The effects of garlic extract upon endothelial function, vascular inflammation, oxidative stress and insulin resistance in adults with type 2 diabetes at high cardiovascular risk. A pilot double blind randomized placebo controlled trial

LDL-Cholesterol-Lowering Effects of a Dietary Supplement Containing Onion and Garlic Extract Used in Healthy Volunteers

Hypercholesterolemia plays a pivotal role in the development and progression of cardiovascular diseases, and its prevention seems to be a crucial healthcare strategy to ameliorate these conditions. Subjects with mild hypercholesterolemia are frequently advised against using cholesterol-lowering drugs due to potential side effects, with an emphasis instead on prioritizing dietary adjustments and lifestyle modifications as the primary strategy. In this context, the use of dietary supplements based on medicinal plants may be recommended as a complementary approach to managing elevated cholesterol levels. The aim of this study was to investigate the safety and potential therapeutic effectiveness of a standardized formulation containing extracts from garlic and onions in addressing the health concerns of individuals with slightly elevated cholesterol levels. A controlled, randomized, double-blind, two parallel-group study was conducted over 8 weeks, with clinical visits scheduled at baseline, weeks 2 and 4, as well as at the end of the study. The results revealed significant reductions in both low-density lipoprotein cholesterol and total cholesterol levels among participants who received the extract. Additionally, improvements in blood pressure, as well as in oxidative and inflammatory markers were observed, thus suggesting its potential as a valuable therapeutic intervention for managing mild hypercholesterolemia.

Randomized, double-blind clinical trial evaluating the impact of freeze-dried garlic extract capsules on blood pressure, lipid profile, and nitric oxide levels in individuals at risk for hypertension

OBJECTIVES

Hypertension, substantially heightens the risk of cardiovascular disease. This study aims to evaluate the effectiveness of freeze-dried garlic extract in blood pressure and lipid profiles in prehypertensive individuals.

METHODS

Participants (age of 30-70 years) were allocated to intervention (n=47) or control (n=49) groups. The intervention group received two capsules of freeze-dried garlic extract daily for eight weeks, while the control group received identical placebo capsules. Primary outcomes, SBP, DBP, PP, MAP, TC, TG, LDL and HDL levels, serum NO levels, were assessed at baseline, four weeks, and eight weeks.

RESULTS

At the end of study, results showed significant changes in the values of SBP, DBP, and MAP except for PP. In comparison to those who received the placebo, a significant drop in SBP, DBP (p<0.001), and MAP (p<0.001) was observed in the intervention group. Also, there were significant changes in TG, LDL, TC, and HDL levels in the interventional group. A noticeable decline was reported in TG (p<0.001), LDL (p<0.001), and TC (p<0.001), while HDL levels increased (p<0.001) in the intervention group compared to those receiving the placebo. Following garlic supplementation, a significant increase in blood NO levels was reported in the intervention group (p<0.001).

CONCLUSIONS

The study showed that garlic supplementation was effective in lowering blood pressure, improving lipid profile, and increasing nitric oxide levels in prehypertensive participants. These results indicate that garlic could be a valuable complementary therapy for managing prehypertension.

Effect of Encapsulated Purple Garlic Oil on Microvascular Function and the Components of Metabolic Syndrome: A Randomized Placebo-Controlled Study-The ENDOTALLIUM Study

Endothelial dysfunction (ED) is associated with progressive changes contributing to clinical complications related to macro- and microvascular diseases. Garlic (Allium sativum L.) and its organosulfur components have been related to beneficial cardiovascular effects and could improve endothelial function. The ENDOTALLIUM Study aimed to evaluate the effect of the regular consumption of encapsulated purple garlic oil on microvascular function, endothelial-related biomarkers, and the components of metabolic syndrome (MetS) in untreated subjects with cardiometabolic alterations. Fifty-two individuals with at least one MetS component were randomized (1:1) in a single-center, single-blind, placebo-controlled, parallel-group study. The participants received encapsulated purple garlic oil (n = 27) or placebo (n = 25) for five weeks. Skin microvascular peak flow during post-occlusive reactive hyperemia significantly increased in the purple garlic oil group compared to the placebo group (between-group difference [95%CI]: 15.4 [1.5 to 29.4] PU; p = 0.031). Likewise, hs-CRP levels decreased in the purple garlic group compared to the control group (-1.3 [-2.5 to -0.0] mg/L; p = 0.049). Furthermore, we observed a significant reduction in the mean number of MetS components in the purple garlic group after five weeks (1.7 ± 0.9 vs. 1.3 ± 1.1, p = 0.021). In summary, regular consumption of encapsulated purple garlic oil significantly improved microvascular function, subclinical inflammatory status, and the overall MetS profile in a population with cardiometabolic alterations.

Garlic oil improves small intestinal motility in experimentally induced type II diabetes mellitus in female Wistar rats

Diabetes mellitus adversely affects the contractile ability of the small intestine. However, there is a paucity of studies investigating the impact of garlic oil on small intestinal motility. This study aimed to evaluate the potential beneficial effects of garlic oil on type 2 diabetes mellitus in rats. Thirty-six adult female Wistar rats (n = 36) were divided into four groups: control, non-diabetic rats supplemented with garlic oil, diabetic rats, and diabetic rats treated with garlic oil. The rats were anesthetized using pentobarbitone (40 mg/kg BW); various motility parameters and oxidative markers were determined in small intestinal segments. Measurements were taken for naso-anal length, waist circumference, fasting blood glucose level (FBG), and plasma insulin level. Compared to the control group, the diabetic rats exhibited a reduction in the average force of contraction and motility index in all small intestinal segments. Furthermore, the rats exhibited a reduction in the average duration of muscle contraction only in the jejunum. The rats also exhibited hyperglycemia, insulin resistance, significant oxidative stress, and obesity. This was proven by changes in motility parameters, fasting blood glucose levels, HOMA-IR values, intestinal MDA levels, and waist circumference. The non-diabetic rats supplemented with garlic oil also exhibited a decrease in the average force of contraction and motility index in all small intestinal segments, despite having consistently higher Lee index and waist circumference values. However, the diabetic rats treated with garlic oil demonstrated improved small intestinal motility in nearly all small intestinal segments and a reduction in oxidative stress. In conclusion, rats with diabetes mellitus experienced a decrease in small intestinal motility, which is primarily driven by oxidative stress. Normal rats administered with garlic oil supplements exhibited similar effects. In contrast, garlic oil treatment in diabetic rats led to enhanced small intestinal motility and a notable anti-hyperglycemic effect, which can be attributed to the potent antioxidant properties of garlic oil.

