In vitro cytotoxic and toxicological activities of ethanolic extract of Kaempferia galanga Linn. and its active component, ethyl-p-methoxycinnamate, against cholangiocarcinoma / 中西医结合学报

OBJECTIVE@#To evaluate the cytotoxic, apoptotic, mutagenic and immunomodulatory activities of Kaempferia galanga Linn. (KG) extract and ethyl-p-methoxycinnamate (EPMC) in vitro.@*METHODS@#The present study investigated the cytotoxic [using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide test], apoptotic (using a mitochondrial membrane potential assay), mutagenic (using a micronucleus test) and immunomodulatory (using flow cytometry) activities of the ethanolic extract of KG and its bioactive component, EPMC, against two cholangiocarcinoma (CCA) cell lines, CL-6 and HuCCT1, and one normal human cell line, OUMS-36T-1F.@*RESULTS@#Both KG extract and EPMC exhibited moderate cytotoxic activity against both CCA cells. The cytotoxic activity was supported by their concentration-dependent induction of apoptosis. CL-6 was most sensitive (3-4 fold) and selective to 5-fluorouracil (5-FU), compared with KG extract and EPMC [median half inhibiting concentration (IC) and selectivity index (SI) were 23.01 μg/mL and 17.32; 78.41 μg/mL and 4.44; 100.76 μg/mL and 2.20, respectively for 5-FU vs. KG extract vs. EPMC]. HuCCT1 was relatively more sensitive and selective to 5-FU and EPMC than KG extract [median IC and SI were 66.03 μg/mL and 6.04; 60.90 μg/mL and 3.65; 156.60 μg/mL and 2.23, respectively for 5-FU vs. EPMC vs. KG extract]. EPMC produced relatively potent cytotoxic activity against polymorphonuclear cells (IC = 92.20 μg/mL). KG extract and EPMC exhibited concentration-dependent mutagenic activity, as well as inhibition of tumor necrosis factor-α and interleukin-6.@*CONCLUSION@#Considering cytotoxic, apoptotic, immunomodulatory and mutagenic activities, further development of KG as a drug candidate is likely to focus on the oral pharmaceutical formulation of a standardized KG extract rather than isolated compounds.

Inhibitory activities of plumbagin on cell migration and invasion and inducing activity on cholangiocarcinoma cell apoptosis

Objective: To investigate the cytotoxic, apoptotic and inhibitory activities on cell migration and invasion of plumbagin in the human cholangiocarcinoma (CCA) cell line (CL-6) in comparison with human embryonic fibroblast cell line (OUMS). Methods: Cytotoxicity activity was evaluated using MTT assay. Inhibitory effect on cell migration and invasion were investigated using label-free real-time cell analysis and QCM ECMatrix cell invasion chamber, respectively. Apoptotic activity was evaluated using flow cytometry and CellEvent™ Caspase 3/7 assay. Results: Based on results of the cytotoxicity test in CL-6 cells, 50% inhibitory concentration (IC

Inhibitory activities of plumbagin on cell migration and invasion and inducing activity on cholangiocarcinoma cell apoptosis

Objective:To investigate the cytotoxic, apoptotic and inhibitory activities on cell migration and invasion of plumbagin in the human cholangiocarcinoma (CCA) cell line (CL-6) in comparison with human embryonic fibroblast cell line (OUMS).Methods:Cytotoxicity activity was evaluated using MTT assay. Inhibitory effect on cell migration and invasion were investigated using label-free real-time cell analysis and QCM ECMatrix cell invasion chamber, respectively. Apoptotic activity was evaluated using flow cytometry and CellEvent™ Caspase 3/7 assay.Results:Based on results of the cytotoxicity test in CL-6 cells, 50% inhibitory concentration (ICConclusions:The cytotoxic activity and inhibition of migration and invasion including apoptosis induction in the human CCA cell line (CL-6) suggest that plumbagin could be a promising candidate for CCA chemotherapeutics. However, its relatively low selective cytotoxic effect on CCA cells is a major concern.

