BRCA genes as candidates for colorectal cancer genetic testing panel: systematic review and meta-analysis.

BACKGROUND: Breast cancer susceptibility gene (BRCA) mutation carriers are at an increased risk for breast, ovarian, prostate and pancreatic cancers. However, the role of BRCA is unclear in colorectal cancer; the results regarding the association between BRCA gene mutations and colorectal cancer risk are inconsistent and even controversial. This study aimed to investigate whether BRCA1 and BRCA2 gene mutations are associated with colorectal cancer risk. METHODS: In this systematic review, we searched PubMed/MEDLINE, Embase and Cochrane Library databases, adhering to PRISMA guidelines. Study quality was assessed using the Newcastle-Ottawa Scale (NOS). Unadjusted odds ratios (ORs) were used to estimate the probability of Breast Cancer Type 1 Susceptibility gene (BRCA1) and Breast Cancer Type 2 Susceptibility gene (BRCA2) mutations in colorectal cancer patients. The associations were evaluated using fixed effect models. RESULTS: Fourteen studies were included in the systematic review. Twelve studies, including seven case-control and five cohort studies, were included in the meta-analysis. A significant increase in the frequency of BRCA1 and BRCA2 mutations was observed in patients with colorectal cancer [OR = 1.34, 95% confidence interval (CI) = 1.02-1.76, P = 0.04]. In subgroup analysis, colorectal cancer patients had an increased odds of BRCA1 (OR = 1.48, 95% CI = 1.10-2.01, P = 0.01) and BRCA2 (OR = 1.56, 95% CI = 1.06-2.30, P = 0.02) mutations. CONCLUSIONS: BRCA genes are one of the genes that may increase the risk of developing colorectal cancer. Thus, BRCA genes could be potential candidates that may be included in the colorectal cancer genetic testing panel.

Protective Effect of Thymidine on DNA Damage Induced by Hydrogen Peroxide in Human Hepatocellular Cancer Cells.

Intracellular ribonucleotide (RN) and deoxyribonucleotide (dRN) pool sizes are critical for the fidelity of DNA synthesis. They are likely to be severely perturbed by many factors which disrupt the integrity and stability of DNA, leading to DNA damage. Exogenously supplied nucleosides are able to increase the deoxynucleoside triphosphate pools, then reverse the DNA damage, and decrease the oncogene-induced transformation dramatically. In this study, the impact of thymidine on the hydrogen peroxide (H2O2)-induced DNA damage was investigated in HepG2 liver cancer cells. From the result of the comet assay, the tail length of cells in the thymidine 600 µM + H2O2 1.0 mM group was dramatically decreased from 42.1 ± 10.8 to 21.9 ± 2.4 µm compared to that exposed with 1.0 mM H2O2 (p < 0.05), suggesting that pretreatment of thymidine reduced the DNA damage of HepG2 cells. Although the RN and dRN contents decreased in the damage group, most of them presented increasing tendency when pretreated with thymidine, especially the key metabolites dCTP, which was mainly related with the decline in the rate of DNA synthesis. The restoration also showed a significant G0/G1 phase arrest of cell cycle progression from 44.6 ± 2.2 to 56.6 ± 0.4% after pretreated with thymidine (p < 0.05). In conclusion, our data demonstrated that the pretreatment with thymidine had a potential protective ability against oxidative damage for DNA in HepG2 cells through the perturbation of RN and dRN pools as well as cell cycle arrest, which should provide new insights into the molecular basis of preventing H2O2-induced oxidative DNA damage in mammalian cells.

Medical students' motivation and academic performance: the mediating roles of self-efficacy and learning engagement.

