Duangporn Thong-Ngam

Distinctive pattern of LINE-1 methylation level in normal tissues and the association with carcinogenesis

Genome-wide losses of DNA methylation have been regarded as a common epigenetic event in malignancies and may play crucial roles in carcinogenesis. Limited information is available on the global methylation status in normal tissues and other cancer types beyond colonic carcinoma. Here we applied the combined bisulfite restriction analysis PCR to evaluate the methylation status of LINE-1 repetitive sequences in genomic DNA derived from microdissected samples from several human normal and neoplastic tissues. We found that methylation of LINE-1 in leukocytes was independent of age and gender. In contrast, normal tissues from different organs showed tissue-specific levels of methylated LINE-1. Globally, most carcinomas including breast, colon, lung, head and neck, bladder, esophagus, liver, prostate, and stomach, revealed a greater percentage of hypomethylation than their normal tissue counterparts. Furthermore, DNA derived from sera of patients with carcinoma displayed more LINE-1 hypomethylation than those of noncarcinoma individuals. Finally, in a colonic carcinogenesis model, we detected significantly greater hypomethylation in carcinoma than those of dysplastic polyp and histological normal colonic epithelium. Thus, the methylation status is a unique feature of a specific tissue type and the global hypomethylation is a common epigenetic process in cancer, which may progressively evolve during multistage carcinogenesis.

Curcumin Decreased Oxidative Stress, Inhibited NF-κB Activation,and Improved Liver Pathology in Ethanol-Induced Liver Injury in Rats

To study the mechanism of curcumin-attenuated inflammation and liver pathology in early stage of alcoholic liver disease, female Sprague-Dawley rats were divided into four groups and treated with ethanol or curcumin via an intragastric tube for 4 weeks. A control group treated with distilled water, and an ethanol group was treated with ethanol (7.5 g/kg bw). Treatment groups were fed with ethanol supplemented with curcumin (400 or 1 200 mg/kg bw). The liver histopathology in ethanol group revealed mild-to-moderate steatosis and mild necroinflammation. Hepatic MDA, hepatocyte apoptosis, and NF-κB activation increased significantly in ethanol-treated group when compared with control. Curcumin treatments resulted in improving of liver pathology, decreasing the elevation of hepatic MDA, and inhibition of NF-κB activation. The 400 mg/kg bw of curcumin treatment revealed only a trend of decreased hepatocyte apoptosis. However, the results of SOD activity, PPARγ protein expression showed no difference among the groups. In conclusion, curcumin improved liver histopathology in early stage of ethanol-induced liver injury by reduction of oxidative stress and inhibition of NF-κB activation.

Ten-day sequential therapy of Helicobacter pylori infection in Thailand.

OBJECTIVES:Antimicrobial resistance has decreased eradication rates of Helicobacter pylori worldwide. The objective of this study was to determine whether a sequential therapy regimen is effective in eradicating H. pylori in adults with nonulcer dyspepsia or peptic ulcer disease in Thailand.METHODS:A total of 115 patients with dyspepsia or peptic ulcer were enrolled in the study. 14C-urea breath test, upper endoscopy, rapid urease test, bacterial culture, and antibiotic resistance assessment were conducted during the course of the treatment. In all, 115 patients underwent a 10-day sequential regimen, which consisted of lansoprazole (30 mg) plus amoxicillin (1 g) twice a day for 5 days, then lansoprazole (30 mg) with metronidazole (500 mg) twice a day, and clarithromycin (1,000 mg) once a day for another 5 consecutive days. Successful eradication was evaluated by negative urea breath test at least 4 weeks after stopping treatment.RESULTS:Successful eradication was achieved in 106 of 115 patients (95%). All patients completed the treatment, without any dropouts. Mild adverse effects included headache and palpitations. The prevalence rate of clarithromycin-resistant H. pylori was found to be 6.1%.CONCLUSIONS:The 10-day sequential treatment for H. pylori is well tolerated and provides a high eradication rate. This regimen can overcome the emergence of antibiotic resistance and may have a role as a first-line treatment for H. pylori infection in Thailand.

Sequential therapy in clarithromycin-sensitive and -resistant Helicobacter pylori based on polymerase chain reaction molecular test

Background and Aim:  The present study was designed to determine the eradication rate of 10 day sequential therapy in genotypic clarithromycin‐resistant Helicobacter pylori group identified by molecular polymerase chain reaction (PCR) detection in Thai patients.

Analysis of eight different methods for the detection of Helicobacter pylori infection in patients with dyspepsia

Background:  The present study was designed to compare the accuracy of eight different methods for the detection of Helicobacter pylori (H. pylori) infection in patients with dyspepsia. These tests included culture, histology, rapid urease test (CLO test), serology, saliva IgA, gastric juice IgA, and two in‐house methods, namely in‐house urease test and Gram stain.