Advances in the study of vascular related protective effect of garlic (Allium sativum) extract and compounds

Garlic (Allium sativum) is a functional food containing multiple bioactive compounds that find widespread applications in culinary and medicinal practices. It consists of multiple chemical components, including allicin and alliin. This article offers a comprehensive review of the protective effects of garlic extracts and their active constituents on the vascular system. In vitro and in vivo experiments have shown that garlic extracts and their active ingredients possess various bioactive properties. These substances demonstrate beneficial effects on blood vessels by demonstrating anti-inflammatory and antioxidant activities, inhibiting lipid accumulation and migration, preventing lipid peroxidation, promoting angiogenesis, reducing platelet aggregation, enhancing endothelial function, and inhibiting endothelial cell apoptosis. In clinical studies, garlic and its extracts have demonstrated their efficacy in managing vascular system diseases, including atherosclerosis, diabetes, and high cholesterol levels. In summary, these studies highlight the potential therapeutic roles and underlying mechanisms of garlic and its constituents in managing conditions like diabetes, atherosclerosis, ischemic diseases, and other vascular disorders.

Meta-analysis of the anti-oxidative and anti-inflammatory effects of hypoglycaemic plant-derived medicines

BACKGROUND

The pivotal role of oxidative stress and inflammation in the pathophysiology of type 2 diabetes mellitus (T2DM) has been firmly established. However, the evidence concerning hypoglycaemic medicinal plants' antioxidant and anti-inflammatory effects remains inconclusive due to inconsistencies in prior studies. To address this gap, our study aims to perform a comprehensive systematic review and meta-analysis of randomized controlled trials (RCTs) to consolidate previous research findings in this field.

METHODS

We conducted a comprehensive search in the PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases to identify relevant English randomized controlled trials (RCTs). Our study adhered to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. All eligible studies that evaluated concurrently the antioxidative and anti-inflammatory effects of hypoglycaemic plant-derived supplements on type 2 diabetes mellitus (T2DM) were included in the meta-analysis. The meta-analysis itself was carried out using both fixed and random effects models to synthesize the findings from the selected studies.

RESULTS

Our study included 47 trials with a total of 2636 participants, both male and female, aged between 20 and 79 years, diagnosed with prediabetes, type 2 diabetes mellitus (T2DM), or metabolic syndrome. The meta-analysis revealed that plant-derived treatments, compared to placebos or other medicines, significantly improved oxidative stress (SMD = - 0.36, 95% CI - 0.64 to - 0.09), inflammation (SMD = - 0.47, 95% CI - 0.63 to - 0.31), total antioxidant capacity (SMD = 0.46, 95% CI 0.16-0.75), and antioxidant enzyme activity (SMD = 1.80, 95% CI 1.26-2.33). The meta-regression analysis showed that treatment duration exceeding 8 weeks significantly impacted the heterogeneity of the oxidative stress data.

CONCLUSIONS

Several hypoglycaemic plant-based treatments appear to positively affect T2DM patients by concurrently lowering oxidative stress and inflammatory indicators and boosting antioxidant enzyme activity.

CLINICAL TRAIL REGISTRY

PROSPERO ID: CRD42021226147.

Effect of Black Garlic Consumption on Endothelial Function and Lipid Profile: A Before-and-After Study in Hypercholesterolemic and Non-Hypercholesterolemic Subjects

BACKGROUND

Black garlic is obtained from raw garlic (Allium sativum L.), by a fermentation process, under humidity and heat treatment, showing a high concentration of organosulfur compounds, which have been related to benefits in the prevention or delay of cardiovascular diseases (CVDs). The objective of the research was to evaluate whether long-term consumption of black garlic improves endothelial function and lipid profile in subjects with hypercholesterolemia.

METHODS

Single center, controlled clinical trial with two branches: Hypercholesterolemia vs. Healthy condition. Sixty-two subjects of both sexes were distributed in two groups, the hypercholesterolemia group (n = 31) (total cholesterol (TC) range 200-300 mg/dL and low-density lipoprotein (LDL)-cholesterol range 135-175 mg/dL) and the healthy group (n = 31). The intervention consisted of the ingestion of 4 cloves of black garlic (12 g) daily for 12 weeks.

RESULTS

significant increases in Apolipoprotein (Apo)A1 occurred in both groups: Hypercholesterolemia (Δ 11.8 mg/dL p < 0.001) vs Healthy (Δ 11.1 mg/dL p < 0.001). Besides, significant reductions for endothelial adhesion molecules monocyte chemoattractant protein-1 (MCP-1) (Δ -121.5 pg/mL p = 0.007 vs. Δ -56.3 pg/mL p = 0.015), intracellular adhesion molecule-1 (ICAM-1) (Δ -39.3 ng/mL p < 0.001 vs. Δ 63.5 ng/mL p < 0.001), and vascular cyto-adhesion molecule-1 (VCAM-1) (Δ -144.4 ng/mL p < 0.001 vs. Δ -83.4 ng/mL p = 0.061) were observed, for hypercholesterolemic and healthy subjects, respectively.

CONCLUSIONS

These data show that black garlic consumption could improve some parameters related to endothelial function and lipid profile, which may have a favorable impact on the risk of CVDs, although more long-term studies are necessary to confirm.

Asprosin Exacerbates Endothelium Inflammation Induced by Hyperlipidemia Through Activating IKKβ-NF-κBp65 Pathway

Vascular endothelium dysfunction caused by endothelium inflammation is a trigger of numerous cardiovascular diseases. Vascular endothelium inflammation often occurs in patients with obesity. Asprosin (ASP) derived from white adipose tissue plays important roles in maintaining glucose homeostasis. However, effect of ASP on the vascular endothelium inflammation induced by hyperlipidemia and its underlying mechanism remains largely unclear. In this study, models of vascular endothelium inflammation were established to investigate the effect of ASP on the endothelium inflammation both in vivo and in vitro. Our data in vivo showed that recombinant ASP or high-fat diet (HFD) significantly increased the circulating levels of IL-6 and TNF-α and enhanced the adhesion of macrophages to endothelia characterized by the expression increase of CD68, ICAM-1, and VCAM-1 in rats. However, neutralization of ASP with an ASP specific antibody (AASP) significantly antagonized the changes induced by HFD. Similarly, our data in vitro also showed that ASP treatment elevated the expressions of IL-6, TNF-α, and ICAM-1 as well as VCAM-1. More important, our data revealed that the pro-inflammation effect of ASP was achieved by activating the IKKβ-NF-κBp65 pathway other than the oxidative stress pathway both in vivo and in vitro. In conclusion, our results demonstrate that ASP is a pro-inflammation player in the obesity-associated endothelium dysfunction. The findings would provide a novel target for the prevention and treatment of obesity-related cardiovascular diseases.

The Use of Medicinal Plants in Blood Vessel Diseases: The Influence of Gender

Data available in the literature on the use of herbal products to treat inflammation-related vascular diseases were considered in this study, while also assessing the influence of gender. To this end, the articles published in PubMed over the past 10 years that described the use of plant extracts in randomized clinical trials studying the effectiveness in vascular pathologies were analyzed. The difference in efficacy of plant-derived preparations in female and male subjects was always considered when reporting. The safety profiles of the selected plants were described, reporting unwanted effects in humans and also by searching the WHO database (VigiBase^®). The medicinal plants considered were Allium sativum, Campomanesia xanthocarpa, Sechium edule, Terminalia chebula. Additionally, an innovative type of preparation consisting of plant-derived nanovesicles was also reported.

