Allicin inhibits the biological activities of cervical cancer cells by suppressing circEIF4G2

Allicin is a safe herbal extract believed to have antitumor effects, which, however, remain unclear. The aim of the present work was to discuss Allicin antitumor effects on cervical cancer using cell experiments. Using Hela and Siha to our research objectives in our study, first step, difference concentration of Allicin (20, 40, and 80 μM) treated Hela and Siha cell lines, and next step, discuss circEIF4G2 effects in Allicin antitumor effects in Hela and Siha cell lines; the cell proliferation and EdU-positive cell number by CCK-8 and EdU staining; cell apoptosis rate by flow cytometry; invasion cell number by transwell assay; wound healing rate by wound healing assay; and relative mRNA and protein levels using qRT-PCR and WB assay. With Allicin supplement, the cell proliferation and EdU-positive cell number were significantly depressed with cell apoptosis rate significantly increasing; invasion cell number and wound healing rate significantly suppressed with circEIF4G2 mRNA expression significantly down-regulation (p < .05, respectively). However, there was no significant difference among Allicin, si-circEIF4G2, and Allicin+si-circEIF4G2 in cell biological activities including cell proliferation, apoptosis, invasion and migration, and relative gene and protein expression. Allicin depresses biological activities of cervical cancer cells through down-regulating circEIF4G2/HOXA1/AKT/mTOR.

Allicin treats myocardial infarction in I/R through the promotion of the SHP2 axis to inhibit p-PERK-mediated oxidative stress

OBJECTIVE

The study attempted to explore how allicin reduces oxidative stress levels by promoting SHP2 expression to inhibit p-PERK in I/R mice.

METHODS

The GEO database and RNA sequencing were used to predict downstream gene. TTC staining was used to visualize the myocardial infarction area. Masson staining was used to assess the level of fibrosis. IF was used to examine the expression of SHP2, CTGF, ROS. RT-PCR analysis was used to quantify the expression of SHP2 mRNA. Western blot was used to detect the protein expression levels of SHP2, p-PERK, MFN1, NLRP3, NOX2, and NOX3.

RESULTS

GEO and transcriptomic data revealed low expression of SHP2 in the heart tissues I/R mice. In the I/R mouse model, TTC staining result showed that allicin can reduce the area of myocardial infarction; Masson staining results indicated that allicin can reduce fibrosis; Macrophage transcriptome sequencing found SHP2 is a target gene of allicin; Immunofluorescence showed allicin can increase SHP2; qPCR results showed allicin can raise SHP2 mRNA level; Immunofluorescence indicated that allicin can inhibit ROS in myocardial infarction tissue, but the specific SHP2-KD eliminates changes in ROS. Western blot analysis demonstrated allicin can increase SHP2 protein and reduce the expression of p-PERK, MFN1, NLRP3, NOX2, and NOX3; SHP2-KD eliminates the expression differences in p-PERK, MFN1, NLRP3, NOX2, and NOX3.

CONCLUSIONS

Allicin can modulate p-PERK activation by enhancing the expression of SHP2, thereby inhibiting myocardial ischemia-reperfusion-induced oxidative stress in mice.

Allicin Promotes Glucose Uptake by Activating AMPK through CSE/H2S-Induced S-Sulfhydration in a Muscle-Fiber Dependent Way in Broiler Chickens

SCOPE

Allicin, a product of enzymatic reaction when garlic is injured, plays an important role in maintaining glucose homeostasis in mammals. However, the effect of allicin on glucose homeostasis in the state of insulin resistance remains to be elucidated. This study investigates the effect of allicin on glucose metabolism using different muscle fibers in a chicken model.

METHODS AND RESULTS

Day-old male Arbor Acres broilers are randomly divided into three groups and fed a basal diet supplemented with 0, 150, or 300 mg kg-1 allicin for 42 days. Results show that allicin improves the zootechnical performance of broilers at the finishing stage. The glucose loading test (2 g kg-1 body mass) indicates the regulatory role of allicin on glucose homeostasis. In vitro results demonstrate allicin increases glutathione (GSH) level and the expression of cystathionine γ lyase (CSE), leading to endogenous hydrogen sulfide (H2S) production in M. pectoralis major (PM) muscle-derived myotubes. Allicin stimulates adenosine monophosphate-activated protein kinase (AMPK) S-sulfhydration and AMPK phosphorylation to promote glucose uptake, which is suppressed in the presence of d,l-propargylglycine (PAG, a CSE inhibitor).

CONCLUSION

This study demonstrates that allicin induces AMPK S-sulfhydration and AMPK phosphorylation to promote glucose uptake via the CSE/H2S system in a muscle fiber-dependent manner.

Genes encoding γ‑glutamyl‑transpeptidases in the allicin biosynthetic pathway in garlic (Allium sativum)

Allicin is a thiosulphate molecule produced in garlic (Allium sativum) and has a wide range of biological actions and pharmaceutical applications. Its precursor molecule is the non-proteinogenic amino acid alliin (S-allylcysteine sulphoxide). The alliin biosynthetic pathway in garlic involves a group of enzymes, members of which are the γ-glutamyl-transpeptidase isoenzymes, Allium sativum γ-glutamyl-transpeptidase AsGGT1, AsGGT2 and AsGGT3, which catalyze the removal of the γ-glutamyl group from γ-glutamyl-S-allyl-L-cysteine to produce S-allyl-L-cysteine. This removal is followed by an S-oxygenation, which leads to the biosynthesis of alliin. The aim of the present study is to annotate previously discovered genes of garlic γ-glutamyl-transpeptidases, as well as a fourth candidate gene (AsGGT4) that has yet not been described. The annotation includes identifying the loci of the genes in the garlic genome, revealing the overall structure and conserved regions of these genes, and elucidating the evolutionary history of these enzymes through their phylogenetic analysis. The genomic structure of γ-glutamyl-transpeptidase genes is conserved; each gene consists of seven exons, and these genes are located on different chromosomes. AsGGT3 and AsGGT4 enzymes contain a signal peptide. To that end, the AsGGT3 protein sequence was corrected; four indel events occurring in AsGGT3 coding regions suggested that at least in the garlic variety Ershuizao, AsGGT3 may be a pseudogene. Finally, the use of protein structure prediction tools allowed the visualization of the tertiary structure of the candidate peptide.

Anti-quorum sensing effects of SidA protein on Escherichia coli receptors: in silico analysis

Quorum sensing enables cell-cell communication in bacteria and regulates biofilm formation. Biofilm production promotes pathogenicity of Escherichia coli and causes infections. However, antibiotic resistance limits conventional treatment efficacy against biofilm infections. Quorum quenching offers an alternative by disrupting quorum sensing signals. Allicin, extracted from garlic, possesses antimicrobial and anti-quorum sensing properties. This study employed molecular docking and dynamics simulations to investigate allicin's interaction with the E. coli quorum sensing system, specifically targeting the cytoplasmic SidA receptor protein. SidA binds to N-acyl-homoserine lactone ligands and regulates quorum sensing in E. coli. The crystal structure of SidA was obtained from the PDB. Molecular docking revealed that allicin competitively binds to the ligand-binding pocket of SidA. Simulations analyzed the effects of allicin binding on SidA stability and affinity for N-acyl-homoserine lactones over 200 ns. Parameters like RMSD, RMSF, and hydrogen bonding indicated SidA was more stable when bound to allicin compared to unbound. Binding free energies suggested allicin reduced SidA's affinity for native ligands. Therefore, allicin binding to SidA alters its conformation and inhibits interaction with N-acyl-homoserine lactones, disrupting quorum sensing signaling and biofilm production in E. coli.Communicated by Ramaswamy H. Sarma.

Effects of allicin on growth performance, antioxidant profile, and microbiota compared to monensin of growing goats

Allicin is a sulfur-containing compound extracted from raw garlic (Allium sativum L.). We compared the effect of allicin addition on growth performance, serum biochemical parameters, and rumen microbiota of goats compared to monensin. Twenty-four Anhui white goats were assigned randomly to one of three dietary treatments: 1) a basal diet (CON); 2) the basal diet with allicin addition at 750 mg per head per day (AC); 3) the basal diet with monensin addition at 30 mg per kg of diet (MS). Animals were fed for 8 weeks. Results showed the average daily gain, and feed efficiency was increased with allicin and monensin addition. Serum levels of IgG, total superoxide dismutase, and glutathione peroxidase were higher in the AC group than those in the CON and MS groups. The microbiota analysis revealed that monensin addition mainly affected genera related to carbohydrate and protein metabolism, and allicin mainly affected genera related to energy metabolism and intestinal health. In conclusion, allicin could improve growth performance and have advantages over monensin in improving the antioxidant capacity and immune function of goats. Allicin may be a potential alternative to monensin.

Garlic against Heart-related Ailments: Chemistry, Pharmacology, and Future Perspective

BACKGROUND

Allium sativum L. (Garlic) is a well-recognized plant of great nutraceutical value with pharmacological evidences. It is full of dietary as well as pharmaceutical properties and has been used in traditional medications for a long time. It is known for good antioxidant, antifungal, antibacterial, anti-diabetic, anti-inflammatory, anticancer, and antiviral effects, along with other therapeutic roles in cardiovascular diseases, anti-atherosclerotic, antihypertensive, anti-thrombotic, blood pressure, bone and skin related problems etc. Objective: Considering the potential of garlic in the treatment of cardiovascular/heart-related diseases, the main objective of this study was to prepare a subject-centric mini-review focusing on its chemistry and pharmacology in heart-related issues.

