Effect of green coffee bean extract supplementation on liver function and inflammatory biomarkers: A meta-analysis of randomized clinical trials

Natural products and dietary interventions on liver enzymes: an umbrella review and evidence map

Background

The association between natural products and dietary interventions on liver enzymes is unclear; therefore, this study aimed to examine their effects on liver enzymes in adults.

Methods

PubMed, Embase, and Cochrane Library of Systematic Reviews databases were searched from inception until March 2023. The Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological and evidence quality, and the therapeutic effects were summarized in a narrative form.

Results

A total of 40 meta-analyses on natural products (n = 25), dietary supplements (n = 10), and dietary patterns (n = 5) were evaluated, and results were presented in a narrative form. The overall methodological quality of the included studies was relatively poor. The results indicated that positive effects were observed for nigella sativa, garlic, artichoke, curcumin, silymarin, vitamin E, vitamin D, L-carnitine, propolis, and polyunsaturated fatty acids on certain liver enzymes. The dietary patterns, including high-protein, Mediterranean, and calorie-restriction diets and evening snacks, may reduce liver enzymes; however, other supplements and herbs did not reduce liver enzyme levels or have minimal effects. The evidence quality was generally weak given the risk of bias, heterogeneity, and imprecision.

Conclusion

This umbrella review suggests that natural products and dietary interventions have beneficial therapeutic effects on liver enzymes levels. Further clinical trials are necessary to establish the effectiveness of supplements that reduce liver enzymes.

Effects of green coffee aqueous extract supplementation on glycemic indices, lipid profile, CRP, and malondialdehyde in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial

Background/objectives

Studies have reported the health benefits of green coffee extract (GCE) in experimental models. In the current study, we aimed to determine whether supplementation with GCE improves glycemic indices, inflammation, and oxidative stress in patients with type 2 diabetes (T2D).

Methods and study design

This randomized, double-blind, placebo-controlled trial included 44 patients (26 male and 18 female) with T2D and overweight/obesity. After blocked randomization, patients received either capsules containing 400 mg GCE twice per day (n = 22) or a placebo (n = 22) and were followed for 10 weeks. In this study, glycemic indices, lipid profiles, anthropometric examinations, blood pressure, high-sensitivity C-reactive protein (hs-CRP), and malondialdehyde (MDA) were measured twice; at baseline and at the end of the study.

Results

After 10 weeks of supplementation, GCE supplementation significantly reduced body weight (p = 0.04) and body mass index (BMI) (p = 0.03) compared to the placebo. The intention-to-treat (ITT) analysis indicated patients in the GCE group had a lower fasting blood glucose (FBG) concentration compared to the placebo group; however, this decreasing was marginally significant (8.48 ± 8.41 vs. 1.70 ± 5.82 mg/dL, p = 0.05). There was no significant difference in insulin levels and HOMA-IR between the groups. At the end of the study, significant changes in systolic blood pressure (SBP) (p = 0.01), triglyceride (TG) level (p = 0.02), high-density lipoprotein (HDL) (p = 0.001), and TG-to-HDL ratio (p = 0.001) were found between the intervention and placebo groups. Our trial indicated GCE supplementation had no effect on diastolic blood pressure (DBP), low-density lipoprotein (LDL), or total cholesterol. During the supplementation period, the hs-CRP level significantly decreased in the GCE group compared to the placebo group (p = 0.02). No significant changes were observed in the MDA level between the two groups at the end of the study (p = 0.54).

Conclusion

Our findings showed beneficial effects of GCE on SBP, TG, hs-CRP, and HDL levels in patients with T2D and overweight/obesity over a 10-week period of supplementation.Clinical trial registration:https://en.irct.ir/trial/48549, identifier [IRCT20090203001640N18].

The Effect of Extraction Methods on Phytochemicals and Biological Activities of Green Coffee Beans Extracts

