The suppression of the differentiation of adipocytes with Mallotus furetianus is regulated through the posttranslational modifications of C/EBPß.

Obesity is a major risk factor for various chronic diseases, especially lifestyle-related diseases. Therefore, finding a protective substance against obesity and elucidating its molecular mechanism is one of the most important problems for improving human health. In this study, we investigated the antiobesity effect of Mallotus furetianus extract (MFE). The aim of the study was to examine the in vivo and in vitro effects of MFE on lipid synthesis. We examined the effect using an in vivo experimental system with obesity model mice and an in vitro experimental system with 3T3-L1 preadipocytes. We found that the treatment of MFE significantly suppressed the increase in body weight and adipose tissue weight and morphological changes in the liver and adipose tissue of the obesity model mice. In the in vitro experimental system, we revealed that MFE treatment suppressed the expression of transcription factors such as C/EBPα, C/EBPß, and PPARγ, which are involved in the early differentiation of 3T3-L1 preadipocytes. As a result, the ability to synthesize triacylglycerol was suppressed. An interesting finding in this study was the clarification that MFE decreases the expression of C/EBPß through post-translation modifications (PTMs), followed by the transcriptional suppression of PPAR𝛾 and C/EBP𝛼.

Kaempferia galanga L. extract and its main component, ethyl p-methoxycinnamate, inhibit the proliferation of Ehrlich ascites tumor cells by suppressing TFAM expression.

Kaempferia galanga L. shows anti-cancer effects; however, the underling mechanism remains unclear. In this study, we explored the underlying mechanism of the anti-cancer effects of Kaempferia galanga L. Kaempferia galanga L. rhizome extracts (KGEs) suppressed Ehrlich ascites tumor cell (EATC) proliferation by inhibiting S-phase progression. The main component of KGE is ethyl p-methoxycinnamate (EMC), which exhibits the same anti-proliferative effect as KGE. Furthermore, EMC induced the downregulation of cyclin D1 and upregulation of p21. EMC also decreased the expression of mitochondrial transcription factor A (TFAM) but did not significantly change mitochondrial DNA copy number and membrane potential. Phosphorylation at Ser62 of c-Myc, a transcription factor of TFAM, was decreased by EMC treatment, which might be due to the suppression of H-ras expression. These results indicate that EMC is the active compound responsible for the anti-cancer effect of KGE and suppresses EATC proliferation by regulating the protein expression of cyclin D1 and p21; TFAM may also regulate the expression of these genes. In addition, we investigated the anticancer effects of KGE and EMC in vivo using EATC bearing mice. The volume of ascites fluid was significantly increased by intraperitoneal administration of EATC. However, the increase in the volume of ascites fluid was suppressed by oral administration of EMC and KGE. This study provides novel insights into the association between the anti-cancer effects of natural compounds and TFAM, indicating that TFAM might be a potential therapeutic target.

Glyoxylic Acid, an α-Keto Acid Metabolite Derived from Glycine, Promotes Myogenesis in C2C12 Cells.

α-Keto acids may help prevent malnutrition in patients with chronic kidney disease (CKD), who consume protein-restricted diets, because they serve as amino acid sources without producing nitrogenous waste compounds. However, the physiological roles of α-keto acids, especially those derived from non-essential amino acids, remain unclear. In this study, we examined the effect of glyoxylic acid (GA), an α-keto acid metabolite derived from glycine, on myogenesis in C2C12 cells. Differentiation and mitochondrial biogenesis were used as myogenesis indicators. Treatment with GA for 6 d resulted in an increase in the expression of differentiation markers (myosin heavy chain II and myogenic regulatory factors), mitochondrial biogenesis, and intracellular amounts of amino acids (glycine, serine, and alanine) and their metabolites (citric acid and succinic acid). In addition, GA treatment suppressed the 2.5-µM dexamethasone (Dex)-induced increase in mRNA levels of ubiquitin ligases (Trim63 and Fbxo32), muscle atrophy markers. These results indicate that GA promotes myogenesis, suppresses Dex-induced muscle atrophy, and is metabolized to amino acids in muscle cells. Although further in vivo experiments are needed, GA may be a beneficial nutrient for ameliorating the loss of muscle mass, strength, and function in patients with CKD on a strict dietary protein restriction.

