Possible inhibition of hydroxy methyl glutaryl CoA reductase activity by nicotinic acid and ergosterol: as targeting for hypocholesterolemic action

OBJECTIVE

Coronary artery diseases including atherosclerosis is considered as commonest problem worldwide. Ergosterols are the main components of vegetable oils and nuts. The objective of this study was to evaluate the potential hypoplipidemic and hypocholesterolemic effects of ergosterol in combination with niacin in rats fed high fat diet (HFD).

METHODS

Eighty male albino rats were included in this study divided into two main groups: Group I: Normal rats fed standard diet treated with either niacin (8.5 mg /kg b.w) or ergosterol (100 mg/Kg b.w) or both. Group II; rats fed HFD treated with either niacin (8.5 mg /kg b.w) or ergosterol (100 mg/Kg b.w) or both The feeding and treatment lasted for 8 weeks.

RESULTS

A significant elevation in the levels of total cholesterol, triacylglycerol, VLDL-c, LDL-c and atherogenic factor (p<0.001) in rats fed on HFD compared with normal control while HDL-c was significantly reduced in HFD rats compared with control group. Supplementation of diet with niacin or ergosterol or combined exerts improvement in the studied parameters by lowering triacylglycerol, total cholesterol, LDL-c and atherogenic factor and elevate HDL-c near to the value of control. Niacin combined with ergosterol were effective in the reduction of hydroxy methyl glutaryl-CoA reducatase (HMGCoA) compared with control (p<0.001). The combined effect was more potent than individual alone.

CONCLUSION

Utilization of niacin and ergosterol may prevent the hypercholesterolemia and incidence of coronary heart diseases. These functional foods act as nutriceutical as dyslipidemics.

Hypermethylation of P15, P16, and E-cadherin genes in ovarian cancer

Both p16 and p15 proteins are inhibitors of cyclin-dependent kinases that prevent the cell going through the G1/S phase transaction. E-cadherin is a transmembrane glycoprotein that mediates calcium-dependent interactions between adjacent epithelial cells. Two groups of patients were selected: the first group suffered from epithelial serous ovarian tumors and the second group suffered from benign ovarian lesions; ovarian tissue samples from all the subjects (benign and malignant) were subjected to methylation-specific polymerase chain reaction for methylated and unmethylated alleles of the genes (E-cadherin, p15, and p16). Results obtained showed that aberrant methylation of p15 and p16 genes were detected in 64.29 and 50% of ovarian cancer patients, while E-cadherin hypermethylation was detected in 78.57% of ovarian cancer patients. Methylation of E-cadherin was significantly correlated with different stage of disease (p < 0.05). It was found that the risk of E-cadherin hypermethylation was 1.347-fold, while risk of p15 hypermethylation was 1.543-fold and p16 was 1.2-fold among patients with ovarian cancer than that among patients with benign ovarian lesions. In conclusion, Dysfunction of the cell cycle and/or the cell-cell adhesion molecule plays a role in the pathogenesis of ovarian cancer and that the analysis of the methylation of p15 and E-cadherin genes can provide clinically important evidence on which to base the treatment.

Evaluation of a PCR-ELISA to detect Wuchereria bancrofti in Culex pipiens from an Egyptian village with a low prevalence of filariasis

The programmes for the elimination of bancroftian filariasis that have been implemented in the Nile delta of Egypt are expected to lead to substantial reductions in filarial loads in the treated populations. Better methods than those currently available are needed for monitoring the efficacy of these and similar efforts at intervention. A PCR-ELISA was therefore evaluated as an epidemiological tool for the detection of the Wuchereria-bancrofti-specific SspI repeat in pools of Culex pipiens collected in a village with a low prevalence of filarial infection in its human residents (2.1%). Indoor-resting mosquitoes were collected by aspiration from 114 randomly selected houses (during one to nine visits/house) and separated into 673 pools, each of which held the mosquitoes collected during one night from one house. Although 18 (2.7%) of the pools showed PCR inhibition and had to be excluded, filarial DNA was detected, using the PCR-ELISA, in 91 (13.9%) of the 655 remaining mosquito pools. The minimum prevalence of W. bancrofti infection in the mosquitoes caught (assuming one infected mosquito/positive pool) was 2.8%. The mean (S.D.) number of mosquitoes/pool did not vary significantly between positive [5.5 (3.4)] and negative [4.9 (3.5)] pools. The assay detected parasite DNA in mosquitoes from 19.3% of 114 houses when only the first visit was considered and from 73.9% of the 88 houses visited more than once. The PCR-ELISA yielded results comparable with those of the regular PCR-SspI assay. The latter assay is recommended for the routine examination, in laboratories in endemic areas, of mosquito pools from randomly selected houses, as the ELISA component of the PCR-ELISA is exceedingly time-consuming, expensive and requires special equipment.

