Application of metabonomic analytical techniques in modernization of Chinese medicine.

Abstract

In the recent years, a wide range of metabonomic analytical techniques are widely used in the modern research of traditional Chinese medicine (TCM). At the same time, the international community has attached increasing importance to TCM toxicity problems. Thus, many studies have been implemented to investigate the toxicity mechanisms of TCM. Among these studies, many metabonomic-based methods have been implemented to facilitate TCM toxicity investigation. At present, the most prevailing methods for TCM toxicity research are mainly single analysis techniques using only one analytical means. These techniques include nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS), etc.; with these techniques, some favourable outcomes have been gained in the toxic reaction studies of TCM, such as the action target organs assay, the establishment of action pattern, the elucidation of action mechanism and the exploration of action material foundation. However, every analytical technique has its advantages and drawbacks, no existing analytical technique can be versatile. Multi-analysed techniques can partially overcome the shortcomings of single-analysed techniques. Combination of GC-MS and LC-MS metabolic profiling approaches has unravelled the pathological outcomes of aristolochic acid-induced nephrotoxicity, which can not be achieved by single-analysed techniques. It is believed that with the further development of metabonomic analytical techniques, especially multi-analysed techniques, metabonomics will greatly promote TCM toxicity research and be beneficial to the modernization of TCM in terms of extending the application of modern means in the TCM safety assessment, assisting the formulation of TCM safety norms and establishing the international standards indicators.

Introduction

Metabonomics is an emerging subject of the post-genome era, which, together with genomics, transcriptomics and proteomics, jointly constitutes the ‘Systems Biology’. Metabonomics is the branch of science concerned with the quantitative understandings of the metabolite component of integrated living systems and its dynamic responses to the changes of both endogenous factors (such as physiology and development) and exogenous factors (such as environmental factors and xenobiotics). Recently, as a novel systemic approach to study metabolic profile and accelerate the course of drug development, metabonomics has achieved great growth, which is attracting more and more concerns from the academic community. The main subjects of metabonomics are a variety of predominantly low molecular weight metabolites that serve as the substrates and products of metabolic pathways, and its main biological samples are urine, plasma and serum. Integrity of metabonomic processes includes sample collection and pretreatment, data collection and analysis, and metabolic variation interpretation. Generally, the main technologies metabonomics relied are the nuclear magnetic resonance (NMR)-based method, chromatography-based method and mass spectrometry (MS)-based method. Depending on a series analysis of different sample spectra and combination with chemical pattern recognition methods, metabonomics can be used to identify organisms in pathophysiological state, gene function, drug toxicity and efficacy, and associated biomarkers.

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Pure Garcinia Cambogia Extract usage as a Weight Loss Supplement

Abstract

The aim of this systematic review is to examine the efficacy of Garcinia extract, hydroxycitric acid (HCA) as a weight reduction agent, using data from randomised clinical trials (RCTs). Electronic and nonelectronic searches were conducted to identify relevant articles, with no restrictions in language or time. Two independent reviewers extracted the data and assessed the methodological quality of included studies. Twenty-three eligible trials were identified and twelve were included. Nine trials provided data suitable for statistical pooling. The meta-analysis revealed a small, statistically significant difference in weight loss favouring HCA over placebo (MD: −0.88 kg; 95% CI: −1.75, −0.00). Gastrointestinal adverse events were twice as common in the HCA group compared with placebo in one included study. It is concluded that the RCTs suggest that Garcinia extracts/HCA can cause short-term weight loss. The magnitude of the effect is small, and the clinical relevance is uncertain. Future trials should be more rigorous and better reported.

Introduction

The prevalence of overweight and obesity has increased over the last decade, and current measures have not been able to stem the tide. A wide variety of weight management strategies are presently available, and some involve the use of dietary supplements marketed as slimming aids. One such slimming aid is Garcinia extract, (-)-hydroxycitric acid (HCA).

HCA is a derivative of citric acid and can be found in plant species native to South Asia such as Garcinia cambogia, Garcinia indica, and Garcinia atroviridis. HCA is usually marketed as a weight loss supplement either alone or in combination with other supplements. Some authors have suggested that HCA causes weight loss by competitively inhibiting the enzyme adenosine triphosphatase-citrate-lyase. HCA has also been reported to increase the release or availability of serotonin in the brain, thereby leading to appetite suppression. Other postulated weight loss mechanisms include inhibition of pancreatic alpha amylase and intestinal alpha glucosidase, thereby leading to a reduction in carbohydrate metabolism.

Animal studies have suggested that HCA causes weight loss, and human trials involving the use of HCA as a weight loss supplement have been carried out.

The primary objective of this systematic review was to examine the efficacy of HCA in reducing body weight in humans, using data from randomised clinical trials.

Methods

Electronic searches of the literature were conducted in the following databases: Medline, Embase, The Cochrane Library, Amed, and Cinahl. The search terms used included dietary supplements, antiobesity agents, body weight, hydroxycitrate, garcinia, and derivatives of these. Each database was searched from inception until March, 2010. We also searched the Internet for relevant conference proceedings and hand searched relevant medical journals, and our own files. The bibliographies of all located articles were also searched.

Only randomised, double-blind, placebo-controlled studies were included in this paper. To be considered for inclusion, studies had to test the efficacy of oral HCA or any of its salts for weight reduction in obese or overweight humans. Included studies also had to report body weight as an outcome. No age, time, or language restrictions were imposed for inclusion of studies. Studies which involved the use of HCA as part of a combination treatment (dietary interventions containing other supplements in addition to HCA), or not involving obese or overweight subjects based on body mass index (BMI) values, were excluded from this paper.