The Effect of ABO Blood Groups, Hemoglobinopathy, and Heme Oxygenase-1 Polymorphisms on Malaria Susceptibility and Severity

Malaria is one of the most important public health problems in tropical areas on the globe. Several factors are associated with susceptibility to malaria and disease severity, including innate immunity such as blood group, hemoglobinopathy, and heme oxygenase-1 (HO-1) polymorphisms. This study was carried out to investigate association among ABO blood group, thalassemia types and HO-1 polymorphisms in malaria. The malarial blood samples were collected from patients along the Thai-Myanmar border. Determination of ABO blood group, thalassemia variants, and HO-1 polymorphisms were performed using agglutination test, low pressure liquid chromatography and polymerase chain reaction, respectively. Plasmodium vivax was the major infected malaria species in the study samples. Distribution of ABO blood type in the malaria-infected samples was similar to that in healthy subjects, of which blood type O being most prevalent. Association between blood group A and decreased risk of severe malaria was significant. Six thalassemia types (30%) were detected, i.e., hemoglobin E (HbE), β-thalassemia, α-thalassemia 1, α-thalassemia 2, HbE with α-thalassemia 2, and β-thalassemia with α-thalassemia 2. Malaria infected samples without thalassemia showed significantly higher risk to severe malaria. The prevalence of HO-1 polymorphisms, S/S, S/L and L/L were 25, 62, and 13%, respectively. Further study with larger sample size is required to confirm the impact of these 3 host genetic factors in malaria patients.

Identification of potential protein targets of atractylodin against cholangiocarcinoma / 中国药理学与毒理学杂志

OBJECTIVE To identify potential cell signaling pathways and protein targets of the active compound isolated from Atracylodes lancea "atractylodin" in cholangiocarcinoma, using proteomics approach. METHODS The holangiocar- cinoma cell line was exposed with atractylodin for 3 and 6 h and the proteins from both intra- and extra- cellular components were extracted. The extract proteins were separated by SDS-PAGE and digested with trypsin.The LC-MS/MS was applied to identify proteins. Signaling pathways and protein expression were analyzed by MASCOT and STITCH software.RESULTS A total of 4,323 and 4,318 proteins were identified from intra-and extracellular components,respectively. Six intracellular proteins were linked with the signaling pathways (apoptosis, cell cycle control, and PI3K-AKT).Four extracellular proteins were linked with the signaling pathways(NF-κB and PI3K-AKT). CONCLUSION All these proteins will further study to confirm the link to the anticholangiocarcinoma ac-tivity of actractylodin.

The role of heme-oxygenase-1 in pathogenesis of cerebral malaria in the co-culture model of human brain microvascular endothelial cell and ITG Plasmodium falciparum-infected red blood cells

OBJECTIVE@#To investigate the role of human host heme-oxygenase-1 (HO-1) in pathogenesis of cerebral malaria in the in vitro model.@*METHODS@#The effect of human host HO-1 [human brain microvascular endothelial cell (HBMEC)] on hemoglobin degradation in the co-culture model of HBMEC and ITG Plasmodium falciparum-infected red cells (iRBC) through measurement of the enzymatic products iron and bilirubin.@*RESULTS@#Following exposure to the HO-1 inducer CoPPIX at all concentrations, the HBMEC cells apoptosis occurred, which could be prominently observed at 15 μM of 3 h exposure. In contrast, there was no significant change in the morphology in the non-exposed iRBC at all concentrations and exposure time. This observation was in agreement with the levels of the enzymatic degradation products iron and bilirubin, of which the highest levels (106.03 and 1753.54% of baseline level, respectively) were observed at 15 μM vs. 20 μM at 3 h vs. 24 h exposure. For the effect of the HO-1 inhibitor ZnPPIX, HBMEC cell morphology was mostly unchanged, but significant inhibitory effect on cell apoptosis was seen at 10 μM for the exposure period of 3 h (37.17% of baseline level). The degree of the inhibitory effect as reflected by the level of iron produced was not clearly observed (highest effect at 10 μM and 3 h exposure).@*CONCLUSIONS@#Results provide at least in part, insight into the contribution of HO-1 on CM pathogenesis and need to be confirmed in animal model.