Background: Motivation matters in medical students' academic performance. However, few studies have specifically examined how motivation and external environmental factors (e.g., institutions) affect medical students' performance with large-scale data sets. The roles of self-efficacy and learning engagement in the mechanisms that govern how motivation affects academic performance are still unclear.Objective: This study aims to advance a comprehensive understanding about the relationships between medical students' motivation, self-efficacy, learning engagement, and academic performance in a nationwide survey, taking students' demographic factors and sociocultural environments into consideration.Design: We collected data from 1930 medical students in China. We probed the relations between studying variables. We then performed structural equation model (SEM) analysis to examine the mediating roles of self-efficacy and learning engagement on the relationship between motivation and academic performance. We further carried out multiple-group SEM analyses to compare differences between males and females, and between students in key universities and colleges (KUCs) and non-key universities and colleges (NKUCs).Results: Medical students in KUCs demonstrated significantly higher intrinsic motivation, better academic performance and lower extrinsic motivation than those in NKUCs. Male students reported higher intrinsic motivation but surprisingly lower academic performance than females. The total effect of intrinsic motivation on academic performance was larger than that of extrinsic motivation. There were significant indirect effects of either intrinsic or extrinsic motivation on academic performance through learning engagement. Besides, both intrinsic motivation and extrinsic motivation predicted self-efficacy; however, the direct effect of self-efficacy on academic performance was not significant.Conclusions: This study provided researchers with a holistic picture of students' types of motivation in relation to academic performance. Findings from this study can help in rethinking the role of self-efficacy in medicine, in finding more effective interventions for promoting medical students' levels of motivation, and in developing motivation-related counselling methods for different groups of medical students.

SERCA and P-glycoprotein inhibition and ATP depletion are necessary for celastrol-induced autophagic cell death and collateral sensitivity in multidrug-resistant tumor cells.

Multidrug resistance (MDR) represents an obstacle in anti-cancer therapy. MDR is caused by multiple mechanisms, involving ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp), which reduces intracellular drug levels to sub-therapeutic concentrations. Therefore, sensitizing agents retaining effectiveness against apoptosis- or drug-resistant cancers are desired for the treatment of MDR cancers. The sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) pump is an emerging target to overcome MDR, because of its continuous expression and because the calcium transport function is crucial to the survival of tumor cells. Previous studies showed that SERCA inhibitors exhibit anti-cancer effects in Bax-Bak-deficient, apoptosis-resistant and MDR cancers, whereas specific P-gp inhibitors reverse the MDR phenotype of cancer cells by blocking efflux of chemotherapeutic agents. Here, we unraveled SERCA and P-gp as double targets of the triterpenoid, celastrol to reverse MDR. Celastrol inhibited both SERCA and P-gp to stimulate calcium-mediated autophagy and ATP depletion, thereby induced collateral sensitivity in MDR cancer cells. In vivo studies further confirmed that celastrol suppressed tumor growth and metastasis by SERCA-mediated calcium mobilization. To the best of our knowledge, our findings demonstrate collateral sensitivity in MDR cancer cells by simultaneous inhibition of SERCA and P-gp for the first time.

Investigation into perturbed nucleoside metabolism and cell cycle for elucidating the cytotoxicity effect of resveratrol on human lung adenocarcinoma epithelial cells.

In an effort to understand the molecular events contributing to the cytotoxicity activity of resveratrol (RSV), we investigated its effects on human lung adenocarcinoma epithelial cell line A549 at different concentrations. Cellular nucleoside metabolic profiling was determined by an established liquid chromatography-mass spectrometry method in A549 cells. RSV resulted in significant decreases and imbalances of deoxyribonucleoside triphosphates (dNTPs) pools suppressing subsequent DNA synthesis. Meanwhile, RSV at high concentration caused significant cell cycle arrest at S phase, in which cells required the highest dNTPs supply than other phases for DNA replication. The inhibition of DNA synthesis thus blocked subsequent progression through S phase in A549 cells, which may partly contribute to the cytotoxicity effect of RSV. However, hydroxyurea (HU), an inhibitor of RNR activity, caused similar dNTPs perturbation but no S phase arrest, finally no cytotoxicity effect. Therefore, we believed that the dual effect of high concentration RSV, including S phase arrest and DNA synthesis inhibition, was required for its cytotoxicity effect on A549 cells. In summary, our results provided important clues to the molecular basis for the anticancer effect of RSV on epithelial cells.