METHODS

In order to prepare this mini-review article, an extensive online literature search was performed to find out the most recent studies related to this topic. These studies were briefly reviewed, assessed, and discussed to explore the possible capability of garlic for the cure of cardiovascular problems.

RESULT

Several experiments on mice models, rat models as well as on humans show the effective role of various forms of garlic in cardiovascular or heart-related ailments. After reviewing the available publications on garlic in heart-related issues, authors found that garlic and its sulfur (S)-based organic constituents may have advantageous applications in the treatment of cardiovascular diseases.

Combating Black Fungus: Using Allicin as a Potent Antifungal Agent against Mucorales

Invasive fungal (IF) diseases are a leading global cause of mortality, particularly among immunocompromised individuals. The SARS-CoV-2 pandemic further exacerbated this scenario, intensifying comorbid IF infections such as mucormycoses of the nasopharynx. In the work reported here, it is shown that zygomycetes, significant contributors to mycoses, are sensitive to the natural product allicin. Inhibition of Mucorales fungi by allicin in solution and by allicin vapor was demonstrated. Mathematical modeling showed that the efficacy of allicin vapor is comparable to direct contact with the commercially available antifungal agent amphotericin B (ampB). Furthermore, the study revealed a synergistic interaction between allicin and the non-volatile ampB. The toxicity of allicin solution to human cell lines was evaluated and it was found that the half maximal effective concentration (EC50) of allicin was 25-72 times higher in the cell lines as compared to the fungal spores. Fungal allicin sensitivity depends on the spore concentration, as demonstrated in a drop test. This study shows the potential of allicin, a sulfur-containing defense compound from garlic, to combat zygomycete fungi. The findings underscore allicin's promise for applications in infections of the nasopharynx via inhalation, suggesting a novel therapeutic avenue against challenging fungal infections.

Bioavailability, Health Benefits, and Delivery Systems of Allicin: A Review

Garlic has been used worldwide as a spice due to its pungent taste and flavor-enhancing properties. As a main biologically active component of the freshly crushed garlic extracts, allicin (diallyl thiosulfinate) is converted from alliin by alliinase upon damaging the garlic clove, which has been reported to have many potent beneficial biological functions. In this work, allicin formation, stability, bioavailability, and metabolism process are examined and summarized. The biological functions of allicin and potential underlying mechanisms are reviewed and discussed, including antioxidation, anti-inflammation, antidiabetic, cardioprotective, antineurodegenerative, antitumor, and antiobesity effects. Novel delivery systems of allicin with enhanced stability, encapsulation efficiency, and bioavailability are also evaluated, such as nanoparticles, gels, liposomes, and micelles. This study could provide a comprehensive understanding of the physiochemical properties and health benefits of allicin, with great potential for further applications in the food and nutraceutical industries.

Effects of Spirulina platensis and/or Allium sativum on Antioxidant Status, Immune Response, Gut Morphology, and Intestinal Lactobacilli and Coliforms of Heat-Stressed Broiler Chicken

This study aims to evaluate the effectiveness of the dietary addition of Spirulina platensis (SP) and/or garlic powder (GP) on heat-stressed broiler chickens. For this purpose, 600 Ross-308 broiler chicks were allocated at 22 days of age into five groups (G1-G5), each comprising six groups of 20 birds each. Chickens kept in G1 (negative control) were fed a basal diet and raised at 26 ± 1 °C. Chickens kept in G2 to G5 were exposed to periodic heat stress (35 ± 1 °C for 9 h/day) from 22 to 35 days old. Chickens in G2 (positive control) were provided a basal diet, while G3, G4, and G5 were fed a basal diet enriched with SP (1 g/kg diet), GP (200 mg/kg diet), or SP/GP (1 g SP/kg + 200 mg GP/kg diet), respectively. The assessment parameters included the chickens' performance, malondialdehyde and total antioxidant capacity, blood biochemistry, intestinal morphology, and modulation of lactobacilli and total coliforms in the intestinal microbiota. Our findings demonstrated that supplementing heat-stressed chickens with SP and/or GP significantly mitigated the negative effects on the European production efficiency index (EPEF), survival rate, cholesterol profile, and oxidative stress markers. Chickens supplemented with GP and/or SP exhibited significantly better EPEF and survivability rates. Heat stress had a significant impact on both the gut structure and gut microbiota. However, SP and/or GP supplementation improved the gut morphology, significantly increased the intestinal lactobacilli, and reduced the coliform contents. It was also found that the simultaneous feeding of SP and GP led to even higher recovery levels with improved lipid metabolites, immunity, and oxidative status. Overall, supplementing chickens with SP and/or GP can alleviate the negative effects of heat stress.

Allicin Alleviates Mitochondrial Dysfunction in Acrylamide-Induced Rat Kidney Involving the Regulation of SIRT1

Acrylamide (AA), commonly formed in carbohydrate-rich thermally processed foods, exerts harmful effects on the kidney. Allicin, from crushed garlic cloves, exhibits strong biological activities. In the current study, the protection mechanisms of allicin against AA-caused nephrotoxicity were comprehensively examined using an in vivo rat model based on previous research that allicin plays a key role in improving renal function. The results showed that allicin attenuated histological changes of the kidney and ameliorated renal function. Damaged mitochondrial structures, upregulated voltage-dependent anion channel 1 expression, and decreased membrane potential and adenosine 5'-triphosphate levels were observed after AA treatment. Surprisingly, allicin notably reversed the adverse effects. Further, allicin effectively restored mitochondrial function via modulating mitochondrial biogenesis and dynamics, which might be associated with the upregulated expression of sirtuin 1 (SIRT1). Meanwhile, allicin dramatically activated the SIRT1 activity and subsequently inhibited p53 acetylation, prevented the translocation of cytochrome c to the cytoplasm, and reduced the caspase expression, thus further inhibiting mitochondrial apoptosis caused by AA. In summary, the relieving effect of allicin on AA-caused nephrotoxicity lies in its inhibition of mitochondrial dysfunction and mitochondrial apoptosis.

Properties of Allicin-Zein Composite Nanoparticle Gelatin Film and Their Effects on the Quality of Cold, Fresh Beef during Storage

Allicin is a kind of natural antimicrobial active substance, but its water solubility is poor, and it is easy to degrade. In order to improve the stability and bioavailability of allicin, allicin-zein composite nanoparticles (Al-Ze) were prepared by the combination method of antisolvent precipitation and electrostatic deposition, and their characteristic parameters, such as average particle size, polydispersity index (PDI), and ζ-potential, were analyzed. Then, Al-Ze was used as the delivery carrier for the active substance (allicin), and gelatin with good film-forming properties was selected as the film-forming matrix to prepare Al-Ze gelatin films. The optical properties, mechanical properties, and characterization parameters were used to analyze the prepared composite materials; the results confirmed that Al-Ze gelatin film has good mechanical properties and barrier properties. The prepared film was applied to the storage of cold, fresh beef, and the quality change of beef was monitored at 4 °C. The results showed that Al-Ze gelatin film could effectively delay the quality deterioration of beef. This paper provides a new idea and data support for the application of Al-Ze gelatin film in meat storage and fresh-keeping, and offers new insight for the promotion and application of allicin in the food industry.

Synergistic Effect of Combined Treatment with Allicin and Antioxidant of Bamboo Leaves and Preservation of Bullfrogs (Lithobates catesbeiana) during Refrigeration Storage

The effects of allicin and antioxidant of bamboo leaves (AOB) on the quality of bullfrogs (Lithobates catesbeiana) during refrigerated storage (4 °C) were investigated. The quality changes in samples treated with deionized water (CK), allicin solution (All), antioxidant of bamboo leaves (AOB), and allicin solution combined with AOB solution (AA) in microbiological, physicochemical, and sensory evaluation were analyzed, respectively. The results demonstrated that combination treatment inhibited the increase in total viable counts, delayed the decrease in amino acid content, and retarded the sensory deterioration. Preservative treatment has an inhibitory effect on the early storage of PBC, which can reduce PBC by about 1.0 log CFU/g. The reduction in thiobarbituric acid (TBA) content and total volatile basic nitrogen (TVB-N) content indicated that combination treatment could better restrain the lipid oxidation and degradation of protein than the CK group and single-treatment group. In addition, the TVB-N content in the AA group still did not exceed the threshold on the 14th day. As a consequence, combination treatment prolonged the shelf life of bullfrogs for another six days. Therefore, allicin and AOB with excellent antioxidant and antimicrobial activity could be an effective approach to delay the biochemical reaction of refrigerated bullfrogs. This study has provided a potential approach for increasing the shelf life of bullfrogs and preserving their quality during refrigerated storage.

