A. Jyothy

Induction of apoptosis in HeLa cells by chloroform fraction of seed extracts of Nigella sativa

BackgroundCancer remains one of the most dreaded diseases causing an astonishingly high death rate, second only to cardiac arrest. The fact that conventional and newly emerging treatment procedures like chemotherapy, catalytic therapy, photodynamic therapy and radiotherapy have not succeeded in reverting the outcome of the disease to any drastic extent, has made researchers investigate alternative treatment options. The extensive repertoire of traditional medicinal knowledge systems from various parts of the world are being re-investigated for their healing properties. This study progresses in the direction of identifying component(s) from Nigella sativa with anti cancer acitivity. In the present study we investigated the efficacy of Organic extracts of Nigella sativa seed powder for its clonogenic inhibition and induction of apoptosis in HeLa cancer cell.ResultsMethanolic, n-Hexane and chloroform extracts of Nigella sativa seedz effectively killed HeLa cells. The IC50 values of methanolic, n-hexane, and chloroform extracts of Nigella sativa were 2.28 μg/ml, 2.20 μg/ml and 0.41 ng/ml, respectively. All three extracts induced apoptosis in HeLa cells. Apoptosis was confirmed by DNA fragmentation, western blot and terminal transferase-mediated dUTP-digoxigenin-end labeling (TUNEL) assay.ConclusionWestern Blot and TUNEL results suggested that Nigella sativa seed extracts regulated the expression of pro- and anti- apoptotic genes, indicating its possible development as a potential therapeutic agent for cervical cancer upon further investigation.

Angiotensin-converting enzyme insertion/deletion polymorphism and the risk of ischemic stroke in a South Indian population

Stroke is one of the most complex diseases with several subtypes, arising from numerous gene-gene and gene-environmental interactions. The aim of our study was to investigate whether the insertion/deletion polymorphism in Angiotensin-converting enzyme gene is associated with ischemic stroke in a South Indian population. One hundred and sixty two patients and one hundred and fifty controls were studied for the presence of ACE gene polymorphism by PCR technique. The stroke patients were subtyped according to TOAST criteria, taking into account all the available data. There were significant differences in the genotypic distribution and allelic frequency between the patients and healthy controls. Furthermore the D allele was significantly associated with intracranial large artery atherosclerosis. However, the association was insignificant with other stroke subtypes. We observed that ACE ID/DD genotypes are associated with an elevated incidence of stroke in a South Indian population from Andhra Pradesh. Moreover, ACE gene polymorphism was found to contribute to the risk of developing intracranial large artery atherosclerosis, which is the most frequent subtype in this region.

Association of LPL gene variant and LDL, HDL, VLDL cholesterol and triglyceride levels with ischemic stroke and its subtypes.

Lipoprotein lipase (LPL) plays an important role in lipid metabolism by hydrolyzing triglycerides in chylomicrons and very low density lipoproteins. An increasing number of studies have suggested an association of LPL gene variants with the risk of cardiovascular and cerebrovascular diseases. The aim of this study was to test whether HindIII polymorphism of LPL gene is associated with ischemic stroke and its subtypes as well as plasma lipid levels in a South Indian population from Andhra Pradesh. Five hundred and twenty five ischemic stroke patients and 500 controls were enrolled in this case-control study. The LPL HindIII polymorphism was determined by PCR-RFLP technique and the lipid levels were estimated using commercially available kits. We found significant difference in the genotypic distribution between patients and controls [for HindIII (+/+) vs. HindIII (-/-), χ(2)=4.916; p=0.02; Odds ratio=1.59 (95%CI; 1.054-2.413); HindIII (+/+) vs. HindIII (-/-) and HindIII (+/-), χ(2)=5.25; p=0.02; Odds ratio=1.24 (95%CI; 1.03-1.503)]. A stepwise multiple logistic regression analysis confirmedthese findings. The relationship between HindIII genotypes and plasma levels of HDL, LDL, VLDL and triglycerides was analyzed using ANOVA and further confirmed by Post-hoc analysis. The levels of triglycerides were found to be elevated in individuals bearing HindIII (+/+) genotype in comparison with HindIII (-/-) genotype. HDL levels were found to be significantly reduced and triglyceride levels significantly elevated in HindIII (+/+) genotype in comparison with HindIII (-/-). However, there was no difference in the levels of LDL and VLDL between the two genotypes. Examining the association of LPL gene HindIII polymorphism with stroke subtypes, we found significant association of HindIII polymorphism with Intracranial large artery atherosclerosis [Odds ratio=2.12 955CI (1.656-2.848); p=0.009]. Our results suggest that the HindIII polymorphism of LPL is significantly associated with ischemic stroke risk and elevated levels of plasma triglycerides and reduced HDL levels. Further, this polymorphism is significantly associated with intracranial large artery atherosclerosis which is the most frequent subtype in our region.

Phosphodiesterase 4D (PDE4D) gene variants and the risk of ischemic stroke in a South Indian population.