The role of heme-oxygenase-1 in pathogenesis of cerebral malaria in the co-culture model of human brain microvascular endothelial cell and ITG Plasmodium falciparum-infected red blood cells

Objective To investigate the role of human host heme-oxygenase-1 (HO-1) in pathogenesis of cerebral malaria in the in vitro model. Methods The effect of human host HO-1 [human brain microvascular endothelial cell (HBMEC)] on hemoglobin degradation in the co-culture model of HBMEC and ITG Plasmodium falciparum-infected red cells (iRBC) through measurement of the enzymatic products iron and bilirubin. Results Following exposure to the HO-1 inducer CoPPIX at all concentrations, the HBMEC cells apoptosis occurred, which could be prominently observed at 15 μM of 3 h exposure. In contrast, there was no significant change in the morphology in the non-exposed iRBC at all concentrations and exposure time. This observation was in agreement with the levels of the enzymatic degradation products iron and bilirubin, of which the highest levels (106.03 and 1753.54% of baseline level, respectively) were observed at 15 μM vs. 20 μM at 3 h vs. 24 h exposure. For the effect of the HO-1 inhibitor ZnPPIX, HBMEC cell morphology was mostly unchanged, but significant inhibitory effect on cell apoptosis was seen at 10 μM for the exposure period of 3 h (37.17% of baseline level). The degree of the inhibitory effect as reflected by the level of iron produced was not clearly observed (highest effect at 10 μM and 3 h exposure). Conclusions Results provide at least in part, insight into the contribution of HO-1 on CM pathogenesis and need to be confirmed in animal model.

Glycoproteomics analysis of plasma proteins associated with Opisthorchis viverrini infection-induced cholangiocarcinoma in hamster model

OBJECTIVE@#To apply lectin affinity chromatography and glycoproteomics-based LC-MS/MS to preliminarily investigate the possible potential plasma biomarkers of Opisthorchis viverrini (OV)-associated CCA in OV/dimethylnitrosamine (DMN)-induced CCA hamster model.@*METHODS@#Nine Syrian hamsters were divided into 3 groups as follows (n = 3 each): normal (healthy control group); OV group; and OV/DMN group (CCA group). Pooled plasma samples collected from animals in each group at the 6th month post-infection with OV metacercarae were subjected to glycoproteomics analysis. Glycoproteins in the pooled sample from each group were initially isolated by concanavalin A (ConA)-based affinity chromatography. The expression of glycoproteins isolated by both enrichment methods were determined using LC-MS/MS.@*RESULTS@#Among the 24 ConA-binding glycoproteins isolated, two proteins, N-myc downstream regulated gene 1 (NDRG1) and fetuin-B (FETUB) were found up-regulated only in the samples from the OV and control groups, but not in the OV/DMN (CCA) groups. On the other hand, one protein, i.e., NSFL1 cofactor p47 isoform ×3 (NSFL1C) was found only in the samples from OV/DMN (CCA) and control groups, but not in the OV group. The remaining 21 proteins were upregulated in the samples from all groups.@*CONCLUSIONS@#NDRG1, FETUB and NSFL1C glycoproteins isolated by ConA-based affinity chromatography could be potential biomarkers for CCA. Plasma samples with negative for NDRG1 and FETUB proteins but positive for NSFL1C are likely to be OV-associated CCA. Nevertheless, this conclusion remains to be confirmed whether this battery test can discriminate OV-associated CCA from other risk factors.

Possible role of PGD2 in malaria infections

OBJECTIVE@#To preliminarily investigate the possible role of prostaglandin D2 (PGD2) in malaria infections.@*METHODS@#Blood and urinary samples (n = 120 each) were collected from Thai patients with Plasmodium falciparum (P. falciparum) with moderate (n = 26) and high (n = 4) parasitemia, patients with Plasmodium vivax (P. vivax) (n = 30), patients with fever associated with other infections (n = 30), and healthy subjects (n = 30). PGD2 concentrations in plasma and urinary samples of healthy subjects, patients with fever associated with other infections and patients with malaria were determined using Prostaglandin D2-MOX express EIA kit (Cayman Chemical, USA).@*RESULTS@#The possible association between PGD2 and malaria infections is clearly demonstrated with PGD2 concentration in urine. The urinary PGD2 concentrations were relatively high (about 5-fold) in patients with P. falciparum with moderate parasitemia and P. vivax infections compared with other groups. Furthermore, the concentration in patients with P. falciparum with moderate parasitemia and P. vivax infection were significantly higher than that in healthy subjects and patients with fever associated with other infections.@*CONCLUSIONS@#Urinary PGD2 concentrations may offer a more dependable and useful tool for predicting malaria severity. Confirmation is this preliminary finding is required with a larger sample size.

