Effects of Glycyrrhizic Acid on Peroxisome Proliferator-Activated Receptor Gamma (PPARgamma), Lipoprotein Lipase (LPL), Serum Lipid and HOMA-IR in Rats

Impact of Phytochemicals on PPAR Receptors: Implications for Disease Treatments

Peroxisome proliferator-activated receptors (PPARs) are members of the ligand-dependent nuclear receptor family. PPARs have attracted wide attention as pharmacologic mediators to manage multiple diseases and their underlying signaling targets. They mediate a broad range of specific biological activities and multiple organ toxicity, including cellular differentiation, metabolic syndrome, cancer, atherosclerosis, neurodegeneration, cardiovascular diseases, and inflammation related to their up/downstream signaling pathways. Consequently, several types of selective PPAR ligands, such as fibrates and thiazolidinediones (TZDs), have been approved as their pharmacological agonists. Despite these advances, the use of PPAR agonists is known to cause adverse effects in various systems. Conversely, some naturally occurring PPAR agonists, including polyunsaturated fatty acids and natural endogenous PPAR agonists curcumin and resveratrol, have been introduced as safe agonists as a result of their clinical evidence or preclinical experiments. This review focuses on research on plant-derived active ingredients (natural phytochemicals) as potential safe and promising PPAR agonists. Moreover, it provides a comprehensive review and critique of the role of phytochemicals in PPARs-related diseases and provides an understanding of phytochemical-mediated PPAR-dependent and -independent cascades. The findings of this research will help to define the functions of phytochemicals as potent PPAR pharmacological agonists in underlying disease mechanisms and their related complications.

Network analysis of atherosclerotic genes elucidates druggable targets

Background

Atherosclerosis is one of the major causes of cardiovascular disease. It is characterized by the accumulation of atherosclerotic plaque in arteries under the influence of inflammatory responses, proliferation of smooth muscle cell, accumulation of modified low density lipoprotein. The pathophysiology of atherosclerosis involves the interplay of a number of genes and metabolic pathways. In traditional translation method, only a limited number of genes and pathways can be studied at once. However, the new paradigm of network medicine can be explored to study the interaction of a large array of genes and their functional partners and their connections with the concerned disease pathogenesis. Thus, in our study we employed a branch of network medicine, gene network analysis as a tool to identify the most crucial genes and the miRNAs that regulate these genes at the post transcriptional level responsible for pathogenesis of atherosclerosis.

Result

From NCBI database 988 atherosclerotic genes were retrieved. The protein–protein interaction using STRING database resulted in 22,693 PPI interactions among 872 nodes (genes) at different confidence score. The cluster analysis of the 872 genes using MCODE, a plug-in of Cytoscape software revealed a total of 18 clusters, the topological parameter and gene ontology analysis facilitated in the selection of four influential genes viz., AGT, LPL, ITGB2, IRS1 from cluster 3. Further, the miRNAs (miR-26, miR-27, and miR-29 families) targeting these genes were obtained by employing MIENTURNET webtool.

Conclusion

Gene network analysis assisted in filtering out the 4 probable influential genes and 3 miRNA families in the pathogenesis of atherosclerosis. These genes, miRNAs can be targeted to restrict the occurrence of atherosclerosis. Given the importance of atherosclerosis, any approach in the understanding the genes involved in its pathogenesis can substantially enhance the health care system.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01195-y.

In-silico efficacy of potential phytomolecules from Ayurvedic herbs as an adjuvant therapy in management of COVID-19