Allicin, an Emerging Treatment for Pulmonary Arterial Hypertension: An Experimental Study

We assessed whether allicin, through its antihypertensive and antioxidant effects, relieves vascular remodeling, endothelial function, and oxidative stress (OS), thereby improving experimental pulmonary arterial hypertension (PAH). Allicin (16 mg/kg) was administered to rats with PAH (monocrotaline 60 mg/kg). Allicin encouraged body weight gain and survival rate, and medial wall thickness and the right ventricle (RV) hypertrophy were prevented. Also, angiotensin II concentrations in the lung (0.37 ± 0.01 vs. 0.47 ± 0.06 pmoles/mL, allicin and control, respectively) and plasma (0.57 ± 0.05 vs. 0.75 ± 0.064, allicin and control respectively) and the expressions of angiotensin-converting enzyme II and angiotensin II type 1 receptor in lung tissue were maintained at normal control levels with allicin. In PAH rats treated with allicin, nitric oxide (NO) (31.72 ± 1.22 and 51.4 ± 3.45 pmoles/mL), tetrahydrobiopterin (8.43 ± 0.33 and 10.14 ± 0.70 pmoles/mL), cyclic guanosine monophosphate (5.54 ± 0.42 and 5.64 ± 0.73 pmoles/mL), and Ang-(1-7) (0.88 ± 0.23 and 0.83 ± 0.056 pmoles/mL) concentrations increased in lung tissue and plasma, respectively. In contrast, dihydrobiopterin increase was prevented in both lung tissue and plasma (5.75 ± 0.3 and 5.64 ± 0.73 pmoles/mL); meanwhile, phosphodiesterase-5 was maintained at normal levels in lung tissue. OS in PAH was prevented with allicin through the increased expression of Nrf2 in the lung. Allicin prevented the lung response to hypoxia, preventing the overexpression of HIF-1α and VEGF. Allicin attenuated the vascular remodeling and RV hypertrophy in PAH through its effects on NO-dependent vasodilation, modulation of RAS, and amelioration of OS. Also, these effects could be associated with the modulation of HIF-1α and improved lung oxygenation. The global effects of allicin contribute to preventing endothelial dysfunction, remodeling of the pulmonary arteries, and RV hypertrophy, preventing heart failure, thus favoring survival. Although human studies are needed, the data suggest that, alone or in combination therapy, allicin may be an alternative in treating PAH if we consider that, similarly to current treatments, it improves lung vasodilation and increase survival. Allicin may be considered an option when there is a lack of efficacy, and where drug intolerance is observed, to enhance the efficacy of drugs, or when more than one pathogenic mechanism must be addressed.

Allicin-Loaded Intelligent Hydrogel Coating Improving Vascular Implant Performance

Coronary atherosclerosis is closely related to inflammation and oxidative stress. Owing to poor biocompatibility, lack of personalized treatment, and late toxic side effects, traditional drug-eluting stent intervention, releasing antiproliferative drugs, can delay endothelial repair and cause late thrombosis. The inflammation caused by atherosclerosis results in an acidic microenvironment and oxidative stress, which can be considered as triggers for precise and intelligent treatment. Here, we used catechol hyaluronic acid (C-HA) and cystamine (Cys) to prepare C-HA-Cys hydrogel coatings by amide reaction. The H2S-releasing donor allicin was loaded in the hydrogel to form an intelligent biomimetic coating. The disulfide bond of Cys made the cross-linked network redox-responsive to the inflammation and oxidative stress in the microenvironment by releasing the drug and H2S intelligently to combat the side effects of stent implantation. This study evaluated the hemocompatibility, anti-inflammatory capacity, vascular wall cytocompatibility, and in vivo histocompatibility of this intelligent hydrogel coating. Furthermore, the effect of H2S released from the coating on atherosclerosis-related signaling pathways such as CD31 and cystathionine γ-lyase (CSE), CD36, and ACAT-1 was investigated. Our results indicate that the C-HA-Cys-Allicin hydrogel coating could be manufactured on the surface of vascular interventional devices to achieve a precise response to the microenvironment of the lesion to release drug, which can attain the purpose of prevention of in-stent restenosis and ensure the effectiveness and safety of the application of interventional devices.

Characterization of the interaction between allicin and soy protein isolate and functional properties of the adducts

BACKGROUND

Soybean meal, a by-product of the soybean oil production industry, has a high protein content but the compact globular structure of the protein from soybean meal limits its wide application in food processing. Allicin has been found to have numerous functional properties. In this study, allicin was interacted with soy protein isolate (SPI). The functional properties of the adducts were investigated.

RESULTS

Binding with allicin significantly quenched the fluorescence intensity of SPI. Static quenching was the main quenching mechanism. The stability of adducts decreased with increasing temperature. The greatest extent of binding between allicin and sulfhydryl groups (SH) of SPI was obtained at an allicin/SH molar ratio of 1:2. The amino groups of SPI did not bind with allicin covalently. Soy protein isolate was modified by allicin through covalent and non-covalent interactions. Compared with SPI, the emulsifying activity index and foaming capacity of adducts with a ratio of 3:1 were improved by 39.91% and 64.29%, respectively. Soy protein isolate-allicin adducts also exhibited obvious antibacterial effects. The minimum inhibitory concentrations (MICs) of SPI-allicin adducts on Escherichia coli and Staphylococcus aureus were 200 and 160 μg mL^-1 , respectively.

CONCLUSION

The interaction of allicin with SPI is beneficial for the functional properties of SPI. These adducts can be used in different food formulations as emulsifiers, foamers, and transport carriers. © 2023 Society of Chemical Industry.

Preparation and Characterization of Allicin-Loaded Solid Lipid Nanoparticles Surface-Functionalized with Folic Acid-Bonded Chitosan: In Vitro Anticancer and Antioxidant Activities

OBJECTIVE

This investigation aimed to increase the bioavailability and anticancer effects of allicin (AC) by encapsulating it in solid lipid nanoparticles (SLN) decorated with chitosan (CS)-conjugated folic acid (FA).

MATERIAL AND METHODS

Nanoparticles (NPs) were synthesized by high-pressure homogenization, and then, Fourier-transform infrared (FTIR), Field-Emission Scanning Electron Microscopy (FESEM), Dynamic Light Scattering (DLS), and zeta potential methods were used to determine their physicochemical characteristics. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to assess the effect of toxicity and flow cytometry, while fluorescent staining methods were used to investigate the type of cell death. Real-time quantitative polymerase chain reaction (qPCR) was used to evaluate the expression levels of apoptotic genes: Bcl-2, and caspase-8.

RESULTS

The presence of AC-SLN-CS-FA with a spherical morphology, an average size of 86.7 ± 9.4 nm, uniform distribution (0.31), a surface charge of +21.3 ± 13.3 mV, an encapsulation percentage of 86.3%, and a folate binding rate of 63% confirmed the success of the preparation method. Suppression of MCF-7 cancer cells and non-toxicity of AC-SLN-CS-FA on Human foreskin fibroblast (HFF) normal cells were confirmed by cytotoxic assay. The results of flow cytometry revealed that the cells were arrested in the sub-G1 phase, and the activation of the intrinsic apoptosis pathway was confirmed by the results of real-time qPCR.

CONCLUSIONS

In general, AC-SLN-CS-FA has the potential to prevent free radicals and trigger apoptosis in cancer cells by activating the intrinsic apoptosis pathway; thus, making it a promising subject in preclinical research.

[Advances in cardiovascular protection effects and mechanisms of allicin]

Cardiovascular diseases(CVD) with high morbidity and mortality pose severe threats to human life. Allicin, a main active ingredient of garlic, possesses multiple pharmaceutical activities. It not only exerts cardioprotective effects but also prevents the risk factors for CVD. Allicin exerts cardioprotective effects via a variety of mechanisms, including inhibiting oxidative stress, apoptosis, autophagy, and inflammatory responses, regulating lipid metabolism and gut microbiota, inducing hydrogen sulfide production, and dilating vessels. Despite the valuable cardioprotective effects, the instability of allicin has hindered the basic research and clinical application. This paper reviews the progress in the cardioprotective effects and mechanisms of allicin in the last decade and summarizes the methods to improve the stability of allicin. In addition, this review provides a reference for further research and development of allicin in cardiovascular protection.

Antifungal Activity and Potential Action Mechanism of Allicin against Trichosporon asahii

Trichosporon asahii is an emerging opportunistic pathogen that causes potentially fatal disseminated trichosporonosis. The global prevalence of coronavirus disease 2019 (COVID-19) poses an increasing fungal infection burden caused by T. asahii. Allicin is the main biologically active component with broad-spectrum antimicrobial activity in garlic. In this study, we performed an in-depth analysis of the antifungal characteristics of allicin against T. asahii based on physiological, cytological, and transcriptomic assessments. In vitro, allicin inhibited the growth of T. asahii planktonic cells and biofilm cells significantly. In vivo, allicin improved the mean survival time of mice with systemic trichosporonosis and reduced tissue fungal burden. Electron microscopy observations clearly demonstrated damage to T. asahii cell morphology and ultrastructure caused by allicin. Furthermore, allicin increased intracellular reactive oxygen species (ROS) accumulation, leading to oxidative stress damage in T. asahii cells. Transcriptome analysis showed that allicin treatment disturbed the biosynthesis of cell membrane and cell wall, glucose catabolism, and oxidative stress. The overexpression of multiple antioxidant enzymes and transporters may also place an additional burden on cells, causing them to collapse. Our findings shed new light on the potential of allicin as an alternative treatment strategy for trichosporonosis. IMPORTANCE Systemic infection caused by T. asahii has recently been recognized as an important cause of mortality in hospitalized COVID-19 patients. Invasive trichosporonosis remains a significant challenge for clinicians, due to the limited therapeutic options. The present work suggests that allicin holds great potential as a therapeutic candidate for T. asahii infection. Allicin demonstrated potent in vitro antifungal activity and potential in vivo protective effects. In addition, transcriptome sequencing provided valuable insights into the antifungal effects of allicin.