Does academic interest play a more important role in medical sciences than in other disciplines? A nationwide cross-sectional study in China.

BACKGROUND: Research examining the effects of academic interest on students learning achievement across various disciplines, especially a comparison of the effects of academic interest between medical sciences and other disciplines, is still scarce. This study addressed this gap by answering 'does academic interest play a more important role in medical sciences than in other disciplines?'. METHODS: A retrospective cross-sectional study, based on a large project of the National Undergraduate Student Development Survey (NUSDS) conducted by the Ministry of Education of China and Peking University in 2014, was designed to explore the role of academic interest in medical sciences and other disciplines. The participants were resampled to better represent the national distribution of undergraduate students in terms of their demographic characteristics. Specifically, survey data from 54,398 undergraduate students from 87 Chinese universities and colleges were used to address our research questions. We then used the propensity score matching (PSM) model to estimate the effect of academic interest on academic achievement and to compare the effects across different disciplines. RESULTS: Academic interest had a significant positive impact on academic performance, with an effect size of 2.545 (p = 0.000). Specifically, the effect sizes for the disciplines of medical sciences, humanities, social sciences, natural sciences and engineering were 2.310 (p = 0.000), 2.231 (p = 0.000), 2.016 (p = 0.000), 3.840 (p = 0.000) and 2.698 (p = 0.000), respectively. The results show that no particular academic interest in medical sciences is needed to achieve academic success when compared with natural sciences and engineering programmes, but success in medical sciences requires more academic interest than success in humanities or social sciences. CONCLUSIONS: This study clarifies the effect of academic interest on undergraduates' academic achievement while controlling for their demographic characteristics and family factors. The results provide insights into the role of academic interest in academic performance across various disciplines and can inform the college admissions practices of both institutions and high school students in China.

Mitochondria-Mediated Pathogenesis and Therapeutics for Non-Alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD) has become a worldwide epidemic over the last decade. Remarkable progress has been made in understanding the pathogenesis of NAFLD and, subsequently, in developing medications to treat this disease. Although the mechanisms of NAFLD are complex and multifactorial, accumulating and emerging evidence indicates that mitochondria play a critical role in the pathogenesis and progression of NAFLD. Pharmacologic therapies acting on mitochondria may therefore pave the way to novel strategies for the prevention and protection against NAFLD. This review focuses on new insights into the role of hepatic mitochondrial dysfunction in NAFLD, and summarizes recent studies on mitochondria-centric therapies for NAFLD utilizing new medications or repurposing of currently available drugs. Although some studies presented may feature controversial results or are still in lack of clinical verification, it is undoubted that medications that may spare the mitochondria from multiple levels of damage are highly promising, and have begun to be used with some degree of success.

ZH-1 enhances the anticancer activity of gemcitabine via deoxyribonucleotide synthesis and apoptotic pathway against A549 cells.

The purpose of this study was to investigate the inhibitory effect of ZH-1 ((6S,9aS,6aR,9bR)-6-(phenylcarbonyl)-6,6a,9a,9b-tetrahydro-8H-azolidino[3,4-a]b enzo [e]indolizine-7,9-dione) and its potential interaction with gemcitabine in A549 cells. MTT assay showed that the combined use of gemcitabine and ZH-1 presented a significant inhibition effect on A549 cell growth with the cell viability from 82.3 ±â€¯5.6% to 51.0 ±â€¯6.6%. The CI value was 0.60 suggesting a synergistic effect between these two drugs. HPLC-MS/MS data indicated that combined treatment with gemcitabine and ZH-1 induced a significant decrease in deoxyadenosine triphosphate, deoxycytidine triphosphate, deoxyguanosine triphosphate and deoxythymidine triphosphate levels compared with use of gemcitabine alone. Five RNs as well as seven dRNs were considered to be significantly contributive to the discrimination of samples. Furthermore, western blot analysis revealed that the combination treatment caused A549 cell apoptosis via the intrinsic pathway by up-regulating Bax/Bcl-2 ratio, activating caspase-9, caspase-3 and poly-ADP-ribose polymerase, and promoting caspase-7, caspase-9 and poly-ADP-ribose polymerase cleavage. Collectively, the combined treatment with gemcitabine and ZH-1 exerted a strong synergistic action on anticancer activity through growth inhibition, perturbations in ribonucleotides and deoxyribonucleotides and the activation of intrinsic apoptotic signaling pathway.

