Effects of annexin A1 on apoptosis and cell cycle arrest in human leukemic cell lines

Recent studies suggest that annexin A1 (ANXA1) promotes apoptosis in cancerous cells. This study aims to investigate the effects of ANXA1 on apoptosis and cell cycle arrest in K562, Jurkat and U937 cells and peripheral blood mononuclear cells (PBMC). Cells were treated with ANXA1 and cyclophosphamide prior to flow cytometry analysis for apoptosis and cell cycle arrest induction. At 2.5µM, ANXA1 induced significant apoptosis in K562 (p ≤ 0.001) and U937 (p ≤ 0.05) cells, with EC50 values of 3.6 and 3.8 µM, respectively. In Jurkat cells, induction was not significant (EC50, 17.0 µM). No significant apoptosis induction was observed in PBMC. ANXA1 caused cycle arrest in the G0/G1 phase in K562 and U937 cells with p ≤ 0.001 for both, and (p ≤ 0.01) for Jurkat cells. ANXA1 induced apoptosis and cycle arrest in the G0/G1 phase in K562 and U937 cells, causing only cell cycle arrest in Jurkat cells

Annexin A1 and leukemia: A systematic review

Purpose: To review systematically the involvement of Annexin A1 (ANXA1) in various leukemia cells in order to advance the understanding of ANXA1 role in leukemia. Methods: The systematic review was carried out via a comprehensive search of electronic databases for all relevant articles published up to September 2017. Specific key words were used to retrieve the articles. All articles were imported into EndNote software while duplicates were removed from the list. The retrieved articles were selected using inclusion and exclusion criteria. Results: FK228, a novel HDACi and FR235222, increased expression of ANXA1 in Kasumi-1, SKNO-1 and U937 cells, respectively, and induced apoptosis. The study also neutralized ANXA1 in the same cells, which caused a complete blockage of the FK228-induced apoptosis. Resveratrol was reported to markedly increase ANXA1 levels which led to caspase 3-mediated apoptosis on HL-60 cells. Dexamethasone, 17β-estradiol (E2β), all-trans retinoic acid and okadaic acid enhanced ANXA1 mRNA expression in U937, human CCRF-CEM, ATRA-NB4 and HL-60 cell lines. Rp-8-Br-cAMPs prevented dexamethasone-, E2β- and dBcAMP-induced ANXA1 synthesis via the activation of cAMP-respondelement binding protein (CREB). ANXA1 levels were reduced dramatically in K562/ADR cells as compared to K562 cells. When ANXA1 was upregulated by transfection in these cells, the cells exhibited a decrease in resistance to ADR and vincristine. Conclusion: ANXA1 expression is induced by different drugs which leads to apoptosis in different types of cell. ANXA1 plays a role in the drug resistance of leukemic cells

Ischemic heart disease: effectiveness and safety of statin treatment in a malaysian tertiary healthcare facility

Purpose: To determine the effectiveness and safety of statins in ischemic heart disease (IHD) patients in a Malaysian tertiary hospital.Methods: This cross-sectional observational study was conducted at Universiti Kebangsaan Malaysia (UKM) Medical Center, Kuala Lumpur, Malaysia and patients were included if they were diagnosed with IHD and treated on statins for three months, or had IHD with no statins prescribed.Results: A total of 72 patients admitted to the medical ward due to IHD were enrolled in this study. Fifty three of them were statin users and 19 patients had no history of statin treatment. The most commonly used statin was lovastatin (n = 42, 79.2 %), atorvastatin (n = 5, 9.4 %), simvastatin (n = 3, 5.7 %) androsuvastatin (n = 3, 5.7 %). Risk factors found in the study population were dyslipidaemia (n = 52, 72 %), hypertension (n = 58, 80.1 %), diabetes (n = 36, 50 %), advanced age (n = 63, 87.5 %), smoking (n = 19, 26.4 %) and family history (n = 16, 22.2 %). Patients that were on statin were more likely to achieve targeted LDL-C levels compared to those that did not achieve LDL-C levels (χ2 = 7.25, p = 0.007). There were also no difference in liver enzyme values between statin users and non-statin users.Conclusion: This study provides information regarding safety and efficacy of statins in the local population and the need for a more stringent approach in achieving targeted lipid levels in IHD patients.Keywords: Effectiveness of statins, Safety of statin, Ischemic heart disease, Cardiovascular, Liver enzymes, Hypretension, Diabete

Effect of Allium sativum (garlic) methanol extract on viability and apoptosis of human leukemic cell lines

