Anti-plasmodial and Chloroquine Resistance Suppressive Effects of Embelin.

BACKGROUND: Emergence of chloroquine (CQ) resistance among different strains of Plasmodium falciparum is the worst catastrophe that has ever perplexed the dedicated efforts to eradicate malaria. This urged the scientists to search for new alternatives or sensitizers to augment its antiplasmodium effect. MATERIALS AND METHOD: In this experiment, the potential of embelin, isolated from Embelia ribes, to inhibit the growth and sensitize CQ action was screened using SYBRE-green-I based drug sensitivity and isobologram assays, respectively. Its effect on red blood cells stability was screened to assess its safety. To explore its molecular mechanism, its effect on plasmodial Hemozoin and the in vitro ß-hematin formation was screened as well. Furthermore, its anti-oxidant activity was measured using the conventional in vitro tests and its molecular characters were obtained using Molispiration program. RESULTS: The results showed that its anti-plasmodial effect was weaker than CQ but synergism was obtained when they were combined at ratios lower than 5:5 CQ/embelin. Furthermore, ß-hematin formation was inhibited by embelin without showing any synergism after mixing with CQ. CONCLUSION: Overall, embelin is not ideal to be suggested as a conventional antiplasmodium but it has a potential to ameliorate CQ resistance. Furthermore, its action is not related to its impact on hemozoin formation. Further, investigations are recommended to illustrate its detailed mechanism of action. Abbreviation used: CQ-DV-PBS-HEPES: Chloroquine-Digestive vacuole-Phosphate-buffer-saline-4-(2-hydroxyethyl-1-piperazin-ethan-sulphoni-acid), EDTA: Ethylen-diamin-tetra-acetic-acid, g.m.wt: Gram molecular weight, cMCM: Complete-malaria-culture-medium, Hct: Hematocrite, PRBCs: Parasitized-redblood-cells, nRBCs: Normal-red-blood-cells, RT: Room temperature, IC: Inhibitory concentration, FIC: Fractional inhibitory concentration, iCM: Incomplete-culturemedium, BSA: Bovin serum albumin, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, DPPH: 2,2-diphenyl-1- picrylhydrazy, BHT: Butylatedhydroxyl-toleuen, PSA: Polar surface area, ClogP: Log partition coefficient (octanol/water), GPCR: G-protein-coupled-receptors, DMSO: Dimethylsulphoxide, NaOH: Sodium hydroxide.

Antiplasmodial and chloroquine chemosensitizing and resistance reversal effects of coumarin derivatives against Plasmodium falciparum 3D7 and K1.

Emergence of chloroquine (CQ) resistance among different strains of Plasmodium falciparum is the worst incident that has ever faced the dedicated efforts to eradicate malaria. The main cause of CQ resistance is over-activity of the pumping mechanism that ousts CQ outside the DV. This urged the scientists to look for other alternatives or adjuvants that augment its action. CQ The study aimed to test the potential of five coumarin derivatives, namely; umbeliferon, esculetin, scopoletine, herniarin and 3-aminocoumarine to inhibit plasmodium growth and reverse CQ resistance in Plasmodium falciparum K1 and 3D7. They are highly ubiquitous in nature and are famous by their diverse pharmacological effects. SYBRE green-1 based drug sensitivity assay was used to screen the effect of CQ and each coumarin on the parasite growth and isobologram technique was to assess the interaction of the coumarins with CQ. Effect of each coumarin on both RBCs and Vero cells stability as well as on RBCs fragility were screened to exclude any toxic impact on normal cells. On the other hand, their effect on hemozoin formation was screened to investigate about their molecular mechanism. For molecular characterization, Their antioxidant properties were determined using the conventional in vitro tests and their characters were obtained from Molinspiration Simulation Software. Results showed that all of them were safe to human cells, have weak to moderate plasmodial growth inhibitory effect and only umbeliferon, 3- aminocoumarin and esculetin has interacted effectively with CQ. These actions are neither correlated with hemozoin formation inhibition nor to the antioxidant mechanisms. Further studies recommended to investigate the mechanism of their action. Overall, all the tested coumarins are not ideal to be used in the conventional malaria therapy and only umbeliferon, 3-aminocoumarin and esculetin can be suggested to potentiate CQ action.

Andrographolide effect on both Plasmodium falciparum infected and non infected RBCs membranes.

OBJECTIVE: To explore whether its antiplasmodium effect of andrographolide is attributed to its plausible effect on the plasma membrane of both Plasmodium falciparum infected and non-infected RBCs. METHODS: Anti-plasmodium effect of andrographolide against Plasmodium falciparum strains was screened using the conventional malaria drug sensitivity assay. The drug was incubated with uninfected RBCs to monitor its effect on their morphology, integrity and osmotic fragility. It was incubated with the plasmodium infected RBCs to monitor its effect on the parasite induced permeation pathways. Its effect on the potential of merozoites to invade new RBCs was tested using merozoite invasion assay. RESULTS: It showed that at andrographolide was innocuous to RBCs at concentrations approach its therapeutic level against plasmodia. Nevertheless, this inertness was dwindled at higher concentrations. CONCLUSIONS: In spite of its success to inhibit plasmodium induced permeation pathway and the potential of merozoites to invade new RBCs, its anti-plasmodium effect can't be attributed to these functions as they were attained at concentrations higher than what is required to eradicate the parasite. Consequently, other mechanisms may be associated with its claimed actions.