Stroke is the third largest cause of death and a major cause of adult disability and mortality worldwide. Experimental evidence suggests that genetic determinants do contribute a large part to stroke risk. The identification of phosphodiesterase 4D gene as a risk factor for stroke caused a great deal of interest in stroke genetics. Many of the studies of PDE4D gene have focused on the original Icelandic findings but the association between specific SNPs and haplotypes has been inconsistent. The aim of the present study was to investigate the association of three SNPs 32 (rs 456009), 83 (rs 966221) and 87 (rs 2910829), originally described by deCODE group; with stroke in a South Indian population from Andhra Pradesh. Two hundred and fifty ischemic stroke patients and two hundred and fifty controls were included in the study. The stroke patients were sub typed according to TOAST classification. SNP 83 showed significant association with stroke in the population under study while SNPs 87 and 32 were monomorphic. Further SNP 83 was found to be significantly associated with two stroke subtypes, intracranial large artery atherosclerosis (the most frequent subtype in the population) and small artery occlusion. The association with other subtypes was found to be insignificant. Further, SNP 83 was found to be associated significantly with some conventional stroke risk factors like diabetes and smoking.

Association of the −344C/T aldosterone synthase (CYP11B2) gene variant with hypertension and stroke

Stroke is a complex disease caused by combination of multiple risk factors. Recent findings have suggested that stroke has a significant genetic component. Various types of genetic polymorphisms have been suggested to contribute to the risk of stroke. Gene polymorphisms of renin-angiontensin aldosterone system (RAAS) have been suggested to be risk factors for hypertension, cardiovascular diseases and stroke. In the present case-control study we investigated the association of -344C/T (rs1799998) [corrected] polymorphism in the promoter region of the human aldosterone (CYP11B2) gene with genetic predisposition to hypertension, ischemic stroke and stroke subtypes classified according to TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. Four hundred and three stroke patients (hypertensives:normotensives=219:184) and three hundred and ninety four, sex and age matched healthy controls (hypertensives:normotensives=118:276) were involved in the study. The region of interest in the CYP11B2 gene was amplified by polymerase chain reaction and genotypes determined by subjecting the PCR products to restriction digestion by the enzyme HaeIII. Significant difference was observed in the genotypic distribution and allelic frequency between the stroke patients and healthy controls. TT genotype and T allele associated significantly with hypertension and stroke (p<0.000 in hypertension and p=0.000 in case of stroke). A stepwise logistic regression analysis confirmed these findings. To establish that this polymorphism is associated with stroke independent of hypertension, we compared stroke patients without hypertension with normotensive controls. Significant difference was observed in genotypic distribution and allelic frequency between the two groups (p=0.000). Further evaluating the association of this polymorphism with stroke subtypes we found significant associations with intracranial large artery atherosclerosis, lacunar stroke and cardioembolic stroke (p=0.000 in each case). In conclusion our study suggests that -344T allele of CYP11B2 gene is an important risk factor for hypertension and ischemic stroke. However, this is a preliminary study and the results need to be confirmed in a larger cohort.

Interleukin-10-1082 promoter polymorphism and ischemic stroke risk in a South Indian population.

Within the past few years there has been increasing evidence that the genetic variation in the genes coding pro- and anti-inflammatory markers may play an important role in the pathogenesis of various human diseases, including stroke. The aim of the study was to evaluate the association of Interleukin-10 (IL-10)-1082 G/A, promoter polymorphism (rs1800896) with ischemic stroke in a South Indian population from Andhra Pradesh. In this study 480 ischemic stroke patients and 470 age and sex matched healthy controls were included. The ischemic stroke patients were classified according to TOAST classification. The region of interest in the IL-10 gene was amplified by polymerase chain reaction with the use of allele specific oligonucleotide primers flanking the polymorphic region. Association between genotypes and stroke was examined by Odds Ratio (OR) with 95% confidence interval (CI) and Chi-square analysis. Significant difference was observed between the patients and healthy controls, in genotypic distribution as well as allelic frequency (p<0.05). Multiple logistic regression analysis with forward stepwise selection using the potential confounders (sex, age, diabetes, hypertension, smoking and alcoholism) and IL-10 gene variant revealed that -1082 G/A polymorphism in the promoter region of IL-10 gene is significantly [adjusted OR=2.26; 95% C.I. (1.24-4.15), p<0.001] associated with ischemic stroke in the South Indian population from Andhra Pradesh. We found significant association of this polymorphism with stroke of undetermined etiology (p<0.001). Moreover, hypertensive and diabetic individuals bearing A allele of IL-10 gene in high frequency were found to be more predisposed to stroke.

VNTR polymorphism in intron 4 of the eNOS gene and the risk of ischemic stroke in a South Indian population.