Phosphodiesterase 4 mRNA Level Suppression is Important for Extract of Black Carrot to Protect Against Hepatic Injury Induced by Ethanol.

Excessive alcohol use often results in alcoholic liver disease (ALD). An early change in the liver due to excessive drinking is hepatic steatosis, which may ultimately progress to hepatitis, liver fibrosis, cirrhosis, and liver cancer. Among these debilitating processes, hepatic steatosis is reversible with the appropriate treatment. Therefore, it is important to find treatments and foods that reverse hepatic steatosis. Black carrot has antioxidant and anti-inflammatory effects. In this study, we examined the effectiveness of black carrot extract (BCE) on hepatic steatosis in in vivo and in vitro ethanol-induced liver injury models. For the in vivo experiments, serum aminotransferase activities enhanced by ethanol- and carbon tetrachloride were significantly suppressed by the BCE diet. Furthermore, morphological changes in the liver hepatic steatosis and fibrosis were observed in the in vivo ethanol-induced liver injury model, however, BCE feeding resulted in the recovery to an almost normal liver morphology. In the in vitro experiments, ethanol treatment induced reactive oxygen species (ROS) levels in hepatocytes at 9 h. Conversely, ROS production was suppressed to control levels and hepatic steatosis was suppressed when hepatocyte culture with ethanol were treated with BCE. Furthermore, we investigated enzyme activities, enzyme protein levels, and messenger RNA levels of alcohol dehydrogenase (ADH), cytochrome p450 2E1 (CYP2E1), and aldehyde dehydrogenase (ALDH) using enzyme assays, western blot, and quantitative reverse transcription-polymerase chain reaction analyses. We found that the activities of ADH, CYP2E1, and ALDH were regulated through the cAMP-PKA pathway at different levels, namely, translational, posttranslational, and transcriptional levels, respectively. The most interesting finding of this study is that BCE increases cAMP levels by suppressing the Pde4b mRNA and PDE4b protein levels in ethanol-treated hepatocytes, suggesting that BCE may prevent ALD.

Black carrot extract protects against hepatic injury through epigenetic modifications.

We studied the epigenetic regulation of how black carrot extract (BCE) protects against ethanol-induced hepatic damage. We have shown that the butanol-extracted fraction of BCE (BCE-BuOH) increased intracellular cyclic adenosine monophosphate (cAMP) levels by suppressing the expression of phosphodiesterase 4b (PDE4b); however, the detailed mechanism remains to be elucidated. We focused on changes in histone modifications involved in the suppression of pde4 expression. The methylation level of histone H3 lysine 9 (H3K9), which regulates gene expression of PDE4b, decreased after treatment with 100 mM ethanol but was significantly increased by treatment with 400 µg/ml BCE-BuOH. In contrast, ethanol induced an increase in H3K9 acetylation. However, treatment with BCE-BuOH inhibited the increase in acetylation through an increase in Sirtuin 1 (Sirt1), a histone deacetylase. Furthermore, BCE-BuOH treatment increased the level of methionine adenosyltransferase (MAT) 2a mRNA and increased intracellular S-adenosylmethionine. The present results indicate that BCE-BuOH is useful for protection against alcohol-induced hepatic injury. PRACTICAL APPLICATIONS: We have reported that black carrot extract (BCE) suppressed liver steatosis and liver fibrosis on a rat alcoholic liver disease model. The results from this study have shown that BCE regulated the alcoholic-induced hepatic injury at the level of epigenetic modifications. These results suggested that BCE is useful for protection against alcoholic-induced hepatic injury.

Ursolic acid improves the indoxyl sulfate-induced impairment of mitochondrial biogenesis in C2C12 cells.