A review on the effect of garlic on diabetes, BDNF, and VEGF as a potential treatment for diabetic retinopathy

BACKGROUND

Garlic is one of the favorite herbs in traditional medicine that has been reported to have many medicinal features. The aim of the current study is to review the latest documents on the effect of garlic on diabetes, VEGF, and BDNF and, finally, to review the existing studies on the effect of garlic on diabetic retinopathy.

MAIN TEXT

The therapeutic effect of garlic on diabetes has been investigated in various studies. Diabetes, especially in advanced stages, is associated with complications such as diabetic retinopathy, which is caused by the alteration in the expression of molecular factors involved in angiogenesis, neurodegeneration, and inflammation in the retina. There are different in-vitro and in-vivo reports on the effect of garlic on each of these processes. Considering the present concept, we extracted the most related English articles from Web of Science, PubMed, and Scopus English databases from 1980 to 2022. All in-vitro and animal studies, clinical trials, research studies, and review articles in this area were assessed and classified.

RESULT AND CONCLUSION

According to previous studies, garlic has been confirmed to have beneficial antidiabetic, antiangiogenesis, and neuroprotective effects. Along with the available clinical evidence, it seems that garlic can be suggested as a complementary treatment option alongside common treatments for patients with diabetic retinopathy. However, more detailed clinical studies are needed in this field.

Evaluation of clinical trials of ethnomedicine used for the treatment of diabetes: A systematic review

Diabetes mellitus (DM) is a widespread metabolic disorder with a yearly 6.7 million deaths worldwide. Several treatment options are available but with common side effects like weight gain, cardiovascular diseases, neurotoxicity, hepatotoxicity, and nephrotoxicity. Therefore, ethnomedicine is gaining the interest of researchers in the treatment of DM. Ethnomedicine works by preventing intestinal absorption and hepatic production of glucose as well as enhancing glucose uptake in muscles and fatty tissues and increasing insulin secretion. A variety of plants have entered clinical trials but very few have gained approval for use. This current study provides an evaluation of such clinical trials. For this purpose, an extensive literature review was performed from a database using keywords like "ethnomedicine diabetes clinical trial", "clinical trials", "clinical trial in diabetes", "diabetes", "natural products in diabetes", "ethno-pharmacological relevance of natural products in diabetes", etc. Clinical trials of 20 plants and natural products were evaluated based on eligibility criteria. Major limitations associated with these clinical trials were a lack of patient compliance, dose-response relationship, and an evaluation of biomarkers with a small sample size and treatment duration. Measures in terms of strict regulations can be considered to achieve quality clinical trials. A specific goal of this systematic review is to discuss DM treatment through ethnomedicine based on recent clinical trials of the past 7 years.

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.

Natural Products in Cardiovascular Diseases: The Potential of Plants from the Allioideae Subfamily (Ex-Alliaceae Family) and Their Sulphur-Containing Compounds

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide and, together with associated risk factors such as diabetes, hypertension, and dyslipidaemia, greatly impact patients' quality of life and health care systems. This burden can be alleviated by fomenting lifestyle modifications and/or resorting to pharmacological approaches. However, due to several side effects, current therapies show low patient compliance, thus compromising their efficacy and enforcing the need to develop more amenable preventive/therapeutic strategies. In this scenario, medicinal and aromatic plants are a potential source of new effective agents. Specifically, plants from the Allioideae subfamily (formerly Alliaceae family), particularly those from the genus Allium and Tulbaghia, have been extensively used in traditional medicine for the management of several CVDs and associated risk factors, mainly due to the presence of sulphur-containing compounds. Bearing in mind this potential, the present review aims to gather information on traditional uses ascribed to these genera and provide an updated compilation of in vitro and in vivo studies validating these claims as well as clinical trials carried out in the context of CVDs. Furthermore, the effect of isolated sulphur-containing compounds is presented, and whenever possible, the relation between composition and activity and the mechanisms underlying the beneficial effects are pointed out.

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.

Antioxidant Interactions between S-allyl-L-cysteine and Polyphenols Using Interaction Index and Isobolographic Analysis

This work aims to study the antioxidant interactions between S-allyl-L-cysteine (SAC) and six natural polyphenols (quercetin, caffeic acid, sinapic acid, catechin, ferulic acid, and 3,4-dihydroxybenzoic acid) through the measurement of free-radical-scavenging activity of 1,1-diphenyl- 2-picryl-hydrazyl (DPPH), the radical-cation-scavenging activity of 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and reducing power. Among the six natural polyphenols, caffeic acid showed the strongest synergistic effect with SAC according to DPPH and reducing power assays. Further investigations based on the results of interaction index and isobologram analysis showed that the antioxidant activity (DPPH, ABTS, and reducing power) of the combination of caffeic acid with SAC presented an increase with the raising of their individual concentrations in their mixture and along with a dose–response manner. The best synergistic effect between caffeic acid and SAC based on DPPH, ABTS, and reducing power assays were observed at the ratio of 1:20, 1:35, and 1:70, respectively. The excellent synergic antioxidant activity of the combination of caffeic acid with SAC in our study suggests SAC has a more broad and effective application prospects in food field.

Evaluating the effects of dark chocolate formulated with micro-encapsulated fermented garlic extract on cardio-metabolic indices in hypertensive patients: A crossover, triple-blind placebo-controlled randomized clinical trial

This study aimed to investigate the health-related effects of microencapsulated fermented garlic extract (FGE) containing dark chocolate in hypertensive adults. For this purpose, 36 hypertensive adults (15 males vs. 21 females) were randomized to receive the FGE (5 g/day) dark chocolate containing 650 mg of FGE powder or the placebo. Intervention periods lasted for 6 weeks and were separated by a 3-week wash-out period. The response variables included blood pressure, anthropometric indices, lipid profile, and inflammatory and oxidative stress indices. Statistical analyses were performed using the Pkcross procedure, and Cohen's d was estimated for all response variables. There was no significant inter-period difference between the mean changes of body weight, waist circumference, and body mass index (BMI). Furthermore, no significant change was confirmed in participants' blood pressure, triglycerides, total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), very low-density lipoprotein (VLDL), serum homocysteine, high-sensitive c-reactive protein (hs-CRP), malondialdehyde (MDA), and total antioxidant capacity (TAC). It seems that the dose of FGE used in this study was not sufficient to cause any significant changes in the outcomes. Therefore, further studies with dose-response designs and longer durations are recommended.

Garlic: A systematic review of the effects on cardiovascular diseases

Allium sativum (garlic) certainly is one of the oldest horticultural crops in the world and presents bioactive compounds that are related to the garlic's effects on human health. Several authors have shown beneficial effects on diabetes, hypertension, dyslipidemia, obesity, and cardiovascular diseases (CVD), which are among the most relevant causes of mortality in the world. The aim of this systematic review was to evaluate the effects of garlic in the risk factors of CVD and evaluate its economic importance. MEDLINE-PubMed, COCHRANE, EMBASE, and Google Scholar databases were searched. The included studies showed that the use of garlic can reduce blood pressure, waist circumference, body mass index, LDL-c, non-HDL-c, total cholesterol, triglycerides, and inflammatory markers. It also can increase the levels of HDL-c and can improve cardiovascular parameters such as coronary artery calcium, microcirculation, epicardial and periaortic adipose tissue, post occlusive reactive hyperemia, low attenuation plaque, carotid intima-media thickness; and carotid intima-media thickness. Due to these reasons, garlic can be considered in the prevention and treatment of CVD risk factors.

