Influence of Garlic on the Glycemic Control and Lipid Profile in Animals with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

Nonalcoholic fatty liver disease is the hepatic sign of metabolic syndrome. Here, we aimed to assess the effects of garlic and its major components on fasting plasma glucose, fasting insulin, and lipid profile levels in animal models of nonalcoholic fatty liver disease. A systematic search in PubMed, Scopus, ProQuest, and Web of Science was performed. After the screening process and data extraction, the pooled effect sizes were estimated using a random-effect model and stated as standardized mean differences and a 95% confidence interval. Out of 839 reports, 22 articles were included in the present study. The pooled results revealed that garlic and its components significantly decreased fasting plasma glucose (standardized mean difference: - 0.77, 95% confidence interval: - 1.42 to - 0.12, I2 : 58.85%), fasting insulin (standardized mean difference: - 1.88, 95% confidence interval: - 3.07 to - 0.69, I2 : 70.42%), serum triglyceride (standardized mean difference: - 1.01, 95% confidence interval: - 1.43 to - 0.59, I2 : 61.41%), cholesterol (standardized mean difference: - 1.00, 95% confidence interval: - 1.39 to - 0.60, I2 : 52.12%), and low-density lipoprotein cholesterol (standardized mean difference: - 0.98, 95% CI: - 1.63 to - 0.32, I2 : 71.58%) and increased high-density lipoprotein cholesterol (standardized mean difference: 1.05, 95% confidence interval: 0.52 to 1.58, I2 : 59.39%) levels. The type of animal, nonalcoholic fatty liver disease induction model, kind and duration of intervention, study model, and risk of bias were detected as possible sources of heterogeneity across studies. We conclude that garlic and its major components have a favorable impact on glycemic control and lipid profile in diet-induced nonalcoholic fatty liver disease animal models.

Resveratrol and Markers of Polycystic Ovary Syndrome: a Systematic Review of Animal and Clinical Studies

Polycystic ovary syndrome (PCOS) is a common disorder affecting childbearing-age women, and is associated with reproductive and metabolic disturbances. The present study aimed to systematically review current animal studies and randomized placebo-controlled clinical trials (RCT) regarding the effects of resveratrol, a natural polyphenolic compound, on PCOS features. PubMed, Scopus, Web of Knowledge, and Google Scholar were comprehensively searched until December 2020. All original animal articles and RCTs evaluating the effects of resveratrol on PCOS were eligible for the review. Out of 289 initial records, eight animal studies and three RCTs met our inclusion criteria. Most of the included animal studies reported beneficial effects of resveratrol on the histomorphological features, sex hormones and gonadotropins, glycemic control, inflammation, and oxidative stress. Resveratrol also ameliorated ovarian volume, high-quality oocyte rate, high-quality embryo rate, androgens and gonadotropins concentrations, angiogenic factors levels, and endoplasmic reticulum stress in PCOS patients. Upregulation of sirtuin-1 was an examined mechanism proposed for some observed effects of resveratrol. The current literature is limited to conclude the beneficial effects of resveratrol on the management of PCOS. Although, according to the promising results of the animal studies and limited RCTs, resveratrol might be an effective phytochemical in PCOS control, especially regarding hormonal and reproductive abnormalities. More mechanistic studies and RCTs are warranted to obvious whether resveratrol can be prescribed in the clinical situation.

Theanine and cancer: A systematic review of the literature

A growing literature indicates several health benefits of theanine, a major nonprotein derivative amino acid special to tea, and a nonedible mushroom. This study aimed to systematically review the scientific evidence regarding the anticarcinogen and anticancer effects of natural theanine. A systematic search for the relevant articles published until January 2021 on MEDLINE, Scopus, and Web of Knowledge was conducted. Out of 377 initial records, 14 in vitro, ex vivo, and in vivo studies met our inclusion criteria. Most of the included in vitro and ex vivo studies reported beneficial effects of theanine on the proliferation, apoptosis, metastasis, migration, and invasion in various cancer cell lines. The in vivo studies also supported the potential impacts of theanine on cancer incidence or progression. Theanine exerted its anticancer function by inhibiting EGFR, VEGFR, Met, and Akt/mTOR, JAK2/STAT3, and ERK/NFκB pathways, as well as activating the intrinsic apoptosis pathway and caspase-independent programmed cell death. In conclusion, the results indicated moderate apoptotic, antimetastatic, antimigration, and anti-invasion effects, along with the mild antiproliferative influence of theanine on cancer. Further studies are necessary to ascertain the effectiveness of theanine on the prevention and suppression of cancer and shed light upon the attributable mechanisms in the in vivo condition.