The recent COVID-19 outbreak caused by SARS-CoV-2 virus has sparked a new spectrum of investigations, research and studies in multifarious directions. Efforts are being made around the world for discovery of effective vaccines/drugs against COVID-19. In this context, Ayurveda, an alternative traditional system of medicine in India may work as an adjuvant therapy in compromised patients. We selected 40 herbal leads on the basis of their traditional applications. The phytomolecules from these leads were further screened through in-silico molecular docking against two main targets of SARS-CoV-2 i.e. the spike protein (S; structural protein) and the main protease (M^PRO; non-structural protein). Out of the selected 40, 12 phytomolecules were able to block or stabilize the major functional sites of the main protease and spike protein. Among these, Ginsenoside, Glycyrrhizic acid, Hespiridin and Tribulosin exhibited high binding energy with both main protease and spike protein. Etoposide showed good binding energy only with Spike protein and Teniposide had high binding energy only with main protease. The above phytocompounds showed promising binding efficiency with target proteins indicating their possible applications against SARS-CoV-2. However, these findings need to be validated through in vitro and in vivo experiments with above mentioned potential molecules as candidate drugs for the management of COVID-19. In addition, there is an opportunity for the development of formulations through different permutations and combinations of these phytomolecules to harness their synergistic potential.

Glycyrrhizic Acid Attenuates Balloon-Induced Vascular Injury Through Inactivation of RAGE Signaling Pathways

Percutaneous coronary intervention is a well-established technique used to treat coronary artery disease, but the risk of coronary artery in-stent restenosis following percutaneous coronary intervention is still high. Previous studies revealed that high mobility group protein B1 (HMGB1) plays a critical role in neointima formation. In this study, we aimed to investigate the role of glycyrrhizic acid (GA), an HMGB1 inhibitor, in the process of neointima formation and the potential mechanisms. We investigated the role of GA in neointima formation through an iliac artery balloon injury model in rabbits. Proliferation, migration, and phenotype transformation of human vascular smooth muscle cells (VSMCs) were observed. Besides, inflammation and receptor for advanced glycosylation end products (RAGE) signaling pathways were studied. The results indicate that GA attenuated neointima formation and downregulated HMGB1 expression in injured artery in rabbits. HMGB1 promoted proliferation, migration, and phenotype transformation through the activation of RAGE signaling pathways in VSMCs, and blockade of HMGB1 by GA (1, 10, and 100 μM) could attenuate those processes and reduce proliferation of human VSMCs. In conclusion, the HMGB1 inhibitor GA might be useful to treat proliferative vascular diseases by downregulating RAGE signaling pathways. Our results indicate a new and promising therapeutic agent for restenosis.

The insulin-sensitising properties of the ellagitannin geraniin and its metabolites from Nephelium lappaceum rind in 3T3-L1 cells

In this study, the insulin-like and insulin sensitising effects of the ellagitannins geraniin, corilagin, ellagic acid, gallic acid and Nephelium lappaceum rind extract in 3T3-L1 adipocytes was investigated. It was observed that non-toxic concentrations of geraniin and its metabolites (0.2-20 μM) and N. lappaceum extract (0.2-20 μg/mL) exhibited insulin-like properties in the absence of insulin and insulin-sensitising properties in the presence of insulin particularly with regards to glucose uptake in 3T3-L1 adipocytes. The compounds were further able to promote adipocyte differentiation and may be involved in the inhibition of lipolysis in 3T3-L1 adipocytes in the presence of insulin. However further study into the molecular mechanisms of action of these compounds need to be carried out to better understand the potential of these compounds/extracts to act as therapeutic agents for hyperglycaemia associated with diabetes mellitus and obesity.

Glycyrrhizic acid and silymarin alleviate the neurotoxic effects of aluminum in rats challenged with fructose-induced insulin resistance: possible role of toll-like receptor 4 pathway

Aluminum is implicated in the etiology of different neurodegenerative diseases, diabetes and cancer. The current study was conducted to evaluate the protective effects of glycyrrhizic acid (GAM) and silymarin (SLY) on AlCl₃-induced neurotoxicity in insulin resistant rats. Insulin resistance (IR) was induced by fructose (10%) in drinking water for 18 weeks. Rats received AlCl₃ (34 mg/kg/day) with or without fructose, GAM (40 mg/kg/day), or SLY (100 mg/kg/day). The administration of GAM or SLY suppressed AlCl₃-induced memory deficit, oxidative stress, and neuroinflammation in brain tissue of IR rats. Both agents inhibited AlCl₃-induced activation of TLR4 signaling pathway including the downstream activation of NF-κB. The results show that IR can partly exacerbate AlCl₃-induced neurotoxicity, particularly memory deficit and neuroinflammation. In addition, GAM and SLY showed promising neuroprotective effect against AlCl₃-induced brain damage in IR rats. The neuroprotection induced by these natural products might be mediated through their antioxidant and anti-inflammatory effects. The latter effect seems to be mediated via inhibition of TLR4 signaling pathway providing new insights on the mechanisms implicated in AlCl₃-induced neurotoxicity and the neuroprotection afforded by GAM and SLY.

