TABLE 2.
Effects of white tea and its ingredients on obesity, diabetes mellitus, and nonalcoholic fatty liver disease.
| Plant/ingredient | Effective dose | Type of study | Effects | Ref. |
|---|---|---|---|---|
| White tea extract | 0.1, 0.25, 0.5 and 0.75% | In vitro preadipocytes | Decreased TG incorporation during adipogenesis without effect on cell viability. Also increased lipolytic activity and downregulated ADD1/SREBP-1c protein expression during adipogenesis. It also decreased Sirt1 mRNA levels compared to control cells. | Söhle et al. (2009) |
| White tea extract | 2.5% | HepG2 cell | Reduced the glucose and cholesterol uptake, while enhanced the LDL receptor binding activity and led to an increase in HDL cell medium concentration. Also, the tea extract revealed the best inhibition capacity against lipase activity and TG levels in cell lines. | Tenore et al. (2013) |
| White tea extract | 1.5% | Rats | Decreased serum levels of glucose, LDL, cholesterol, and triglyceride, while increased levels of HDL compared to control diabetic rats | Amanzadeh et al. (2020) |
| White tea extract | 0.5% | Mice | Reduced blood triacylglycerols associated with increased cecal lipids. White tea extract also reduced oxidative stress in the liver and adipose tissue. Moreover, tea extract was not able to reduce food intake and body weight in animals. | Teixeira et al. (2012) |
| White tea polysaccharide and polyphenol | 400 or 800 mg kg−1 | Rats | Suppressed body weight increases and fat accumulation. Moreover, polyphenols and polysaccharides improved blood lipid and antioxidant levels. In addition, reduced the serum leptin levels and gene expression levels of IL-6 and TNF-α. Furthermore, polysaccharides and polyphenols showed a synergistic effect in reduction of serum leptin levels and in anti-inflammatory activity. | Xu et al. (2015) |
| Catechin | 0.1, 0.2 and 0.5% | Mice | Reduced body weight, visceral and liver fat accumulation as well as development of hyperinsulinemia and hyperleptinemia. Furthermore, treatment with catechins significantly increased acyl-CoA oxidase and medium chain acyl-CoA dehydrogenase mRNA expression and β-oxidation activity in the liver of mice. | Murase et al. (2002) |
| Catechins | 118.5 and 483.0 mg/day | Clinical study | Significantly decreased weight, body mass index (BMI), waist circumference, body fat ratio, abdominal fat and total cholesterol, glucose and plasminogen activator inhibitor-1 (PAI-1) in the serum compared to the baseline in healthy male subjects. | Hase et al. (2001) |
| Beverage containing catechins | 625 mg | Clinical study | Induced loss of body weight compared with the control group. Percentage changes in total abdominal fat, subcutaneous abdominal fat, and fasting serum TG were greater in the catechins compared with the control group. | Maki et al. (2009) |
| White tea extract | 0.5% | Rats | Increased the drink intake compared to the normal control or diabetic control rats. Decreased blood glucose concentrations and improved glucose tolerance ability. Also, total cholesterol and LDL-cholesterol were significantly decreased. | Islam, (2011) |
| White tea extract | 1% | Prediabetic rats | Increased mRNA and protein expression levels of glucose transporters (GLUT1 and GLUT3) in the heart tissue. White tea also increased cardiac acetate and alanine contents, Ferric reducing antioxidant power and lactate dehydrogenase (LDH) in protein expression and activity. | Alves et al. (2015) |
| White tea extract | 1% | Prediabetic rats | Ameliorated glucose tolerance and insulin sensitivity. Decreased the protein expression levels of GLUT 1 and GLUT3 in the cortex of animals. Increased the antioxidant capacity and suppressed lipid peroxidation and protein oxidation in the cortex of prediabetic animals. | Nunes et al. (2015) |
| White tea extract | 2% | Diabetic rats | Increased glutathione peroxidase (GSH-px), superoxide dismutase (SOD), and catalase (CAT) activities in the serum and liver compared to the diabetic control group. | Al-Shiekh et al. (2014) |
| White tea ethanolic extract | 100 mg/kg, BW | Diabetic rats | Decreased fasting FBG level. | Ardiana et al. (2018) |
| Catechin | 25 and 50 mg/kg | Diabetic rats | Decreased body weight. Reduced heart hypertrophy, plasma glucose levels, and MMP-9 levels. Improved oxidative stress parameters in the nerves. | Addepalli and Suryavanshi, (2018) |
| (+)-catechin | 0.2, 1.0, and 5.0 mmol/L | Mice | Ameliorated renal dysfunction in type 2 diabetic mice, and protective effects against structural nephropathies. Downregulated the level of NF-κB p65 phosphorylation as well as lowered pro-inflammatory mediators such as TNF- α and IL-1β in diabetic mice. | Zhu et al. (2014) |
| Catechin-rich beverage | 96.3 mg | Clinical study | Decreased waist circumference compared to the control group. Increased adiponectin and insulin levels in type 2 diabetic patients compared to the control group | Nagao et al. (2009) |
| Catechin-rich beverage | 540–588 mg | Clinical studies | Reduced abdominal fat, visceral fat area, subcutaneous fat area, body weight, and waist circumference as well as improved blood pressure. | Hibi et al. (2018) |
| Catechin-rich beverage | 615 mg/350 ml | Clinical study | Reduce the risk of metabolic syndrome (MetS) due to reduction of abdominal fat. Lowered postprandial glucose levels and serum postprandial thioredoxin. Increases antioxidant capacity and inhibited protein oxidation in postprandial hyperglycaemia. | Nunes et al. (2015) |
| White tea extract | 200 μg/ml | HepG2 cells | Downregulated apolipoprotein B (APOB) and microsomal TG transfer protein (MTTP) expression and reduced production of very-low-density lipoprotein (VLDL) in HepG2 cells. Stimulated LDL-cholesterol (LDL-c) uptake through its targeting receptor (LDLR). Downregulated TG synthetic genes and reduced intracellular TG accumulation. | Luo et al. (2020) |
| White tea extract | 15 mg/d or 45 mg/d | Rats | Improved antioxidant activity and the fatty acid profiles of the liver and heart microsomes on Adriamycin-induced hepatotoxicity | Espinosa et al. (2015) |
| White tea extract | 5% | Mice | Reduced water intake and food consumption and lowered the serum total LDLc and TG levels. Reduced lipid synthesis related to gene fatty acid synthase and blood glucose level, but increased glucose tolerance. Prevented the fatty liver formation and restored the normal hepatic structure. | Teng et al. (2018) |
| Epigallocatechin-3-gallate and caffeine | 40–160 mg/kg | Rats | Reduced white adipose tissue and energy intake than single use. These effects may be due to the alteration in serum lipid profile, oxidative stress, and inflammatory cytokines in rats with NAFLD. | Yang et al. (2019) |
| (-) epigallocatechin gallate (EGCG) | 85% | Rats | Improved hepatic histology including reduced number of fatty score, necrosis, and inflammatory foci. Reduced liver injury, decreased fibrosis with downregulation in the expressions of oxidative parameters and pro-inflammatory markers. | Xiao et al. (2014) |
| Catechin-rich beverage | 1,080 mg/700 ml or 200 mg/700 | Clinical studies | Reduced body fat and improved the liver-to-spleen computed tomography (CT) attenuation ratio. Decreased the level of alanine aminotransferase (ALT) and urinary 8-isoprostane. | Sakata et al. (2013) |