White Tea extract induces lipolytic activity and inhibits adipogenesis in human subcutaneous (pre)-adipocytes.

Source: Nutr Metab (Lond). 2009 May 1;6(1):20. [Epub ahead of print]

ABSTRACT: BACKGROUND: The dramatic increase in obesity-related diseases emphasizes the need to elucidate the cellular and molecular mechanisms underlying fat metabolism. To investigate how natural substances influence lipolysis and adipogenesis, we determined the effects of White Tea extract on cultured human subcutaneous preadipocytes and adipocytes. METHODS: For our in vitro studies we used a White Tea extract solution that contained polyphenols and methylxanthines. Utilizing cultured human preadipocytes we investigated White Tea extract solution-induced inhibition of triglyceride incorporation during adipogenesis and possible effects on cell viability. In vitro studies on human adipocytes were performed aiming to elucidate the efficacy of White Tea extract solution to stimulate lipolytic activity. To characterize White Tea extract solution-mediated effects on a molecular level, we analyzed gene expression of essential adipogenesis-related transcription factors by qRT-PCR and determined the expression of the transcription factor ADD1/SREBP-1c on the protein level utilizing immunofluorescence analysis. RESULTS: Our data show that incubation of preadipocytes with White Tea extract solution significantly decreased triglyceride incorporation during adipogenesis in a dose- dependent manner (n = 10) without affecting cell viability (n = 10). These effects were, at least in part, mediated by EGCG (n = 10, 50 muM). In addition, White Tea extract solution also stimulated lipolytic activity in adipocytes (n = 7). Differentiating preadipocytes cultivated in the presence of 0.5% White Tea extract solution showed a decrease in PPARgamma, ADD1/SREBP-1c, C/EBPalpha and C/EBPdelta mRNA levels. Moreover, the expression of the transcription factor ADD1/SREBP-1c was not only decreased on the mRNA but also on the protein level. CONCLUSIONS: White Tea extract is a natural source that effectively inhibits adipogenesis and stimulates lipolysis-activity. Therefore, it can be utilized to modulate different levels of the adipocyte life cycle.

Funny Business- Hydroxycut

Abstract

Aim: The efficacy of optimal doses of highly bioavailable (–)-hydroxycitric acid (HCA-SX) alone and in combination with niacin-bound chromium (NBC) and a standardized Gymnema sylvestre extract (GSE) on weight loss in moderately obese subjects was evaluated by monitoring changes in body weight, body mass index (BMI), appetite, lipid profiles, serum leptin and excretion of urinary fat metabolites. HCA-SX has been shown to reduce appetite, inhibit fat synthesis and decrease body weight without stimulating the central nervous system. NBC has demonstrated its ability to maintain healthy insulin levels, while GSE has been shown to regulate weight loss and blood sugar levels.
Methods: A randomized, double-blind, placebo-controlled human study was conducted in Elluru, India for 8 weeks in 60 moderately obese subjects (ages 21–50, BMI >26 kg/m2). Subjects were randomly divided into three groups. Group A was administered HCA-SX 4667 mg, group B was administered a combination of HCA-SX 4667 mg, NBC 4 mg and GSE 400 mg, while group C was given placebo daily in three equally divided doses 30–60 min before meals. All subjects received a 2000 kcal diet/day and participated in supervised walking.
Results: At the end of 8 weeks, body weight and BMI decreased by 5–6% in both groups A and B. Food intake, total cholesterol, low-density lipoproteins, triglycerides and serum leptin levels were significantly reduced in both groups, while high-density lipoprotein levels and excretion of urinary fat metabolites increased in both groups. A marginal or non-significant effect was observed in all parameters in group C.
Conclusion: The present study shows that optimal doses of HCA-SX and, to a greater degree, the combination of HCA-SX, NBC and GSE can serve as an effective and safe weight-loss formula that can facilitate a reduction in excess body weight and BMI, while promoting healthy blood lipid levels.

Reference

Preuss, H.G., Bagchi, D., Bagchi, M., Sanyasi Rao, C.V., & Satyanarayana, S. (2004). Effects of a natural extract of (-)-hydroxycitric acid (HCA-SX) and a combination of HCA-SX plus niacin-bound chromium and Gymnema sylvestre extract on weight loss. Diabetes, Obesity, and Metabolism, 6, 171-180.

My Take

The most interesting thing about this paper is that the same research team published it in two different journals in the same year, using a slightly different title and subject group, which changed the stats but still produced the same results. This paper shows that HCA, NBC, and GSE together have the greatest effect on weight loss, more so than just taking the HCA alone. I looked up the amounts of these components in Hydroxycut and compared them to the amounts in the study. I found that it is very hard to tell exactly how much of each is actually in the product because it is not clearly listed on the label. It seems that the amounts in the product are almost equal to those researched. However, although positive gains were seen, studies still need to be done on Hydroxycut as a whole to claim that it works.

Thermogenic Supplement Ratches Up Metabolism

The acute effects of the thermogenic supplement Meltdown on energy expenditure, fat oxidation, and hemodynamic responses in young, healthy males

Jean Jitomir , Erika Nassar , Julie Culbertson , Jen Moreillon , Thomas Buford , Geoffrey Hudson , Matt Cooke , Richard Kreider and Darryn S Willoughby

Journal of the International Society of Sports Nutrition 2008, 5:23doi:10.1186/1550-2783-5-23

Published:	16 December 2008

Abstract (provisional)

The purpose of this study was to evaluate the effects of a thermogenic supplement, Meltdown, on energy expenditure, fat oxidation, and hemodynamics before and after maximal treadmill exercise. In a double-blind, randomized, placebo-controlled, cross-over design, 12 male participants underwent two testing sessions after consuming either the Meltdownor placebo supplement. While in a fasted state, participants rested for one hour, orally ingested either Meltdown or placebo, rested for another hour, performed a maximal treadmill exercise test, and then rested for another hour. Throughout the testing protocol resting energy expenditure (REE), respiratory exchange ratio (RER), heart rate (HR), and blood pressure (BP) were assessed. Meltdown increased REE significantly more than placebo at 45 min (1.44 + 0.25 vs. 1.28 + 0.23 kcal/min; p= 0.003), 60 min (1.49 + 0.28 vs. 1.30 + 0.22 kcal/min; p= 0.025), and 120 min (1.51 + 0.26 vs. 1.33 + 0.27 kcals/min; p = 0.014) post-ingestion. Meltdown significantly decreased RER at 30 min (0.84 + 0.03 vs. 0.91 + 0.04; p = 0.022) and 45 min post-ingestion (0.82 + 0.04 vs. 0.89 + 0.05; p = 0.042), and immediately post-exercise (0.83 + 0.05 vs. 0.90 + 0.07; p = 0.009). Furthermore, over the course of the evaluation period, area under the curve assessment demonstrated that REE was significantly increased with Meltdown compared to placebo (9,925 + 1,331 vs. 8,951 + 2,961 kcals; p = 0.043), while RER was significantly less than placebo (5.55 + 0.61 vs. 5.89 + 0.44; p = 0.002) following ingestion. HR and BP were not significantly affected prior to exercise with either supplement (p > 0.05) and the exercise-induced increases for HR and BP decreased into recovery and were not different between supplements (p > 0.05). These data suggest that Meltdown enhances REE and fat oxidation more than placebo for several hours after ingestion in fully rested and post-exercise states without any adverse hemodynamic responses.