Two independent reviewers assessed the eligibility of studies to be included in the paper. Data were extracted systematically by two independent reviewers according to the patient characteristics, interventions, and results. The methodological quality of all included studies was assessed by the use of a quality assessment checklist adapted from the Consolidated Standard of Reporting Trials (CONSORT) guidelines. In addition, the Jadad score was also used to assess the quality of included studies. Disagreements were resolved through discussion with the other authors.

Data are presented as means with standard deviations. Mean changes in body weight were used as common endpoints to assess the differences between HCA and placebo groups. Using the standard meta-analysis software , we calculated mean differences (MDs) and 95% confidence intervals (CIs). Studies included in the meta-analysis were weighted by SD (a proxy for study size). If a trial had 3 arms, only the HCA and placebo arms were included in the meta-analysis. The I2 statistic was used to assess for statistical heterogeneity amongst studies. A funnel plot was used to test for publication bias.

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Explorations of Chemistry and Biology of the Caged Garcinia Xanthones

Abstract

Natural products have been a great source of many small molecule drugs for various diseases. In spite of recent advances in biochemical engineering and fermentation technologies that allow us to explore microorganisms and the marine environment as alternative sources of drugs, more than 70% of the current small molecule therapeutics derive their structures from plants used in traditional medicine. Natural-product-based drug discovery relies heavily on advances made in the sciences of biology and chemistry. Whereas biology aims to investigate the mode of action of a natural product, chemistry aims to overcome challenges related to its supply, bioactivity, and target selectivity. This review summarizes the explorations of the caged Garcinia xanthones, a family of plant metabolites that possess a unique chemical structure, potent bioactivities, and a promising pharmacology for drug design and development.

Introduction

The trees of the genus Garcinia belong to the family of Guttiferae (Clusiaceae) and are found mostly in lowland rainforests of India, Indochina, Indonesia, West and Central Africa, and Brazil. They are slow-growing polygamous trees that produce scented flowers and fruits that often contain a fleshy, edible endocarp. Throughout the years Garcinia trees have retained considerable value as sources for medicines, pigments, gums, waxes, resins, foodstuffs (fruit), fuel (wood, seed oil), and lumber. Arguably, the most widely cultivated and well-known Garcinia tree is Garcinia mangostana. It yields one of the most highly prized tropical fruits, the mangosteen, valued for its delicious endocarp and rind, both of which are thought to have medicinal potential.

The utility of the Garcinia trees in the arts and sciences is well documented. In fact, gamboge, the pulverized gold-colored resin collected primarily from Garcinia hanburyi, and to a lesser extent from Garcinia morella, has a particularly long and rich history in the arts and sciences. For instance, the yellow colorant used on 8th century artifacts from East Asia is presumed to be a gamboge-based water-color. The importation of gamboge in Europe took place in the 15–16th century where it was used mainly as a coloring material by Flemish painters. In fact, this pigment has been noted on a painting by Rembrandt, currently found in the Staatliche Kunstsammlungen Museum in Dresden.The toxicity of gamboge was also noted early on and several accounts warn against licking brushes containing gamboge. In the recent years, gamboge has been utilized primarily for research on identification of biologically active substances. Nonetheless, it is worth noting that Jean Baptiste Perrin used a colloidal suspension of gamboge particles to investigate Brownian motion and derive a value for the Avogadro number in a series of experiments that gave him the Nobel Prize in physics in 1926.

Resource: http://www.ncbi.nlm.nih.gov
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Protective effect of Garcinia against oxidative stress

Abstract

 
Background
Obesity became major health problem in the world, the objective of this work was to examine the effect of high sucrose and high fat diet to induce obesity on antioxidant defense system, biochemical changes in blood and tissue of control, non treated and treated groups by administration of Garcinia cambogia, and explore the mechanisms that link obesity with altered renal function.

Methods

Rats were fed a standard control diet for 12 week (wk) or a diet containing 65% high sucrose (HSD) or 35% fat (HFD) for 8 wk and then HFD group divided into two groups for the following 4 wks. One group was given Garcinia+HFD, the second only high fat, Also the HSD divided into two groups, 1st HSD+Garcinia and 2nd HSD. Blood and renal, mesenteric, Perirenal and epididymal adipose tissues were collected for biochemical assays.

Results

HFD and HSD groups of rats showed a significant increase in feed intake, Body weight (BW) and body mass index (BMI). Also there were significant increases in weights of mesenteric, Perirenal and epididymal adipose tissues in HFD and HSD groups.

HFD and HSD affect the kidney by increasing serum urea and creatinine levels and decreased level of nitric oxide (NO) and increased blood glucose, low density lipoproteins (LDL), triacylglycerol (TG), total cholesterol (TC) and malondialdehyde (MDA). Glucose 6-phosphate dehydrogenase (G6PD) activities were significantly decreased in HFD while there were significant increases in HSD and HSD+G groups p ≤ 0.05 compared with control. Moreover, renal catalase activities and MDA levels were significantly increased while NO level was lowered. These changes improved by Garcinia that decreased the oxidative stress biomarkers and increased NO level.

There were significant positive correlations among BMI, kidney functions (Creatinine and urea), TG and Oxidative markers (renal MDA and catalase).

Conclusions

Rats fed a diet with HFD or HSD showed, hypertriglyceridemia, increased LDL production, increased oxidative stress and renal alteration. Moreover, suggesting association between lipid peroxidation, obesity and nephropathy, while Garcinia ameliorated the damaging effects of the HFD or HSD and decreased feed intake, MDA level and decreased oxidative stress in renal tissues.

Resource: http://www.ncbi.nlm.nih.gov
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