DNA Microarray Analysis of Estrogen Responsive Genes in Ishikawa Cells by Glabridin

Based on a previous study, glabridin displayed a dose-dependent increase in estrogenic activity and cell proliferative activity in Ishikawa cells. However, when treated in combination with 17β-E₂, synergistic estrogenic effect was observed but without the same synergistic increase in cell proliferative effect. This study aimed to identify the estrogen and nonestrogen-regulated activities induced by glabridin and in combination with 17β-E₂ in comparison with 17β-E₂. The results showed that 10 µM glabridin and the combination treatment of 100 nM glabridin with 1 nM 17β-E₂ regulated both the genomic and nongenomic estrogen pathways to possibly provide benefits of estrogens in cardiovascular, circulatory, and vasculature systems. Meanwhile, the combination of 100 nM glabridin with 1 nM 17β-E₂ seems to be more suitable to be used as an estrogen replacement. Finally, the results of this study have added on to the present knowledge of glabridin’s function as a phytoestrogen and suggested new ideas for the usage of glabridin.

Glycyrrhizin and glycyrrhetinic acid inhibits alpha-naphthyl isothiocyanate-induced liver injury and bile acid cycle disruption

Alpha-naphthyl isothiocyanate (ANIT) is a common hepatotoxicant experimentally used to reproduce the pathologies of drug-induced liver injury in humans, but the mechanism of its toxicity remains unclear. To determine the metabolic alterations following ANIT exposure, metabolomic analyses was performed by use of liquid chromatography-mass spectrometry. Partial least squares discriminant analysis (PLS-DA) of liver, serum, bile, ileum, and cecum of vehicle- and ANIT-treated mice revealed significant alterations of individual bile acids, including increased tauroursodeoxycholic acid, taurohydrodeoxycholic acid, taurochenodeoxycholic acid, and taurodeoxycholic acid, and decreased ω-, β- and tauro-α/β- murideoxycholic acid, cholic acid, and taurocholic acid in the ANIT-treated groups. In accordance with these changes, ANIT treatment altered the expression of mRNAs encoded by genes responsible for the metabolism and transport of bile acids and cholesterol. Pre-treatment of glycyrrhizin (GL) and glycyrrhetinic acid (GA) prevented ANIT-induced liver damage and reversed the alteration of bile acid metabolites and Cyp7a1, Npc1l1, Mttp, and Acat2 mRNAs encoding bile acid transport and metabolism proteins. These results suggested that GL/GA could prevent drug-induced liver injury and ensuing disruption of bile acid metabolism in humans.

Low-power laser irradiation in salivary glands reduces glycemia in streptozotocin-induced diabetic female rats

Low-power laser irradiation (LPLI) has been extensively employed to modulate inflammation in vitro and in vivo. Previous reports from our group indicated that LPLI might regulate glycemia in diabetic animals. Diabetes results in chronic hyperglycemia and therefore chronic inflammation by upregulation of inflammatory markers such as the high mobility group box 1 (HMGB1) protein. Thus this study aimed to analyze the LPLI effects upon blood glucose levels, plasma insulin and HMGB1 concentrations in a diabetes experimental rat model. Streptozotocin-induced diabetic rats were irradiated in the salivary glands area with a diode laser applied at 660 nm, 70 mW, 20 J/cm² , 22.4 J, with a spot area of 0.028 cm² and its effects were evaluated. LPLI significantly reduced diabetic rat hyperglycemia, without changing insulin or HMGB1 plasma levels, but possibly by ameliorating the insulin resistance in these animals. These findings suggest that LPLI might have a systemic effect, but more studies are necessary to better understand its mechanisms. Fasting blood glucose measured by peroxidase-glucose oxidase (PGO) method (A), showing a reduction of diabetic animals glycemia after LPLI. LPLI probably reduced the hyperglycemia in diabetes by improving the insulin resistance in these animals (B). C n = 10, CL n = 10, D n = 7 and DL n = 8. Data are expressed as mean ± SD; * P < 0.05 vs. respective control group; # P < 0.05 vs. D group.