Possible role of PGD

Objective To preliminarily investigate the possible role of prostaglandin D

Glycoproteomics analysis of plasma proteins associated with Opisthorchis viverrini infection-induced cholangiocarcinoma in hamster model

Objective To apply lectin affinity chromatography and glycoproteomics-based LC-MS/MS to preliminarily investigate the possible potential plasma biomarkers of Opisthorchis viverrini (OV)-associated CCA in OV/dimethylnitrosamine (DMN)-induced CCA hamster model. Methods Nine Syrian hamsters were divided into 3 groups as follows (n = 3 each): normal (healthy control group); OV group; and OV/DMN group (CCA group). Pooled plasma samples collected from animals in each group at the 6th month post-infection with OV metacercarae were subjected to glycoproteomics analysis. Glycoproteins in the pooled sample from each group were initially isolated by concanavalin A (ConA)-based affinity chromatography. The expression of glycoproteins isolated by both enrichment methods were determined using LC-MS/MS. Results Among the 24 ConA-binding glycoproteins isolated, two proteins, N-myc downstream regulated gene 1 (NDRG1) and fetuin-B (FETUB) were found up-regulated only in the samples from the OV and control groups, but not in the OV/DMN (CCA) groups. On the other hand, one protein, i.e., NSFL1 cofactor p47 isoform ×3 (NSFL1C) was found only in the samples from OV/DMN (CCA) and control groups, but not in the OV group. The remaining 21 proteins were upregulated in the samples from all groups. Conclusions NDRG1, FETUB and NSFL1C glycoproteins isolated by ConA-based affinity chromatography could be potential biomarkers for CCA. Plasma samples with negative for NDRG1 and FETUB proteins but positive for NSFL1C are likely to be OV-associated CCA. Nevertheless, this conclusion remains to be confirmed whether this battery test can discriminate OV-associated CCA from other risk factors.

Genetic Polymorphisms in Plasmodium vivax Dihydrofolate Reductase and Dihydropteroate Synthase in Isolates from the Philippines, Bangladesh, and Nepal

Genetic polymorphisms of pvdhfr and pvdhps genes of Plasmodium vivax were investigated in 83 blood samples collected from patients in the Philippines, Bangladesh, and Nepal. The SNP-haplotypes of the pvdhfr gene at the amino acid positions 13, 33, 57, 58, 61, 117, and 173, and that of the pvdhps gene at the positions 383 and 553 were analyzed by nested PCR-RFLP. Results suggest diverse polymorphic patterns of pvdhfr alone as well as the combination patterns with pvdhps mutant alleles in P. vivax isolates collected from the 3 endemic countries in Asia. All samples carried mutant combination alleles of pvdhfr and pvdhps. The most prevalent combination alleles found in samples from the Philippines and Bangladesh were triple mutant pvdhfr combined with single mutant pvdhps allele and triple mutant pvdhfr combined with double wild-type pvdhps alleles, respectively. Those collected from Nepal were quadruple mutant pvdhfr combined with double wild-type pvdhps alleles. New alternative antifolate drugs which are effective against sulfadoxine-pyrimethamine (SP)-resistant P. vivax are required.