BERBERIS VULGARIS FRUIT CRUDE EXTRACT AS A NOVEL ANTI-LEUKAEMIC AGENT.

Tumor protein p53 encoded by the TP53 gene in humans is known as a cancer biomarker in patients diagnosed with cancer, and it plays an essential role in apoptosis, genomic stability, and inhibition of angiogenesis. Cancer therapies with common chemotherapy methods are effective, as known, but have some side effects. Berberis vulgaris is traditionally administrated as a cancer drug. The current research aims to evaluate p53 as a biomarker in WEHI-3 cell line and to demonstrate the Berberis vulgaris fruit crude extract (BVFCE) as a new anticancer drug. For this purpose, we evaluated the effect of BVFCE in different concentrations against WEHI-3cell line in vitro and determined the quantitative level of p53 gene in the treated WEHI-3 cells. The results demonstrated that even at only 1 mg/ml concentration of Berberis vulgaris crude extract, there was a low level of p53 biomarker expression on WEHI-3 cells in comparison with doxorubicin. Therefore, the current study suggests BVFCE as a reliable anti-leukaemic drug and candidate for anticancer therapy. However, further investigation need be carried out to confirm its efficiency in vivo.

Antigen expression pattern of acute promyelocytic leukaemia cases in malaysia.

INTRODUCTION: Acute Promyelocytic Leukaemia (APL) is associated with devastating coagulopathy and life threatening condition which requires immediate medical attention. It is crucial to establish an expedited diagnosis as early therapeutic intervention has led to optimal patient management. In this study, we assessed the type and frequency of antigen expressions in APL and correlated these findings with genetic studies. METHODS: Multiparametric immunophenotyping was performed on 30 samples and findings were correlated with karyotypes, FISH for t(15;17) translocation and RT-PCR for PML-RARΑ for detection of breakpoint cluster regions (bcr1,bcr2 and bcr3). RESULTS: On SSC/CD45, APL cells displayed high to moderate SSC, with the expression of CD33 (100%), CD13 (96.8%), cMPO (71%) but lacked CD34 (3.2%) and HLA-DR (9.7%). Aberrant expression of CD4 was seen in 12.9% and CD56 in 6.5% of the cases. A significant association between cumulative aberrant antigen expression and bcr1 were observed bcr1 (X2(2) =6.833,p<.05). However there were no significant association seen in bcr2 and bcr3; (X2(2) =.199,p>.05) and (X2(2)=4.599,p>.05) respectively. CONCLUSIONS: Flow cytometry is a rapid and effective tool in detecting APL. It is interesting to note that there is significant association between cumulative aberrant antigen expression and genotype analysis. Further validation is required to corroborate this relationship.

MTHFR C677T polymorphism, homocysteine and B-vitamins status in a sample of Chinese and Malay subjects in Universiti Putra Malaysia.

INTRODUCTION: Methylenetetrahydrofolate reductase (MTHFR) C677T is involved in folate and homocysteine metabolism. Disruption in the activity of this enzyme will alter their levels in the body. METHODOLOGY: This study assessed MTHFR C677T polymorphism and its relationship with serum homocysteine and B-vitamins levels in a sample of Chinese and Malays subjects in UPM, Serdang. One hundred subjects were randomly selected from among the university population. Folate, vitamin B12, B6, and homocysteine levels were determined using MBA, ECLIA, and HPLC, respectively. PCR coupled with HinfI digestion was used for detection of MTHFR C677T polymorphism. RESULTS: The frequency of T allele was higher in the Chinese subjects (0.40) compared to the Malay (0.14). Folate, vitamin B12 and B6 levels were highest in the wild genotype in both ethnic groups. Subjects with heterozygous and homozygous genotype showed the highest homocysteine levels. The serum folate and homocysteine were mainly affected by homozygous genotype. CONCLUSION: MTHFR C677T polymorphism plays an important role in influencing the folate and homocysteine metabolism.

Childhood idiopathic myelofibrosis: a case report and review of literature.

Idiopathic myelofibrosis occurs predominantly in older adults. It is very rarely seen in children. We describe a 3-year-old girl with Down's syndrome who presented with recurrent chest infections associated with anaemia and easy bruising. There was mild hepatosplenomegaly. Full blood picture revealed pancytopaenia with leucoerythroblastosis with absence of circulating blast cells. Repeated attempts at bone marrow aspiration and trephine biopsy were unsuccessful. A trephine biopsy from the tibia showed depressed myelopoiesis and erythropoiesis, megakaryocytes with atypical morphology and increased bone marrow reticulin fibres, findings compatible with idiopathic myelofibrosis. She was treated symptomatically as she was clinically stable. Review of the English literature online yielded 46 reported cases of childhood idiopathic myelofibrosis with variable outcome from spontaneous remission to an indolent course with shortened survival. 6 cases evolved to another malignancy. 5 cases were associated with Down's syndrome.