Effects of Nigella sativa, Camellia sinensis, and Allium sativum as Food Additives on Metabolic Disorders, a Literature Review

Objective: Metabolic disorders (MD) can disturb intracellular metabolic processes. A metabolic disorder can be resulted from enzyme deficits or disturbances in function of various organs including the liver, kidneys, pancreas, cardiovascular system, and endocrine system. Some herbs were used traditionally for spices, food additives, dietary, and medicinal purposes. Medicinal plants possess biological active compounds that enhance human health. We aimed to provide evidence about therapeutic effects of some medicinal herbs on MD.

Data Sources: PubMed, Scopus, and Google Scholar were explored for publications linked to MD until February 2021. The most literature reports that were published in the last 10 years were used. All types of studies such as animal studies, clinical trials, and in vitro studies were included. The keywords included “Metabolic disorders,” “Nigella sativa L.,” “Thymoquinone,” “White tea”OR “Camellia sinensis L.” “catechin,” and “Allium sativum L.” OR “garlic” were searched.

Results: Based on the results of scientific studies, the considered medicinal plants and their active components in this review have been able to exert the beneficial therapeutic effects on obesity, diabetes mellitus and non-alcoholic fatty liver disease.

Conclusions: These effects are obvious by inhibition of lipid peroxidation, suppression of inflammatory reactions, adjustment of lipid profile, reduction of adipogenesis and regulation of blood glucose level.

Bioactive Foods and Medicinal Plants for Cardiovascular Complications of Type II Diabetes: Current Clinical Evidence and Future Perspectives

Cardiovascular diseases (CVDs) are the main cause of mortality in type 2 diabetes mellitus (T2DM); however, not all patients are fully satisfied with the current available treatments. Medicinal plants have been globally investigated regarding their effect in CVD, yet the field is far from getting exhausted. The current paper aims to provide an evidence-based review on the clinically evaluated medicinal plants and their main therapeutic targets for the management of CVD in T2DM. Electronic databases including PubMed, Cochrane, Embase, Scopus, and Web of Science were searched from 2000 until November 2019, and related clinical studies were included. Lipid metabolism, glycemic status, systemic inflammation, blood pressure, endothelial function, oxidative stress, and anthropometric parameters are the key points regulated by medicinal plants in T2DM. Anti-inflammatory and antioxidant properties are the two most important mechanisms since inflammation and oxidative stress are the first steps triggering a domino of molecular pathological pathways leading to T2DM and, subsequently, CVD. Polyphenols with potent antioxidant and anti-inflammatory effects, essential oil-derived compounds with vasorelaxant properties, and fibers with demonstrated effects on obesity are the main categories of phytochemicals beneficial for CVD of T2DM. Some medicinal plants such as garlic (Allium sativum) and milk thistle (Silybum marianum) have strong evidences regarding their beneficial effects; however, others have low level of evidence which reveals the need for further clinical studies with larger sample sizes and longer follow-up periods to confirm the safety and efficacy of medicinal plants for the management of CVD in T2DM.

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.

Evaluation of clinical trials for natural products used in diabetes: An evidence-based systemic literature review

BACKGROUND RELEVANCE

A plethora of literature is available regarding the clinical trials for natural products however; no information is available for critical assessments of the quality of these clinical trials.

AIM OF STUDY

This is a first time report to critically evaluate the efficacy, safety and large scale applications of up-to-date clinical trials for diabetes, based on the three scales of Jadad, Delphi, and Cochrane.

METHODOLOGY

An in-depth and extensive literature review was performed using various databases, journals, and books. The keywords searched included, "clinical trials," "clinical trial in diabetes," "diabetes," "natural products in diabetes," "ethnopharmacological relevance of natural products in diabetes," etc.

RESULTS

Based on eligibility criteria, 16 plants with 74 clinical trials were found and evaluated. Major drawbacks observed were; "non-randomization and blindness of the studies," "non-blindness of patients/healthcare/outcome assessors," "lack of patient compliance and co-intervention reports," "missing information regarding drop-out/withdrawal procedures," and "inappropriate baseline characteristics." Principal component analysis and Pearson correlation revealed four components with %variability; PC1: 23.12, PC2: 15.83, PC3: 13.11, and PC4: 11.38 (P ≤ .000). According to descriptive statistics, "non-blinding of outcome assessors" was the major drawback (82%) whereas, "not mentioning the timing of outcome assessment" was observed lowest (6.8%). An in-house quality grading (scale 0-24) classified these clinical trials as; poor (67.6%), acceptable (19.9%), and good quality trials (13.5%).

CONCLUSION

Proper measures in terms of more strict regulations with pharmacovigilance of plants are utmost needed in order to achieve quality compliance of clinical trials.

From the distinctive smell to therapeutic effects: Garlic for cardiovascular, hepatic, gut, diabetes and chronic kidney disease

Garlic, a member of the Allium family, widely used in cooking for many centuries, displays well described antioxidant and anti-inflammatory properties, as a result of its constituent organosulfur compounds, such as alliin, allicin, ajoene S-allyl-cysteine, diallyl sulfide and diallyl disulfide, among others. Although garlic has demonstrated beneficial effects in cardiovascular disease, diabetes, and cancer, its efficacy as a therapeutic intervention in chronic kidney disease remains to be proven. This review thus focuses on the potential benefits of garlic as a treatment option in chronic kidney disease. and its ability to mitigate associated cardiovascular complications and gut dysbiosis.

Exploring Phytotherapeutic Alternatives for Obesity, Insulin Resistance and Diabetes Mellitus

At present, the pathologic spectrum of obesity-insulin resistance (IR)-diabetes mellitus (DM) represents not only a pressing matter in public health but also a paramount object of study in biomedical research, as they constitute major risk factors for cardiovascular disease (CVD), and other chronic non-communicable diseases (NCD). Phytotherapy, the use of medicinal herbs (MH) with treatment purposes, offers a wide array of opportunities for innovation in the management of these disorders; mainly as pharmacological research on small molecules accumulates. Several MH has displayed varied mechanisms of action relevant to the pathogenesis of obesity, IR and DM, including immunological and endocrine modulation, reduction of inflammation and oxidative stress (OS), regulation of appetite, thermogenesis and energy homeostasis, sensitisation to insulin function and potentiation of insulin release, among many others. However, the clinical correlates of these molecular phenomena remain relatively uncertain, with only a handful of MH boasting convincing clinical evidence in this regard. This review comprises an exploration of currently available preclinical and clinical research on the role of MH in the management of obesity, IR, and DM.