BACKGROUND/OBJECTIVES: Patients with chronic kidney disease (CKD) have a high concentration of uremic toxins in their blood and often experience muscle atrophy. Indoxyl sulfate (IS) is a uremic toxin produced by tryptophan metabolism. Although an elevated IS level may induce muscle dysfunction, the effect of IS on physiological concentration has not been elucidated. Additionally, the effects of ursolic acid (UA) on muscle hypertrophy have been reported in healthy models; however, it is unclear whether UA ameliorates muscle dysfunction associated with chronic diseases, such as CKD. Thus, this study aimed to investigate whether UA can improve the IS-induced impairment of mitochondrial biogenesis. MATERIALS/METHODS: C2C12 cells were incubated with or without IS (0.1 mM) and UA (1 or 2 µM) to elucidate the physiological effect of UA on CKD-related mitochondrial dysfunction and its related mechanisms using real-time reverse transcription-polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay. RESULTS: IS suppressed the expression of differentiation marker genes without decreasing cell viability. IS decreased the mitochondrial DNA copy number and ATP levels by downregulating the genes pertaining to mitochondrial biogenesis (Ppargc1a, Nrf1, Tfam, Sirt1, and Mef2c), fusion (Mfn1 and Mfn2), oxidative phosphorylation (Cycs and Atp5b), and fatty acid oxidation (Pdk4, Acadm, Cpt1b, and Cd36). Furthermore, IS increased the intracellular mRNA and secretory protein levels of interleukin (IL)-6. Finally, UA ameliorated the IS-induced impairment in C2C12 cells. CONCLUSIONS: Our results indicated that UA improves the IS-induced impairment of mitochondrial biogenesis by affecting differentiation, ATP levels, and IL-6 secretion in C2C12 cells. Therefore, UA could be a novel therapeutic agent for CKD-induced muscle dysfunction.

Carob pod polyphenols suppress the differentiation of adipocytes through posttranscriptional regulation of C/EBPß.

Obesity is a major risk factor for various chronic diseases such as diabetes, cardiovascular disease, and cancer; hence, there is an urgent need for an effective strategy to prevent this disorder. Currently, the anti-obesity effects of food ingredients are drawing attention. Therefore, we focused on carob, which has high antioxidant capacity and various physiological effects, and examined its anti-obesity effect. Carob is cultivated in the Mediterranean region, and its roasted powder is used as a substitute for cocoa powder. We investigated the effect of carob pod polyphenols (CPPs) on suppressing increases in adipose tissue weight and adipocyte hypertrophy in high fat diet-induced obesity model mice, and the mechanism by which CPPs inhibit the differentiation of 3T3-L1 preadipocytes into adipocytes in vitro. In an in vivo experimental system, we revealed that CPPs significantly suppressed the increase in adipose tissue weight and adipocyte hypertrophy. Moreover, in an in vitro experimental system, CPPs acted at the early stage of differentiation of 3T3-L1 preadipocytes and suppressed cell proliferation because of differentiation induction. They also suppressed the expression of transcription factors involved in adipocyte differentiation, thereby reducing triacylglycerol synthesis ability and triglycerol (TG) accumulation. Notably, CPPs regulated CCAAT/enhancer binding protein (C/EBP)ß, which is expressed at the early stage of differentiation, at the posttranscriptional level. These results demonstrate that CPPs suppress the differentiation of adipocytes through the posttranscriptional regulation of C/EBPß and may serve as an effective anti-obesity compound.

Sesaminol prevents Parkinson's disease by activating the Nrf2-ARE signaling pathway.

Parkinson's disease (PD) is a neurodegenerative disease caused by the degeneration of substantia nigra neurons due to oxidative stress. Sesaminol has strong antioxidant and anti-cancer effects. We investigated the preventive effect on PD as a new physiological action of sesaminol produced from sesaminol glycoside using in vitro and in vivo PD models. To prepare an in vitro PD model, 6-hydroxydopamine (6-OHDA) was added to human neuroblastoma (SH-SY5Y cells). The viability of SH-SY5Y cells decreased dose-dependently following 6-OHDA treatment, but the addition of sesaminol restored viability to the control level. 6-OHDA increased intracellular reactive oxygen species production, and the addition of sesaminol significantly suppressed this increase. No Nrf2 expression in the nucleus was observed in the control group, but a slight increase was observed in the 6-OHDA group. The sesaminol group showed strong expression of Nrf2 in the cytoplasm and nucleus. NAD(P)H: quinone oxidoreductase (NQO1) activity was enhanced in the 6-OHDA group and further enhanced in the sesaminol group. Furthermore, the neurotoxine rotenone was orally administrated to mice to prepare an in vivo PD model. The motor function of rotenone-treated mice was shorter than that of the control group, but a small amount of sesaminol restored it to the control level. The intestinal motility in the rotenone group was significantly lower than that in the control group, but it remained at the control level in the sesaminol group. The expression of α-synuclein in the substantia nigra increased in the rotenone group but decreased in the sesaminol group. The rotenone group exhibited shortening and damage to the colonic mucosa, but these abnormalities of the colonic mucosa were scarcely observed in the sesaminol group. These results suggest that sesaminol has a preventative effect on PD.