The objectives of the present study consisted of identifying the impact of extraction methods and parameters held over the phytochemistry and biological activities of green coffee beans. Extraction processes belonging to two categories were performed: classical methods-maceration, Soxhlet extraction, and such innovative methods as turboextraction, ultrasound-assisted extraction, and a combination of the latter two. Total polyphenolic and flavonoid content, as well as in vitro antioxidant activity of the resulted extracts were spectrophotometrically determined. Extracts displaying the highest yields of bioactive compounds were subjected to High Performance Liquid Chromatography-Mass Spectrometry analysis. The extracts with the best phytochemical profiles were selected for biological activity assessment. In vivo, a model of plantar inflammation in Wistar rats was used to determine antioxidant activity, by evaluating the oxidative stress reduction potential, and anti-inflammatory activity. In vitro antimicrobial activity was also determined. The Soxhlet extraction and ultrasound-assisted extraction gave the highest bioactive compound yields. The highest total polyphenolic content was 2.691 mg/mL gallic acid equivalents and total flavonoid content was 0.487 mM quercetin equivalents for the Soxhlet extract subjected to 60 min extraction time. Regarding the antioxidant activity, ultrasound-assisted extraction reached the highest levels, i.e., 9.160 mg/mL Trolox equivalents in the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay and 26.676 mM Trolox equivalents in the FRAP (Ferric Reducing Antioxidant Power) assay, at a 30 min extraction time and 50 °C extraction temperature. The 60 min Soxhlet extract reached the highest level for the ABTS⁺ (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay, 16.136 mM Trolox equivalents, respectively. Chlorogenic acid was present in the highest concentration in the same Soxhlet extract, 1657.179 µg/mL extract, respectively. Sterolic compounds were found in high concentrations throughout all the analyzed extracts. A proportional increase between yields and extraction parameter values was observed. Increased inhibition of Gram-negative bacteria was observed. The finally selected Soxhlet extract, that of 60 min extraction time, presented a significant in vivo antioxidant activity, with a slight anti-inflammatory activity. Antioxidant levels were elevated after 2 h of extract administration. Pro-inflammatory cytokine secretion was not influenced by the administration of the extract.

Coffee or tea: Anti-inflammatory properties in the context of atherosclerotic cardiovascular disease prevention

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of premature death worldwide. Inflammation and its biomarkers, like C-reactive protein (CRP), among the risk factors, such as hypertension, lipid disorders, and diabetes, may be also responsible for the residual cardiovascular disease (CVD) risk. Modern lipid-lowering treatment with statins, ezetimibe, PCSK9 inhibitors, or bempedoic acid does not fully protect against inflammation. The recommendations of the International Lipid Expert Panel (ILEP) indicate selected nutraceuticals with anti-inflammatory properties. Diet may have a significant impact on inflammation. Especially interesting in the context of inflammation is the consumption of coffee and tea. These drinks in many observational studies significantly reduced cardiovascular risk and mortality. The question is whether the anti-inflammatory effects of these drinks contribute significantly to the observed clinical effects. Thus, in this narrative review, we primarily discuss the anti-inflammatory properties of consuming tea and coffee. Based on a comprehensive analysis of the studies and their meta-analyses, inconsistent results were obtained, which makes it impossible to conclusively state how clinically significant the potential anti-inflammatory properties of black and green tea and coffee are. A number of confounding factors can cause the inconsistency of the available results. Consumption of tea and coffee appears to increase adiponectin concentrations, decrease reactive oxygen species, decrease low density lipoprotein (LDL) cholesterol concentrations (effect of green tea, etc.). Despite the still uncertain anti-inflammatory effect of tea and coffee, we recommend their consumption as a part of the healthy diet.

Natural Foods for the Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. The etiology of NAFLD is highly heterogeneous, which occurs and develops under the joint action of metabolism, inflammation, genetics, environment, and gut microbiota. At present, the principal therapeutic modalities targeting NAFLD are lifestyle interventions such as weight loss through diet and exercise. At present, there is no established therapy for the treatment of NAFLD, and many therapies are associated with a variety of side effects. A great number of in vitro and in vivo experiments have indicated that there are many natural foods that have therapeutic potential for NAFLD. This review summarizes the natural foods and their mechanisms that were found in recent years, furthermore, provides further information relevant to the treatment of NAFLD.

The effect of grape products on liver enzymes: A systematic review and meta-analysis of randomized controlled trials

The favorable influence of grape consumption on metabolic diseases has previously been shown in studies. We sought to assess the effects of grape intake on liver enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), in adults. We performed literature search in online databases, to find eligible randomized controlled trials (RCTs). we considered RCTs that met the following criteria: RCTs consisted of use of grape products on ALT, AST, and ALP in adults (≥18 years) with at least 2 weeks intervention duration. Pooling data from 11 trials showed that grape products intake significantly reduced ALP (p = .010), without any significant changes in ALT (p = .234) and AST (p = .300). In subgroup analysis, we found a significant reduction in ALP, ALT, and AST when the duration of intervention was ≥12 weeks, and when grape seed extract (GSE) was administered. The variable duration and dosage of intervention was one of the sources of bias in our meta-analysis. Additionally, participants involved in included studies had different physiological status and various age groups. Grape products administration may significantly improve ALT, AST, and ALP in adults in long-term interventions and/or when GSE is administered. It should be noted that the favorable effects of grape consumption were small and may not reach clinical importance.