Glycyrrhizic Acid Reduces Heart Rate and Blood Pressure by a Dual Mechanism

Beta adrenergic receptors are crucial for their role in rhythmic contraction of heart along with their role in the pathological conditions such as tachycardia and high risk of heart failure. Studies report that the levels of beta-1 adrenergic receptor tend to decrease by 50%, whereas, the levels of beta-2 adrenergic receptor remains constant during the risk of heart failure. Beta blockers—the antagonistic molecules for beta-adrenergic receptors, function by slowing the heart rate, which thereby allows the left ventricle to fill completely during tachycardia incidents and hence helps in blood pumping capacity of heart and reducing the risk of heart failure. In the present study, we investigate the potential of glycyrrhizic acid (GA) as a possible principal drug molecule for cardiac arrhythmias owing to its ability to induce reduction in the heart rate and blood pressure. We use in vitro and in silico approach to study GA′s effect on beta adrenergic receptor along with an in vivo study to examine its effect on heart rate and blood pressure. Additionally, we explore GA′s proficiency in eliciting an increase in the plasma levels of vasoactive intestinal peptide, which by dilating the blood vessel consequently, can be a crucial aid during the occurrence of a potential heart attack. Therefore, we propose GA as a potential principal drug molecule via its potential in modulating heart rate and blood pressure.

New insight into determining indicators of metabolic status in women: Expression of PPARγ and FABP4 in PBMCs

Adiposity and its metabolic disturbances could be regulated by adipocyte-specific peroxisome proliferator-activated receptor gamma and fatty acid-binding protein4. Although these two proteins are mainly expressed in adipose tissues, they can also be expressed in peripheral blood mononuclear cells, which could be useful for predicting body composition and blood parameters. Thus, this cross-sectional study was performed during January 2013-January 2014 with 229 women (age range, 22-52 years) who were classified as obese or nonobese. Serum glucose, insulin, lipids, and body composition were measured in the fasting state. Peripheral blood mononuclear cells were isolated to extract ribonucleic acid (RNA) and to determine gene expression by real time polymerase chain reaction (PCR). All serum parameters and components of body composition were significantly higher in obese than in nonobese women. Gene expression analysis showed that serum levels of glucose and lipids, except high-density lipoprotein (HDL), were higher in the group that expressed high fatty acid-binding protein4. Increased expression of the peroxisome proliferator-activated receptor gamma was associated with a significant reduction of blood sugar and increased HDL and other lipids and visceral fat. Therefore, it seems that the level of expression of these genes in peripheral blood mononuclear cells may indicate metabolic status.

Beneficial effects of legumes on parameters of the metabolic syndrome: a systematic review of trials in animal models

Legume consumption plays a pivotal role in the prevention and treatment of the metabolic syndrome (MetS). This systematic review aimed to highlight the beneficial effects of legume interventions for the prevention and/or improvement of parameters related to the MetS and the implicated metabolic pathways so far reported. The methodology involved a search in four electronic databases (Medline, Web of Science, Scopus, Cochrane Library) from January 2007 to December 2014, considering as descriptors ‘Metabolic Syndrome’ and ‘Fabaceae’ and adequately adjusting the equation in each one of them. In total, forty-one studies were finally included. The majority of the studies described a regulating effect on glucose and lipid metabolism due to legume administration, whereas effects on blood pressure and renal parameters are not fully described. Regarding the metabolic pathways involved, they include the up-regulation of genes related to β-oxidation and acetyl-CoA degradation and the down-regulation of glycolytic and lipogenesis genes, as well as those associated with the acetyl-CoA synthesis. The ameliorating effects of legume consumption on the alterations associated with the MetS are clearly reported and coincide with changes in the expression of protein and genes involved in lipid and glucose metabolism. More research needs to be conducted including more legume species that are highly consumed as part of a healthy dietary pattern.