Curcumin prevents indomethacin-induced gastropathy in rats

AIM To investigate the effects of curcumin on gastric microcirculation and inflammation in rats with indomethacin-induced gastric damage. METHODS Male Sprague-Dawley rats were randomly divided into three groups. Group 1 (control group, n = 5) was fed with olive oil and 5% NaHCO(3) (-) (vehicle). Group 2 [indomethacin (IMN) group, n = 5] was fed with olive oil 30 min prior to indomethacin 150 mg/kg body weight (BW) dissolved in 5% NaHCO(3) (-) at time 0th and 4th h. Group 3 (IMN + Cur group, n = 4) was fed with curcumin 200 mg/kg BW dissolved in olive oil 0.5 mL, 30 min prior to indomethacin at 0th and 4th h. Leukocyte-endothelium interactions at postcapillary venules were recorded after acridine orange injection. Blood samples were determined for intercellular adhesion molecule (ICAM)-1 and tumor necrosis factor (TNF)-α levels using enzyme linked immunosorbent assay method. Finally, the stomach was removed for histopathological examination for gastric lesions and grading for neutrophil infiltration. RESULTS In group 2, the leukocyte adherence in postcapillary venules was significantly increased compared to the control group (6.40 ± 2.30 cells/frame vs 1.20 ± 0.83 cells/frame, P = 0.001). Pretreatment with curcumin caused leukocyte adherence to postcapillary venule to decline (3.00 ± 0.81 cells/frame vs 6.40 ± 2.30 cells/frame, P = 0.027). The levels of ICAM-1 and TNF-α increased significantly in the indomethacin-treated group compared with the control group (1106.50 ± 504.22 pg/mL vs 336.93 ± 224.82 pg/mL, P = 0.011 and 230.92 ± 114.47 pg/mL vs 47.13 ± 65.59 pg/mL, P = 0.009 respectively). Pretreatment with curcumin significantly decreased the elevation of ICAM-1 and TNF-α levels compared to treatment with indomethacin alone (413.66 ± 147.74 pg/mL vs 1106.50 ± 504.22 pg/mL, P = 0.019 and 58.27 ± 67.74 pg/mL vs 230.92 ± 114.47 pg/mL, P = 0.013 respectively). The histological appearance of the stomach in the control group was normal. In the indomethacin-treated group, the stomachs showed a mild to moderate neutrophil infiltration score. Gastric lesions were erosive and ulcerative. In rats treated with indomethacin and curcumin, stomach histopathology improved and showed only a mild neutrophil infiltration score and fewer erosive lesions in the gastric mucosa. CONCLUSION The results indicate that curcumin prevents indomethacin-induced gastropathy through the improvement of gastric microcirculation by attenuating the level of ICAM-1 and TNF-α.

SEN virus infection in patients with chronic liver disease and hepatocellular carcinoma in Thailand

Background: SEN virus (SENV) has been recently identified as a candidate agent of non-A-E hepatitis virus. However, the exact role of this novel virus in the pathogenesis of chronic liver disease, including chronic hepatitis and cirrhosis, and the development of hepatocellular carcinoma (HCC) remains to be established. Methods: Using seminested polymerase chain reaction (PCR) amplification to detect SENV-D and SENV-H strains in serum, we investigated SENV infection in voluntary blood donors and in patients with chronic liver disease and HCC. Results: SENV was detected in 5 of 100 blood donors (5%), in 15 of 60 patients with chronic liver disease (25%), and in 25 of 60 patients with HCC (42%). The prevalence of SENV in patients with HCC was higher than that in patients with chronic liver disease (P = 0.05) and in blood donors (P < 0.001). An age-specific prevalence of SENV was found at high levels among individuals aged 21–40 years, but was not detected among individuals in the lower age group. No differences between SENV-infected and non-infected patients were demonstrated with respect to demographic data, assumed source of infection, biochemical abnormalities, and severity of chronic liver disease and HCC. Moreover, SENV infection had no apparent effect on the survival of patients with HCC. Conclusions: Our data suggest that SENV infection is frequent among patients with chronic liver disease and HCC. However, pathogenic effects associated with SENV infection in chronic liver disease and HCC need further investigation.

