Independent beneficial effects of aged garlic extract intake with regular exercise on cardiovascular risk in postmenopausal women

The effects of aerobic and resistant exercises on the lipid profile in healthy women: a systematic review and meta-analysis

Exercise can have a wide range of health benefits, including improving blood lipid profiles. For women to achieve optimal cardiovascular health, it is vital to determine the effect of exercise on their health and whether different exercise intensities can affect their blood lipid profile. A systematic review and meta-analysis were conducted to examine the effects of exercise on improving the lipid profile of healthy women. A database search was conducted using PubMed, Google Scholar, Embase, Scopus, and Web of Science from inception until July 2, 2021, for randomized controlled trials (RCTs) investigating exercise's effects on healthy women's blood lipid profiles. A total of 10 eligible articles (or 17 trials) with 576 participants were identified as eligible for the study. Overall, the meta-analysis shows that physical activity significantly improved total cholesterol (TC), triglycerides (TG), and high-density lipoprotein (HDL-C) levels: TC [WMD = -5.77 mg/dL, 95% CI: -10.41, -1.13, P < 0.01]; TG [WMD = -5.60 mg/dL, 95% CI: -8.96, -2.23, P < 0.01]; HDL [WMD = 4.49 mg/dL, 95% CI: 0.33, 8.65, P = 0.03]. Additionally, sub-group analyses indicated that combined exercise training improved TG and TC (p 0.05), and aerobic exercise significantly increased HDL. In this study, physical activity appears to be one of the most effective non-pharmacological means for improving HDL, TG, and TC in healthy women. In terms of TG and TC, CT was the most effective.

Phytochemical components analysis and hypolipidemic effect on hyperlipidemia mice of the aerial parts from Allium sativum

Background

The bulbs of Allium sativum are widely used as food or seasoning (garlic), while they have also been utilized as a famous traditional medicine since ancient eras for the treatment of scabies, tuberculosis, pertussis, diarrhea and dysentery, etc. However, very few studies focus on their abundant aerial parts, which are normally discarded during the harvest season.

Methods

The hyperlipidemic mice model has been used to study the lipid-lowering effect of the aerial parts in this article. 180 mice were randomly divided into 18 groups, including blank control (BC), model (Mod), positive control (PC), and low-, medium-, and high-dose groups of the crude extract, petroleum ether, ethyl acetate, n-butanol, and residual water extracts (corresponding to CE, PEE, EAE, NBE, WE), with 10 mice in each group. The preventive effects of the extracts on hyperlipidemic mice lasted for four weeks. Ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) and gas chromatography tandem mass spectrometry (GC-MS/MS) were used to analyze the chemical components of NBE and PEE respectively.

Results

The results of the mice experiment showed that n-butanol extract (NBE) and petroleum ether extract (PEE) from the aerial parts could significantly reduce the contents of total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), alanine transaminase (ALT) and aspartate transaminase (AST) in serum of hyperlipidemic mice, and increase the contents of high density lipoprotein cholesterol (HDL-C). They could enhance the activity of superoxide dismutase (SOD) in liver and reduce the level of malondialdehyde (MDA). At the same time, they could improve steatosis and inflammation of liver cells. The results of phytochemical components analysis showed that NBE was rich in organic acids, flavonoids and nitrogen-containing constituents, while PEE contained organic sulfur compounds, aliphatic acids and derivatives, alkaloids, phytosterols, etc.

Conclusion

These results support that the aerial parts of A. sativum are an interesting source of bioactive ingredients that may be useful in the prevention and treatment of hyperlipidemia.

The Role of Garlic in Metabolic Diseases: A Review

Garlic (Allium sativum L.) is a popular spice that has been widely used for thousands of years in traditional medicine. Several organosulfur compounds in garlic have been linked to its beneficial effects on health. Evidence from preclinical studies and clinical trials supports garlic's antihypertensive, antidiabetic, antiobesity, and hypolipidemic effects. This study aims to summarize clinical trial evidence regarding the effects of garlic on metabolic diseases and its mechanisms of action.

Black Garlic and Its Bioactive Compounds on Human Health Diseases: A Review

Black garlic (BG) is a form of aged garlic obtained from raw garlic (Allium sativum) 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.