Glycyrrhizic acid Attenuates Neuroinflammation and Oxidative Stress in Rotenone Model of Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting humans. It is characterized by dopaminergic neurodegeneration, mitochondrial impairment, and oxidative stress, enhanced lipid peroxidation, and induction of pro-inflammatory cytokines. We evaluated the neuroprotective efficacy of glycyrrhizic acid (GA), an active component of licorice, against rotenone-induced-oxidative stress and neuroinflammation in a PD rat model. Since PD is progressive and chronic, we investigated the effect of chronic administration of GA for 4 weeks (50 mg/kg/day), 30 min prior to rotenone administration. Rotenone administration significantly reduced the activity of superoxide dismutase and catalase, and caused the depletion of reduced glutathione. A concomitant increase in the levels of the lipid peroxidation product malondialdehyde was observed. It also significantly enhanced the levels of pro-inflammatory cytokines in the midbrain and elevated the levels of inflammatory mediators such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Immunohistochemical analysis revealed significant increments in ionized calcium-binding adaptor molecule-1 (Iba-1) levels, and in glial fibrillary acidic protein (GFAP) levels, and loss of dopamine neurons in the substantia nigra pars compacta upon rotenone challenge. GA treatment significantly attenuated the dopamine neuron loss and decreased the Iba-1 and GFAP activation induced by the rotenone insult. GA also improved antioxidant enzyme activity, prevented glutathione depletion, inhibited lipid peroxidation, and attenuated induction of pro-inflammatory cytokines. Subsequently, GA attenuated the increased levels of the inflammatory mediators COX-2 and iNOS. In conclusion, GA protects against rotenone-induced-PD. The neuroprotective effects of GA are attributed to its potent antioxidative and anti-inflammatory properties.

Modulation of lipid metabolism in glycyrrhizic acid-treated rats fed on a high-calorie diet and exposed to short or long-term stress

Stress and high-calorie diets increase the risk of developing metabolic syndrome. Glycyrrhizic acid (GA) has been shown to improve dyslipidaemia in rats fed on a high-calorie diet. This study aimed to examine the effects of GA on lipid metabolism in rats exposed to short- or long-term stress and on a high-calorie diet. The parameters examined included serum lipid profiles, serum free fatty acids and fatty acid profiles in tissues, and expression of peroxisome proliferator-activated receptors (PPAR), lipoprotein lipase (LPL), elongases and desaturases. Within the 14- or 28-day exposure groups, neither stress nor GA affected the lipid profile and serum free fatty acids. Stress did not affect PPAR-α expression in both the 14- and 28-day exposure groups. However, GA-treated rats from the former group had increased PPAR-α expression only in the kidney while all other tissues from the latter group were unaffected. Stress increased PPAR-γ expression in the heart of the 28-day exposure group but its expression was unaffected in all tissues of the 14-day exposure group. GA elevated PPAR-γ expression in the kidney and the skeletal muscles. Neither stress nor GA affected LPL expressions in all tissues from the 14-day exposure group but its expressions were elevated in the QF of the stressed rats and heart of the GA-treated rats of the 28-day exposure group. As for the elongases and desaturases in the liver, stress down-regulated ELOVL5 in the long-term exposure group while up-regulated ELOVL6 in the short-term exposure group while hepatic desaturases were unaffected by stress. Neither elongase nor desaturase expressions in the liver were affected by GA. This research is the first report of GA on lipid metabolism under stress and high-calorie diet conditions and the results gives evidence for the role of GA in ameliorating MetS via site-specific regulation of lipid metabolism gene expressions and modification of fatty acids.