Synergistic effect of ultrahigh pressure and allicin on gel properties, flavor characteristics, and myosin structure of the obturator muscle of the scallop (Patinopecten yessoensis)

The synergistic effects of the combination of ultrahigh pressure (UHP) with allicin on the gel properties, flavor characteristics, and myosin structure of scallops were investigated. The results indicated that chewiness reached maximum, uniform, and dense microstructures at B-300 MPa, and scallops with favorable gel properties. In addition, the electronic nose and tongue could clearly distinguish the olfactory and gustatory properties of scallops, and the interaction of UHP and allicin increased the variety of volatile compounds in scallops, which mainly included 1-hydroxy-2-propanone, 1-hexenal, 2-butanone-D, and 1-octen-3-ol. The main performance was fruit aroma and a plantlike aroma and mushroomlike odor. UHP and allicin changed the microenvironment of tryptophan residues, and allicin formed larger aggregates by forming disulfides with myosin. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis results could show that myosin had low degradation in B-300 MPa. Thus, comprehensively viewed, UHP and allicin play a role in gel formation of myosin from obturator muscle at 300 MPa, whereas allicin and myosin form disulfides as the main factor of myosin gelation. PRACTICAL APPLICATION: To enhance the diversity of scallop preparation methods and improve the quality of the obtained product, UHP and allicin treatment result in scallops with satisfactory chewiness and flavor, which provides application prospects for scallop processing.

Diallyl trisulfide induces pro-apoptotic autophagy via the AMPK/SIRT1 signalling pathway in human hepatocellular carcinoma HepG2 cell line

Background

Liver cancer is associated with a high mortality rate worldwide. Hepatocellular carcinoma (HCC) constitutes a large proportion of primary liver cancers, and most of its alterations currently remain untreatable. Diallyl trisulfide (DATS), the main chemical constituent of allicin, affects tumour development by regulating cell apoptosis. Allicin-induced autophagy could contribute to apoptosis in HepG2 cells. We rigorously examined the autophagy-related mechanism of allicin-induced apoptosis in HepG2 cells. We treated HepG2 cells with DATS to explore the effect of DATS on pro-apoptotic autophagy in HepG2 cell lines and examine its specific molecular mechanism.

Methods

HepG2 cells were treated with various concentrations of DATS for 24 and 48 h. Subsequently, cell viability was measured using the cell counting kit-8 (CCK-8) assay and cell clone formation assay. The HepG2 cell apoptosis was measured using Hoechst 33258 staining and western blotting. Autophagy and the AMP-activated protein kinase (AMPK)/NAD-dependent deacetylase sirtuin-1 (SIRT1) signalling pathway were detected using western blotting.

Results

Our results indicated that DATS inhibited HepG2 cell growth. Moreover, the ability of DATS to promote apoptosis in HepG2 cells increased with increasing concentration. We verified the phenomenon of DATS-induced autophagy in HepG2 cells and demonstrated that DATS treatment upregulated the protein expression of LC3-II/I. By measuring the expression of potential autophagy stimulators, we documented that DATS could induce pro-apoptotic autophagy by activating the AMPK/SIRT1 signalling pathway.

Conclusion

DATS induced pro-apoptotic autophagy via the AMPK/SIRT1 signalling pathway in the human HCC HepG2 cell line. Our findings further implicate allicin as a potential therapeutic agent against liver tumours in clinical settings, providing a basis for combining allicin with an autophagy agonist for treating liver cancer.

Phytochemical Characterization and Antimicrobial Activity of Several Allium Extracts

Microbial infections affect both the human population and animals. The appearance of more and more microbial strains resistant to classical treatments led to the need to develop new treatments. Allium plants are known for their antimicrobial properties due to their high content of thiosulfinates, especially allicin, polyphenols or flavonoids. The hydroalcoholic extracts of six Allium species obtained by cold percolation were analyzed regarding their phytochemical compounds and antimicrobial activity. Among the six extracts, Allium sativum L. and Allium ursinum L. have similar contents of thiosulfinates (approx. 300 μg allicin equivalents/g), and the contents of polyphenols and flavonoids were different between the tested species. The HPLC-DAD method was used to detail the phytochemical composition of species rich in thiosulfinates. A. sativum is richer in allicin (280 μg/g) than A. ursinum (130 μg/g). The antimicrobial activity of A. sativum and A. ursinum extracts against Escherichia coli, Staphylococcus aureus, Candida albicans and Candida parapsilosis can be correlated with the presence of large amounts of thiosulfinates. Both extracts have shown results against Candida species (inhibition zones of 20-35 mm) and against Gram-positive bacteria, Staphylococcus aureus (inhibition zones of 15-25 mm). These results demonstrate the antimicrobial effect of the extracts and suggest their use as an adjuvant treatment for microbial infections.

Allicin Inhibits Porcine Reproductive and Respiratory Syndrome Virus Infection In Vitro and Alleviates Inflammatory Responses

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important pathogens to the swine industry worldwide over the past three decades. No approved effective antiviral drug is available to control this virus. The antiviral effects of allicin (diallyl thiosulfinate) on many human and animal viruses have been documented. However, the antiviral effect of allicin on PRRSV infection remains unknown. In this study, we found that allicin exhibited an inhibitory effect on HP-PRRSV and NADC30-like PRRSV in a dose-dependent manner by interfering with viral entry, replication, and assembly. Furthermore, allicin alleviated the expression of pro-inflammatory cytokines (IFN-β, IL-6, and TNFα) induced by PRRSV infection. The pro-inflammatory signaling pathways, TNF signaling pathway and MAPK signaling pathway, up-regulated by PRRSV infection were restored by allicin treatment. Taken together, these results demonstrate that allicin has antiviral activity against PRRSV and ameliorates inflammatory responses induced by PRRSV infection, suggesting that allicin is a promising drug candidate for anti-PRRSV therapy in vivo.

Potential diagnostic biomarkers for lead-induced hepatotoxicity and the role of synthetic chelators and bioactive compounds

Lead (Pb2+) poisoning is a public health concern of global dimensions. Although several public health guidelines and workplace safety policies are existing and enforced, lead toxicity cases are drastically increasing. Lead exposure leads to numerous harmful consequences and causes adverse effects on different body organs and systems, mainly via the generation of reactive oxygen species, leading to augmented oxidative stress, competing with metal ions, and binding with the sulfhydryl groups. In several instances, lead poisoning cases remain undiagnosed and untreated or receive only symptomatic treatment. Estimation of blood lead levels reflects only a recent exposure, however, which does not reveal the total body burden. This review summarizes the effects of lead with special reference to hepatotoxicity and some of the potential diagnostic biomarkers. Furthermore, it also focuses on synthetic chelators used in the treatment of lead poisoning and the advantage of using bioactive compounds with an emphasis on the ameliorative effect of garlic.

Allicin ameliorates imiquimod-induced psoriasis-like skin inflammation via disturbing the interaction of keratinocytes with IL-17A

BACKGROUND AND PURPOSE

Psoriasis is an inflammatory skin disease of chronic recurrence mediated by the interaction between IL-17 and keratinocytes, which sustains a vicious circle of inflammation. Safe and effective natural medicine is a potential strategy for the clinical treatment of psoriasis. Given its prominent anti-proliferative and anti-inflammatory properties, we investigated the actions of allicin in improving psoriasis.

EXPERIMENTAL APPROACH

Pharmacodynamic studies were carried out in mice after topical administration of allicin against psoriasis-like lesions induced by imiquimod. Skin sensitization tests were evaluated on guinea pigs. Toxicological studies and skin irritation tests were assessed by consecutive topical allicin alone on the skin of rabbits. RNA-seq probed transcriptomic changes following allicin. Western blot explored the actions of allicin on the interaction between IL-17A and keratinocytes. Changes in inflammatory factor expression were analysed by qPCR and immunohistochemistry.

KEY RESULTS

Allicin significantly improved the epidermal structure by inhibiting the excessive proliferation and reduced apoptosis of keratinocytes. Furthermore, allicin reduced the secretion of inflammatory cytokines (IL-17A/F, IL-22, IL-12, and IL-20), chemokines (CXCL2, CXCL5, and CCL20), and anti-bacterial peptides (S100a8/9). Mechanistically, allicin directly inhibited the IL-17-induced TRAF6/MAPK/NF-κB and STAT3/NF-κB signalling cascades in keratinocytes, thus breaking the positive inflammatory feedback and alleviating imiquimod-induced psoriasis-like dermatitis in mice. Importantly, topical administration of allicin did not cause skin allergy, and the safety and adaptability of long-term application were verified.

CONCLUSIONS AND IMPLICATIONS

Interfering with IL-17 signalling in keratinocytes with allicin is a promising strategy for treating psoriasis, given its safety and effectiveness.