The effects of garlic supplementation on weight loss: A systematic review and meta-analysis of randomized controlled trials

Abstract. Obesity is related to increase in the incidence of morbidity and mortality. Studies have suggested anti-obesity properties of garlic; however, results are inconsistent. This systematic review and meta-analysis is done to summarize the data obtained from available randomized clinical trials on the effect of garlic supplementation on body weight, Body Mass Index (BMI), and Waist Circumference (WC). The online databases of Scopus, PubMed, Google Scholar and Cochrane library were searched until March 2018 for related publications using relevant keywords. Effect sizes of eligible studies were pooled using random-effects models. Cochran’s Q-test and I2 index were used for assessing heterogeneity. We found 1241 records in our initial search, of which 13 randomized clinical trials (RCTs) with 15 treatment arms were included. Pooled analysis showed that garlic administration might significantly decrease WC (Weighed Mean Difference (WMD): −1.10 cm, 95% CI: −2.13, −0.07, P = 0.03, I2 = 0%). However, garlic intervention had no significant effect on body weight (WMD): −0.17 kg, 95% CI: −0.75 to 0.39, P = 0.54, I2 = 0%) and BMI (WMD: −0.17 kg/m2, 95% CI: −0.52, 0.16, P = 0.30, I2 = 44.5%) as compared to controls. From Subgroup analysis, it was ascertained that the effect of garlic supplementation on BMI was significant in trials with duration < 12 weeks (WMD: −0.58 kg/m2, 95% CI: −1.08, −0.08, I2 = 19.8%, P = 0.02) compared to those with higher duration (>12 weeks). The current meta-analysis results suggest that garlic supplementation seems to reduce waist circumference unlike body weight and BMI.

Synergistic effects of black ginseng and aged garlic extracts for the amelioration of nonalcoholic fatty liver disease (NAFLD) in mice

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that can lead to carcinoma, cirrhosis, and death. Since no approved medications are available, dietary interventions that include bioactive compounds have been recommended. This study investigated the effects of black ginseng extracts (BGE) and aged black garlic extracts (AGE) on high-fat diet (HFD)-induced obese mice. Micrograph of liver tissues of mice fed with BGE and AGE showed less lipid droplets. The BGE and AGE supplements individually and in combination lowered the marker enzymes, aminotransferase (AST), and alanine aminotransferase (ALT) levels indicating their hepatoprotective effects. Compared to the plants extracts alone, the combination of the extracts resulted in lower total cholesterol (TC) and low-density lipoproteins cholesterol (LDL-C), which are risk markers for cardiovascular morbidity and mortality. Diets with the combination of BGE and AGE supplements had higher superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities, and lower malondialdehyde indicating the synergistic effects of the extracts. Irrespective of the diet type, all treated groups showed lower tumor necrosis factor (TNF-α) values as compared to HFD, which indicated overall immunomodulatory effect of both extracts. Therefore, the innovative formulation formed by the combination of BGE and AGE can provide hepatoprotective effects via modulating glycometabolism, lipometabolism, oxidative stress, and inflammation in mice.

The Effects of Medicinal Plants and Bioactive Natural Compounds on Homocysteine

BACKGROUND

Among non-communicable diseases, cardiovascular diseases (CVDs) are the leading cause of mortality and morbidity in global communities. By 2030, CVD-related deaths are projected to reach a global rise of 25 million. Obesity, smoking, alcohol, hyperlipidemia, hypertension, and hyperhomocysteinemia are several known risk factors for CVDs. Elevated homocysteine is tightly related to CVDs through multiple mechanisms, including inflammation of the vascular endothelium. The strategies for appropriate management of CVDs are constantly evolving; medicinal plants have received remarkable attention in recent researches, since these natural products have promising effects on the prevention and treatment of various chronic diseases. The effects of nutraceuticals and herbal products on CVD/dyslipidemia have been previously studied. However, to our knowledge, the association between herbal bioactive compounds and homocysteine has not been reviewed in details. Thus, the main objective of this study is to review the efficacy of bioactive natural compounds on homocysteine levels according to clinical trials and animal studies.

RESULTS

Based on animal studies, black and green tea, cinnamon, resveratrol, curcumin, garlic extract, ginger, and soy significantly reduced the homocysteine levels. According to the clinical trials, curcumin and resveratrol showed favorable effects on serum homocysteine. In conclusion, this review highlighted the beneficial effects of medicinal plants as natural, inexpensive, and accessible agents on homocysteine levels based on animal studies. Nevertheless, the results of the clinical trials were not uniform, suggesting that more well-designed trials are warranted.

