Review

Authors: Gaber El-Saber Batiha, Amany Magdy Beshbishy, Lamiaa G Wasef...

Medicinal plants have been used from ancient times for human healthcare as in the form of traditional medicines, spices, and other food components. Garlic ( L.) is an aromatic herbaceous plant that is consumed worldwide as food and traditional remedy for various diseases. It has been reported to possess several biological properties including anticarcinogenic, antioxidant, antidiabetic, renoprotective, anti-atherosclerotic, antibacterial, antifungal, and antihypertensive activities in traditional medicines. is rich in several sulfur-containing phytoconstituents such as alliin, allicin, ajoenes, vinyldithiins, and flavonoids such as quercetin. Extracts and isolated compounds of have been evaluated for various biological activities including antibacterial, antiviral, antifungal, antiprotozoal, antioxidant, anti-inflammatory, and anticancer activities among others. This review examines the phytochemical composition, pharmacokinetics, and pharmacological activities of extracts as well as its main active constituent, allicin.

Topics: Animals; Biological Products; Disulfides; Drug Stability; Garlic; Humans; Phytochemicals; Plant Extracts; Sulfinic Acids

PubMed: 32213941
DOI: 10.3390/nu12030872

Review

Authors: Christopher Sleiman, Rose-Mary Daou, Antonio Al Hazzouri...

Hypertension is a major risk factor for heart disease and stroke. Garlic has a long history of use in traditional medicine for various conditions, including hypertension. This narrative review examined the scientific evidence on the efficacy of garlic in lowering blood pressure. It explores the historical uses of garlic in different cultures for medicinal purposes and delves into the phytochemical composition of garlic, highlighting key components, like allicin and ajoene, that are believed to contribute to its potential health benefits. Clinical studies that investigated the effects of garlic and garlic-based supplements on blood pressure are presented, with the findings suggesting that garlic consumption may modestly reduce blood pressure, particularly in individuals with mild hypertension. Potential mechanisms of action include increased nitric oxide production, improved endothelial function, and antioxidant properties. While garlic may offer some benefits for blood pressure management, it should not be considered a substitute for conventional antihypertensive medications. Further large-scale, long-term clinical trials are warranted to establish the efficacy of garlic in managing hypertension, including the optimal dosage and formulation.

Topics: Garlic; Humans; Hypertension; Blood Pressure; Antihypertensive Agents; Disulfides; Sulfinic Acids; Dietary Supplements; Phytotherapy; Plant Extracts; Antioxidants; Sulfoxides

PubMed: 39275211
DOI: 10.3390/nu16172895

Review

Authors: Yan Zhang, Xingping Liu, Jun Ruan...

Of the numerous health benefits of garlic, the anticancer effect is probably the most noticeable. Observations over the past years have shown that the consumption of garlic in the diet provides strong protection against cancer risk. Previous studies involving garlic phytochemicals have usually focused on the cancer chemopreventive properties, but there is little published evidence showing its therapeutic potential in cancer treatment. In view of the multitargeted carcinoma actions and lack of severe toxicity, some components of garlic are likely to play vital roles in the selective killing of cancer cells. However, the rational design of experimental studies and clinical trials are required to verify this concept. This paper discusses the promises and pitfalls of garlic for the treatment of cancer.

Topics: Antineoplastic Agents, Phytogenic; Garlic; Humans; Neoplasms; Phytochemicals

