Roles and mechanisms of garlic and its extracts on atherosclerosis: A review

Identifying atheroprotective fruits and vegetables by Mendelian Randomization analysis

Background

Fruits and vegetables (FVs) are widely believed to mitigate the risk of atherosclerosis (AS). However, the causal relationships between specific FVs and AS risk factors remain unclear.

Methods

This study performed two-sample Mendelian Randomization (MR) analysis to infer the causality of the intake of 28 kinds of FVs with AS, as well as its risk factors including blood low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and C-reactive protein (CRP). GWAS genetic data for these exposures and outcomes were extracted from the IEU open GWAS project. Heterogeneity was evaluated using both Inverse Variance Weighted (IVW) and MR-Egger methods. MR-Egger regression was specifically deployed to detect potential pleiotropy. Furthermore, a "leave-one-out" sensitivity analysis was conducted to determine the impact of each individual single nucleotide polymorphism (SNP) on the combined outcome.

Results

The analysis confirms a causal relationship between total fruit consumption and reduced levels of LDL-C (OR = 0.911, p = 0.007) and CRP (OR = 0.868, p = 0.008). Similarly, total vegetable intake is also causally associated with a reduction in CRP levels (OR = 0.858, p = 0.018). Specifically, garlic intake exhibits the most significant causal relationship with reduced risk of AS (OR = 0.985, p = 0.036) and also causally associated with lower levels of LDL-C and TG. Berry (OR = 0.929, p = 0.010) and potato (OR = 0.957, p = 0.020) intake both display a significant causal negative association with TG levels, while peach/nectarine consumption is significantly associated with reduced CRP levels (OR = 0.913, p = 0.010).

Conclusion

This is the first MR study that systemically examined the causality between commonly consumed FVs and AS. Our findings highlight the atheroprotective effects of various FVs, particularly garlic, on cardiovascular health and the importance of tailored nutritional recommendations to prevent AS.

Licorice and liver function in patients with primary liver disease: A systematic review and meta-analysis of RCTs

Licorice (Glycyrrhiza spp.) has been a cornerstone of traditional Chinese and Japanese medicine. This systematic review and meta-analysis aimed to evaluate the efficacy of licorice formulations, alone or in combination with other herbs, on liver function enzymes in patients with primary liver disease. We systematically searched MEDLINE, Embase, Scopus, Web of Science, and Cochrane Library up to April 2024. Randomized controlled trials (RCTs) comparing the effects of Glycyrrhiza spp. preparations versus placebo or standard of care controls were included. Standard Cochrane methods were used to extract data and appraise eligible studies. A total of 15 RCTs, involving 1367 participants, were included in the analysis. The studies varied widely in geographical location, duration, and licorice preparations used. Licorice significantly reduced alanine aminotransferase (ALT) by 15.63 U/L (95% CI: -25.08, -6.18; p = 0.001) and aspartate aminotransferase (AST) by 7.37 U/L (95% CI: -13.13, -1.61; p = 0.01) compared to control groups. Subgroup analyses revealed that purified glycyrrhizic acid compounds were particularly effective, showing greater reductions in ALT and AST without significant heterogeneity. Although licorice treatment did not significantly impact gamma-glutamyl transferase and total bilirubin (TBIL) levels overall, specific licorice-herb preparations did show a notable reduction in TBIL. The safety profile of licorice was consistent with known side effects, predominantly mild and related to its mineralocorticoid effects. Despite heterogeneity and potential language bias, the findings suggest that licorice can enhance liver function. Further studies should standardize licorice preparations and explore its role in multifaceted herbal formulations to better understand its hepatoprotective mechanisms.

Exploring the health benefits of raw white garlic consumption in humans: a mini review

Introduction

Raw white garlic, a fundamental food in both culinary and medicinal practices globally, has gained attention for its potential health benefits. Despite widespread use, clinical research has predominantly focused on aged black garlic or garlic extracts, leaving raw white garlic consumption in humans underexplored. This mini review aims to summarize the evidence from clinical and observational studies on the health effects of raw white garlic consumption.