Effects of garlic supplementation on oxidative stress and antioxidative capacity biomarkers: A systematic review and meta-analysis of randomized controlled trials

Evidence suggests that garlic supplementation may have an effect on oxidative stress by augmenting the rate of enzymatic and non-enzymatic antioxidants and diminishing pro-oxidant enzymes. Given inconsistencies across studies, we aimed to systematically review the current literature and quantify the effects of garlic supplementation on oxidative stress. We conducted a systematic search with multiple databases (Scopus, PubMed, and Web of Science) to find relevant articles published prior to October 2020. Results were reported as bias-corrected standardized mean difference (Hedges' g) with 95% confidence intervals (CI) using random-effects models. Cochrane's Q and I squared (I² ) tests were used to determine heterogeneity among the studies included. Twelve randomized controlled trials (RCTs) were included. Garlic doses ranged from 80 to 4,000 mg/day, and intervention duration varied between 2 and 24 weeks. Garlic supplementation increased serum level of total antioxidant capacity (TAC) (Hedges' g: 2.77, 95% CI: 1.37 to 4.17, p < 0.001) and superoxide dismutase (SOD) (Hedges' g: 13.76, 95% CI: 4.24 to 23.29, p = 0.004), while it reduced the malondialdehyde serum level (MDA) (Hedges' g: -1.94, 95% CI: -3.17 to -0.70, p = 0.002). Due to limited data available, glutathione (GSH) was not considered for the current meta-analysis. The nonlinear dose-response effect of garlic supplementation was not observed with regard to serum TAC and MDA levels (TAC: p-nonlinearity = 0.398; MDA: p-nonlinearity = 0.488). Garlic supplementation appears to improve serum levels of TAC, MDA, and SOD. Garlic supplementation may be useful to reduce oxidative stress and related diseases. Future studies with large sample sizes and longer duration are required to confirm these findings.

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

BACKGROUND AND AIMS

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

The effect of garlic on lipid profile and glucose parameters in diabetic patients: A systematic review and meta-analysis

PURPOSE

Several studies have been published about the effect of garlic on lipid profile and blood glucose in diabetic patients. Which, the results mostly contradict with each other. This study aimed to investigate the effect of garlic on lipid profile and serum glucose levels in diabetic patients using a systematic review and meta-analysis.

METHODS

This study was a systematic review and meta-analysis of articles published between 1988 and 2016. For this purpose, two independent researchers searched SID medical information databases including MagIran, Irandoc, Medlib, Iran Medex, Science Direct, Scopus, Google and PubMed using keywords. Data were analyzed using STATA software.

RESULTS

After the initial search, 23,000 articles were found, of which 33 had the required criteria for the meta-analysis. In the present study, the total sample under review was 1273 individuals, with a mean of 39 samples per study. Overall, the garlic was more influential than placebo in reducing the levels of lipid parameters including triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), and fasting blood sugar (FBS) and HbA_1C. In the meta-analysis, the concentration of serum TC, LDL, TG, and HDL in the group receiving garlic compared with the placebo showed a significant decreased for 16.87mg/dl (95% CI, -21.01, -12.73) (P=0.001), 9.65mg/dl (95% CI, -15.07, -4.23) (P=0.001), 12.44mg/dl (95% CI, -18.19, -6.69) (P=0.001), and increased for 3.19mg/dl (95% CI, 1.85, 4.53) (P=0.001), respectively. Also, the concentration of serum FBS and HbA_1C serum showed a significant decreased for 10.90mg/dl (95% CI, -16.40, -5.40) (P=0.001) and 0.60mg/dl (95% CI, -0.98, -0.22) (P=0.001), respectively.

CONCLUSION

Garlic can reduce lipid profile as well as glucose parameters and be therapeutically effective in patients suffering from cardiovascular diseases and diabetes.

Garlic and Heart Disease

BACKGROUND

Thousands of studies have been published based on animal and human studies evaluating garlic's effects and safety.

OBJECTIVE

We reviewed the available literature investigating the effects of garlic supplements on hypertension, hypercholesterolemia, C-reactive protein (CRP), pulse wave velocity (PWV), and coronary artery calcium (CAC), as well as available data on side effects.

METHODS

We searched PubMed for all human studies using medical subject heading words through 30 May 2013 and assessed relevant review articles and original studies. Only double-blind, randomized, controlled trials and meta-analyses of double-blind, randomized, controlled trials were included. The review of articles and data extraction were performed by 2 independent authors, with any disagreements resolved by consensus.

RESULTS

Garlic supplementation reduced blood pressure by 7-16 mm Hg (systolic) and 5-9 mm Hg (diastolic) (4 meta-analyses and 2 original studies). It reduced total cholesterol by 7.4-29.8 mg/dL (8 meta-analyses). The most consistent benefits were shown in studies that used aged garlic extract (AGE). A few small studies that used AGE also showed favorable effects on CAC, CRP, and PWV. Although garlic is generally safe, rare adverse reactions have been documented with limited causality established.

CONCLUSION

We conclude that garlic supplementation has the potential for cardiovascular protection based on risk factor reduction (hypertension and total cholesterol) and surrogate markers (CRP, PWV, and CAC) of atherosclerosis. Larger studies are warranted to evaluate these effects further.