Types of garlic and their anticancer and antioxidant activity: a review of the epidemiologic and experimental evidence

Garlic, an Allium vegetable, contains rich flavonoids organosulfur compounds (OSCs) that have potent anticancer properties. The aim of the review is to provide an overview of the different types of garlic, their active compounds, and the potential anticancer benefits with a focus on antioxidant activity. Animal and cell line studies have provided convincing evidence that garlic and its organosulfur compounds inhibit carcinogenesis through a number of events including induction of apoptosis, inhibiting cellular proliferation, scavenging radical oxygen species (ROS), increasing the activities of enzymes such as glutathione S-transferase, and reducing tumor size. Epidemiological studies showed compelling evidence that garlic consumption is associated with decreased risk of colorectal cancer, but inconsistent evidence for stomach, breast, and prostate cancers. Studies also suggest that the presence and potency of garlic OSCs varies with respect to the preparation and form of garlic. Further epidemiological studies with information on garlic form consumed or preparation methods and molecular studies regarding its antioxidant mechanisms, such as increasing enzymatic and nonenzymatic antioxidants levels, 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.

Medicinal Plants and Phytochemicals Regulating Insulin Resistance and Glucose Homeostasis in Type 2 Diabetic Patients: A Clinical Review

Diabetes is a major health problem affecting more than four hundred million adults worldwide. The transition from normal glucose tolerance to type 2 diabetes (T2D) is preceded by increased Insulin resistance (IR), an independent predictor of the development of T2D in high risk (e.g. obese populations, pre-diabetes) individuals. Insulin deficiency resulting from increased IR results in progressive glucose homeostasis dysfunction. Data has shown that IR is affected by many different factors such as genetics, age, exercise, dietary nutrients, obesity, and body fat distribution. One of the most important factors is diet, which plays an essential role in addressing T2D and metabolic syndrome. Nutraceuticals and medicinal plants have been shown to have efficacy in preventing chronic diseases like cancer, non-alcoholic fatty liver disease (NAFLD), cardiovascular disease, diabetes mellitus and metabolic syndrome, likely through the anti-inflammatory properties found in nutraceuticals. However, the effect of these compounds, including traditional plant medicines, herbal formulations or their extracts on IR have not been systematically investigated. The objective of this review was to assess the reported effects of medicinal plants and bioactive natural compounds on IR. The findings confirm that most of the herbal bioactive compounds including resveratrol, garlic, curcumin, cinnamon, ginger, nuts, berberine, anthocyanin, soybean, flaxseed, vegetable oils, and soluble fibers have benefit in their efficacy for decreasing IR, fasting blood sugar (FBS), fasting insulin and HbA1c.

Effects of garlic supplementation on serum inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Previous studies have indicated that garlic consumption may be beneficial in improving inflammation. This systematic review and meta-analysis aimed to examine the effect of garlic supplementation on inflammatory biomarkers.

METHODS

PubMed/Medline, Scopus and ISI web of science were searched up to February 2019. Random effects model was used to calculate the overall effects on C-reactive protein (CRP), Interleukin-6 (IL-6), and Tumor necrosis factor- α (TNF-α).

RESULTS

17 randomized controlled trials (RCTs) were included in the meta-analyses. Garlic supplementation significantly reduced the level of circulating CRP (P < 0.05), whereas it did not have any significant effect on IL-6 level (p > 0.05). Sub-group analysis showed that aged garlic extract (AGE) was able to reduce CRP and TNF-α significantly (P < 0.05).

CONCLUSIONS

This meta-analysis showed that supplementation with garlic could reduce the level of circulating CRP and AGE could reduce the level of TNF-α and CRP, whereas it had no significant effect on the IL-6 level.

Potential Health Benefit of Garlic Based on Human Intervention Studies: A Brief Overview

Garlic is a polyphenolic and organosulfur enriched nutraceutical spice consumed since ancient times. Garlic and its secondary metabolites have shown excellent health-promoting and disease-preventing effects on many human common diseases, such as cancer, cardiovascular and metabolic disorders, blood pressure, and diabetes, through its antioxidant, anti-inflammatory, and lipid-lowering properties, as demonstrated in several in vitro, in vivo, and clinical studies. The present review aims to provide a comprehensive overview on the consumption of garlic, garlic preparation, garlic extract, and garlic extract-derived bioactive constituents on oxidative stress, inflammation, cancer, cardiovascular and metabolic disorders, skin, bone, and other common diseases. Among the 83 human interventional trials considered, the consumption of garlic has been reported to modulate multiple biomarkers of different diseases; in addition, its combination with drugs or other food matrices has been shown to be safe and to prolong their therapeutic effects. The rapid metabolism and poor bioavailability that have limited the therapeutic use of garlic in the last years are also discussed.

Effect of a Combination of Citrus Flavones and Flavanones and Olive Polyphenols for the Reduction of Cardiovascular Disease Risk: An Exploratory Randomized, Double-Blind, Placebo-Controlled Study in Healthy Subjects

A single-center, randomized, double-blind controlled trial was conducted to assess the efficacy of a food supplement based on a combination of grapefruit, bitter orange, and olive extracts administered for eight weeks (n = 51) versus placebo (n = 45) on reduction of cardiovascular risk in healthy volunteers. Study variables included flow-mediated vasodilation (FMD), blood pressure (BP), lipid profile, thrombotic status, oxidative stress biomarkers, inflammation-related biomarkers, anthropometric variables, quality of life, and physical activity. The per-protocol data set was analyzed. In the active product group, there were statistically significant within-group differences at eight weeks as compared with baseline in FMD, systolic and diastolic BP, total cholesterol, LDL-C, LDL-oxidase, oxidized/reduced glutathione ratio, protein carbonyl, and IL-6. Significant between-group differences in these variables were also found. Significant changes in anthropometric variables and quality of life were not observed in the study groups. Changes in the level of physical activity were not recorded. Treatment with the active product was well tolerated. All these findings, taken together, support a beneficial effect of supplementation with a mixture of grapefruit, bitter orange fruits, and olive leaf extracts on underlying mechanisms that may interact each other to decrease the cardiovascular risk in healthy people.

Comparison Among Garlic, Berberine, Resveratrol,Hibiscus sabdariffa, GenusZizyphus, Hesperidin, Red Beetroot,Catha edulis,Portulaca oleracea, and Mulberry Leaves in the Treatment of Hypertension and Type 2 DM: A Comprehensive Review

Diabetes mellitus (DM) and hypertension are 2 of the most prevalent diseases with poor impact on health status worldwide. In most cases, they coexist with other metabolic disorders as well as cardiac, micro- and macrovascular complications. Many plants are known for their hypotensive, cardioprotective, and/or antidiabetic activities. Their active ingredients either identified and isolated or still utilized as herbal preparations of certain plant parts. The use of medicinal plants comprises the main basis for most of the traditional medicine (TM) systems and procedures. As conventional medicines seem insufficient to control such progressive diseases, herbal agents from TM could be used as adjuvant with good impact on disease control and progression as well as other concomitant health conditions. The aim of this study is to compare the efficacy of 10 different herbal medicines of botanical origin or herbal preparations in the management of hypertension and its cardiovascular complications and type 2 DM along with various coexisting health disorders. These herbal medicines are garlic, berberine, resveratrol, Hibiscus sabdariffa, Zizyphus ( oxyphylla, mucronate, jujube, rugosa), hesperidin, red beetroot, Catha edulis, mulberry leaves, and Portulaca oleracea.