Methods

A search in PubMed and Scopus databases was conducted to identify clinical and observational studies on raw white garlic consumption. Twelve clinical trials and 10 observational studies meeting the predefined inclusion criteria were selected for review.

Results

Results from clinical trials revealed diverse health effects of raw garlic consumption, including improved lipid profiles, blood pressure regulation, fibrinolytic activity, antioxidant status, and glucose metabolism. Observational studies reported the association of raw garlic consumption with improvements of important health outcomes, including cancer risk, cardiovascular disease, insulin homeostasis, and liver function. However, both clinical and observational studies were heterogenous in design, participant characteristics, durations, and outcome measures. Observational studies were limited to Asian populations.

Conclusion

While human studies indicate that raw garlic may exert various health benefits, larger randomized controlled trials with longer follow-up and cohort studies are needed to explore the full potential of raw garlic consumption in human health promotion. Our mini-review aims to summarize the currently available evidence on raw garlic consumption in humans.

Which Constituents Determine the Antioxidant Activity and Cytotoxicity of Garlic? Role of Organosulfur Compounds and Phenolics

Garlic is a vegetable with numerous pro-health properties, showing high antioxidant capacity, and cytotoxicity for various malignant cells. The inhibition of cell proliferation by garlic is mainly attributed to the organosulfur compounds (OSCs), but it is far from obvious which constituents of garlic indeed participate in the antioxidant and cytotoxic action of garlic extracts. This study aimed to obtain insight into this question by examining the antioxidant activity and cytotoxicity of six OSCs and five phenolics present in garlic. Three common assays of antioxidant activity were employed (ABTS● decolorization, DPPH● decolorization, and FRAP). Cytotoxicity of both classes of compounds to PEO1 and SKOV-3 ovarian cancer cells, and MRC-5 fibroblasts was compared. Negligible antioxidant activities of the studied OSCs (alliin, allicin, S-allyl-D-cysteine, allyl sulfide, diallyl disulfide, and diallyl trisulfide) were observed, excluding the possibility of any significant contribution of these compounds to the total antioxidant capacity (TAC) of garlic extracts estimated by the commonly used reductive assays. Comparable cytotoxic activities of OSCs and phenolics (caffeic, p-coumaric, ferulic, gallic acids, and quercetin) indicate that both classes of compounds may contribute to the cytotoxic action of garlic.

Correlation between changes in serum YKL-40, LXRs, PPM1A, and TGF-β1 levels and airway remodeling and lung function in patients with bronchial asthma

OBJECTIVE

This study investigates the correlation between serum levels of YKL-40, LXRs, PPM1A, and TGF-β1 and airway remodeling and lung function in bronchial asthma patients.

METHODS

The study involved 80 bronchial asthma patients and 92 healthy individuals. Serum cytokines, airway remodeling, and lung function markers were compared across mild, moderate, and severe asthma cases using high-resolution CT, t-tests, ANOVA, and Pearson correlation analysis.

RESULTS

Asthmatic patients exhibited higher levels of serum YKL-40, LXRα, LXRβ, TGF-β1, airway wall thickness (T)/outer diameter (D), and WA% of total cross-sectional area compared to controls. Conversely, their serum PPM1A, Peak Expiratory Flow (PEF), and Forced Expiratory Volume in 1 s (FEV1) were lower. Serum YKL-40 and TGF-β1 levels were positively correlated with T/D and WA%, and negatively correlated with PEF and FEV1. PPM1A levels were strongly associated with T/D, WA%, PEF, and FEV1.

CONCLUSION

The severity of bronchial asthma is associated with increased serum levels of YKL-40, LXRα, LXRβ, and TGF-β1 and decreased PPM1A. The levels of YKL-40, PPM1A, and TGF-β1 have a significant correlation with airway remodeling and lung function.