Effect of garlic powder consumption on body composition in patients with nonalcoholic fatty liver disease: A randomized, double-blind, placebo-controlled trial

Background:

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease that is becoming a public health problem in recent decades. Obesity and overweight play a key role in NAFLD pathogenesis. Thus, weight loss (especially body fat mass) is one component of therapeutic strategies in NAFLD. Results from experimental studies have shown that garlic (Allium sativum L.) can reduce body weight and body fat mass. However, the effect of garlic on body fat mass and weight in the human population, which is addressed in this study, is still obscure.

Materials and Methods:

In this clinical trial, 110 subjects with NAFLD were randomly assigned to the intervention or the control group. The intervention group received two garlic tablets (containing 400 mg of garlic powder) daily while the control group received placebo tablets. Dietary intake and physical activity of participants were obtained by a validated questionnaire. Body composition was measured by bioelectrical impedance analysis. Data were analyzed using SPSS software version 16.

Results:

In the intervention group, significant reductions were observed in body weight and body fat mass (P < 0.05). We also observed a significant reduction in body weight in the control group, but there were no significant changes in total body water and lean body mass in both groups (P > 0.05). In the intervention group, the percentage change in body weight was significantly greater than the control group (−2.6 vs. −0.7, P = 0.02). No serious side effects associated with the intervention were reported.

Conclusion:

Our trial suggests that garlic supplemfrom experimental studies have shown thatentation can reduce body weight and fat mass among subjects with NAFLD.

Ursolic Acid-induced elevation of serum irisin augments muscle strength during resistance training in men

Ursolic acid (UA), a type of pentacyclic triterpenoid carboxylic acid purified from natural plants, can promote skeletal muscle development. We measured the effect of resistance training (RT) with/without UA on skeletal muscle development and related factors in men. Sixteen healthy male participants (age, 29.37±5.14 years; body mass index=27.13±2.16 kg/m²) were randomly assigned to RT (n=7) or RT with UA (RT+UA, n=9) groups. Both groups completed 8 weeks of intervention consisting of 5 sets of 26 exercises, with 10~15 repetitions at 60~80% of 1 repetition maximum and a 60~90-s rest interval between sets, performed 6 times/week. UA or placebo was orally ingested as 1 capsule 3 times/day for 8 weeks. The following factors were measured pre-and post-intervention: body composition, insulin, insulin-like growth factor-1 (IGF-1), irisin, and skeletal muscle strength. Body fat percentage was significantly decreased (p<0.001) in the RT+UA group, despite body weight, body mass index, lean body mass, glucose, and insulin levels remaining unchanged. IGF-1 and irisin were significantly increased compared with baseline levels in the RT+UA group (p<0.05). Maximal right and left extension (p<0.01), right flexion (p<0.05), and left flexion (p<0.001) were significantly increased compared with baseline levels in the RT+UA group. These findings suggest that UA-induced elevation of serum irisin may be useful as an agent for the enhancement of skeletal muscle strength during RT.

Effects of aged garlic extract and endurance exercise on skeletal muscle FNDC-5 and circulating irisin in high-fat-diet rat models

BACKGROUND/OBJECTIVES

Irisin, a newly identified hormone, is associated with energy homeostasis. We investigated whether aged garlic extract (AGE) and exercise training intervention could improve body weight, insulin sensitivity, skeletal muscle fibronectin domain containing protein 5 (FNDC-5) levels, and plasma irisin in high-fat diet (HFD).

MATERIALS/METHODS

Male Sprague Dawley rats were fed a ND (normal diet, n = 5) or HFD (n = 28) for 6 weeks. After 6 weeks, all rats were divided into 5 groups for the next 4 weeks: ND, (normal diet, n = 5), HFD (high-fat diet, n = 7), HFDA (high-fat diet + aged garlic extract, n = 7), HFDE (high-fat diet + exercise, n = 7), and HFDEA (high-fat diet + exercise + aged garlic extract, n = 7). Exercise groups performed treadmill exercises for 15-60 min, 5 days/week, and AGE groups received AGE (2.86 g/kg, orally injected) for 4 weeks.

RESULTS

Significant decreases in body weight were observed in the ND, HFDE, and HFDEA groups, as compared with the HFD group. Neither intervention affected the masses of the gastrocnemius muscle or liver. There were no significant differences in glucose levels across the groups. The homeostatic model assessments of insulin resistance were significantly higher in the HFD group, as compared with the ND, HFDA, HFDE, and HFDEA groups. However, skeletal muscle FNDC-5 levels and plasma irisin concentrations were unaffected by AGE or exercise in obese rats. AGE supplementation and exercise training did not affect skeletal muscle FNDC-5 or plasma irisin, which are associated with insulin sensitivity in obese rats.

CONCLUSION

Our results suggest that the protection against HFD-induced increases in body fat/weight and insulin resistance that are provided by AGE supplementation and exercise training may not be mediated by the regulation of FNDC-5 or irisin.