Profiling of ribonucleotides and deoxyribonucleotides pools in response to DNA damage and repair induced by methyl methanesulfonate in cancer and normal cells.

The absolute and relative pool sizes of deoxyribonucleotides (dRNs) are essential in DNA replication fidelity, DNA damage and repair. We found in this study that although DNA damage induced by methyl methanesulfonate (MMS) seemed similar in cancer (HepG2) and normal (LO2) cells, more extensive alterations in ribonucleotides (RNs) and dRNs pools occurred in HepG2 cells indicating that HepG2 cells were more vigilant to DNA damage. After 10 h repair, RNs pools were still severely perturbed in LO2 cells. Compared to LO2 cells, deoxyribonucleotide triphosphates (dNTPs) pools in HepG2 cells elevated by more folds which could facilitate more efficient DNA repair and improve survival probability following DNA damage, although this should definitely lead to higher mutation rates. DNA repair was more efficient in HepG2 cells at S phase and it partly came to an end while DNA repair was still uncompleted in LO2 cells outside S phase. In conclusion, our results demonstrated that HepG2 and LO2 cells presented many differences in nucleotide metabolism, cell cycle checkpoints and DNA repair pathways in response to DNA damage, which could be potential targets for cancer treatment.

Thalidezine, a novel AMPK activator, eliminates apoptosis-resistant cancer cells through energy-mediated autophagic cell death.

Cancers illustrating resistance towards apoptosis is one of the main factors causing clinical failure of conventional chemotherapy. Innovative therapeutic methods which can overcome the non-apoptotic phenotype are needed. The AMP-activated protein kinase (AMPK) is the central regulator of cellular energy homeostasis, metabolism, and autophagy. Our previous study showed that the identified natural AMPK activator is able to overcome apoptosis-resistant cancer via autophagic cell death. Therefore, AMPK is an ideal pharmaceutical target for chemoresistant cancers. Here, we unravelled that the bisbenzylisoquinoline alkaloid thalidezine is a novel direct AMPK activator by using biolayer interferometry analysis and AMPK kinase assays. The quantification of autophagic EGFP-LC3 puncta demonstrated that thalidezine increased autophagic flux in HeLa cancer cells. In addition, metabolic stress assay confirmed that thalidezine altered the energy status of our cellular model. Remarkably, thalidezine-induced autophagic cell death in HeLa or apoptosis-resistant DLD-1 BAX-BAK DKO cancer cells was abolished by addition of autophagy inhibitor (3-MA) and AMPK inhibitor (compound C). The mechanistic role of autophagic cell death in resistant cancer cells was further supported through the genetic removal of autophagic gene7 (Atg7). Overall, thalidezine is a novel AMPK activator which has great potential to be further developed into a safe and effective intervention for apoptosis- or multidrug-resistant cancers.

Exploring the Antitumor Mechanism of High-Dose Cytarabine through the Metabolic Perturbations of Ribonucleotide and Deoxyribonucleotide in Human Promyelocytic Leukemia HL-60 Cells.

Despite the apparent clinical benefits of high-dose cytarabine (Ara-C) over lower dose Ara-C in acute myeloid leukemia (AML) therapy, the mechanism behind high-dose Ara-C therapy remains uncertain. In this study, a LC-MS-based method was carried out to investigate the metabolic alteration of ribonucleotide and deoxyribonucleotide in human promyelocytic leukemia cells (HL-60) after treatment with Ara-C to reveal its antitumor mechanism. The metabolic results revealed that four nucleotides (ATP, ADP, CDP, and dCTP) could be used as potential biomarkers indicating the benefit of high-dose Ara-C over lower dose Ara-C treatment. Combining metabolic perturbation and cell cycle analysis, we conjectured that, apart from the acknowledged mechanism of Ara-C on tumor inhibition, high-dose Ara-C could present a specific action pathway. It was suggested that the pronounced rise in AMP/ATP ratio induced by high-dose Ara-C can trigger AMP-activated protein kinase (AMPK) and subsequently Forkhead Box, class O (FoxO), to promote cell cycle arrest. Moreover, the significant decrease in CDP pool induced by high-dose Ara-C might further accelerate the reduction of dCTP, which then aggravates DNA synthesis disturbance. As a result, all of these alterations led to heightened tumor inhibition. This study provides new insight in the investigation of potential mechanisms in the clinical benefits of high-dose Ara-C in therapy for AML.