Mallotus furetianus extract protects against ethanol-induced liver injury via the activation of the cAMP-PKA pathway.

The protective effects of Mallotus furetianus extract (MF) on liver fibrosis induced with ethanol were examined using in vivo and in vitro model. MF treatment suppressed plasma alanine aminotransferase and aspartate aminotransferase activities in ethanol plus carbon tetrachloride (CCl4)-induced cirrhosis rat model. MF also suppressed the increase in type l collagen and α-smooth muscle actin expression in the livers of ethanol plus CCl4-induced rat by the maintenance of intracellular glutathione levels. Furthermore, we evaluated the effect of MF on the alcohol-induced activation of hepatic stellate cells (HSCs), which are responsible for the increased production and deposition of the extracellular matrix in liver injury. Here, we observed the enhancement of the intracellular reactive oxygen species (ROS) levels and the increase in type I collagen and a-SMA expression in HSCs activated with ethanol. However, the enhanced ROS levels were suppressed with the treatments of MF or diphenyleneiodonium (DPI). Furthermore, the treatment of MF or DPI suppressed the increase in type I collagen and a-SMA expression activated with ethanol. We also observed that the treatment of MF or LY194002 suppressed the increase in type I collagen expression in HSCs activated with ethanol, suggesting that ethanol induced type I collagen expression via the PI3K-Akt signaling pathway. On the other hand, the suppression of the synthesis of type I collagen in ethanol and MF-treated HSCs was inhibited by H-89. From these results, MF may suppress the increase in the activity of NADPH oxidase in HSCs activated with ethanol through the cAMP-PKA pathway.

Pharmacological Effects of 1'-Acetoxychavicol Acetate, a Major Constituent in the Rhizomes of Alpinia galanga and Alpinia conchigera.

1'-Acetoxychavicol acetate (ACA) is found in the rhizomes or seeds of Alpinia galanga and Alpinia conchigera, which are used as traditional spices in cooking and traditional medicines in Southeast Asia. ACA possesses numerous medicinal properties. Those include anticancer, antiobesity, antiallergy, antimicrobial, antidiabetic, gastroprotective, and anti-inflammatory activities. ACA is also observed to exhibit antidementia activity. Recent studies have demonstrated that combining ACA with other substances results in synergistic anticancer effects. The structural factors that regulate the activity of ACA include (1) the acetyl group at position 1', (2) the acetyl group at position 4, and (3) the unsaturated double bond between positions 2' and 3'. ACA induces the activation of AMP-activated protein kinase (AMPK), which regulates the signal transduction pathways, and has an important role in the prevention of diseases, including cancer, obesity, hyperlipidemia, diabetes, and neurodegenerative disorders. Such findings suggest that AMPK has a central role in different pharmacological functions of ACA, and ACA is useful for the prevention of life-threatening diseases. However, more studies should be performed to evaluate the clinical effects of ACA and to better understand its potential.

1'-Acetoxychavicol Acetate Increases Proteasome Activity by Activating cAMP-PKA Signaling.