The Effect of Green Coffee Supplementation on Lipid Profile, Glycemic Indices, Inflammatory Biomarkers and Anthropometric Indices in Iranian Women With Polycystic Ovary Syndrome: A Randomized Clinical Trial

Polycystic ovary syndrome (PCOS) is a heterogeneous clinical syndrome. Recent studies examine different strategies to modulate its related complications. Chlorogenic acid, as a bioactive component of green coffee (GC), is known to have great health benefits. The present study aimed to determine the effect of GC on lipid profile, glycemic indices, and inflammatory biomarkers. Forty-four PCOS patients were enrolled in this randomized clinical trial of whom 34 have completed the study protocol. The intervention group (n = 17) received 400 mg of GC supplements, while the placebo group (n = 17) received the same amount of starch for six weeks. Then, glycemic indices, lipid profiles, and inflammatory parameters were measured. After the intervention period, no significant difference was shown in fasting blood sugar, insulin level, Homeostasis model assessment of insulin resistance index, low-density lipoprotein, high-density lipoprotein, Interleukin 6 or 10 between supplementation and placebo groups. However, cholesterol and triglyceride serum levels decreased significantly in the intervention group (p < 0.05). This research confirmed that GC supplements might improve some lipid profiles in women with PCOS. However, more detailed studies with larger sample sizes are required to prove the effectiveness of this supplement.

A review of transglycosylated compounds as food additives to enhance the solubility and oral absorption of hydrophobic compounds in nutraceuticals and pharmaceuticals

Transglycosylation has been used to modify the physicochemical properties of original compounds. As a result, transglycosylated compounds can form molecular aggregates in size ranges of a few nanometers in an aqueous medium when their concentrations exceed a specific level. Incorporating these hydrophobic compounds has been observed to enhance the solubility of hydrophobic compounds into aggregate structures. Thus, this review introduces four transglycosylated compounds as food additives that can enhance the solubility and oral absorption of hydrophobic compounds. Here, transglycosylated hesperidin, transglycosylated rutin, transglycosylated naringin, and transglycosylated stevia are the focus as representative substances. Significantly, we observed that amorphous formations containing hydrophobic compounds with transglycosylated compounds improved solubility and oral absorption compared to untreated hydrophobic compounds. Moreover, combining transglycosylated compounds with hydrophilic polymers or surfactants enhanced the solubilizing effects on hydrophobic compounds. Furthermore, the enhanced solubility of hydrophobic compounds improved their oral absorption. Transglycosylated compounds also influenced nanoparticle preparation of hydrophobic compounds as a dispersant. This study demonstrated the benefits of transglycosylated compounds in developing supplements and nutraceuticals of hydrophobic compounds with poor aqueous solubility.

The Protective Effect of Panax notoginseng Mixture on Hepatic Ischemia/Reperfusion Injury in Mice via Regulating NR3C2, SRC, and GAPDH

Panax notoginseng mixture (PNM) has the characteristics of multicomponent, multitarget, and multieffect, which can cope with the multidirectional and multidimensional complex pathological process caused by hepatic ischemia/reperfusion injury (HIRI). Our animal experiments showed that PNM composed of notoginseng, dogwood, and white peony root could significantly reduce the level of aspartate transaminase and alanine aminotransferase in the blood of mice with HIRI, indicating that this preparation had a protective effect on HIRI in mice. Therefore, on this basis, the molecular mechanism of PNM intervention in HIRI was further explored by network pharmacology. First, target genes corresponding to active components and HIRI were obtained through databases such as TCMSP, Pharm Mapper, Swiss Target Prediction, GeneCards, and so on. All target genes were standardized by Uniprot database, and a total of 291 target genes with their intersection were obtained. Then, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and biological processes (BPs) of 291 target genes were obtained through the online public platform of DAVID. A total of 177 KEGG pathways and 337 BPs were obtained by setting p < 0.01 and false discovery rate <0.05. The network mapping map of components and disease targets was drawn by Cytoscape, and the top 10 Hub target genes related to HIRI were obtained. At the same time, the String database was used to obtain the protein-protein interaction dataset, which was imported into Cytoscape, and the first 10 Hub target genes were obtained. The Hub target genes obtained by the above two methods were molecular docking with their corresponding small molecule compounds through DockThor online tool. The results showed that the docking of paeoniflorin with glyceraldehyde 3-phosphate dehydrogenase (GAPDH), paeoniflorin and loganin with SRC, ginsenoside Rb1 with NR3C2, ursolic acid and oleanolic acid with IL-6, paeoniflorin docking VEGFA, and MMP9. Finally, NR3C2, SRC, and GAPDH were identified as target genes in this study by referring to relevant literature reports. After verification by immunohistochemical experiments, compared with the sham group, the above three target genes were highly expressed in the HIRI group (p < 0.01). Compared with the HIRI group, the expression of three target genes in the PNM + HIRI group was significantly decreased (p < 0.01). The results showed that PNM could protect mouse HIRI by decreasing the expression of NR3C2, SRC, and GAPDH.