Profiling ribonucleotide and deoxyribonucleotide pools perturbed by gemcitabine in human non-small cell lung cancer cells.

In this study, we investigated the dosage effect of gemcitabine, an inhibitor of ribonucleotide reductase (RR), on cellular levels of ribonucleotides and deoxyribonucleotides using high performance liquid chromatography-electrospray ionization tandem mass spectrometric method. As anticipated, after 4-h incubation of non-small cell lung cancer (A549) cells with gemcitabine at 0.5 and 2 µM, there were consistent reductions in levels of deoxyribonucleoside diphosphates (dNDP) and their corresponding deoxyribonucleoside triphosphates (dNTP). However, after 24-h exposure to 0.5 µM gemcitabine, the amounts of dNTP were increased by about 3 fold, whereas cells after 24-h 2 µM gemcitabine treatment exhibited deoxycytidine diphosphate (dCDP), deoxyadenosine diphosphate (dADP) and deoxyguanosine diphosphate (dGDP) levels less than 50% of control values, with deoxycytidine triphosphate (dCTP) and deoxyguanosine triphosphate (dGTP) returning to the control level. Using cell cycle analysis, we found that 24-h incubation at 0.5 µM gemcitabine resulted in a significant increase in S phase arrest, while 2 µM treatment increased G0/G1 population. Our data demonstrated the correlation between the level of RR and the increased levels of dNTPs in the group of 0.5 µM treatment for 24-h with a markedly reduced level of dFdCTP. Accordingly, we proposed that the dosage of dFdC could determine the arrested phase of cell cycle, in turn affecting the recovery of dNTPs pools.

Effect of Phyllanthus amarus Extract on 5-Fluorouracil-Induced Perturbations in Ribonucleotide and Deoxyribonucleotide Pools in HepG2 Cell Line.

The aim of this study was to investigate the antitumor activities of Phyllanthus amarus (PHA) and its potential of herb-drug interactions with 5-Fluorouracil (5-FU). Cell viability, ribonucleotides (RNs) and deoxyribonucleotides (dRNs) levels, cell cycle distribution, and expression of thymidylate synthase (TS) and ribonucleotide reductase (RR) proteins were measured with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS) method, flow cytometry and Western blot analysis, respectively. Our standardized PHA extract showed toxicity to HepG2 cells at high concentrations after 72 h exposure and induced G2/M cell cycle arrest. Combined use of 5-FU with PHA resulted in significant decreases in ATP, CTP, GTP, UTP and dTTP levels, while AMP, CMP, GMP and dUMP levels increased significantly compared with use of 5-FU alone. Further, PHA could increase the role of cell cycle arrest at S phase induced by 5-FU. Although PHA alone had no direct impact on TS and RR, PHA could change the levels of RNs and dRNs when combined with 5-FU. This may be due to cell cycle arrest or regulation of key enzyme steps in intracellular RNs and dRNs metabolism.

Quantitation of ligupurpurosides B and C in rat plasma using HPLC-MS/MS.