Protein degradation systems are critical pathways for the maintenance of protein homeostasis. The age-dependent attenuation of the proteasome activity contributes to age-related neurodegenerative processes. The molecule 1'-acetoxychavicol acetate (ACA) is naturally obtained from the rhizomes and seeds of Zingiberaceae plants, such as Languas galangal and Alpinia galangal, and exhibits anti-carcinogenic effects. Recently, we have shown that ACA protected the age-related learning and memory impairments in senescence-accelerated mice and maintained cognitive performance. Therefore, we here examined the effects of ACA on the protein degradation systems and cell protection against neurotoxicity in differentiated PC12 cells. ACA increased proteasome activity in PC12 cells. Increased proteasome activity occurred during the initial stages of ACA treatment and lasted at least 9 h. The activity returned to control levels within 24 h. The increase in proteasome activity by ACA was suppressed by H-89, which is a cAMP-dependent protein kinase A inhibitor. ACA increased the adenylate cyclase activity and therefore the intracellular cAMP levels. Furthermore, ACA recovered the initial cell viability, which was reduced after the addition of the amyloid ß-protein fragment to neuronally differentiated PC12 cells. The effects of ACA on amyloid toxicity were reduced after treatment with MG132, a proteasome inhibitor. These results demonstrated a neuroprotective effect of ACA via activation of cAMP/cAMP-dependent protein kinase A signaling in neuronally differentiated PC12 cells.

Anti-steatosis compounds from leaves of Mallotus furetianus.

There is no drug administration-approved therapy for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). In this study, eight compounds, gallic acid (1), methyl gallate (2), corilagin (3), 3,4,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (4), repandinin B (5), (Z)-3-hexenyl-ß-D-glucopyranoside (6), (+)-lyoniresinol-3α-O-α-L-rhamnopyranoside (7) and mallophenol A (8) were isolated from the active fractions of Mallotus furetianus. Three compounds, (6, 7 and 8) revealed potent anti-steatosis activity in the oleic acid (OA)-induced steatosis cell model, with the minimum effective concentration of 0.05 (6), 0.0005 (7) and 0.0005 (8) µg/mL, which were much lower than the control compound, fibrate (72.4 µg/mL).

Protective Effects of Hydrolyzed Nucleoproteins from Salmon Milt against Ethanol-Induced Liver Injury in Rats.

Dietary nucleotides play a role in maintaining the immune responses of both animals and humans. Oral administration of nucleic acids from salmon milt have physiological functions in the cellular metabolism, proliferation, differentiation, and apoptosis of human small intestinal epithelial cells. In this study, we examined the effects of DNA-rich nucleic acids prepared from salmon milt (DNSM) on the development of liver fibrosis in an in vivo ethanol-carbon tetrachloride cirrhosis model. Plasma aspartate transaminase and alanine transaminase were significantly less active in the DNSM-treated group than in the ethanol plus carbon tetrachloride (CCl4)-treated group. Collagen accumulation in the liver and hepatic necrosis were observed histologically in ethanol plus CCl4-treated rats; however, DNSM-treatment fully protected rats against ethanol plus CCl4-induced liver fibrosis and necrosis. Furthermore, we examined whether DNSM had a preventive effect against alcohol-induced liver injury by regulating the cytochrome p450 2E1 (CYP2E1)-mediated oxidative stress pathway in an in vivo model. In this model, CYP2E1 activity in ethanol plus CCl4-treated rats increased significantly, but DNSM-treatment suppressed the enzyme's activity and reduced intracellular thiobarbituric acid reactive substances (TBARS) levels. Furthermore, the hepatocytes treated with 100 mM ethanol induced an increase in cell death and were not restored to the control levels when treated with DNSM, suggesting that digestive products of DNSM are effective for the prevention of alcohol-induced liver injury. Deoxyadenosine suppressed the ethanol-induced increase in cell death and increased the activity of alcohol dehydrogenase. These results suggest that DNSM treatment represents a novel tool for the prevention of alcohol-induced liver injury.

Phosphonate-based irreversible inhibitors of human γ-glutamyl transpeptidase (GGT). GGsTop is a non-toxic and highly selective inhibitor with critical electrostatic interaction with an active-site residue Lys562 for enhanced inhibitory activity.