Irregularities in glucose metabolism induced by stress and high-calorie diet can be attenuated by glycyrrhizic acid

Stress and high-calorie diet increase the risk of developing metabolic syndrome. Glycyrrhizic acid (GA) has been shown to improve hyperglycaemia and dyslipidaemia under various physiological conditions. This study was aimed at examining the effects of stress and GA on glucose metabolism under short- or long-term stress. Forty-eight Sprague Dawley rats were divided into two groups with constant stress induced by light (300-400 lux) for either 14 days (short-term stress) or 28 days (long-term stress). Within each group, the rats were subdivided into three treatment groups i.e. Group A (control group): high-calorie diet (HCD) only; Group B: HCD + stress (14 or 28 days) and Group C: HCD + stress (14 or 28 days) + GA (100 mg/kg). The blood glucose concentrations of the rats exposed to 14-day stress were elevated significantly and GA lowered blood glucose concentration significantly in the 14-day exposure group. The 28-day exposure group adapted to stress as shown by the lower adrenaline level and gluconeogenic enzymes activities in most of the tissues than the 14-day exposure group. With regards to adrenaline and corticosterone, GA was found to increased adrenaline significantly in the short-term exposure group while lowering corticosterone in the long-term exposure group. GA-treated short- and long-term exposure groups had significant reduction in hexose-6-phosphate dehydrogenase activities in the visceral adipose tissues and quadriceps femoris respectively. The results may indicate the role of GA in improving blood glucose concentration in individuals exposed to short-term stress who are already on a high-calorie diet via selective action on gluconeogenic enzymes in different tissues.

Novel Inhibitory Effects of Glycyrrhizic Acid on the Accumulation of Advanced Glycation End Product and Its Receptor Expression

Beneficial effects of glycyrrhizic acid (GA), a bioactive extract of licorice root, in the prevention of metabolic syndrome have been consistently reported while advanced glycation end products (AGE) and receptor for advanced glycation end product (RAGE) are the leading factors in the development of diabetes mellitus. The aim of this study was to investigate the effects of GA on the AGE-RAGE axis using high-fat/high-sucrose (HF/HS) diet-induced metabolic syndrome rat models. Twenty four male Sprague-Dawley rats were randomly assigned into three groups for 4 weeks: (1) Group A, normal diet with standard rat chow; (2) Group B, HF/HS diet; (3) Group C, HF/HS diet and oral administration of 100 mg/kg GA per day. The results showed that HF/HS diet elevated the fasting blood glucose level and insulin resistance index which was prevented by GA supplementation. GA treatment significantly lowered the circulating AGE independent of its glucose-lowering effect. HF/HS diet also triggered RAGE upregulation in the abdominal muscles while GA administration downregulated RAGE expression in the abdominal muscles, aorta and subcutaneous adipose tissues. In conclusion, HF/HS diet could cause glucose intolerance, insulin resistance and upregulation of RAGE expression while GA ameliorated the metabolic dysregulation besides exhibiting inhibitory effects on the AGE-RAGE axis.

Effects of simvaglyzin and atorvaglyzin on the expression of 3-hydroxy-3-methyl-glutaryl-CoA reductase in rat liver

Activity and levels of protein and mRNA of 3-hydroxy-3-methyl-glutaryl-CoA reductase were estimated in rat liver after the administration of atorvastatin and simvastatin and their complexes with glycyrrhizic acid (atorvaglyzin and simvaglyzin). The amount of 3-hydroxy-3-methyl-glutaryl-CoA reductase protein in rats decreased by 13 and 25% (p<0.05) 24 h after treatment with atorvaglyzin and simvaglyzin, respectively. Activity of this enzyme decreased by 46% in rats treated with atorvaglyzin. The amount of messenger RNA in these groups significantly increased as compared to control group (untreated animals).