The effect of diet on oxidative stress and metabolic diseases-Clinically controlled trials

Oxidative stress is associated with several chronic diseases. It is acknowledged that molecules damaged by reactive oxygen species activate the inflammatory process and that this response increases the production of free radicals. Modifications in a diet can improve or decrease redox state markers. The aim of this revision was to provide an update of clinical controlled trials, to assess changes in diet and markers of oxidative stress in subjects with metabolic diseases. They were investigated randomized controlled intervention studies (RCTs) published in MEDLINE (U.S. National Library of Medicine, National Institutes of Health) that were conducted in subjects with obesity, hypertension, diabetes, or dyslipidemia; with dietary intervention; where markers of oxidative stress have been evaluated and published in the last 5 years. Food antioxidants, hypocaloric diets with loss of adipose tissue, substitution of animal protein by vegetable, and changes in the microbiota improve antioxidant status in people with chronic disease. PRACTICAL APPLICATIONS: Hyperglycemia in diabetes mellitus and adipose tissue in obesity are known to trigger oxidative stress. Oxidative stress, in turn, decreases insulin sensitivity and favors an inflammatory state producing adhesion molecules. Oxidative stress and adhesion molecules, can increase blood pressure and oxidation of lipoproteins, that ultimately could lead to a cerebrovascular event. Consumption of high-antioxidant and polyphenol foods increases plasma antioxidant capacity and decreases oxidative stress markers in people with diabetes, obesity, hypertension, and hypertriglyceridemia. In addition, weight loss caused by caloric restriction with or without exercise increases the endogenous antioxidant capacity. Therefore, it is likely that the combination of a hypocaloric diet with a high content of antioxidants and polyphenols will have a greater effect. Other dietary changes with antioxidant effect, such as the substitution of animal for vegetable protein or the addition of fiber, might be mediated by changes in the microbiota. However, this aspect requires further study.

The effect of garlic on vascular function: A systematic review of randomized clinical trials

BACKGROUNDS AND AIMS

Atherosclerosis and its associated cardiovascular disease (CVD) represent a major global health problem worldwide and vascular dysfunction is important in its pathogenesis. Clinical trials investigating the effect of garlic on vascular function measured by several non-invasive methods and their results are inconsistent. This study aimed to summarize the current evidence regarding the effectiveness of garlic as one of the world's most ancient medicines on measures of vascular reactivity and/or stiffness in adults.

METHODS

All published RCTs in English were systematically searched on PubMed, Scopus and Google Scholar search engines up to Oct 2019. The exposure and outcome variable of interest were garlic and vascular function measurements. Ten trials which met inclusion criteria were included in this study.

RESULTS

A total of 45 studies were found through search databases. After excluding duplicates, the 25 remaining studies were screened by title and abstract which 15 of them excluded. Finally, ten trials were included in this review study, which were published between 2004 and 2018.

CONCLUSIONS

Findings were inconsistent. However, garlic has the potential to improve vascular function, particularly in subjects with cardiovascular risk factors. Additional human studies on garlic and its constituents should consider the population and the specific type of garlic preparation.

Effect of garlic intake on inflammatory mediators: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Garlic is a species in the onion genus, Allium. Data have shown that garlic has anti-inflammatory activity; however, the findings are inconclusive and inconsistent. We aimed to evaluate the impact of garlic intake on inflammatory mediators through systematic review and meta-analysis of existing data.

METHODS

Electronic databases were completely investigated using databases of ISI Web of Science, Medline, Scopus, Cochrane Library and EMBASE until October 2019. A random effects model and the generic reverse variance procedure were used for quantitative data production. Sensitivity analyses and prespecified subgroup were done to evaluate potential heterogeneity. Random effect meta-regression was conducted to investigate the effects of possible confounders on the assessed effect size.

RESULTS

Ten trials with one observational study, including 530 participants, met the eligibility criteria. The findings showed reduction in the tumour necrosis factor alpha (TNF-α) (-0.31 pg/mL, 95% CI -1.07 to 0.46) and C reactive protein (CRP) levels (-0.20 mg/L, 95% CI -1.4 to 1.05) following supplementation with garlic, although it had no marked impact on the interleukin 6 (IL-6) level (0.37 pg/mL, 95% CI -0.58 to 1.33). In the subgroup analysis, we found that garlic supplementation significantly decreased TNF-α, highly sensitive CRP and IL-6 levels in subgroups of >8, >6 and ≥4 weeks of intervention duration, respectively, and dose of garlic consumption between 2 and 2.4 g/day.

CONCLUSION

These findings suggested that current evidence may support garlic as an adjunct to pharmacological management of metabolic diseases.

PROSPERO REGISTRATION NUMBER

CRD42018108816.

An evaluation of randomized controlled trials on nutraceuticals containing traditional Chinese medicines for diabetes management: a systematic review

BACKGROUND

Nutraceuticals containing traditional Chinese medicine (TCM) are promoted for use in the management of diabetes. The evidence to support such use is largely unknown. This study aimed to summarise and evaluate the literature reporting the results of randomized controlled trials (RCTs) investigating the effects of nutraceuticals in people living with diabetes.

METHODS

Literature from four electronic databases (PubMed, Scopus, CINAHL and Web of Science) was searched following PRISMA guidelines to yield RCT publications on nutraceutical for diabetes management published since 2009. The quality of reporting was assessed using the CONSORT 2010 checklist statement. Risk-of-bias for each study was assessed using the Cochrane risk of bias tool.

RESULTS

Out of 1978 records identified in the initial search, 24 randomized, double/triple-blinded, controlled trials that investigated the effect of nutraceuticals covering 17 different TCM herbs for diabetes management were selected. Participants included people who were diabetic (n = 16), pre-diabetic (n = 3) or predisposed to diabetes (n = 5). Sample sizes ranged between 23 and 117 for 2 arms, or 99-165 for 3 arms. Comparisons were made against placebo (n = 22), conventional medicine (n = 1), or regular diet (n = 1) for a duration between 4 and 24 weeks. All but one study tested the effect on fasting blood glucose levels (n = 23) or glycated haemoglobin levels (n = 18), and/or postprandial 2-h blood glucose levels (n = 4) as the primary outcomes. Nineteen studies reported some statistically significant reductions in the respective measures while 5 studies showed no effect on primary or secondary outcomes. None of the included studies met all the criteria for the CONSORT guidelines. Incomplete reporting about randomization and blinding, and a lack of ancillary analyses to explore other influential factors and potential harms associated with the use were repeatedly noted. Based on the Cochrane risk-of-bias tool, 19 studies were deemed to have a high risk of bias mainly attributed to sponsor bias.

CONCLUSIONS

There is some evidence to suggest positive clinical outcomes in response to the administration of a range of nutraceuticals containing TCM in the management of diabetes. However, these results must be interpreted with caution due to the overall low quality of the trials.