Effect of Coffee Consumption on Non-Alcoholic Fatty Liver Disease Incidence, Prevalence and Risk of Significant Liver Fibrosis: Systematic Review with Meta-Analysis of Observational Studies

Background and aim: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Given the anti-fibrotic and antioxidant properties of coffee, this systematic review and meta-analysis aims to provide updated results on the impact of coffee consumption on NAFLD incidence, prevalence, and risk of significant liver fibrosis. Methods: We conducted a comprehensive search in MEDLINE (OvidSP) and Scopus from January 2010 through January 2021. Relative risks for the highest versus the lowest level of coffee consumption were pooled using random-effects models. Heterogeneity and publication bias were evaluated using the Higgins’ I² statistic and Egger’s regression test, respectively. Results: Eleven articles consisting of two case-control studies, eight cross-sectional studies, and one prospective cohort study were included in the meta-analysis. Of those, three studies with 92,075 subjects were included in the analysis for NAFLD incidence, eight studies with 9558 subjects for NAFLD prevalence, and five with 4303 subjects were used for the analysis of liver fibrosis. There was no association between coffee consumption and NAFLD incidence (RR 0.88, 95% CI 0.63–1.25, p = 0.48) or NAFLD prevalence (RR 0.88, 95% CI 0.76–1.02, p = 0.09). The meta-analysis showed coffee consumption to be significantly associated with a 35% decreased odds of significant liver fibrosis (RR 0.65, 95% CI 0.54–0.78, p < 0.00001). There was no heterogeneity (I² = 11%, p = 0.34) and no evidence of publication bias (p = 0.134). Conclusion: This meta-analysis supports the protective role of coffee consumption on significant liver fibrosis in patients with NAFLD. However, the threshold of coffee consumption to achieve hepatoprotective effects needs to be established in prospective trials.

Green coffee: economic relevance and a systematic review of the effects on human health

Coffee is probably the most popular beverage after water and is an important component in diet and health since its consumption is high worldwide. Globally, it is the most relevant food commodity being just behind crude oil. Besides its pleasant flavor, it is an antioxidant source due to polyphenols, which are protective compounds against several diseases. This study aimed to evaluate the economic relevance and perform a systematic review of green coffee's effects on human health. Databases such as MEDLINE-PubMed, EMBASE, COCHRANE, and GOOGLE SCHOLAR were searched, and PRISMA guidelines were followed. Green coffee is considered a novel food product because consumers usually consume only roasted coffee. It can be marketed as such or as an extract. Due to the content of bioactive compounds, which are partially lost during the roasting process, the extracts are usually marketed concerning the potential regarding health effects. Green coffee can be used as dietary supplements, cosmetics, and pharmaceuticals, as a source of antioxidants. It can benefit human health, such as improvement in blood pressure, plasma lipids, and body weight (thus contributing to the improvement of risk components of Metabolic Syndrome). Moreover, benefits for cognitive functions may also be included.

The Effects of Curcumin on Diabetes Mellitus: A Systematic Review

Diabetes mellitus (DM) is an ensemble of metabolic conditions that have reached pandemic proportions worldwide. Pathology's multifactorial nature makes patient management, including lifelong drug therapy and lifestyle modification, extremely challenging. Currently, there is growing evidence about the effectiveness of using herbal supplements in preventing and controlling DM. Curcumin is a bioactive component found Curcuma longa, which exhibits several physiological and pharmacological properties such as antioxidant, anti-inflammatory, anticancer, neuroprotective, and anti-diabetic activities. For these reasons, our objective is to systematically review the effects of Curcuma longa or curcumin on DM. Databases such as PUBMED and EMBASE were searched, and the final selection included sixteen studies that fulfilled the inclusion criteria. The results showed that curcumin's anti-diabetic activity might be due to its capacity to suppress oxidative stress and inflammatory process. Also, it significantly reduces fasting blood glucose, glycated hemoglobin, and body mass index. Nanocurcumin is also associated with a significant reduction in triglycerides, VLDL-c, total cholesterol, LDL-c, HDL-c, serum C reactive protein, and plasma malonaldehyde. Therefore, it can be considered in the therapeutic approach of patients with DM.