Purpose: To investigate the effect of Allium sativum (garlic) methanol extract on viability and apoptosis of human leukemic cells.Methods: Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at concentrations of 3.125, 6.25, 12.5, 25, 50, 100, 200, 400 and 800 ug/mL of Allium sativum extract following 48-h treatment on U-937, Jurkat Clone E6-1 and K-562 cell lines. The mode of cell death was determined by Annexin V-FITC staining and analyzed by flow cytometry.Results: The results show that the half-maximal inhibitory concentration (IC50) of A. sativum on U-937, Jurkat Clone E6-1, K-562 cell lines was 105 ± 2.21, 489 ± 4.51 and 455 ± 3.13 μg/mL, respectively, compared with negative control, while apoptosis was 17.93 ± 0.95 % for U-937 cells (p ≤ 0.05), 38.37 ± 1.88 % for Jurkat Clone E6-1 cells (p ≤ 0.001) and 16.37 ± 1.10 % for K-562 cells. A majority of the cells were inhibited by the extract via apoptosis. Only U-937 cells (6.87 ± 0.65 %) showed significant necrosis compared to negative control (p ≤ 0.05).Conclusion: K-562 cells are the most resistant against garlic extract, in contrast to Jurkat Clone E6-1 cells. Garlic extract does not induce necrosis in Jurkat Clone E6-1 and K-562 cells.Keywords: Anti-leukemic, Garlic, Allium sativum, Annexin V-FITC staining,  Necrosis, Apoptosis, Flow cytometry, Jurkat Clone E6-1 cell

Interaction between green tea and perindopril reduces inhibition of angiotensin-converting enzyme activity

Purpose: To investigate the blood pressure-lowering effect of green tea (GT) extract alone and in combination with an angiotensin converting enzyme (ACE) inhibitor, perindopril, on rats. Methods: The study consisted of four groups of five spontaneously hypertensive rats (SHR): negative control (2 % tragacanth mucilage), positive control group (perindopril, 0.36 mg/kg/day) and two treatment groups (green tea, 25 mg/kg/day; and combined green tea/perindopril). The treatments were given orally for 14 days. Systolic blood pressure was measured before and after treatment using the tail cuff technique. Angiotensin converting enzyme activity in the lung homogenate of the hypertensive rats was determined spectrophotometrically. Results: Green tea extract significantly reduced the rats’ systolic blood pressure (p < 0.05) but did not inhibit the angiotensin-converting enzyme. The combination of green tea extract with perindopril also caused a significant decline in blood pressure (p < 0.001). However, the green tea extract attenuated the inhibition of the angiotensin-converting enzyme activity by perindopril. Conclusion: Green tea extract produces anti-hypertensive activity in rats, but its mechanism of action is not via inhibition of angiotensin-converting enzyme. The interaction of GT extract with perindopril results in a reduction of ACE inhibitory activity

Knockdown of Annexin A1 induces apoptosis, causing G2/M arrest and facilitating phagocytosis activity in human leukemia cell lines

Annexin A1 (ANXA1) is an endogenous protein involved in the control of proliferation, cell cycle, phagocytosis, and apoptosis in several types of cancer. To investigate the effects of ANXA1 knockdown in leukemia cells, transfection with specific ANXA1 siRNA was performed. Cell cycle and apoptosis were analyzed using flow cytometry and a mechanism involving caspases and Bcl-2 was quantified using Western blotting. Phagocytosis activity was evaluated using hematoxylin & eosin staining. The ANXA1 expression was significantly downregulated after the knockdown and apoptosis was induced in tested cells. The expression of caspase-9 and -3 increased in U937 and Jurkat cells respectively. Bcl-2 expression was downregulated in K562 and Jurkat cells while upregulated in U937. The number of leukemic cells arrested at the G2/M phase and the phagocytosis index were significantly increased in transfected cells. This suggests that ANXA1 knockdown might be a potential approach in the therapeutic strategy for leukemia

Immunostimulant activity of standardised extracts of Mangifera indica leaf and Curcuma domestica rhizome in mice