The present study was designed to develop a sensitive and selective specific high performance liquid chromatography (HPLC)-tandem mass spectrometric method (MS/MS) for the determination of ligupurpurosides B and C in rat plasma. The samples were prepared after protein precipitation and analyzed by liquid chromatography equipped with a C18 column interfaced with a triple quadrupole tandem mass spectrometer using ESI as the ionization source in the negative ion mode. The mobile phase consisted of water (0.01 % formic acid)-methanol (57 : 43, V/V) at the flow rate of 0.3 mL·min(-1). The analytes and internal standard acteoside were both detected by use of multiple reaction monitoring mode. The total run time was 6.0 min. The method was linear in the concentration range of 2.5-500.0 ng·mL(-1) and the lower limit of quantifiation (LLOQ) was 2.5 ng·mL(-1). The intra-day and inter-day relative standard deviations across three validation runs over the entire concentration range were less than 9.8 %. The accuracy determined at three concentrations was within ± 6.1% in terms of relative error. In conclusion, this assay offers advantages in terms of expediency and suitability for the analysis of ligupurpuroside B and ligupurpuroside C in various biological fluids.

Dendrobium officinale Prevents Early Complications in Streptozotocin-Induced Diabetic Rats.

Background. Dendrobium officinale (DO) Kimura et Migo is a precious Chinese herb that is considered beneficial for health due to its antioxidant and antidiabetes properties, and so on. In this research, we try to determine the preventive effect of DO on the early complications of STZ-induced diabetic rats. Methods. Type 1 diabetic rats were produced with a single intraperitoneal injection of STZ (50 mg/kg). DO (1 g/kg/day) was then orally administered for 5 weeks. Blood glucose, TC, TG, BUN, CREA, and GSH-PX levels were determined, and electroretinographic activity and hypoalgesia were investigated. Pathological sections of the eyes, hearts, aortas, kidneys, and livers were analyzed. Results. Treatment with DO significantly attenuated the serum levels of TC, TG, BUN, and CREA, markedly increased the amplitudes of ERG a- and b-waves and Ops, and reduced the hypoalgesia and histopathological changes of vital organs induced by hyperglycemia. The protective effect of DO in diabetic rats may be associated with its antioxidant activity, as evidenced by the marked increase in the serum level of glutathione peroxidase. However, DO had no significant effect on blood glucose levels and bodyweight of diabetic rats. Conclusions. DO supplementation is an effective treatment to prevent STZ-induced diabetic complications.

Rh2E2, a novel metabolic suppressor, specifically inhibits energy-based metabolism of tumor cells.

Energy metabolism in cancer cells is often increased to meet their higher proliferative rate and biosynthesis demands. Suppressing cancer cell metabolism using agents like metformin has become an attractive strategy for treating cancer patients. We showed that a novel ginsenoside derivative, Rh2E2, is as effective as aspirin in preventing the development of AOM/DSS-induced colorectal cancer and suppresses tumor growth and metastasis in a LLC-1 xenograft. A sub-chronic and acute toxicity LD50 test of Rh2E2 showed no harmful reactions at the maximum oral dosage of 5000 mg/kg body weight in mice. Proteomic profiling revealed that Rh2E2 specifically inhibited ATP production in cancer cells via down-regulation of metabolic enzymes involving glycolysis, fatty acid ß-oxidation and the tricarboxylic acid cycle, leading to specific cytotoxicity and S-phase cell cycle arrest in cancer cells. Those findings suggest that Rh2E2 possesses a novel and safe anti-metabolic agent for cancer patients by specific reduction of energy-based metabolism in cancer cells.

Application of artificial neural network to investigate the effects of 5-fluorouracil on ribonucleotides and deoxyribonucleotides in HepG2 cells.

Endogenous ribonucleotides and deoxyribonucleotides are essential metabolites that play important roles in a broad range of key cellular functions. Their intracellular levels could also reflect the action of nucleoside analogues. We investigated the effects of 5-fluorouracil (5-FU) on ribonucleotide and deoxyribonucleotide pool sizes in cells upon exposure to 5-FU for different durations. Unsupervised and supervised artificial neural networks were compared for comprehensive analysis of global responses to 5-FU. As expected, deoxyuridine monophosphate (dUMP) increased after 5-FU incubation due to the inhibition of thymine monophosphate (TMP) synthesis. Interestingly, the accumulation of dUMP could not lead to increased levels of deoxyuridine triphosphate (dUTP) and deoxyuridine diphosphate (dUDP). After the initial fall in intracellular deoxythymidine triphosphate (TTP) concentration, its level recovered and increased from 48 h exposure to 5-FU, although deoxythymidine diphosphate (TDP) and TMP continued to decrease compared with the control group. These findings suggest 5-FU treatment caused unexpected changes in intracellular purine polls, such as increases in deoxyadenosine triphosphate (dATP), adenosine-triphosphate (ATP), guanosine triphosphate (GTP) pools. Further elucidation of the mechanism of action of 5-FU in causing these changes should enhance development of strategies that will increase the anticancer activity of 5-FU while decreasing its resistance.