A review on garlic as a supplement for Alzheimer's disease: a mechanistic insight in its direct and indirect effects

Alzheimer's disease (AD) is one of the most complicated neurodegenerative diseases causing dementia in human beings. Aside from that incidence of AD is increasing also its treatment is very complicated. There are several known hypotheses regarding the pathology of Alzheimer's disease, including the Amyloid beta hypothesis, Tau hypothesis, inflammation hypothesis, and cholinergic hypothesis, which are investigated in different researches to completely elucidate the pathology of AD. Aside from these some new mechanisms such as immune, endocrine, and vagus pathways, as well as bacteria metabolite secretions are being explained as other causes that are somehow related to AD pathogenesis. There is still no definite treatment for Alzheimer's disease that can completely cure and eradicate AD. Garlic (Allium sativum) is a traditional herb used as a spice in different cultures and due to the organosulfur compounds like allicin it possesses highly anti-oxidant properties and the benefits of garlic in cardiovascular diseases like hypertension and atherosclerosis is examined and reviewed, although its beneficiary effects in neurodegenerative diseases such as AD is not completely understood. In this review, we discuss the effects of garlic based on its components such as allicin, S-allyl cysteine on Alzheimer's disease and the mechanisms that garlic components can be beneficiary for AD patients, including its effects amyloid beta, oxidative stress, tau protein, gene expression, and cholinesterase enzymes. Based on the literature review we have done, garlic has revealed beneficiary effects on Alzheimer's disease, especially in animal studies; however, more studies should be done on human populations to find the exact mechanism of garlic effects on AD patients.

Medicinal and therapeutic properties of garlic, garlic essential oil, and garlic-based snack food: An updated review

Garlic (Allium sativum) is an edible tuber belonging to the family Liliaceae. It has been used since ancient times as a spice to enhance the sensory characteristics of food and as a household remedy for the treatment of a variety of ailments. Garlic has been studied for its medicinal and therapeutic effects in the treatment of various human diseases for a long time. Health benefits associated with the consumption of garlic are attributed to the various sulfur compounds present in it such as allicin, ajoene, vinyl-dithiin, and other volatile organosulfur compounds which are all metabolized from alliin. Several researches in the literature have shown evidence that garlic exhibits antioxidant, antiviral, anti-microbial, anti-fungal, antihypertensive, anti-anemic, anti-hyperlipidemic, anticarcinogenic, antiaggregant, and immunomodulatory properties. The present review identifies and discusses the various health benefits associated with the consumption of garlic, its essential oil, and bioactive constituents, along with exploring the various snack-food products developed by incorporating garlic.

Synergistic Antibacterial Effect and Mechanism of Allicin and an Enterobacter cloacae Bacteriophage

Enterobacter cloacae is a troublesome pathogen causing refractory infections of the lower respiratory tract, urethra and abdominal cavity, endocarditis, osteomyelitis, and neonatal septicemia. It is prone to developing resistance to ordinary antibiotics and has brought a serious problem to clinical treatment. An artful synergistic combination of an antibacterial natural product allicin and a newly isolated bacteriophage, named BD523, was constructed herein. This combination significantly lowered effective dosage of allicin and effectually overcame bacterial drug-resistance. We experimentally evidenced that allicin interacts with bacterial DNA in the groove region by inserting itself into the DNA double helix and, subsequently, disrupts the bacterial DNA by cleaving phosphate diester bonds of deoxynucleotides. Further, BD523 destroys the cell wall and membrane of bacteria by synthesizing lyase proteins, including holin and endolysins. Thus, the synergistic effect of the combination benefits from complementary targeting mechanisms of allicin and BD523. They cooperatively act on bacterial DNA, cell wall, and membrane to improve antibacterial efficiency and avoid drug-resistance. IMPORTANCE Bacterial drug-resistance is a serious problem afflicting pharmacologists all over the world. Many strategies have been developed and practiced to overcome it, but almost no one is satisfactory due to the continual change of bacteria. Combinations of antibiotics and bacteriophages are promising because of the cooperation of 2 bacterial killers with distinct mechanisms. The combination of allicin and an Enterobacter cloacae bacteriophage reported herein can significantly improve the effect of allicin against E. cloacae. Its synergistic effect was even superior to the combination of bacteriophage and neomycin, of which the MIC was significantly lower than allicin. It was ascribed to the complementary antibacterial and the possible resistance-proof mechanism of bacteriophage and allicin. This study provided a pragmatic way to conquer the cunning bacterium, and may offer reference for research and development of new bacterial killers.

Allicin Alleviated LPS-Induced Mastitis via the TLR4/NF-κB Signaling Pathway in Bovine Mammary Epithelial Cells

Dairy farming is the most important economic activity in animal husbandry. Mastitis is the most common disease in dairy cattle and has a significant impact on milk quality and yield. The natural extract allicin, which is the main active ingredient of the sulfur-containing organic compounds in garlic, has anti-inflammatory, anticancer, antioxidant, and antibacterial properties; however, the specific mechanism underlying its effect on mastitis in dairy cows needs to be determined. Therefore, in this study, whether allicin can reduce lipopolysaccharide (LPS)-induced inflammation in the mammary epithelium of dairy cows was investigated. A cellular model of mammary inflammation was established by pretreating bovine mammary epithelial cells (MAC-T) with 10 µg/mL LPS, and the cultures were then treated with varying concentrations of allicin (0, 1, 2.5, 5, and 7.5 µM) added to the culture medium. MAC-T cells were examined using RT-qPCR and Western blotting to determine the effect of allicin. Subsequently, the level of phosphorylated nuclear factor kappa-B (NF-κB) was measured to further explore the mechanism underlying the effect of allicin on bovine mammary epithelial cell inflammation. Treatment with 2.5 µM allicin considerably decreased the LPS-induced increase in the levels of the inflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) and inhibited activation of the NOD-like receptor protein 3 (NLRP3) inflammasome in cow mammary epithelial cells. Further research revealed that allicin also inhibited the phosphorylation of inhibitors of nuclear factor kappa-B-α (IκB-α) and NF-κB p65. In mice, LPS-induced mastitis was also ameliorated by allicin. Therefore, we hypothesize that allicin alleviated LPS-induced inflammation in the mammary epithelial cells of cows probably by affecting the TLR4/NF-κB signaling pathway. Allicin will likely become an alternative to antibiotics for the treatment of mastitis in cows.

The protective roles of allicin on type 1 diabetes mellitus through AMPK/mTOR mediated autophagy pathway

Background: Type 1 diabetes mellitus (T1DM) is one of the most common endocrine and metabolic diseases in children. Pancreatic β cells are thought to be critical cells involved in the progression of T1DM, and their injury would directly lead to impaired insulin secretion. Purpose: To investigate the protective effects of allicin on pancreatic β cell injury and elucidate the underlying mechanism. Methods: The streptozotocin (STZ)-induced mouse T1DM model in vivo and STZ-induced pancreatic β cell Min6 model in vitro were used to explore the effects of allicin on T1DM. The experiments include fasting blood glucose test, oral glucose tolerance detection, HE staining, immunohistochemistry, immunofluorescence, TUNEL staining, western blot, real-time quantitative PCR (RT-qPCR), and flow cytometry. Results: Allicin could significantly decrease blood glucose level, improve islet structure and insulin expression, and inhibit apoptosis to reduce STZ-induced pancreatic β cell injury and loss through activating AMPK/mTOR mediated autophagy pathway. Conclusion: Allicin treatment significantly reduced STZ-induced T1DM progression, suggesting that allicin may be a potential therapy option for T1DM patients.

Natural Compound Allicin Containing Thiosulfinate Moieties as Transmembrane Protein 16A (TMEM16A) Ion Channel Inhibitor for Food Adjuvant Therapy of Lung Cancer

Cancer is one of the most serious malignant diseases, and chemotherapy is cancer's main clinical treatment method. However, chemotherapy inevitably produces drug resistance, and side effects accompany them. Adjuvant therapy is an effective way to enhance chemotherapeutic drug sensitivity and reduce side effects. This study found allicin, garlic's active ingredient, is an inhibitor of transmembrane protein 16A (TMEM16A), a novel drug target of lung adenocarcinoma. Allicin concentration-dependently inhibited TMEM16A currents with an IC₅₀ of 24.35 ± 4.14 μM. Allicin thiosulfinate moieties bound with R535A/E624A/E633A residues of TMEM16A blocked the ion transport function and downregulated TMEM16A protein expression affecting the mitogen-activated protein kinase signal transduction. Then, allicin reduced the viability and migration of LA795 cells, and induced cell apoptosis. Moreover, multitarget combination administration results indicated that the therapeutic effect of 3.56 mg/kg allicin and 3 mg/kg cisplatin combined administration was superior to the superposition of the two drugs alone, demonstrating that the anticancer effects of allicin and cisplatin were synergistic. In addition, low-concentration combined administration also avoided the side effects of cisplatin in mice. Based on the good tumor suppressor effect and high biosafety of allicin and cisplatin combination in vivo, allicin can be used for food adjuvant therapy of cisplatin chemotherapy.