Enhanced anti-obesity activities of red mold dioscorea when fermented using deep ocean water as the culture water

Deep ocean water (DOW) has, in previous studies, been found to be a novel anti-obesity drink and useful in raising Monascus-produced monascin and ankaflavin levels. This may resolve the limited anti-obesity ability of red mold dioscorea (RMD) known as the Monascus purpureus-fermented Disocorea batatas. This study aims to compare the anti-obesity effect of DOW-cultured RMD (DOW-RMD) and ultra-pure water-cultured RMD (UPW-RMD) in rats fed on a high fat diet. Moreover, the effect of ions composition of DOW and DOW-influenced functional metabolites change of RMD on the differentiation and lipogenesis regulation were investigated using 3T3-L1 pre-adipocytes. In the animal test, compared to UPW-RMD, DOW-RMD possessed better ability to inhibit increases in weight gain, and better feed efficiency, body-fat pad and cross-sectional area of adipocytes. In the cell test, the anti-obesity abilities of DOW-RMD in inhibiting PPARγ and C/EBPα expression in differentiation and lipoprotein lipase activity in lipogenesis were contributed to by the DOW-increased monascin and ankaflavin levels and the ions of DOW, respectively.

Monascus-fermented yellow pigments monascin and ankaflavin showed antiobesity effect via the suppression of differentiation and lipogenesis in obese rats fed a high-fat diet

Monascus-fermented monascin and ankaflavin are found to strongly inhibit differentiation and lipogenesis and stimulate lipolysis effects in a 3T3-L1 preadipocyte model, but the in vivo regulation mechanism is unclear. This study uses obese rats caused by a high-fat diet to examine the effects of daily monascin and ankaflavin feeding (8 weeks) on antiobesity effects and modulation of differentiation, lipogenesis, and lipid absorption. The results show that monascin and ankaflavin had a significant antiobesity effect, which should result from the modulation of monascin and ankaflavin on the inhibition of differentiation by inhibiting CCAT/enhancer-binding protein β (C/EBPβ) expression (36.4% and 48.3%) and its downstream peroxisome proliferator-activated receptor γ (PPARγ) (55.6% and 64.5%) and CCAT/enhancer-binding protein α (C/EBPα) expressions (25.2% and 33.2%) and the inhibition of lipogenesis by increasing lipase activity (14.0% and 10.7%) and decreasing heparin releasable lipoprotein lipase (HR-LPL) activity (34.8% and 30.5%). Furthermore, monascin and ankaflavin are the first agents found to suppress Niemann-Pick C1 Like 1 (NPC1L1) protein expression (73.6% and 26.1%) associated with small intestine tissue lipid absorption. Importantly, monascin and ankaflavin are not like monacolin K, which increases creatine phosphokinase (CPK) activity, known as a rhabdomyolysis indicator.

Quantitative analysis of Glycyrrhizic acid from a polyherbal preparation using liquid chromatographic technique

Glycyrrhizic acid has been used in Indian traditional medicine for ages. It is obtained from the root extract of Glycyrrhizaglabra. There is seasonal variation of Glycyrrhizic acid content in the roots of the plant. So a proper method for quantification of the same is necessary from the polyherbal preparation available in the market. A simple, rapid, sensitive and specific reverse phase high performance liquid chromatographic method have been developed for the quantitative estimation of glycyrrhizic acid from polyherbal preparation containing aqueous root extract of Glycyrrhizaglabra using a photodiode array detector. The identity confirmation was carried out using mass spectrometry. Baseline resolution of the glycyrrhizic acid peak was achieved on a reverse phase C18 column (125 mm × 4.0 mm, 5 μ) using an isocratic mobile phase consisting of 5.3 mM phosphate buffer and acetonitrile in the ratio 65:35 v/v. Chromatograms were monitored at 252 nm.5.3 mM phosphate buffer was replaced with 0.5mM ammonium acetate buffer in the mobile phase when MS detector was used. The method was found to be linear in the concentration range of 12.4 to124 μg/ml with a correlation co-efficient of 0.999. The limit of detection and the limit of quantitation were 3.08 μg/ml and 10.27 μg/ml respectively. The average recovery from three spike levels was 99.93 ± 0.26%. Identity confirmation of the chromatographic peak was achieved by electrospray ionization mass spectrometry and similar molecular ion peak was obtained for both sample and standard. The developed method is suitable for the routine analysis, stability testing and assay of glycyrrhizic acid from polyherbal preparations containing aqueous extracts of Glycyrrhizaglabra.