γ-Glutamyl transpeptidase (GGT, EC 2.3.2.2) that catalyzes the hydrolysis and transpeptidation of glutathione and its S-conjugates is involved in a number of physiological and pathological processes through glutathione metabolism and is an attractive pharmaceutical target. We report here the evaluation of a phosphonate-based irreversible inhibitor, 2-amino-4-{[3-(carboxymethyl)phenoxy](methoyl)phosphoryl}butanoic acid (GGsTop) and its analogues as a mechanism-based inhibitor of human GGT. GGsTop is a stable compound, but inactivated the human enzyme significantly faster than the other phosphonates, and importantly did not inhibit a glutamine amidotransferase. The structure-activity relationships, X-ray crystallography with Escherichia coli GGT, sequence alignment and site-directed mutagenesis of human GGT revealed a critical electrostatic interaction between the terminal carboxylate of GGsTop and the active-site residue Lys562 of human GGT for potent inhibition. GGsTop showed no cytotoxicity toward human fibroblasts and hepatic stellate cells up to 1mM. GGsTop serves as a non-toxic, selective and highly potent irreversible GGT inhibitor that could be used for various in vivo as well as in vitro biochemical studies.

1'-Acetoxychavicol acetate ameliorates age-related spatial memory deterioration by increasing serum ketone body production as a complementary energy source for neuronal cells.

1'-Acetoxychavicol acetate (ACA) is naturally obtained from the rhizomes and seeds of Alpinia galangal. Here, we examined the effect of ACA on learning and memory in senescence-accelerated mice prone 8 (SAMP8). In mice that were fed a control diet containing 0.02% ACA for 25 weeks, the learning ability in the Morris water maze test was significantly enhanced in comparison with mice that were fed the control diet alone. In the Y-maze test, SAMP8 mice showed decreased spontaneous alterations in comparison with senescence-accelerated resistant/1 (SAMR1) mice, a homologous control, which was improved by ACA pretreatment. Serum metabolite profiles were obtained by GC-MS analysis, and each metabolic profile was plotted on a 3D score plot. Based upon the diagram, it can be seen that the distribution areas for the three groups were completely separate. Furthermore, the contents of ß-hydroxybutyric acid and palmitic acid in the serum of SAMP8-ACA mice were higher than those of SAMP8-control mice and SAMR1-control mice. We also found that SAMR1 mice did not show histological abnormalities, whereas histological damage in the CA1 region of the hippocampus in SAMP8-control mice was observed. However, SAMP8-ACA mice were observed in a similar manner as SAMR1 mice. These findings confirm that ACA increases the serum concentrations of ß-hydroxybutyric acid and palmitic acid levels and thus these fuels might contribute to the maintenance of the cognitive performance of SAMP8 mice.

Ecklonia cava Polyphenol Has a Protective Effect against Ethanol-Induced Liver Injury in a Cyclic AMP-Dependent Manner.

Previously, we showed that Ecklonia cava polyphenol (ECP) treatment suppressed ethanol-induced increases in hepatocyte death by scavenging intracellular reactive oxygen species (ROS) and maintaining intracellular glutathione levels. Here, we examined the effects of ECP on the activities of alcohol-metabolizing enzymes and their regulating mechanisms in ethanol-treated hepatocytes. Isolated hepatocytes were incubated with or without 100 mM ethanol. ECP was dissolved in dimethylsulfoxide. ECP was added to cultured cells that had been incubated with or without ethanol. The cells were incubated for 0-24 h. In cultured hepatocytes, the ECP treatment with ethanol inhibited cytochrome P450 2E1 (CYP2E1) expression and activity, which is related to the production of ROS when large quantities of ethanol are oxidized. On the other hand, ECP treatment with ethanol increased the activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase. These changes in activities of CYP2E1 and ADH were suppressed by treatment with H89, an inhibitor of protein kinase A. ECP treatment with ethanol enhanced cyclic AMP concentrations compared with those of control cells. ECP may be a candidate for preventing ethanol-induced liver injury via regulating alcohol metabolic enzymes in a cyclic AMP-dependent manner.

Synergistic Anticancer Activities of Natural Substances in Human Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is highly resistant to currently available chemotherapeutic agents. The clinical outcome of HCC treatment remains unsatisfactory. Therefore, new effective and well-tolerated therapy strategies are needed. Natural products are excellent sources for the development of new medications for disease treatment. Recently, we and other researchers have suggested that the combined effect of natural products may improve the effect of chemotherapy treatments against the proliferation of cancer cells. In addition, many combination treatments with natural products augmented intracellular reactive oxygen species (ROS). In this review we will demonstrate the synergistic anticancer effects of a combination of natural products with chemotherapeutic agents or natural products against human HCC and provide new insight into the development of novel combination therapies against HCC.