Oxidative Stress Indexes for Diagnosis of Health or Disease in Humans

Oxidative stress (OS) is the imbalance between oxidant and antioxidant molecules, in favor of oxidants, that causes aging and disease. Many studies have been published that demonstrate the relationship between OS and human health and disease; however, the following questions arise: (i) how are we sure that the OS is present in a biological process? (ii) Is the OS reported in the different investigations equivalent? (iii) What are the best oxidant and antioxidant markers for OS diagnosis? (iv) Can we establish the types and the intensity of the OS? (v) Does OS index could be useful for research and/or application in clinical medicine? In this regard, several indexes have been proposed to measure OS in humans relative to the state of health and disease, among which the following can be highlighted: Oxidative Stress Index (OSI), Tiol Ratios (-SH/TT, -SS/-SH, and-SS/TT), Glutathione Ratio (GSSG/GSH), Oxidative Stress Score (OSS), and OXY-index. Therefore, the aim of this review is to present the state of the art of knowledge about OS indexes for diagnosis of health or disease in humans. We searched for articles in English or Spanish in the PubMed/MEDLINE and Scopus electronic databases published up until May 2019. The keywords used were “oxidative stress,” “index,” and “oxidative stress index.” It was identified 11479 records in both databases, and 490 articles were analyzed. Our review suggests that all indexes analyzed allow diagnose and differentiate the OS related to human health and disease. Also, the studies on OSI, Oxy-score, and OSS indexes have proven to be reliable, practical, and with clinical utility. However, it is necessary to continue with longitudinal studies, especially assess the usefulness of the indexes in the clinical prognosis, and make comparative studies between the different indexes.

Relation of Fruits and Vegetables with Major Cardiometabolic Risk Factors, Markers of Oxidation, and Inflammation

Noncommunicable diseases (NCDs) are considered to be the leading cause of death worldwide. Inadequate fruit and vegetable intake have been recognized as a risk factor for almost all NCDs (type 2 diabetes mellitus, cancer, and cardiovascular and neurodegenerative diseases). The main aim of this review is to examine the possible protective effect that fruit and vegetable consumption or their bioactive compounds may have on the development of NCDs such as atherosclerosis. The accumulated evidence on the protective effects of adequate consumption of fruits and vegetables in some cases, or the lack of evidence in others, are summarized in the present review. The main conclusion of this review is that well-designed, large-scale, long-term studies are needed to truly understand the role fruit and vegetable consumption or their bioactive compounds have in atherosclerosis.

Hepatoprotective and Renoprotective Properties of Lovastatin-Loaded Ginger and Garlic Oil Nanoemulsomes: Insights into Serum Biological Parameters

Background and Objectives: Dyslipidemia is gaining much attention among healthcare professionals because of its high association with the malfunctioning of a number of normal physiological and metabolic processes in the body. Obesity is directly interconnected with dyslipidemia and is said to be a denouement of hyperlipidemia and, if left untreated, may lead to intense damage to organs that are directly involved in fat metabolism. The objective of this study was to investigate the synergistic antiobesity and anti-hyperlipidemic activities along with hepato- and renoprotective potential of nanoemulsomes (NES) of lovastatin (LTN)-loaded ginger (GR) and garlic (GL) oils. Materials and Methods: LTN nanoemulsomes co-encapsulated with GR oil and GL oil were prepared by a thin hydration technique. Eight-week-old male Wistar rats weighing 200-250 g were induced with hyperlipidemia via a high-fat diet (HFD) comprising 40% beef tallow. Body weight, serum biochemical lipid parameters, and those for liver and kidney functions, serum TC, LDL-C, vLDL-C, HDL-C, TG, atherogenic index (AI), ALT, AFT, ALP, γ-GT, total protein (TP), serum albumin and globulin ratio (A/G), serum creatinine, blood urea nitrogen (BUN) and blood urea, and histopathology of hematoxylin and eosin (H&E) stained liver and kidney sections of all aforementioned groups were examined in the treated animals. Results: Nanoemulsomes of LTN-loaded GR and GL oils provided synergistic effects with LTN, exerted better ameliorative actions in reducing serum TC, LDL-C, vLDL-C, triglycerides, and AI, and improved serum HDL-C levels. Serum ALT, AST, ALP, and γ-GT levels were in the normal range for nanoemulsome groups. H&E stained liver and kidney sections of these animals confirmed better hepatoprotective and renoprotective effects than LTN alone. Serum biochemical parameters for renal functions also claimed to be in the moderate range for nanoemulsome-treated groups. Conclusion: This study demonstrated that nanoemulsomes of LTN-loaded GR and GL oils synergistically provided better antihyperlipidemic, hepatoprotective, and renoprotective effects as compared to LTN alone.

Natural Hydrogen Sulfide Donors from Allium sp. as a Nutraceutical Approach in Type 2 Diabetes Prevention and Therapy

Type 2 diabetes mellitus (DM) is a socially relevant chronic disease with high prevalence worldwide. DM may lead to several vascular, macrovascular, and microvascular complications (cerebrovascular, coronary artery, and peripheral arterial diseases, retinopathy, neuropathy, and nephropathy), often accelerating the progression of atherosclerosis. Dietary therapy is generally considered to be the first step in the treatment of diabetic patients. Among the current therapeutic options, such as insulin therapy and hypoglycemic drugs, in recent years, attention has been shifting to the effects and properties-that are still not completely known-of medicinal plants as valid and inexpensive therapeutic supports with limited side effects. In this review, we report the relevant effects of medicinal plants and nutraceuticals in diabetes. In particular, we paid attention to the organosulfur compounds (OSCs) present in plant extracts that due to their antioxidant, hypoglycemic, anti-inflammatory, and immunomodulatory effects, can contribute as cardioprotective agents in type 2 DM. OSCs derived from garlic (Allium sp.), due to their properties, can represent a valuable support to the diet in type 2 DM, as outlined in this manuscript based on both in vitro and in vivo studies. Moreover, a relevant characteristic of garlic OSCs is their ability to produce the gasotransmitter H₂S, and many of their effects can be explained by this property. Indeed, in recent years, several studies have demonstrated the relevant effects of endogenous and exogenous H₂S in human DM, including by in vitro and in vivo experiments and clinical trials; therefore, here, we summarize the effects and the underlying molecular mechanisms of H₂S and natural H₂S donors.