In vitro inhibitory effects of plumbagin, the promising antimalarial candidate, on human cytochrome P450 enzymes

OBJECTIVE@#To investigate the propensity of plumbagin to inhibit the three isoforms of human cytochrome P450 (CYP), i.e., CYP1A2, CYP2C19, and CYP3A4 using human liver microsomes in vitro.@*METHODS@#Inhibitory effects of plumbagin on the three human CYP isoforms were investigated using pooled human liver microsomes. Phenacetin O-deethylation, omeprazole hydroxylation and nifedipine oxidation were used as selective substrates for CYP1A2, CYP2C19 and CYP3A4 activities, respectively. Concentrations of paracetamol, 5-hydroxyomeprazole, and oxidized nifedipine were determined in microsomal incubation mixture using high-performance liquid chromatography.@*RESULTS@#Plumbagin showed significant inhibitory effects on all CYP isoforms, but with the most potent activity on CYP2C19-mediated omeprazole hydroxylation. The IC50 (concentration that inhibits enzyme activity by 50%) values of plumbagin and nootkatone (selective inhibitor) for CYP2C19 were (0.78 ± 0.01) and (27.31 ± 0.66) μM, respectively. The inhibitory activities on CYP1A2-mediated phenacetin O-deethylation and CYP3A4-mediated nifedipine oxidation were moderate. The IC50 values of plumbagin and α-naphthoflavone (selective inhibitor) for CYP1A2 were (1.39 ± 0.01) and (0.02 ± 0.36) μM, respectively. The corresponding IC50 values of plumbagin and ketoconazole (selective inhibitor) for CYP3A4 were (2.37 ± 0.10) and (0.18 ± 0.06) μM, respectively.@*CONCLUSIONS@#Clinical relevance of the interference of human drug metabolizing enzymes should be aware of for further development scheme of plumbagin as antimalarial drug when used in combination with other antimalarial drugs which are metabolized by these CYP isoforms.

A brief review on biomarkers and proteomic approach for malaria research

Malaria remains as one of the significant health threat to people living in countries throughout tropical and subtropical zones. Proteomic studies of Plasmodium, the protozoan causing malaria, is essential for understanding its cellular structure, growth stage-specific expression of protein metabolites and complex interaction with host. In-depth knowledge of the pathogen is required for identification of novel biomarkers that can be utilized to develop diagnostic tests and therapeutic antimalarial drugs. The alarming rise in drug-resistant strains of Plasmodium has created an urgent need to identify new targets for drug development that can act by obstructing life cycle of this parasite. In the present review, we briefly discuss on role of various biomarkers including Plasmodium-associated aldolase, histidine-rich proteins and lactate dehydrogenase for diagnosis of malaria. Here we also summarize the present and future prospects of currently used techniques in proteomic approaches such as two dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) for diagnosis and potential identification of novel proteins for malaria research.

Plasmodium vivax Drug Resistance Genes; Pvmdr1 and Pvcrt-o Polymorphisms in Relation to Chloroquine Sensitivity from a Malaria Endemic Area of Thailand

The aim of the study was to explore the possible molecular markers of chloroquine resistance in Plasmodium vivax isolates in Thailand. A total of 30 P. vivax isolates were collected from a malaria endemic area along the Thai-Myanmar border in Mae Sot district of Thailand. Dried blood spot samples were collected for analysis of Pvmdr1 and Pvcrt-o polymorphisms. Blood samples (100 mul) were collected by finger-prick for in vitro chloroquine susceptibility testing by schizont maturation inhibition assay. Based on the cut-off IC50 of 100 nM, 19 (63.3%) isolates were classified as chloroquine resistant P. vivax isolates. Seven non-synonymous mutations and 2 synonymous were identified in Pvmdr1 gene. Y976F and F1076L mutations were detected in 7 (23.3%) and 16 isolates (53.3%), respectively. Analysis of Pvcrt-o gene revealed that all isolates were wild-type. Our results suggest that chloroquine resistance gene is now spreading in this area. Monitoring of chloroquine resistant molecular markers provide a useful tool for future control of P. vivax malaria.

Plasmodium vivax Drug Resistance Genes; Pvmdr1 and Pvcrt-o Polymorphisms in Relation to Chloroquine Sensitivity from a Malaria Endemic Area of Thailand

The aim of the study was to explore the possible molecular markers of chloroquine resistance in Plasmodium vivax isolates in Thailand. A total of 30 P. vivax isolates were collected from a malaria endemic area along the Thai-Myanmar border in Mae Sot district of Thailand. Dried blood spot samples were collected for analysis of Pvmdr1 and Pvcrt-o polymorphisms. Blood samples (100 mul) were collected by finger-prick for in vitro chloroquine susceptibility testing by schizont maturation inhibition assay. Based on the cut-off IC50 of 100 nM, 19 (63.3%) isolates were classified as chloroquine resistant P. vivax isolates. Seven non-synonymous mutations and 2 synonymous were identified in Pvmdr1 gene. Y976F and F1076L mutations were detected in 7 (23.3%) and 16 isolates (53.3%), respectively. Analysis of Pvcrt-o gene revealed that all isolates were wild-type. Our results suggest that chloroquine resistance gene is now spreading in this area. Monitoring of chloroquine resistant molecular markers provide a useful tool for future control of P. vivax malaria.