Garlic (Allium sativum L.) as an Ally in the Treatment of Inflammatory Bowel Diseases

For centuries, garlic (Allium sativum) has been used both as a traditional remedy for most health-related ailments and for culinary purposes. Current preclinical investigations have suggested that dietary garlic intake has beneficial health effects, such as antioxidant, anti-inflammatory, antitumor, antiobesity, antidiabetic, antiallergic, cardioprotective, and hepatoprotective effects. Its therapeutic potential is influenced by the methods of use, preparation, and extraction. Of particular importance is the Aged Garlic Extract (AGE). During the aging process, the odorous, sour, and irritating compounds in fresh raw garlic, such as allicin, are naturally converted into stable and safe compounds that have significantly greater therapeutic effects than fresh garlic. In AGE, S-allylcysteine (SAC) and S-allylmercaptocysteine (SAMC) are the major water-soluble organosulfurized compounds (OSCs). SAC has been extensively studied, demonstrating remarkable antioxidant, anti-inflammatory, and immunomodulatory capacities. Recently, AGE has been suggested as a promising candidate for the maintenance of immune system homeostasis through modulation of cytokine secretion, promotion of phagocytosis, and activation of macrophages. Since immune dysfunction plays an important role in the development and progress of various diseases, given the therapeutic effects of AGE, it can be thought of exploiting its immunoregulatory capacity to contribute to the treatment and prevention of chronic inflammatory bowel diseases (IBD).

Isolation of Garlic Bioactives by Pressurized Liquid and Subcritical Water Extraction

Garlic (Allium sativum L.) is widely used in various food products and traditional medicine. Besides unique taste and flavour, it is well known for its chemical profile and bioactive potential. The aim of this study was to apply subcritical water extraction (SWE) and pressurized liquid extraction (PLE) for the extraction of bioactive compounds from the Ranco genotype of garlic. Moreover, PLE process was optimized using response surface methodology (RSM) in order to determine effects and optimize ethanol concentration (45-75%), number of cycles (1-3), extraction time (1-3 min) and temperature (70-110 °C) for maximized total phenols content (TP) and antioxidant activity evaluated by various in vitro assays. Furthermore, temperature effect in SWE process on all responses was evaluated, while allicin content (AC), as a major organosulphur compound, was determined in all samples. Results indicated that PLE provided tremendous advantage over SWE in terms of improved yield and antioxidant activity of garlic extracts. Therefore, high-pressure processes could be used as clean and green procedures for the isolation of garlic bioactives.

Effects of allicin on human Simpson-Golabi-Behmel syndrome cells in mediating browning phenotype

INTRODUCTION

Obesity is a major health problem because it is associated with increased risk of cardiovascular disease, diabetes, hypertension, and some cancers. Strategies to prevent or reduce obesity focus mainly on the possible effects of natural compounds that can induce a phenotype of browning adipocytes capable of releasing energy in the form of heat. Allicin, a bioactive component of garlic with numerous pharmacological functions, is known to stimulate energy metabolism.

METHODS

In the present study, the effects of allicin on human Simpson-Golabi-Behmel Syndrome (SGBS) cells were investigated by quantifying the dynamics of lipid droplets (LDs) and mitochondria, as well as transcriptomic changes after six days of differentiation.

RESULTS

Allicin significantly promoted the reduction in the surface area and size of LDs, leading to the formation of multilocular adipocytes, which was confirmed by the upregulation of genes related to lipolysis. The increase in the number and decrease in the mean aspect ratio of mitochondria in allicin-treated cells indicate a shift in mitochondrial dynamics toward fission. The structural results are confirmed by transcriptomic analysis showing a significant arrangement of gene expression associated with beige adipocytes, in particular increased expression of T-box transcription factor 1 (TBX1), uncoupling protein 1 (UCP1), PPARG coactivator 1 alpha (PPARGC1A), peroxisome proliferator-activated receptor alpha (PPARA), and OXPHOS-related genes. The most promising targets are nuclear genes such as retinoid X receptor alpha (RXRA), retinoid X receptor gamma (RXRG), nuclear receptor subfamily 1 group H member 3 (NR1H3), nuclear receptor subfamily 1 group H member 4 (NR1H4), PPARA, and oestrogen receptor 1 (ESR1).

DISCUSSION

Transcriptomic data and the network pharmacology-based approach revealed that genes and potential targets of allicin are involved in ligand-activated transcription factor activity, intracellular receptor signalling, regulation of cold-induced thermogenesis, and positive regulation of lipid metabolism. The present study highlights the potential role of allicin in triggering browning in human SGBS cells by affecting the LD dynamics, mitochondrial morphology, and expression of brown marker genes. Understanding the potential targets through which allicin promotes this effect may reveal the underlying signalling pathways and support these findings.

Garlic (Allium sativum L.) in diabetes and its complications: Recent advances in mechanisms of action

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia and impaired islet secretion that places a heavy burden on the global health care system due to its high incidence rate, long disease course and many complications. Fortunately, garlic (Allium sativum L.), a well-known medicinal plant and functional food without the toxicity and side effects of conventional drugs, has shown positive effects in the treatment of diabetes and its complications. With interdisciplinary development and in-depth exploration, we offer a clear and comprehensive summary of the research from the past ten years, focusing on the mechanisms and development processes of garlic in the treatment of diabetes and its complications, aiming to provide a new perspective for the treatment of diabetes and promote the efficient development of this field.

Allicin Alleviates Diabetes Mellitus by Inhibiting the Formation of Advanced Glycation End Products

Advanced glycation end products (AGEs) cause damage to pancreatic β-cells and trigger oxidative stress and inflammation, which promotes the development and progression of diabetes and its complications. Therefore, it is important to inhibit the formation of AGEs as part of the treatment of diabetes. Allicin is a natural antimicrobial agent with abundant pharmacological activities, and recent studies have reported its therapeutic effects in diabetes; however, the mechanism of these therapeutic effects is still unclear. Thus, the purpose of this study was to further investigate the association between allicin treatment of diabetes and AGEs. First, we established a streptozocin (STZ)-induced diabetic rat model and treated the rats with allicin for six weeks. We measured glycolipid metabolism, AGE levels, receptor of advanced glycation end products (RAGE) levels, oxidative stress, and other related indicators. The results showed that allicin improved blood glucose and body weight, reduced lipid accumulation, and inhibited AGE formation in rats. Treatment with allicin also inhibited RAGEs and thereby prevented AGE activity, which, in turn, alleviated oxidative stress and promoted insulin secretion. To further verify the effect of allicin on AGEs, we also performed in vitro nonenzymatic glycation simulation experiments. These results showed that allicin inhibited the production of AGEs by suppressing the production of AGEs intermediates. Thus, our research suggests that allicin may alleviate diabetes by inhibiting the formation of AGEs and reducing RAGE levels to relieve oxidative stress and promote insulin secretion.

Black Garlic and Thiosulfinate-Enriched Extracts as Adjuvants to Ceftriaxone Treatment in a Rat Peritonitis Model of Sepsis

To date, there have been no new drugs or adjuvants able to decrease both morbidity and mortality in the context of sepsis and septic shock. Our objective was to evaluate the use of thiosulfinate-enriched Allium sativum and black garlic extracts as adjuvants in the management of sepsis. An experimental in vivo study was carried out with male Sprague-Dawley^® rats. Animals were randomized in four treatment groups: antibiotic (ceftriaxone) treatment (group I), ceftriaxone plus thiosulfinate-enriched extract (TASE, group II), ceftriaxone plus thiosulfinate-enriched extract and black garlic extracts (TASE + BGE, group III), and ceftriaxone plus black garlic extract (BGE, group IV). All animals were housed and inoculated with 1 × 10¹⁰ CFU/15 mL of intraperitoneal Escherichia coli ATCC 25922. Subsequently, they received a daily treatment according to each group for 7 days. Clinical, analytical, microbiological, and histopathological parameters were evaluated. Statistically significant clinical improvement was observed in rats receiving garlic extracts in weight (groups II and III), ocular secretions, and piloerection (group IV). Moreover, less liver edema, vacuolization, and inflammation were observed in groups receiving adjuvant support (groups II, III, and IV). When comparing interleukins 24 h after bacteria inoculum, we found statistically significant differences in TNF-alpha levels in groups receiving BGE (groups III and IV, p ≤ 0.05). Blood and peritoneal liquid cultures were also analyzed, and we detected a certain level of Enterococcus faecalis in peritoneal cultures from all treatment groups and less bacteria presence in blood cultures in rats receiving garlic extracts (groups II, III, and IV). In conclusion, TASE and BGE could be promising nutraceutical or medicinal agents as coadjuvants in the treatment of sepsis because of its effects in modulating the inflammatory response.

Allicin and Capsaicin Ameliorated Hypercholesterolemia by Upregulating LDLR and Downregulating PCSK9 Expression in HepG2 Cells

Hypercholesterolemia is a common cause of cardiovascular diseases (CVDs). Although allicin and capsaicin possess hypolipidemic effects through several molecular mechanisms, their effects on LDLR and PCSK9 expression are still unknown. This study aimed to investigate the effects of allicin and capsaicin on LDLR and PCSK9 expression in HepG2 cells. The effects of allicin and capsaicin on cell viability were evaluated by MTT assay and trypan blue exclusion assay. Low-density lipoprotein receptor (LDLR) levels and LDL uptake were determined by flow cytometry and confocal laser scanning microscopy (CLSM), respectively. RT-qPCR and Western blot analyses were performed to evaluate the expression of PCSK9, LDLR, SREBP-2, and HNF1α. ELISA was used to measure PCSK9 levels in culture media. Allicin and capsaicin increased the protein expression levels of LDLR via activation of the transcription factor SREBP2. However, allicin and capsaicin decreased the expression of PCSK9 protein and the secretion of PCSK9 in culture media via the suppression of HNF1α. Moreover, allicin and capsaicin increased LDL uptake into HepG2 cells. The efficacies of the hypolipidemic effects of allicin (200 µM) and capsaicin (200 µM) were comparable to that of atorvastatin (10 µM) in this study. In conclusion, allicin and capsaicin possessed hypolipidemic effects via the upregulation of LDLR and downregulation of PCSK9 expression, thereby enhancing LDL uptake into HepG2 cells. This indicates that allicin and capsaicin should be used as potent supplements to ameliorate hypercholesterolemia.