Therapeutic Mechanisms of Herbal Medicines Against Insulin Resistance: A Review

Insulin resistance is a condition in which insulin sensitivity is reduced and the insulin signaling pathway is impaired. Although often expressed as an increase in insulin concentration, the disease is characterized by a decrease in insulin action. This increased workload of the pancreas and the consequent decompensation are not only the main mechanisms for the development of type 2 diabetes (T2D), but also exacerbate the damage of metabolic diseases, including obesity, nonalcoholic fatty liver disease, polycystic ovary syndrome, metabolic syndrome, and others. Many clinical trials have suggested the potential role of herbs in the treatment of insulin resistance, although most of the clinical trials included in this review have certain flaws and bias risks in their methodological design, including the generation of randomization, the concealment of allocation, blinding, and inadequate reporting of sample size estimates. These studies involve not only the single-flavored herbs, but also herbal formulas, extracts, and active ingredients. Numerous of in vitro and in vivo studies have pointed out that the role of herbal medicine in improving insulin resistance is related to interventions in various aspects of the insulin signaling pathway. The targets involved in these studies include insulin receptor substrate, phosphatidylinositol 3-kinase, glucose transporter, AMP-activated protein kinase, glycogen synthase kinase 3, mitogen-activated protein kinases, c-Jun-N-terminal kinase, nuclear factor-kappaB, protein tyrosine phosphatase 1B, nuclear factor-E2-related factor 2, and peroxisome proliferator-activated receptors. Improved insulin sensitivity upon treatment with herbal medicine provides considerable prospects for treating insulin resistance. This article reviews studies of the target mechanisms of herbal treatments for insulin resistance.

Garlic Supplementation Reduces Circulating C-reactive Protein, Tumor Necrosis Factor, and Interleukin-6 in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Conflicting findings on the effects of garlic supplementation on inflammatory biomarkers have been observed in randomized clinical trials (RCTs).

OBJECTIVES

The aim of this study was to summarize study results regarding the effects of garlic supplementation on serum inflammatory biomarkers in adults.

METHODS

We searched Scopus, PubMed, Google Scholar and Cochrane library databases for relevant papers published until April 2018, using keywords such as "garlic" and "inflammatory biomarker." We included RCTs that 1) were conducted in adults, 2) examined the effects of garlic supplementation on inflammatory biomarkers compared to a control group, and 3) reported sufficient data on inflammatory biomarkers. Results were reported as weighted mean differences (WMD) with 95% CI using random effects models. Cochrane's Q and I-squared (I2) tests were used to determine heterogeneity among studies. Funnel plots and Egger's regression test were used to assess publication bias.

RESULTS

Sixteen RCTs were included. Garlic doses ranged from 12 to 3600 mg/d, and intervention duration ranged from 2 to 52 wk. Garlic administration significantly reduced serum C-reactive protein (CRP) (n = 13) (WMD: -0.61 mg/L, 95% CI: -1.12, -0.11, P = 0.018, I2 = 76.9%), IL-6 (n = 5) (WMD: -0.73 ng/L, 95% CI: -1.06, -0.40, P < 0.001, I2 = 0%), and TNF (n = 7) (WMD: -0.26 ng/L, 95% CI: -0.41, -0.12, P < 0.001, I2 = 0.0%), compared to controls. However, the effect of garlic supplementation on serum adiponectin (n = 3) (WMD: 0.18 µg/L, 95% CI: -0.21, 0.57, P = 0.35, I2 = 60.7%) and leptin (n = 2) (WMD: -1.25 µg/L, 95% CI: -2.64, 0.14, P = 0.07, I2 = 0.0%) concentrations were not significant.

CONCLUSION

In this meta-analysis of RCTs, we found that garlic supplementation reduced serum concentrations of CRP, TNF, IL-6, but did not affect serum adiponectin and leptin in adults. More RCTs are needed to test the effects of garlic supplementation on inflammation.

Beneficial Effects of an Aged Black Garlic Extract in the Metabolic and Vascular Alterations Induced by a High Fat/Sucrose Diet in Male Rats

Aged black garlic (ABG) is a functional food with antioxidant and anti-inflammatory properties. Recent studies also report its beneficial metabolic effects in a context of obesity or diabetes, although the mechanisms involved are poorly understood. The aim of this work was to analyze the effects of an ABG extract in the vascular and metabolic alterations induced by a high-fat/sucrose diet in rats. For this purpose, male Sprague–Dawley rats were fed either a standard chow (controls; n = 12) or a high-fat/sucrose diet (HFD; n = 24) for 16 weeks. From week 8 on, half of the HFD rats were treated with a commercial ABG extract concentrated in S-allyl cysteine and melanoidins (ABG10+®; 250 mg/kg daily by gavage; 5 mL/kg). ABG10+®-treated rats showed lower mean caloric intake, body weight, triglycerides, low density lipoprotein cholesterol (LDL-c), insulin and leptin serum concentrations and higher high density lipoprotein cholesterol (HDL-c) and adiponectin serum concentrations than non-treated rats. In the hypothalamus, ABG10+® treatment induced an increase in the gene expression of proopiomelanocortin (POMC) and a decrease in leptin receptor (ObR) mRNA levels. No significant changes were found in visceral adipose tissue except for an overexpression of β3-adrenergic receptor (β3-ADR) in ABG-treated rats. In subcutaneous adipose tissue, ABG10+® treatment decreased adipose weight and downregulated the gene expression of PPAR-γ, LPL, ObR and HSL. In brown adipose tissue, an overexpression of InsR, GLUT-4, UCP-1 and β3-ADR in ABG10+®-treated rats was found, whereas PPAR-γ mRNA levels were significantly decreased. Regarding vascular function, ABG10+® treatment attenuated the obesity-induced vasoconstriction in response to potassium chloride both in presence/absence of perivascular adipose tissue (PVAT). On the contrary, aorta segments from ABG-treated rats showed and improved relaxation in response to acetylcholine only when PVAT was present, with this fact possible being related to the decreased gene expression of proinflammatory cytokines in this tissue. In conclusion, ABG10+® administration partially improves the metabolic and vascular alterations induced by a high-fat/high-sucrose diet in rats through modifications in the gene expression of proteins and neuropeptides involved in inflammation, fat metabolism and food intake regulation. Further studies are required to assess the bioavailability of ABG between rats and humans.

A new methodology for sensory quality assessment of garlic based on metabolomics and an artificial neural network

This study has established a new method for the sensory quality determination of garlic and garlic products on the basis of metabolomics and an artificial neural network. A total of 89 quality indicators were obtained, mainly through the metabolomics analysis using gas chromatography/mass spectrometry (GC/MS) and high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The quality indicator data were standardized and fused at a low level, and then seven representative indicators including the a* (redness) value, and the contents of S-methyl-l-cysteine, 3-vinyl-1,2-dithiacyclohex-5-ene, glutamic acid, l-tyrosine, d-fructose and propene were screened by partial least squares discriminant analysis (PLS-DA), analysis of variance (ANOVA) and correlation analysis (CA). Subsequently, the seven representative indicators were employed as the input data, while the sensory scores for the garlic obtained by a traditional sensory evaluation were regarded as the output data. A back propagation artificial neural network (BPANN) model was constructed for predicting the sensory quality of garlic from four different areas in China. The R² value of the linear regression equation between the predicted scores and the traditional sensory scores for the garlic was 0.9866, with a mean square error of 0.0034, indicating that the fitting degree was high and that the BPANN model built in this study could predict the sensory quality of garlic accurately. In general, the method developed in this study for the sensory quality determination of garlic and garlic products is rapid, simple and efficient, and can be considered as a potential method for application in quality control in the food industry.

This study has established a new method for the sensory quality determination of garlic and garlic products on the basis of metabolomics and an artificial neural network.