Two new and effective food-extracted immunomodulatory agents exhibit anti-inflammatory response activity in the hACE2 acute lung injury murine model of COVID-19

Objective

The coronavirus disease 2019 (COVID-19) spread rapidly and claimed millions of lives worldwide. Acute respiratory distress syndrome (ARDS) is the major cause of COVID-19-associated deaths. Due to the limitations of current drugs, developing effective therapeutic options that can be used rapidly and safely in clinics for treating severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections is necessary. This study aims to investigate the effects of two food-extracted immunomodulatory agents, ajoene-enriched garlic extract (AGE) and cruciferous vegetables-extracted sulforaphane (SFN), on anti-inflammatory and immune responses in a SARS-CoV-2 acute lung injury mouse model.

Methods

In this study, we established a mouse model to mimic the SARS-CoV-2 infection acute lung injury model via intratracheal injection of polyinosinic:polycytidylic acid (poly[I:C]) and SARS-CoV-2 recombinant spike protein (SP). After the different agents treatment, lung sections, bronchoalveolar lavage fluid (BALF) and fresh faeces were harvested. Then, H&E staining was used to examine symptoms of interstitial pneumonia. Flow cytometry was used to examine the change of immune cell populations. Multiplex cytokines assay was used to examine the inflammatory cytokines.16S rDNA high-throughput sequencing was used to examine the change of gut microbiome.

Results

Our results showed that AGE and SFN significantly suppressed the symptoms of interstitial pneumonia, effectively inhibited the production of inflammatory cytokines, decreased the percentage of inflammatory cell populations, and elevated T cell populations in the mouse model. Furthermore, we also observed that the gut microbiome of genus Paramuribaculum were enriched in the AGE-treated group.

Conclusion

Here, for the first time, we observed that these two novel, safe, and relatively inexpensive immunomodulatory agents exhibited the same effects on anti-inflammatory and immune responses as neutralizing monoclonal antibodies (mAbs) against interleukin 6 receptor (IL-6R), which have been suggested for treating COVID-19 patients. Our results revealed the therapeutic ability of these two immunomodulatory agents in a mouse model of SARS-CoV-2 acute lung injury by promoting anti-inflammatory and immune responses. These results suggest that AGE and SFN are promising candidates for the COVID-19 treatment.

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.

Nutritional Modulation of Hepcidin in the Treatment of Various Anemic States

Twenty years after its discovery, hepcidin is still considered the main regulator of iron homeostasis in humans. The increase in hepcidin expression drastically blocks the flow of iron, which can come from one's diet, from iron stores, and from erythrophagocytosis. Many anemic conditions are caused by non-physiologic increases in hepcidin. The sequestration of iron in the intestine and in other tissues poses worrying premises in view of discoveries about the mechanisms of ferroptosis. The nutritional treatment of these anemic states cannot ignore the nutritional modulation of hepcidin, in addition to the bioavailability of iron. This work aims to describe and summarize the few findings about the role of hepcidin in anemic diseases and ferroptosis, as well as the modulation of hepcidin levels by diet and nutrients.

Characterization of garlic oil/β-cyclodextrin inclusion complexes and application

Garlic oil is a liquid extracted from garlic that has various natural antibacterial and anti-inflammatory properties and is believed to be used to prevent and treat many diseases. However, the main functional components of garlic oil are unstable. Therefore, in this study, encapsulating garlic oil with cyclodextrin using the saturated co-precipitation method can effectively improve its chemical stability and water solubility and reduce its characteristic odor and taste. After preparation, the microcapsules of garlic oil cyclodextrin were characterized, which proved that the encapsulation was successful. Finally, the results showed that the encapsulated garlic oil still had antioxidant ability and slow-release properties. The final addition to plant-based meat gives them a delicious flavor and adds texture and mouthfeel. Provided a new reference for the flavor application of garlic cyclodextrin micro-capsules in plant-based meat patties.