Ischemic stroke is a leading cause of death throughout the world. An increasing number of studies have suggested that genetic factors are important in the stroke risk. The aim of our study was to investigate whether the Variable Number of Tandem Repeats (VNTR) polymorphism in intron 4 of the endothelial nitric oxide synthase (eNOS) gene is associated with ischemic stroke in a South Indian population. 357 patients and 283 controls were enrolled in this case-control study. The ischemic stroke patients were classified according to TOAST classification. The eNOS gene polymorphism was determined by polymerase chain reaction-polyacrylamide gel electrophoresis. The genotypes were confirmed by sequencing the PCR products. There were significant differences in the genotype and allele frequencies of eNOS polymorphism between the patients with ischemic stroke and healthy controls (p=0.000). Multiple logistic regression analysis with forward stepwise selection using the potential confounders (sex, age, diabetes, hypertension, smoking and alcoholism) and eNOS gene variant revealed that the VNTR polymorphism in intron 4 of the eNOS gene is significantly [adjusted odds ratio=6.23, 95%CI (4.30-9.29), p=0.000] associated with ischemic stroke in the South Indian population from Andhra Pradesh. We did not find significant association of this polymorphism with any specific stroke subtype. Further hypertensives bearing 4a allele in high frequency are more predisposed to stroke.

Association of genetic variants of fibrinolytic system with stroke and stroke subtypes.

Genetic variants of tPA (PLAT) and PAI-1 genes have been suggested to be the risk factors for stroke. In the present case-control study we investigated the association of -7351C/T polymorphism (rs2020918) and I/D polymorphism of tPA gene and Insertion/deletion polymorphism (4G/5G) of PAI-1 gene with genetic predisposition to ischemic stroke. 516 stroke patients and 513, sex and age matched healthy controls were involved in the study. We did not find a significant association of tPA -7351C/T polymorphism and PAI-1 4G/5G polymorphism with stroke. However, in case of I/D polymorphism significant difference was observed in the genotypic distribution and allelic frequency between the stroke patients and healthy controls. DD genotype and D allele associated significantly with stroke (p=0.002 and <0.001 respectively). We also found significant association of I/D polymorphism with intracranial large artery atherosclerosis and stroke of undetermined etiology. Exploring the association between gene-gene interaction (26 combinations including the three variants) and stroke, we found that individuals with CC+4G4G+DD, CC+5G5G+ID, CT+4G5G+ID, CT+5G5G+II, CT+5G5G+ID and TT+4G5G+II had a significantly higher risk of stroke. The results of this study suggest that -7351C/T polymorphism of tPA and 4G/5G polymorphism of PAI-1 are not associated with stroke, while as DD genotype and D allele of tPA gene are important risk factors for ischemic stroke. Further we found that the subjects with different tPA and PAI genotype combinations displayed a significantly high risk for overall ischemic stroke suggesting that gene-gene interaction involving more variants may change the susceptibility of particular subjects to the disease.

Significance of MDR1 gene polymorphism C3435T in predicting drug response in epilepsy.

Antiepileptic drug (AED) treatment in epilepsy is often compromised by the unpredictability of efficacy and inter-individual variability among patients, which at least in part is the result of genetic variation. The idea to determine an individuals response to a prescribed medicine came into inception around 29 years ago. Pharmacogenetics is used to predict the drug response and efficacy, as well as potential adverse effects. We investigated the functional significance of the C3435T polymorphism of the MDR1 gene in a South Indian population. The patients were divided into responders and non-responders based on their clinical outcome and AED response. The risk of drug resistance was significantly higher in patients bearing TT genotype in comparison to carriers of the homozygous CC genotype [TT vs. CC, χ(2)=12.52; p=0.001, Odds ratio=2.34 (95% CI: 1.942-11.32)]. We suggest that the influence of the C3435T polymorphism in predicting the drug-resistance in epilepsy, might be significant and further investigations focusing on carbamazepine and phenytoin, in various ethnic populations are necessary to clarify the effect of C3435T polymorphism on the multidrug resistance in epilepsy patients.

Inherited hemoglobin disorders in Andhra Pradesh, India: a population study.

BACKGROUND The hemoglobinopathies are a very heterogeneous group of congenital hemolytic anemias. They include thalassemias, hemoglobin variants and hereditary persistence of fetal hemoglobin. Beta-thalassemia is the most common monogenic disorder in India. Molecular characterization of this disease has revealed an extremely heterogeneous picture. METHODS 1592 blood samples from suspected cases were studied using high performance liquid chromatography, amplification refractory mutation system polymerase chain reaction and reverse dot blot techniques. RESULTS Out of 1592 cases, we found 119 cases of beta-thalassemia major, and 347 cases of beta-thalassemia trait. In addition to this, cases with structural variants like sickle cell anemia, sickle cell trait, D-thalassemia (Hb DD), E-thalassemia (Hb EE), double heterozygotes and the hereditary persistence of fetal hemoglobin were also found. Molecular analysis revealed the presence of different beta-thalassemia mutations in the population under study. CONCLUSIONS Molecular analysis revealed that IVS1-5(G-C) and 619 bp deletion are the most common mutations in the population under study. The knowledge about the frequency of predominant mutations in the present population helps in offering prenatal diagnosis to the families having fetus at risk.