Allicin shows antifungal efficacy against Cryptococcus neoformans by blocking the fungal cell membrane

Allicin, which is generated by the catalytic reaction between alliin and alliinase extracted from garlic, has been shown to have a wide range of antimicrobial activities, but its anti-Cryptococcus efficacy and mechanism are not quite clear. Here, we have determined that the Conversion rate of allicin in the reaction product reached 97.5%. The minimal inhibitory concentration (MIC) of allicin against Cryptococcus neoformans (C. neoformans) H99 was 2 μg/ml, which is comparable to fluconazole (FLU, 1 μg/ml). Furthermore, allicin exhibited effective antifungal activity against 46 clinical isolates of C. neoformans, and the MICs ranged from 1 to 8 μg/ml, even for AmB-insensitive strains. Interestingly, allicin also exerted additive or synergistic effects when combined with amphotericin B (AmB) and FLU. Time-killing curves and long-term live cell imaging of H99 showed that 4 MIC of allicin had fungicide activity. Additionally, allicin (4 and 8 mg/kg) exerted a dose-dependent therapeutic effect on H99-infected mice by significantly reducing the wet pulmonary coefficient and Cryptococcus load and reducing lung damage. Even the efficacy of 8 mg/kg was comparable to FLU (20 mg/kg). Transcriptomics revealed that allicin may act on the cell membrane of H99. Subsequently, transmission electron microscopy (TEM) observations showed that allicin clearly breached the cell membrane and organelles of H99. Confocal laser scanning microscopy (CLSM) results further confirmed that allicin disrupted the permeability of the cell membranes of H99 in a dose-dependent manner. Allicin exhibits strong anti-C. neoformans activity in vitro and in vivo, mainly by destroying the permeability and related functions of Cryptococcus cell membranes.

AGR2-induced cholesterol synthesis drives lovastatin resistance that is overcome by combination therapy with allicin

Anterior gradient 2 (AGR2), a protein disulfide isomerase (PDI), is a multifunctional protein under physiological and pathological conditions. In this study we investigated the roles of AGR2 in regulating cholesterol biogenesis, lipid-lowering efficiency of lovastatin as well as in protection against hypercholesterolemia/statin-induced liver injury. We showed that AGR2 knockout significantly decreased hepatic and serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in mice with whole-body or hepatocyte-specific Agr2-null mutant, compared with the levels in their wild-type littermates fed a normal chow diet (NCD) or high-fat diet (HFD). In contrast, mice with AGR2 overexpression (Agr2/Tg) exhibited an increased cholesterol level. Mechanistic studies revealed that AGR2 affected cholesterol biogenesis via activation of AKT/sterol regulatory element-binding protein-2 (SREBP2), to some extent, in a PDI motif-dependent manner. Moreover, elevated AGR2 led to a significant decrease in the lipid-lowering efficacy of lovastatin (10 mg· kg-1· d-1, ip, for 2 weeks) in mice with hypercholesterolemia (hyperCho), which was validated by results obtained from clinical samples in statin-treated patients. We showed that lovastatin had limited effect on AGR2 expression, but AGR2 was inducible in Agr2/Tg mice fed a HFD. Further investigations demonstrated that drug-induced liver toxicity and inflammatory reactions were alleviated in hypercholesterolemic Agr2/Tg mice, suggesting the dual functions of AGR2 in lipid management and hyperCho/statin-induced liver injury. Importantly, the AGR2-reduced lipid-lowering efficacy of lovastatin was attenuated, at least partially, by co-administration of a sulfhydryl-reactive compound allicin (20 mg· kg-1· d-1, ip, for 2 weeks). These results demonstrate a novel role of AGR2 in cholesterol metabolism, drug resistance and liver protection, suggesting AGR2 as a potential predictor for selection of lipid-lowering drugs in clinic.

Allicin-Inspired Heterocyclic Disulfides as Novel Antimicrobial Agents

In this work, a series of derivatives with disulfide bonds containing pyridine, pyrimidine, thiophene, thiazole, benzothiazole, and quinoline were designed and synthesized based on the various biological activities of allicin disulfide bond functional groups. The antimicrobial activities of the target compounds were determined, and the structure-activity relationships were discussed. Among them, compound S8 demonstrated the most potent antifungal activity in vitro against Monilinia fructicola (M. fructicola), with an EC₅₀ value of 5.92 μg/mL. Furthermore, an in vivo bioassay revealed that compound S8 exhibited equivalent curative and higher protective effects as the positive drug thiophanate methyl at a concentration of 200 μg/mL. The preliminary mechanism experiments showed that compound S8 could inhibit the growth of M. fructicola' s hyphae in a time- and concentration-dependent manner, and compound S8 could induce the shrinkage of hyphae, disrupt the integrity of the plasma membrane, and cause the damage and leakage of cell contents. More than that, compound S5 also demonstrated an excellent antibacterial effect on Xanthomonas oryzae (X. oryzae), with a MIC₉₀ value of 1.56 μg/mL, which was superior to the positive control, thiodiazole copper.

Cellular Mechanisms Underlying the Cardioprotective Role of Allicin on Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a group of diseases in which the common denominator is the affection of blood vessels, heart tissue, and heart rhythm. The genesis of CVD is complex and multifactorial; therefore, approaches are often based on multidisciplinary management and more than one drug is used to achieve the optimal control of risk factors (dyslipidemia, hypertension, hypertrophy, oxidative stress, endothelial dysfunction, inflammation). In this context, allicin, a sulfur compound naturally derived from garlic, has shown beneficial effects on several cardiovascular risk factors through the modulation of cellular mechanisms and signaling pathways. Effective pharmacological treatments for CVD or its risk factors have not been developed or are unknown in clinical practice. Thus, this work aimed to review the cellular mechanisms through which allicin exerts its therapeutic effects and to show why it could be a therapeutic option for the prevention or treatment of CVD and its risk factors.

Allicin as a Volatile or Nebulisable Antimycotic for the Treatment of Pulmonary Mycoses: In Vitro Studies Using a Lung Flow Test Rig

Fungal infections of the lung are an increasing problem worldwide and the search for novel therapeutic agents is a current challenge due to emerging resistance to current antimycotics. The volatile defence substance allicin is formed naturally by freshly injured garlic plants and exhibits broad antimicrobial potency. Chemically synthesised allicin was active against selected fungi upon direct contact and via the gas phase at comparable concentrations to the pharmaceutically used antimycotic amphotericin B. We investigated the suppression of fungal growth by allicin vapour and aerosols in vitro in a test rig at air flow conditions mimicking the human lung. The effect of allicin via the gas phase was enhanced by ethanol. Our results suggest that allicin is a potential candidate for development for use in antifungal therapy for lung and upper respiratory tract infections.

Anti-inflammatory and Anti-bacterial Effects of Allicin-coated Tracheal Tube on Trachea Mucosa

BACKGROUND/AIM

Allicin has been known to improve wound healing via antimicrobial and anti-inflammatory properties. The aim of this study was to evaluate whether an allicin-coated tracheal tube can prevent tracheal stenosis through improving wound healing after tracheal injury.

MATERIALS AND METHODS

Allicin-coated silicone tracheal tube (t-tube) was prepared by the polydopamine-mediated coating method. Tracheal mucosa was injured, and an allicin-coated t-tube was placed into the trachea to evaluate mucosal changes until designated time point. Anti-inflammatory, anti-bacterial and cytotoxic effects of allicin were also investigated in in vitro.

RESULTS

Allicin- coated silicone was not cytotoxic, and it showed anti-inflammatory and anti-bacterial effects in in vitro analysis. The use of allicin-coated t-tube in a rabbit model showed favorable mucosal healing with significant decrease of proinflammatory cytokines compared to the non-coated tube group. The allicin-coated tube showed obvious decreased number of cocci-shaped bacterial attached to the tube surface. From the histological point of view, the allicin- coated tube showed faster regeneration of the normal respiratory epithelial structure compared to the non-coated group.

CONCLUSION

Allicin-coated t-tube showed anti-inflammatory and anti-bacterial effects on injured tracheal mucosa. We suggest that allicin-coated t-tube can be used for promoting physiological wound healing to prevent laryngotracheal stenosis.