Cytotoxic activity of two natural sesquiterpene lactones, isobutyroylplenolin and arnicolide D, on human colon cancer cell line HT-29.

In this study, we found that two sesquiterpene lactones, isobutyroylplenolin and arnicolide D, from Centipeda minima L. (Compositae) exerted stronger cytotoxic activity than cisplatin on the human colon carcinoma HT-29 cell line. Furthermore, the cytotoxicity of these two compounds on normal cells was weaker than that of cisplatin. Treatment with isobutyroylplenolin and arnicolide D increased the levels of intracellular reactive oxygen species and decreased the levels of nuclear factor-κB protein, resulting in cell cycle arrest in G1 phase and apoptosis. We also discuss the difference in structure and activity between these two compounds.

The synergistic effect of 1'-acetoxychavicol acetate and sodium butyrate on the death of human hepatocellular carcinoma cells.

It has been suggested that the combined effect of natural products may improve the effect of treatment against the proliferation of cancer cells. In this study, we evaluated the combination of 1'-acetoxychavicol acetate (ACA), obtained from Alpinia galangal, and sodium butyrate, a major short chain fatty acid, on the growth of HepG2 human hepatocellular carcinoma cells and found that treatment had a synergistic inhibitory effect. The number of HepG2 cells was synergistically decreased via apoptosis induction when cells were treated with both ACA and sodium butyrate. In ACA- and sodium butyrate-treated cells, intracellular reactive oxygen species (ROS) levels and NADPH oxidase activities were increased significantly. The decrease in cell number after combined treatment of ACA and sodium butyrate was diminished when cells were pretreated with catalase. These results suggest that an increase in intracellular ROS levels is involved in cancer cell death. AMP-activated protein kinase (AMPK), a cellular energy sensor, plays an essential role in controlling processes related to tumor development. In ACA- and sodium butyrate-treated cells, AMPK phosphorylation was induced significantly, and this induction improved when cells were pretreated with catalase. These results suggest that the increase in intracellular ROS is involved in the increase of AMPK phosphorylation. In normal hepatocyte cells, treatment with ACA and sodium butyrate did not decrease cell numbers or increase ROS levels. In conclusion, combined treatment with ACA and sodium butyrate synergistically induced apoptotic cell death via an increase in intracellular ROS and phosphorylation of AMPK. Our findings may provide new insight into the development of novel combination therapies against hepatocellular carcinoma.

AMPK synergizes with the combined treatment of 1'-acetoxychavicol acetate and sodium butyrate to upregulate phase II detoxifying enzyme activities.

SCOPE: Phase II enzymes play important roles in detoxifying xenobiotics. We previously reported that both 1'-acetoxychavicol acetate (ACA) and sodium butyrate individually increased phase II enzyme activities. Here, we determined the combined action of ACA and sodium butyrate on phase II enzyme activities in intestinal epithelial cells (IEC 6). METHODS AND RESULTS: ACA and sodium butyrate synergistically increased phase II enzyme activities. Protein levels of intranuclear transcription factor NF-E2-related factor 2 (Nrf2) were increased by ACA or sodium butyrate treatment, but treatment with both did not produce a synergistic effect. Intranuclear p53 protein levels were increased by ACA but decreased by sodium butyrate alone or combined treatment with ACA and sodium butyrate. In contrast, p53 acetylation was promoted by sodium butyrate and the ACA and sodium butyrate combination. Inhibition of AMPK activity decreased phase II enzyme activities that were upregulated by treatment with ACA plus sodium butyrate or other phytochemicals, including kaempferol, quercetin, and epigallocatechin-3-gallate. Combined treatment with ACA and sodium butyrate increased phosphorylated AMPK levels. CONCLUSION: These results suggest that ACA and sodium butyrate synergistically contribute to xenobiotics metabolism. The combined ACA and sodium butyrate treatment synergistically upregulated phase II enzyme activities through AMPK activation and p53 acetylation.