Purpose: To investigate the immunomodulating activity of Mangifera indica. (MI) and Curcuma domestica (CD) extracts in mice.Methods: Mice were randomly divided into 4 groups, namely, vehicle, untreated, MI and CD groups (n = 6). They were treated with MI (160 mg/kg) or CD (200 mg/kg) extracts, and vehicle for control group, for 14 days and sacrificed on day 15. In innate immunity test, the mice were challenged with sheep red blood cells (SRBCs) antigen on day 8, while in adaptive immunity test, mice were immunized and challenged on days 7 and 14, respectively, with SRBC. White blood cells count (WBC), spleen index (SI), and haemagglutination (HA) titer, and delayed type hypersensitivity (DTH) responses were determined.Results: For both plant extracts, adaptive immunity groups showed the highest response compared to innate groups. In adaptive immunity, the WBC count of MI and CD treated animals was significantly higher than in the untreated and vehicle treated groups (p < 0.001). Moreover, the SI of mice from MI and CD treated groups differed significantly that of the untreated group (p < 0.01 and p < 0.05, respectively). HA titer in CD (both non-challenged and challenged) groups was significantly higher than in the non-challenged vehicle group (p < 0.001). HA titer in MI group (non-challenged) was significantly lower than in non-challenged CD and challenged groups (p < 0.01 and p < 0.001, respectively).Conclusion: MI and CD extracts, in appropriate doses, exerted immunostimulant effects in mice by enhancing both innate and adaptive immune systems via increase in WBC, SI, HA titer and DTH responses.Keywords: Mangifera indica, Curcuma domestica, Immunostimulant activity, Spleen index,Haemagglutination, Hypersensitivity respons

Effects of durian fruit on blood pressure of spontaneously hypertensive rats

Durian or scientifically known as Durio zibethinus is one of the most well-known seasonal fruits in the Southeast Asia region. However, its safe consumption in individuals with hypertension is still controversial. This study was conducted to investigate the effect of durian on blood pressure of spontaneously hypertensive rat model. Four groups of rats (n=5) were fed with either a low dose durian (26 g/kg), a high dose durian (52 g/kg), sugar solution (8 mL/kg) which has similar sugar composition in the durian as placebo control, and distilled water as vehicle control (8 mL/kg) for 14 days. The durian doses for rats were obtained by converting from human doses. Baseline reading of blood pressure and heart rate were recorded before the first oral administration of durian. The blood pressure and heart rate were also measured 1 h after the durian oral administration on day 1, 3, 7 and 14 of the experiment. In conclusion, durian fruit possessed an acute effect on the blood pressure of hypertensive rats but heart rate was unaffected. High dose administration of durian led to significant elevation of blood pressure after 1 h of consumption. Meanwhile, low dose of durian (26 g/kg) caused an insignificant reduction in systolic and diastolic blood pressure. Tolerance to the durian fruit was observed after three to seven days of the oral administration and low dose consumption of durian fruit was safe in the hypertensive rat

Protective effects of Phyllanthus amarus against lipopolysaccharide-induced neuroinflammation and cognitive impairment in rats

Background:Phyllanthus amarus (PA) is widely studied for its hepatoprotective properties but has recently received increasing attention due to its diverse anti-inflammatory effects. However, the effects of PA in modulating immune responses in the central nervous system leading to protection against functional changes remain unexplored. Therefore, we sought to examine the protective effects of 80% v/v ethanol extract of PA on lipopolysaccharide (LPS)-induced non-spatial memory impairment and neuroinflammation. Methods: Selected major phytoconstituents of PA extract were identified and quantified using high-performance liquid chromatography. Subchronic neurotoxicity was performed in male Wistar rats given daily oral administration of 100, 200, and 400 mg/kg of the PA extract. Their neurobehavioral activities (functional observation battery and locomotor activity) were scored, and the extracted brains were examined for neuropathological changes. Rats were treated orally with vehicle (5% Tween 20), PA extract (100, 200, and 400 mg/kg), or ibuprofen (IBF; 40 mg/kg) for 14 and 28 days before being subjected to novel object discrimination test. All groups were challenged with LPS (1 mg/kg) given intraperitoneally a day prior to the behavioral tests except for the negative control group. At the end of the behavioral tests, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, nitric oxide (NO), inducible nitric oxide synthase (iNOS), CD11b/c integrin expression, and synaptophysin immunoreactivity were determined in the brain tissues. Results: Gallic acid, ellagic acid, corilagin, geraniin, niranthin, phyllanthin, hypophyllanthin, phyltetralin, and isonirtetralin were identified in the PA extract. Subchronic administration of PA extract (100, 200, and 400 mg/kg) showed no abnormalities in neurobehavior and brain histology. PA extract administered at 200 and 400 mg/kg for 14 and 28 days effectively protected the rodents from LPS-induced memory impairment. Similar doses significantly (p < 0.05) decreased the release of proteins like TNF-α, IL-1β, and iNOS in the brain tissue. NO levels, CD11b/c integrin expression, and synaptophysin immunoreactivity were also reduced as compared with those in the LPS-challenged group. Conclusion: Pre-treatment with PA extract for 14 and 28 days was comparable with pre-treatment with IBF in prevention of memory impairment and alleviation of neuroinflammatory responses induced by LPS. Further studies are essential to identify the bioactive phytochemicals and the precise underlying mechanisms