PubMed: 31877551
DOI: 10.1016/j.biopha.2019.109730

Review

Authors: Michał Majewski

Garlic (Allium sativum L. fam. Alliaceae) is one of the most researched and best-selling herbal products on the market. For centuries it was used as a traditional remedy for most health-related disorders. Also, it is widely used as a food ingredient--spice and aphrodisiac. Garlic's properties result from a combination of variety biologically active substances which all together are responsible for its curative effect. The compounds contained in garlic synergistically influence each other so that they can have different effects. The active ingredients of garlic include enzymes (e.g. alliinase), sulfur-containing compounds such as alliin and compounds produced enzymatically from alliin (e.g. allicin). There is a lot of variation among garlic products sold for medicinal purposes. The concentration of Allicin (main active ingredient) and the source of garlic's distinctive odor depend on processing method. Allicin is unstable, and changes into a different chemicals rather quickly. It's documented that products obtained even without allicin such as aged garlic extract (AGE), have a clear and significant biological effect in immune system improvement, treatment of cardiovascular diseases, cancer, liver and other areas. Some products have a coating (enteric coating) to protect them against attack by stomach acids. Clinically, garlic has been evaluated for a number of purposes, including treatment of hypertension, hypercholesterolemia, diabetes, rheumatoid arthritis, cold or the prevention of atherosclerosis and the development of tumors. Many available publications indicates possible antibacterial, anti-hypertensive and anti-thrombotic properties of garlic. Due to the chemical complexity of garlic and the use of different processing methods we obtain formulations with varying degrees of efficacy and safety.

Topics: Antioxidants; Carbon-Sulfur Lyases; Cardiovascular Diseases; Cysteine; Disulfides; Garlic; Humans; Hypercholesterolemia; Neoplasms; Phytotherapy; Plant Extracts; Protective Agents; Sulfinic Acids

PubMed: 24964572
DOI: No ID Found

Review

Authors: Tanvir Ahmed, Chin-Kun Wang

Black garlic (BG) is a form of aged garlic obtained from raw garlic () via Millard reaction under high temperature (60-90 °C) and humidity (70-90%) for a period of time. Several studies reported higher contents of water-soluble antioxidants compounds (S-allyl cysteine, S-allyl-mercapto cysteine), 5-hydroxymethylfurfural, organosulfur compounds, polyphenol, volatile compounds, and products of other Millard reactions compared to fresh garlic after the thermal processing. Recent studies have demonstrated that BG and its bioactive compounds possess a wide range of biological activities and pharmacological properties that preserve and show better efficacy in preventing different types of diseases. Most of these benefits can be attributed to its anti-oxidation, anti-inflammation, anti-obesity, hepatoprotection, hypolipidemia, anti-cancer, anti-allergy, immunomodulation, nephroprotection, cardiovascular protection, and neuroprotection. Substantial studies have been conducted on BG and its components against different common human diseases in the last few decades. Still, a lot of research is ongoing to find out the therapeutic effects of BG. Thus, in this review, we summarized the pre-clinical and clinical studies of BG and its bioactive compounds on human health along with diverse bioactivity, a related mode of action, and also future challenges.

Topics: Garlic; Humans; Antioxidants; Plant Extracts; Phytochemicals; Animals; Anti-Inflammatory Agents

PubMed: 34443625
DOI: 10.3390/molecules26165028

Review

Authors: Mohamed T El-Saadony, Ahmed M Saad, Sameh A Korma...

Garlic ( L.) is a widely abundant spice, known for its aroma and pungent flavor. It contains several bioactive compounds and offers a wide range of health benefits to humans, including those pertaining to nutrition, physiology, and medicine. Therefore, garlic is considered as one of the most effective disease-preventive diets. Many and studies have reported the sulfur-containing compounds, allicin and ajoene, for their effective anticancer, anti-diabetic, anti-inflammatory, antioxidant, antimicrobial, immune-boosting, and cardioprotective properties. As a rich natural source of bioactive compounds, including polysaccharides, saponins, tannins, linalool, geraniol, phellandrene, β-phellandrene, ajoene, alliin, S-allyl-mercapto cysteine, and β-phellandrene, garlic has many therapeutic applications and may play a role in drug development against various human diseases. In the current review, garlic and its major bioactive components along with their biological function and mechanisms of action for their role in disease prevention and therapy are discussed.

Topics: Garlic; Humans; Animals; Plant Extracts; Antioxidants; Phytochemicals; Sulfinic Acids; Disulfides

PubMed: 38915405
DOI: 10.3389/fimmu.2024.1277074

Meta-Analysis

Authors: Dinesh Gyawali, Rini Vohra, David Orme-Johnson...

