comparison, the RGE was significantly more effective in killing the cultured cancer cells in vitro than the extracts from other 21 raw vegetables and fruits. In cell culture, RGE killed a wide variety of different cancer cells regardless of species of origin and cell types. Cancer cells generally are well known to be defective in many common metabolic pathways present in their normal cell counterpart for processing normal nutrients. The metabolism of these otherwise normal nutrients could be stalled in the cancer cells and become cytotoxic. The most-effective way of treating cancer by RGE may be the direct injection instead of eating the cooked garlic.

Garlic-derived compound S-allylmercaptocysteine inhibits hepatocarcinogenesis through targeting LRP6/Wnt pathway

Whether and how garlic-derived S-allylmercaptocysteine (SAMC) inhibits hepatocellular carcinoma (HCC) is largely unknown. In the current study, the role of low-density lipoprotein receptor (LDLR)-related protein 6 (LRP6) in HCC progression and the anti-HCC mechanism of SAMC was examined in clinical sample, cell model and xenograft/orthotopic mouse models. We demonstrated that SAMC inhibited cell proliferation and tumorigenesis, while induced apoptosis of human HCC cells without influencing normal hepatocytes. SAMC directly interacted with Wnt-pathway co-receptor LRP6 on the cell membrane. LRP6 was frequently over-expressed in the tumor tissue of human HCC patients (66.7% of 48 patients) and its over-expression only correlated with the over-expression of β-catenin, but not with age, gender, tumor size, stage and metastasis. Deficiency or over-expression of LRP6 in hepatoma cells could partly mimic or counteract the anti-tumor properties of SAMC, respectively. In vivo administration of SAMC significantly suppressed the growth of Huh-7 xenograft/orthotopic HCC tumor without causing undesirable side effects. In addition, stable down-regulation of LRP6 in Huh-7 facilitated the anti-HCC effects of SAMC. In conclusion, LRP6 can be a potential therapeutic target of HCC. SAMC is a promising specific anti-tumor agent for treating HCC subtypes with Wnt activation at the hepatoma cell surface.

Anti-obesity and Hypolipidemic effects of garlic oil and onion oil in rats fed a high-fat diet

Background

Until now, little research concerning the lipid-lowering and anti-obesity functions of garlic oil and onion oil has been performed. The objective of this study was to explore the effects of garlic oil and onion oil on serum lipid levels in hyperlipidemia model rats, to provide a scientific basis for the prevention of hyperlipidemia through a dietary approach, and to explore the potential health benefits of garlic and onion.

Method

Ninety-six male Sprague-Dawley rats were randomly allocated into eight groups based on their body weight and serum levels of triglycerides (TG) and total cholesterol (TC). The rats received repeated oral administration of volatile oils extracted from garlic and onion for 60 days. Serum lipids and parameters of obesity were examined.

Results

The volatile oils suppressed the HFD-induced body weight gain and tended to decrease adipose tissue weight. The oils decreased the levels of TG, TC and LDL-C and increased the serum level of HDL-C compared with the rats in the hyperlipidemia model groups (P < 0.05). The oils were also effective at improving the lipid profile and alleviating hepatic steatosis.

Conclusion

Our results implied that garlic oil and onion oil have anti-obesity properties that can counteract the effects of an HFD on body weight, adipose tissue weight, and serum lipid profiles.

Electronic supplementary material

The online version of this article (10.1186/s12986-018-0275-x) contains supplementary material, which is available to authorized users.