Protective Effects of Allicin on Acute Myocardial Infarction in Rats via Hydrogen Sulfide-mediated Regulation of Coronary Arterial Vasomotor Function and Myocardial Calcium Transport

Acute myocardial infarction (AMI) is a condition with high morbidity and mortality, for which effective treatments are lacking. Allicin has been reported to exert therapeutic effects on AMI, but the underlying mechanisms of its action have not been fully elucidated. To investigate this, a rat model of AMI was generated by ligating the left anterior descending branch of the coronary artery. DL-propargylglycine (PAG), a specific hydrogen sulfide (H₂S) synthetase inhibitor, was used to examine the effects of allicin on H₂S production. Isolated coronary arteries and cardiomyocytes were assessed for vascular reactivity and cellular Ca²⁺ transport using a multiwire myography system and a cell-contraction-ion detection system, respectively. Allicin administration improved cardiac function and myocardial pathology, reduced myocardial enzyme levels, and increased H₂S and H₂S synthetase levels. Allicin administration resulted in concentration-dependent effects on coronary artery dilation, which were mediated by receptor-dependent Ca²⁺ channels, ATP-sensitive K⁺ channels, and sarcoplasmic reticulum (SR) Ca²⁺ release induced by the ryanodine receptor. Allicin administration improved Ca²⁺ homeostasis in cardiomyocytes by increasing cardiomyocyte contraction, Ca²⁺ transient amplitude, myofilament sensitivity, and SR Ca²⁺ content. Allicin also enhanced Ca²⁺ uptake via SR Ca²⁺-ATPase and Ca²⁺ removal via the Na⁺/Ca²⁺ exchanger, and it reduced SR Ca²⁺ leakage. Notably, the protective effects of allicin were partially attenuated by blockade of H₂S production with PAG. Our findings provide novel evidence that allicin-induced production of H₂S mediates coronary artery dilation and regulation of Ca²⁺ homeostasis in AMI. Our study presents a novel mechanistic insight into the anti-AMI effects of allicin and highlights the therapeutic potential of this compound.

Allicin, an Antioxidant and Neuroprotective Agent, Ameliorates Cognitive Impairment

Allicin (diallylthiosulfinate) is a defense molecule produced by cellular contents of garlic (Allium sativum L.). On tissue damage, the non-proteinogenic amino acid alliin (S-allylcysteine sulfoxide) is converted to allicin in an enzyme-mediated process catalysed by alliinase. Allicin is hydrophobic in nature, can efficiently cross the cellular membranes and behaves as a reactive sulfur species (RSS) inside the cells. It is physiologically active molecule with the ability to oxidise the thiol groups of glutathione and between cysteine residues in proteins. Allicin has shown anticancer, antimicrobial, antioxidant properties and also serves as an efficient therapeutic agent against cardiovascular diseases. In this context, the present review describes allicin as an antioxidant, and neuroprotective molecule that can ameliorate the cognitive abilities in case of neurodegenerative and neuropsychological disorders. As an antioxidant, allicin fights the reactive oxygen species (ROS) by downregulation of NOX (NADPH oxidizing) enzymes, it can directly interact to reduce the cellular levels of different types of ROS produced by a variety of peroxidases. Most of the neuroprotective actions of allicin are mediated via redox-dependent pathways. Allicin inhibits neuroinflammation by suppressing the ROS production, inhibition of TLR4/MyD88/NF-κB, P38 and JNK pathways. As an inhibitor of cholinesterase and (AChE) and butyrylcholinesterase (BuChE) it can be applied to manage the Alzheimer's disease, helps to maintain the balance of neurotransmitters in case of autism spectrum disorder (ASD) and attention deficit hyperactive syndrome (ADHD). In case of acute traumatic spinal cord injury (SCI) allicin protects neuron damage by regulating inflammation, apoptosis and promoting the expression levels of Nrf2 (nuclear factor erythroid 2-related factor 2). Metal induced neurodegeneration can also be attenuated and cognitive abilities of patients suffering from neurological diseases can be ameliorates by allicin administration.

In vitro Activity of Allicin Alone and in Combination With Antifungal Drugs Against Microsporum canis Isolated From Patients With Tinea Capitis

The checkerboard broth method based on the Clinical and Laboratory Standards Institute M38-A3 document was used in this study to evaluate the in vitro activity of allicin alone and in combination with the antifungal drugs (griseofulvin, fluconazole, itraconazole and terbinafine) against Microsporum canis isolated from patients with tinea capitis. When allicin was used alone, only weak anti-M. canis effects were found. The MIC₅₀, MIC₉₀ and geometric mean (GM) of terbinafine were the lowest among the compounds tested. Synergism was observed for the combinations of allicin with itraconazole and terbinafine. Only indifference was observed for the combinations of allicin with griseofulvin and fluconazole. Our study illustrated the synergism of allicin in combination with itraconazole and terbinafine, which could be a reference for the treatment of tinea capitis due to M. canis.

Co-Application of Allicin and Chitosan Increases Resistance of Rosa roxburghii against Powdery Mildew and Enhances Its Yield and Quality

Powdery mildew, caused by Sphaerotheca sp., annually causes severe losses in yield and quality in Rosa roxburghii production areas of southwest China. In this study, the role of the co-application of allicin and chitosan in the resistance of R. roxburghii against powdery mildew and its effects on growth, yield and quality of R. roxburghii were investigated. The laboratory toxicity test results show that allicin exhibited a superior antifungal activity against Sphaerotheca sp. with EC₅₀ value of 148.65 mg kg⁻¹. In the field, the foliar application of allicin could effectively enhance chitosan against powdery mildew with control efficacy of 85.97% by spraying 5% allicin microemulsion (ME) 100–time liquid + chitosan 100–time liquid, which was significantly (p < 0.01) higher than 76.70% of allicin, 70.93% of chitosan and 60.23% of polyoxin. The co-application of allicin and chitosan effectively enhanced the photosynthetic rate and chlorophyll of R. roxburghii compared with allicin, chitosan or polyoxin alone. Moreover, allicin used together with chitosan was more effective than allicin or chitosan alone in enhancing R. roxburghii plant growth and fruit yield as well as improving R. roxburghii fruit quality. This work highlights that the co-application of allicin and chitosan can be used as a green, cost-effective and environmentally friendly alternative strategy to conventional antibiotics for controlling powdery mildew of R. roxburghii.

The Effect of Allicin on the Proteome of SARS-CoV-2 Infected Calu-3 Cells

Allicin (diallyl thiosulfinate) is the major thiol-reactive organosulfur compound produced by garlic plants (Allium sativum) upon tissue damage. Allicin exerts its strong antimicrobial activity against bacteria and fungi via S-thioallylation of protein thiols and low molecular weight thiols. Here, we investigated the effect of allicin on SARS-CoV-2 infected Vero E6 and Calu-3 cells. Toxicity tests revealed that Calu-3 cells showed greater allicin tolerance, probably due to >4-fold higher GSH levels compared to the very sensitive Vero E6 cells. Exposure of infected Vero E6 and Calu-3 cells to biocompatible allicin doses led to a ∼60–70% decrease of viral RNA and infectious viral particles. Label-free quantitative proteomics was used to investigate the changes in the Calu-3 proteome after SARS-CoV-2 infection and the effect of allicin on the host-virus proteome. SARS-CoV-2 infection of Calu-3 cells caused a strong induction of the antiviral interferon-stimulated gene (ISG) signature, including several antiviral effectors, such as cGAS, Mx1, IFIT, IFIH, IFI16, IFI44, OAS, and ISG15, pathways of vesicular transport, tight junctions (KIF5A/B/C, OSBPL2, CLTCL1, and ARHGAP17) and ubiquitin modification (UBE2L3/5), as well as reprogramming of host metabolism, transcription and translation. Allicin treatment of infected Calu-3 cells reduced the expression of IFN signaling pathways and ISG effectors and reverted several host pathways to levels of uninfected cells. Allicin further reduced the abundance of the structural viral proteins N, M, S and ORF3 in the host-virus proteome. In conclusion, our data demonstrate the antiviral and immunomodulatory activity of biocompatible doses of allicin in SARS-CoV-2-infected cell cultures. Future drug research should be directed to exploit the thiol-reactivity of allicin derivatives with increased stability and lower human cell toxicity as antiviral lead compounds.

In silicoinvestigation of Alliin as potential activator for AMPA receptor

Natural products from plants, such as flavonoids, arouse immense interest in medicine because of the therapeutic and many other bioactive properties. The molecular docking is a very useful method to screen the molecules based on their free binding energies and give important structural suggestions about how molecules might activate or inhibit the target receptor by comparing reference molecules. Alliin and Allicin differ from many other flavonoids because of containing no benzene rings and having nitrogen and sulfur atoms in their structure. In this study Alliin and Allicin affinity on AMPA, NMDA and GABA-A receptors were evaluated in the central nervous system by using the molecular docking method. Both Alliin and Allicin indicated no inhibitory effects. However Alliin showed significant selectivity to human AMPA receptor (3RN8) as an excitatory. The binding energy of glutamate to 3RN8 was -6.61 kcal mol^-1, while the binding energy of Allin was -8.08 kcal mol^-1. Furthermore Alliin's affinity to the other AMPA and NMDA receptors is quite satisfactory compared to the reference molecule glutamate. In conclusion based on the molecular docking study, Alliin can be useful for synaptic plasticity studies whereas might be enhance seizure activity because of the increased permeability to cations. It also can be beneficial to improve learning and memory and can be used as a supportive product to the hypofunction of NMDA associated problems.