In vitro inhibitory effects of plumbagin, the promising antimalarial candidate, on human cytochrome P450 enzymes

Objective: To investigate the propensity of plumbagin to inhibit the three isoforms of human cytochrome P450 (CYP), i.e., CYP1A2, CYP2C19, and CYP3A4 using human liver microsomes in vitro. Methods: Inhibitory effects of plumbagin on the three human CYP isoforms were investigated using pooled human liver microsomes. Phenacetin O-deethylation, omeprazole hydroxylation and nifedipine oxidation were used as selective substrates for CYP1A2, CYP2C19 and CYP3A4 activities, respectively. Concentrations of paracetamol, 5-hydroxyomeprazole, and oxidized nifedipine were determined in microsomal incubation mixture using high-performance liquid chromatography. Results: Plumbagin showed significant inhibitory effects on all CYP isoforms, but with the most potent activity on CYP2C19-mediated omeprazole hydroxylation. The IC

A brief review on biomarkers and proteomic approach for malaria research

Malaria remains as one of the significant health threat to people living in countries throughout tropical and subtropical zones. Proteomic studies of Plasmodium, the protozoan causing malaria, is essential for understanding its cellular structure, growth stage-specific expression of protein metabolites and complex interaction with host. In-depth knowledge of the pathogen is required for identification of novel biomarkers that can be utilized to develop diagnostic tests and therapeutic antimalarial drugs. The alarming rise in drug-resistant strains of Plasmodium has created an urgent need to identify new targets for drug development that can act by obstructing life cycle of this parasite. In the present review, we briefly discuss on role of various biomarkers including Plasmodium-associated aldolase, histidine-rich proteins and lactate dehydrogenase for diagnosis of malaria. Here we also summarize the present and future prospects of currently used techniques in proteomic approaches such as two dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) for diagnosis and potential identification of novel proteins for malaria research.

Preliminary investigation on the prevalence of malaria and HIV co-infection in Mae Sot District, Tak Province of Thailand

OBJECTIVE: To preliminarily investigate the prevalence of HIV co-infection in patients with malaria in Mae Sot District, Tak Province of Thailand. METHODS: The study was a retrospective study on blood samples collected from a total of 256 patients with malaria (all species and severity) who attended Mae Tao clinic for migrant workers, Tak Province during 2005-2007 (148 samples) and 2010-2012 (108 samples). Malaria diagnosis was performed based on microscopic examination of patients' blood smears. Chemiluminescent microparticle immunoassay and gel particle passive agglutination were employed for the detection of HIV antigen in patients' plasma. RESULTS: Plasmodium falciparum (P. falciparum) and Plasmodium vivax (P. vivax) are the two predominant malaria species with the ratio of about 1: 1 to 1.5:1. Most of the P. falciparum cases were presented with acute uncomplicated signs and symptoms with highest parasitemia of 1 045 000 asexual parasites/μL bloods. The prevalence of malaria and HIV co-infection during 2005-2007 was 1.35% (2/148 cases, 1 each for P. falciparum and P. vivax co-infection), but was increased to 2.78% (3/108 cases, 2 and 1 for P. falciparum and P. vivax co-infection, respectively) during 2010-2012. CONCLUSIONS: The increasing trend of prevalence of malaria and HIV co-infection in Mae Sot, Tak province was of a great concern on either pharmacodynamics or pharmacokinetics aspect. The study in a larger numbers of malaria patients in different endemic areas throughout the country with different time periods is underway.

Coexistence of Malaria and Thalassemia in Malaria Endemic Areas of Thailand

Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and alpha-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and alpha-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients.