Effect of garlic extract on markers of lipid metabolism and inflammation in coronary artery disease (CAD) patients: A systematic review and meta-analysis

Immunomodulatory effect of allium sativum in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a metabolic disorder marked by chronic hyperglycemia and low-grade inflammation, contributing to various complications. Natural agents with immunomodulatory and antioxidant properties have gained attention as adjunct therapies. To review the effects of Allium sativum on inflammatory pathways and metabolic alterations associated with T2DM. A narrative review was performed using PubMed/MEDLINE, EMBASE, and Scielo databases. The search included terms such as “allium sativum”, “inflammation", “oxidative stress”, and “diabetes mellitus”. Studies in English and Spanish - ranging from clinical trials to meta-analyses - were selected based on relevance. Bioactive compounds such as allicin, S-allyl cysteine, and diallyl disulfide exhibit anti-inflammatory, antioxidant, hypoglycemic, and lipid-lowering actions. Preclinical studies show improved glucose metabolism, insulin sensitivity, and organ function. Moreover, clinical evidence supports reductions in fasting glucose, hemoglobin A1c, blood pressure, and oxidative stress, with good safety profiles. Allium sativum appears to be a promising adjuvant in T2DM management, offering metabolic and anti-inflammatory benefits. Nonetheless, further high-quality clinical trials are needed to confirm its long-term efficacy and standardize its therapeutic use.

Effects of aged garlic extract on experimental periodontitis in mice

Aged garlic extract (AGE) has been reported to exert anti-inflammatory effects. AGE has been recently found to reduce the inflammatory symptoms of periodontitis, a widespread chronic inflammatory disease caused by oral bacterial infection. However, the mechanisms underlying these effects remain unclear. In the present study, it was aimed to determine the effects of AGE on experimental periodontitis and the related inflammatory factors. AGE (2 g/kg/day) was orally administered to 15 mice during the experimental period, while a control group consisted of 15 mice that received pure water. A total of 3 days after initiation of administration, the left maxillary second molar was ligated with a 5-0 silk thread for 7 days. Blood biochemical tests were performed to monitor the systemic effects of AGE. Alveolar bone loss was measured morphometrically using a stereomicroscope, and reverse transcription-quantitative PCR was performed to assay mRNAs of proinflammatory cytokines in gingival tissues. A histological survey was also performed to identify osteoclasts in periodontitis lesions (five mice per group). The total protein and albumin levels showed no significant differences between the AGE and control groups. However, ligation-induced bone resorption was lower in the AGE group than in the control group (P=0.01). Additionally, ligature increased the mRNA expression of inflammatory cytokines, whereas AGE administration tended to suppress them. Remarkably, tumor necrosis factor gene expression was significantly suppressed (P=0.04). The number of osteoclasts in periodontitis lesions was reduced in the AGE-treated group. These results indicate that AGE prevents alveolar bone loss by suppressing the inflammatory responses related to osteoclast differentiation in the periodontal tissue. Further research is needed to elucidate the role of AGE in reducing inflammatory bone resorption.

Aged garlic oligosaccharides modulate host metabolism and gut microbiota to alleviate high-fat and high-cholesterol diet-induced atherosclerosis in ApoE-/- mice

Atherosclerosis (AS) is a cardiovascular disease caused by excessive accumulation of lipids in arterial walls. In this study, we developed an AS model in ApoE-/- mice using a high-fat, high-cholesterol diet and investigated the anti-AS mechanism of aged garlic oligosaccharides (AGOs) by focusing on the gut microbiota. Results revealed that AGOs exhibited significant anti-AS effects, reduced trimethylamine N-oxide levels from 349.9 to 189.2 ng/mL, and reduced aortic lipid deposition from 31.7 % to 9.5 %. AGOs significantly increased the levels of short-chain fatty acids in feces, in which acetic, propionic, and butyric acids were increased from 1.580, 0.364, and 0.469 mg/g to 2.233, 0.774, and 0.881 mg/g, respectively. An analysis of the gut microbiota indicated that AGOs restored alpha and beta diversity, decreased the Firmicutes/Bacteroidetes ratio, and promoted the dominance of the genus Akkermansia. A metagenomic analysis revealed that AGOs alleviated AS through the ABC transporter pathway and the lipopolysaccharide biosynthesis pathway.

Effects of aged garlic extract on blood pressure in hypertensive patients: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

There is no consensus based on the existing literature regarding the effect of aged garlic extract (AGE) on blood pressure. The present systematic review and meta-analysis was conducted to synthesize existing data from randomized clinical trials (RCTs) concerning the impact of AGE supplementation on blood pressure in hypertensive patients.

METHODS

We searched English web databases including, PubMed, Scopus, Embase, Web of Science until August 2024. Random-effects meta-analysis was used to pool weighted mean differences (WMD) and 95 % CI for the outcomes.

RESULTS

Overall, nine RCTs with584 participants met inclusion criteria. AGE tea supplementation reduces systolic blood pressure (SBP) (WMD: -4.03; %95CI: -6.87, -1.20; I2: 57.1 %) and diastolic blood pressure (DBP) (WMD: -1.44; 95 % CI= -2.87, -0.02; P = 0.052; I2: 36.8 %; P: 0.105). Moreover, subgroup analysis indicated that higher doses of AGE supplementation in hypertensive patients significantly decreased DBP, and SBP.

CONCLUSION

The results of this study suggest that AGE supplements may be beneficial for improving blood pressure in hypertensive patients, but significant effects are observed only at doses over 1200 mg/day. To confirm these results, well-designed future trials will be needed.

Therapeutic effect of targeted antioxidant natural products

The exploration of targeted therapy has proven to be a highly promising avenue in the realm of drug development research. The human body generates a substantial amount of free radicals during metabolic processes, and if not promptly eliminated, these free radicals can lead to oxidative stress, disrupting homeostasis and potentially contributing to chronic diseases and cancers. Before the development of contemporary medicine with synthetic pharmaceuticals and antioxidants, there was a long-standing practice of employing raw, natural ingredients to cure a variety of illnesses. This practice persisted even after the active antioxidant molecules were known. The ability of natural antioxidants to neutralise excess free radicals in the human body and so prevent and cure a wide range of illnesses. The term "natural antioxidant" refers to compounds derived from plants or other living organisms that have the ability to control the production of free radicals, scavenge them, stop free radical-mediated chain reactions, and prevent lipid peroxidation. These compounds have a strong potential to inhibit oxidative stress. Phytochemicals (antioxidants) derived from plants, such as polyphenols, carotenoids, vitamins, and others, are central to the discussion of natural antioxidants. Not only may these chemicals increase endogenous antioxidant defenses, affect communication cascades, and control gene expression, but they have also shown strong free radical scavenging properties. This study comprehensively summarizes the primary classes of natural antioxidants found in different plant and animal source that contribute to the prevention and treatment of diseases. Additionally, it outlines the research progress and outlines future development prospects. These discoveries not only establish a theoretical groundwork for pharmacological development but also present inventive ideas for addressing challenges in medical treatment.

Garlic consumption can reduce the risk of dyslipidemia: a meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

Garlic is used as an important medicinal food for treatment of many diseases, however, the association between garlic consumption and dyslipidemia have yielded inconsistent results. So we carried this meta-analysis to explore the blood lipid-lowering effects of garlic.

METHODS

Databases such as PubMed, Scopus, Web of science, Embase, Cochrane Library were systematically searched until June 2024. Heterogeneity among studies was examined using Q and I2 statistics. Also subgroup analysis were conducted to explore the potential heterogeneity. Combined weighted mean differences (WMD) with their 95% confidence interval (CI) were calculated using a random-effects model. The GRADE approach was used to evaluate the overall certainty of the evidence in the meta-analyses.

RESULTS

A total of 21 RCTs studies involved association between garlic consumption and blood lipids level of dyslipidemia patients were included in the meta-analysis. The pooled results showed that garlic consumption significantly reduced total cholesterol (TC)(WMD = -0.64mmol/L, 95%CI = -0.75 --0.54, P < 0.001), triglyceride (TG)(WMD = -0.17mmol/L, 95%CI = -0.26 --0.09, P < 0.001), low-density lipoprotein(LDL-C)(WMD = -0.44mmol/L, 95%CI = -0.57 --0.31, P < 0.001) while slightly increased high-density lipoprotein (HDL-C)(WMD = 0.04mmol/L, 95%CI = -0.00 - 0.08, P < 0.001). And subgroup analyses showed that TC, TG and LDL-C significantly decreased in patients aged > 50 years compared to those aged ≤ 50 years. And garlic oil greatly reduced TC and LDL-C compared with garlic power. Finally, sensitivity analysis and publication bias showed that the results were reliable.

CONCLUSIONS

Evidence from this meta-analysis suggested that garlic consumption could be effective in reducing the risk of dyslipidemia and preventing CVDs. Particularly the older people were more susceptible to the protective effects of garlic.

A systematic review of randomized controlled trials on the health effects of chocolate enriched/fortified/supplemented with functional components

The most significant contributor to global mortality are cardiovascular diseases. Dietary factors significantly impact the risk, advancement, and treatment of cardiometabolic conditions. Chocolate, known for its adaptability and capacity to stimulate pleasure centers, emerges as a promising vehicle for integrating different bioactive elements. This systematic review analyzed 10 randomized controlled trials investigating the health effects of consuming enriched, fortified, or supplemented chocolate. These trials varied in chocolate intake amounts (ranging from 5 to 101 g day-1), incorporated bioactive components (co-crystalized astaxanthin, lycopene, wood-based phytosterol-phytostanol mixture, canola sterol esters, etc.), and duration (from 2 weeks to 1 year). Some enriched chocolates were found to reduce total and LDL cholesterol and influence markers of oxidative damage, inflammation, immune function, and skin parameters. However, certain trials showed a minimal impact on health outcomes. Therefore, while enriched chocolate holds promise as a carrier for beneficial bioactive compounds, rigorous scientific inquiry and methodological rigor are crucial to fully substantiate these claims. Comprehensive evaluations covering cardiovascular health, metabolic function, immune response, and other aspects are needed to understand its potential benefits and limitations. Advancing robust research initiatives could help realize the full potential of enriched chocolate in promoting human health and well-being.

Dietary supplements: clinical cholesterol-lowering efficacy and potential mechanisms of action

This review aims to analyse the efficacy of dietary supplements in reducing plasma cholesterol levels. Focusing on evidence from meta-analyses of randomised controlled clinical trials, with an emphasis on potential mechanisms of action as supported by human, animal, and cell studies. Certain dietary supplements including phytosterols, berberine, viscous soluble dietary fibres, garlic supplements, soy protein, specific probiotic strains, and certain polyphenol extracts could significantly reduce plasma total and low-density lipoprotein (LDL) cholesterol levels by 3-25% in hypercholesterolemic patients depending on the type of supplement. They tended to be more effective in reducing plasma LDL cholesterol level in hypercholesterolemic individuals than in normocholesterolemic individuals. These supplements worked by various mechanisms, such as enhancing the excretion of bile acids, inhibiting the absorption of cholesterol in the intestines, increasing the expression of hepatic LDL receptors, suppressing the activity of enzymes involved in cholesterol synthesis, and activating the adenosine monophosphate-activated protein kinase signalling pathway.

A Scoping Review of the Clinical Evidence for the Health Benefits of Culinary Doses of Herbs and Spices for the Prevention and Treatment of Metabolic Syndrome

Metabolic syndrome (MetS) is a growing global health problem. Evidence suggests that diets rich in phytochemical-containing herbs and spices can contribute to reducing the risk of chronic diseases. This review assesses the scope of evidence supporting the use of herbs and spices in the diet for the prevention or treatment of MetS and its associated health conditions. A search of the PubMed, Scopus and Google Scholar databases was carried out to assess the available clinical evidence for culinary doses of commonly used herbs and spices. Trials that were measuring health factors related to metabolic disorders in healthy individuals, or the health of individuals with MetS or associated diseases, were included. Out of a total of 1738 papers identified, there were 142 relevant studies on black pepper, chilli, cardamom, cinnamon, coriander, cumin, fennel, fenugreek, garlic, ginger, nigella seed, rosemary, sage and turmeric. No relevant research was found for cloves, mint, oregano, parsley or thyme. Cinnamon, fenugreek and ginger were the herbs/spices with the most published trials on them and that showed promise for glycaemic control. Cardamom appears to have potential to reduce inflammatory markers, and cinnamon, ginger and turmeric to reduce blood lipids. Patients with type 2 diabetes were the population most likely to be included in studies, but the preventative benefits of herbs/spices in healthy populations were also investigated, particularly for chilli, ginger and cinnamon. There is evidence for the beneficial effect of culinary doses of many common herbs/spices in the prevention and treatment of MetS and associated disorders.