Cardiovascular disease (CVD) is the leading cause of death globally and hypercholesterolemia is one of the major risk factors associated with CVD. Due to a growing body of research on side effects and long-term impacts of conventional CVD treatments, focus is shifting towards exploring alternative treatment approaches such as Ayurveda. However, because of a lack of strong scientific evidence, the safety and efficacy profiles of such interventions have not been well established. The current study aims to conduct a systematic review and meta-analyses to explore the strength of evidence on efficacy and safety of Ayurvedic herbs for hypercholesterolemia. : Literature searches were conducted using databases including Medline, Cochrane Database, AMED, Embase, AYUSH research portal, and many others. All randomized controlled trials on individuals with hypercholesterolemia using Ayurvedic herbs (alone or in combination) with an exposure period of ≥ 3 weeks were included, with primary outcomes being total cholesterol levels, adverse events, and other cardiovascular events. The search strategy was determined with the help of the Cochrane Metabolic and Endocrine Disorders Group. Two researchers assessed the risk of each study individually and discrepancies were resolved by consensus or consultation with a third researcher. Meta-analysis was conducted using the inverse variance method and results are presented as forest plots and data summary tables using Revman v5.3. A systematic review of 32 studies with 1386 participants found randomized controlled trials of three Ayurvedic herbs, (garlic), (guggulu), and (black cumin) on hypercholesterolemia that met inclusion criteria. The average duration of intervention was 12 weeks. Meta-analysis of the trials showed that guggulu reduced total cholesterol and low-density lipoprotein levels by 16.78 mg/dL (95% C.I. 13.96 to 2.61; -value = 0.02) and 18.78 mg/dL (95% C.I. 34.07 to 3.48; = 0.02), respectively. Garlic reduced LDL-C by 10.37 mg/dL (95% C.I. -17.58 to -3.16; -value = 0.005). Black cumin lowered total cholesterol by 9.28 mg/dL (95% C.I. -17.36, to -1.19, -value = 0.02). Reported adverse side effects were minimal. There is moderate to high level of evidence from randomized controlled trials that the Ayurvedic herbs guggulu, garlic, and black cumin are moderately effective for reducing hypercholesterolemia. In addition, minimal evidence was found for any side effects associated with these herbs, positioning them as safe adjuvants to conventional treatments.

Topics: Cardiovascular Diseases; Garlic; Humans; Hypercholesterolemia; Hyperlipidemias; Medicine, Ayurvedic

PubMed: 34071454
DOI: 10.3390/medicina57060546

Authors: Kumaran Sundaram, Jingyao Mu, Anil Kumar...

Obesity is becoming a global epidemic and reversing the pathological processes underlying obesity and metabolic co-morbidities is challenging. Obesity induced chronic inflammation including brain inflammation is a hallmark of obesity via the gut-brain axis. The objective of this study was to develop garlic exosome-like nanoparticles (GaELNs) that inhibit systemic as well as brain inflammatory activity and reverse a HFD induced obesity in mice. GELNs were isolated and administrated orally into HFD fed mice. GaELNs were fluorescent labeled for monitoring their trafficking route after oral administration and quantified the number particles in several tissues. The brain inflammation was determined by measuring inflammatory cytokines by ELISA and real-time PCR. Mitochondrial membrane permeability of microglial cells was determined using JC-10 fluorescence dye. The apoptotic cell death was quantified by TUNEL assay. The brain metabolites were identified and quantified by LC-MS analysis. Memory function of the mice was determined by several memory functional analysis. The effect of GaELNs on glucose and insulin response of the mice was determined by glucose and insulin tolerance tests. c-Myc localization and interaction with BASP1 and calmodulin was determined by confocal microscopy. Our results show that GaELNs is preferentially taken up microglial cells and inhibits the brain inflammation in HFD mice. GaELN phosphatidic acid (PA) (36:4) is required for the uptake of GaELNs via interaction with microglial BASP1. Formation of the GaELNs/BASP1 complex is required for inhibition of c-Myc mediated expression of STING. GaELN PA binds to BASP1, leading to inhibition of c-Myc expression and activity through competitively binding to CaM with c-Myc transcription factor. Inhibition of STING activity leads to reducing the expression of an array of inflammatory cytokines including IFN-γ and TNF-α. IFN-γ induces the expression of IDO1, which in turn the metabolites generated as IDO1 dependent manner activate the AHR pathway that contributes to developing obesity. The metabolites derived from the GaELNs treated microglial cells promote neuronal differentiation and inhibit mitochondrial mediated neuronal cell death. GaELNs treated HFD mice showed improved memory function and increased glucose tolerance and insulin sensitivity in these mice. : Collectively, these results demonstrate how nanoparticles from a healthy diet can inhibit unhealthy high-fat diet induced brain inflammation and reveal a link between brain microglia/diet to brain inflammatory disease outcomes via diet-derived exosome-like nanoparticles.