Effects of karanjin on cell cycle arrest and apoptosis in human A549, HepG2 and HL-60 cancer cells.

BACKGROUND: We have investigated the potential anticancer effects of karanjin, a principal furanoflavonol constituent of the Chinese medicine Fordia cauliflora, using cytotoxic assay, cell cycle arrest, and induction of apoptosis in three human cancer cell lines (A549, HepG2 and HL-60 cells). RESULTS: MTT cytotoxic assay showed that karanjin could inhibit the proliferation and viability of all three cancer cells. The induction of cell cycle arrest was observed via a PI (propidium iodide)/RNase Staining Buffer detection kit and analyzed by flow cytometry: karanjin could dose-dependently induce cell cycle arrest at G2/M phase in the three cell lines. Cell apoptosis was assessed by Annexin V-FITC/PI staining: all three cancer cells treated with karanjin exhibited significantly increased apoptotic rates, especially in the percentage of late apoptosis cells. CONCLUSION: Karanjin can induce cancer cell death through cell cycle arrest and enhance apoptosis. This compound may be effective clinically for cancer pharmacotherapy.

Determination of corilagin in rat plasma using a liquid chromatography-electrospray ionization tandem mass spectrometric method.

A sensitive and simple liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method for the determination of corilagin in rat plasma has been developed. Samples were prepared with protein precipitation method and analyzed with a triple quadrupole tandem mass spectrometer. We employed negative electrospray ionization as the ionization source and the analytes were detected in multiple reaction monitoring mode. Separation was achieved on a C8 column eluted with mobile phase consisting of methanol-0.1% formic acid in a gradient mode at the flow rate of 0.3 mL/min. The total run time was 7.0 min.This method was proved to have good linearity in the concentration range of 2.5-1000.0 ng/mL. The lower limit of quantification of corilagin was 2.5 ng/mL. The intra- and inter-day relative standard deviationa across three validation runs for four concentration levels were both <9.8%. The relative error was within ±6.0%. This assay offers advantages in terms of expediency and suitability for the analysis of corilagin in rat plasma. The practical utility of this new HPLC-MS/MS method was confirmed in pilot plasma concentration studies in rats following oral administration.

Comparison of two exploratory data analysis methods for classification of Phyllanthus chemical fingerprint: unsupervised vs. supervised pattern recognition technologies.

In this study, unsupervised and supervised classification methods were compared for comprehensive analysis of the fingerprints of 26 Phyllanthus samples from different geographical regions and species. A total of 63 compounds were identified and tentatively assigned structures for the establishment of fingerprints using high-performance liquid chromatography time-of-flight mass spectrometry (HPLC/TOFMS). Unsupervised and supervised pattern recognition technologies including principal component analysis (PCA), nearest neighbors algorithm (NN), partial least squares discriminant analysis (PLS-DA), and artificial neural network (ANN) were employed. Results showed that Phyllanthus could be correctly classified according to their geographical locations and species through ANN and PLS-DA. Important variables for clusters discrimination were also identified by PCA. Although unsupervised and supervised pattern recognitions have their own disadvantage and application scope, they are effective and reliable for studying fingerprints of traditional Chinese medicines (TCM). These two technologies are complementary and can be superimposed. Our study is the first holistic comparison of supervised and unsupervised pattern recognition technologies in the TCM chemical fingerprinting. They showed advantages in sample classification and data mining, respectively.