Curcumin attenuated paracetamol overdose induced hepatitis

AIM To investigate whether curcumin could attenuate hepatitis in mice with paracetamol overdose. METHODS Male mice were divided into four groups. Group 1 (control, n = 8); was fed with distilled water; Group 2 [N-acetyl-P-aminophenol (APAP), n = 8]; was fed with a single dose of 400 mg/kg APAP dissolved in distilled water; Group 3 [APAP + curcumin (CUR) 200, n = 8], was fed with a single dose of 400 mg/kg APAP and 200 mg/kg CUR; Group 4 (APAP + CUR 600, n = 8), was fed with a single dose of 400 mg/kg APAP and 600 mg/kg CUR. Twenty-four hours later, the liver was removed to examine hepatic glutathione (GSH), hepatic malondialdehyde (MDA), and histopathologically. Then whole blood was withdrawn from heart to determine transaminase (serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase) and inflammatory cytokines [interleukin (IL)-12 and IL-18] levels by enzyme linked immunosorbent assay. RESULTS Serum transaminase, hepatic MDA, and inflammatory cytokines increased significantly in the APAP compared with the control group. Curcumin supplementation in APAP + CUR 200 and APAP + CUR 600 groups significantly decreased these parameters compared with the APAP group. The level of GSH decreased significantly in the APAP compared with the control group. Curcumin supplementation in APAP + CUR 200 and APAP + CUR 600 groups significantly increased these parameters compared with the APAP group. The histological appearance of the liver in the control group showed normal. In the APAP-treated group, the liver showed extensive hemorrhagic hepatic necrosis at all zones. Curcumin supplementation in APAP + CUR 200 and APAP + CUR 600 groups, caused the liver histopathology to improve. In the APAP + CUR 200 group, the liver showed focal necrosis and but the normal architecture was well preserved in APAP + CUR 600 group. CONCLUSION APAP overdose can cause liver injury. Results indicate that curcumin prevents APAP-induced hepatitis through the improvement of liver histopathology by decreased oxidative stress, reduced liver inflammation, and restoration of GSH.

Lactobacillus plantarum B7 inhibits Helicobacter pylori growth and attenuates gastric inflammation

AIM To determine the anti-Helicobacter property of Lactobacillus plantarum B7 (L. plantarum) B7 supernatants in vitro and the protective effects of L. plantarum B7 on serum tumor necrosis factor-alpha (TNF-α), gastric malondialdehyde (MDA) level, apoptosis, and histopathology in Helicobacter pylori (H. pylori)-induced gastric inflammation in rats. METHODS In vitro, the inhibition of H. pylori growth was examined using L. plantarum B7 supernatants at pH 4 and pH 7 and at the concentration of 1×, 5× and 10× on plates inoculated with H. pylori. The inhibitory effect of H. pylori was interpreted by the size of the inhibition zone. In vitro, male Sprague-Dawley rats were randomly divided into four groups including group 1 (control group), group 2 (H. pylori infected group), group 3 (H. pylori infected with L. plantarum B7 10(6) CFUs/mL treated group) and group 4 (H. pylori infected with L. plantarum B7 10(10) CFUs/mL treated group). One week after H. pylori inoculation, L. plantarum B7 10(6) CFUs/mL or 10(10) CFUs/mL were fed once daily to group 3 and group 4, respectively, for one week. Blood and gastric samples were collected at the end of the study. RESULTS In vitro, at intact pH 4, mean inhibitory zone diameters of 8.5 mm and 13 mm were noted at concentrations of 5× and 10× of L. plantarum B7 supernatant disks, respectively. At adjusted pH 7, L. plantarum B7 supernatants at concentrations of 5× and 10× yielded mean inhibitory zone diameters of 6.5 mm and 11 mm, respectively. In the in vitro study, in group 2, stomach histopathology revealed mild to moderate H. pylori colonization and inflammation. The level of gastric MDA and epithelial cell apoptosis were significantly increased compared with group 1. The serum TNF-α level was significant decreased in group 3 compared with group 2 (P < 0.05). In addition, L. plantarum B7 treatments resulted in a significant improvement in stomach pathology, and decreased gastric MDA level and apoptotic epithelial cells. CONCLUSION L. plantarum B7 supernatant inhibits H. pylori growth. This inhibition was dose-dependent and greater at pH 4. Moreover, L. plantarum B7 attenuated H. pylori-induced gastric inflammation.

Curcumin Attenuates Gastric Cancer Induced by N-Methyl-N-Nitrosourea and Saturated Sodium Chloride in Rats

To determine effects of curcumin on N-methyl-N-nitrosourea (MNU) and saturated sodium chloride (s-NaCl)-induced gastric cancer in rats. Male Wistar rats were divided into 5 groups: control (CO), control supplemented with 200 mg/kg curcumin (CC), MNU + s-NaCl, MNU + s-NaCl supplemented with 200 mg/kg curcumin daily for the first 3 weeks (MNU + s-NaCl + C3W), and MNU + s-NaCl supplemented with curcumin for 20 weeks (MNU + s-NaCl + C20W). To induce stomach cancer, rats except for CO and CC were orally treated with 100 mg/kg MNU on day 0 and 14, and s-NaCl twice-a-week for the first 3 weeks. The experiment was finished and rats were sacrificed at the end of 20 weeks. Cancers were found in forestomachs of all rats in MNU + s-NaCl. The expressions of phosphorylated inhibitor kappaB alpha (phospho-IκBα), 8-hydroxy-2′-deoxyguanosine (8-OHdG), and cyclin D1 significantly increased in MNU + s-NaCl compared with CO. Curcumin treatments for 3 and 20 weeks reduced the cancer incidence resulting in a decrease of phospho-IκBα expression in benign tumor-bearing rats compared with MNU + s-NaCl. Curcumin treatment for 20 weeks also decreased 8-OHdG expression in benign tumor-bearing rats compared with MNU + s-NaCl. Curcumin can attenuate cancer via a reduction of phospho-IκBα and 8-OHdG expressions, which may play a promising role in gastric carcinogenesis.