Topics: Animals; Antioxidants; Brain; Cytokines; Diet, High-Fat; Encephalitis; Garlic; Glucose; Inflammation; Insulin; Mice; Mice, Inbred C57BL; Nanoparticles; Obesity

PubMed: 35154484
DOI: 10.7150/thno.65427

Randomized Controlled Trial

Antihypertensive Effects of an Optimized Aged Garlic Extract in Subjects with Grade I Hypertension and Antihypertensive Drug Therapy: A Randomized, Triple-Blind Controlled Trial.

Authors: José C E Serrano, Eva Castro-Boqué, Alicia García-Carrasco...

The use of garlic () for treating arterial hypertension has been recognized as effective for several decades. However, tolerance to treatment is low, and several technological modifications have been developed to improve its tolerability, such as the aging process at controlled temperature and humidity. This study aims to validate the antihypertensive effects of an optimized extract of aged black garlic with low doses of s-allyl-cysteine (SAC) in a Grade I hypertensive population with drug treatment. A randomized, triple-blind, placebo-controlled parallel trial was developed, where a daily supplementation with 0.25 mg/day of SAC for 12 weeks was performed. A reduction in systolic and diastolic blood pressure of 1.8 mmHg (0.7 to 4.1 95% CI) and 1.5 mmHg (0.3 to 3.0 95% CI), respectively, was observed. Similarly, an increase in blood nitric oxide (10.3 µM, 1.1 to 19.5 95% CI) and antioxidant capacity (7 × 10 µM TE/min, (1.2 to 13 × 10 95% CI) and a reduction in uric acid levels (-0.3 mg/dL, -0.5 to -0.001 95% CI) and ACE activity (-9.3 U/L; -18.4 to -0.4 95% CI) were observed. No changes in endothelial function and inflammatory cytokines were observed. It was concluded that low-dose SAC supplementation in an optimized black-garlic extract allows for an extra-significant reduction in blood pressure in a Grade I hypertensive population receiving drug treatment.

Topics: Humans; Antihypertensive Agents; Garlic; Antioxidants; Hypertension; Biological Products; Plant Extracts

PubMed: 37686723
DOI: 10.3390/nu15173691

Authors: Kumaran Sundaram, Yun Teng, Jingyao Mu...

Gut microbiota function has numerous effects on humans and the diet humans consume has emerged as a pivotal determinant of gut microbiota function. Here, a new concept that gut microbiota can be trained by diet-derived exosome-like nanoparticles (ELNs) to release healthy outer membrane vesicles (OMVs) is introduced. Specifically, OMVs released from garlic ELN (GaELNs) trained human gut Akkermansia muciniphila (A. muciniphila) can reverse high-fat diet-induced type 2 diabetes (T2DM) in mice. Oral administration of OMVs released from GaELNs trained A. muciniphila can traffick to the brain where they are taken up by microglial cells, resulting in inhibition of high-fat diet-induced brain inflammation. GaELNs treatment increases the levels of OMV Amuc-1100, P9, and phosphatidylcholines. Increasing the levels of Amuc-1100 and P9 leads to increasing the GLP-1 plasma level. Increasing the levels of phosphatidylcholines is required for inhibition of cGas and STING-mediated inflammation and GLP-1R crosstalk with the insulin pathway that leads to increasing expression of Insulin Receptor Substrate (IRS1 and IRS2) on OMV targeted cells. These findings reveal a molecular mechanism whereby OMVs from plant nanoparticle-trained gut bacteria regulate genes expressed in the brain, and have implications for the treatment of brain dysfunction caused by a metabolic syndrome.

Topics: Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Garlic; Animals; Nanoparticles; Exosomes; Mice; Brain-Gut Axis; Akkermansia; Humans; Male; Diet, High-Fat; Mice, Inbred C57BL; Brain

PubMed: 38225709
DOI: 10.1002/smll.202308680