Studies on the molluscicidal and larvicidal properties of Solanum nigrum L. leaves ethanol extract

Toxicological studies on three ethanol extract preparations of Solanum nigrum L. leaves were made on Biomphalaria alexandrina. Extract (A), made by soaking leaves powder over night in cold 70% ethanol, has the highest activity, (LC50 3.37 mg/L within 24 hr). This extract also showed larvicidal activity against larvae of two mosquito species, Aedes caspius and Culex pipiens, (LC50 51.29 and 125.89 mg/L within 24 hr, and 21.38 and 38.11 mg/L within 48 hr, respectively). Sunlight, pH, and turbidity did not affect the activity of this extract, but the molluscicidal activity seems to be correlated with the increase of temperature. The concentrated extract (1000 mg/L) can be stored at room temperature for six months without any change in its activity, but diluted solutions of this extract lost their activity after four weeks.

Detection of Wuchereria bancrofti in mosquitoes by the polymerase chain reaction: a potentially useful tool for large-scale control programmes

Focally endemic bancroftian filariasis is targeted for elimination in the Nile delta of Egypt. Improved methods are needed for identifying endemic villages to be included in the control programme and for monitoring its success. We have evaluated the performance of a polymerase chain reaction (PCR) assay in estimating Wuchereria bancrofti infection in pools of Culex pipiens (1-25 females) from 2 adjacent villages with high (El Qolzom, 10.8%) and low (Kafr Shorafa, 2.1%) prevalence rates of human filariasis. This assay detects a repeated sequence in W. bancrofti deoxyribonucleic acid (DNA). Mosquitoes resting within houses were captured by aspiration and pooled by house. Houses were classified as positive or negative for human filarial infection based on night blood examinations of residents. The assay detected parasite DNA in mosquitoes from 60% of 25 infected houses and 24% of 25 uninfected houses. PCR processing of mosquitoes caught within houses of unknown filariasis infection status (44 in El Qolzom, 37 in Kafr Shorafa) identified 31.8% and 8.1% of houses, respectively, as containing infected mosquitoes. These results support the validity of the PCR assay for evaluating filarial prevalence in different villages. C. pipiens collected outdoors in dry ice-baited traps and tested by PCR (266 in Qolzom, 82 in Kafr Shorafa) did not contain parasite DNA. Pools of female mosquitoes (296 in Qolzom, 240 in Kafr Shorafa) captured in oviposition traps were also negative. We concluded that the PCR based assay is a powerful epidemiological tool that can be used for evaluating W. bancrofti infection in villages in the Nile delta and for monitoring the application of control programmes in filariasis endemic areas.

Homologs of the Caenorhabditis elegans masculinizing gene her-1 in C. briggsae and the filarial parasite Brugia malayi

The masculinizing gene her-1 in Caenorhabditis elegans (Ce-her-1) encodes a novel protein, HER-1A, which is required for male development. To identify conserved elements in her-1 we have cloned and characterized two homologous nematode genes: one by synteny from the closely related free-living species C. briggsae (Cb-her-1) and the other, starting with a fortuitously identified expressed sequence tag, from the distantly related parasite Brugia malayi (Bm-her-1). The overall sequence identities of the predicted gene products with Ce-HER-1A are only 57% for Cb-HER-1, which is considerably lower than has been found for most homologous briggsae genes, and 35% for Bm-HER-1. However, conserved residues are found throughout both proteins, and like Ce-HER-1A, both have putative N-terminal signal sequences. Ce-her-1 produces a larger masculinizing transcript (her-1a) and a smaller transcript of unknown function (her-1b); both are present essentially only in males. By contrast, Cb-her-1 appears to produce only one transcript, corresponding to her-1a; it is enriched in males but present also in hermaphrodites. Injection of dsRNA transcribed from Cb-her-1 into C. briggsae hermaphrodites (RNA interference) caused XO animals to develop into partially fertile hermaphrodites. Introducing a Cb-her-1 construct as a transgene under control of the C. elegans unc-54 myosin heavy chain promoter caused strong masculinization of both C. briggsae and C. elegans hermaphrodites. Introduction of a similar Bm-her-1 construct into C. elegans caused only very weak, if any, masculinization. We conclude that in spite of considerable divergence the Cb gene is likely to be a functional ortholog of Ce-her-1, while the function of the distantly related Bm gene remains uncertain.

Development of a quantitative, competitive polymerase chain reaction--enzyme-linked immunosorbent assay for the detection of Wuchereria bancrofti DNA

A quantitative, competitive polymerase chain reaction (QC-PCR) assay for the sensitive detection of Wuchereria bancrofti DNA was developed. A competitor sequence was constructed by an exchange of nucleotides in the Wuchereria-specific Ssp I repeat. The PCR products were hybridized to specific DNA probes and their amounts, determined by an enzyme-linked immunosorbent assay (ELISA). In laboratory-prepared samples the QC-PCR-ELISA assay was capable of detecting the amount of DNA equivalent to 0.1 microfilaria (mf) added to 200 microl of blood lysate. The assay was also tested on 78 blood samples collected in endemic areas in Egypt. All 28 samples that were positive both for mf and for circulating antigen were also QC-PCR-ELISA-positive. In addition, one mf-negative but antigen-positive sample was also positive as determined by QC-PCR-ELISA. A positive correlation of mf density with the QC-PCR-ELISA was observed. Samples containing 10 or fewer mf/ml had a mean relative amount of Ssp I PCR product of 19.7 units, whereas samples with 11-100 mf/ml had a mean of 36.3 units and those with more than 100 mf/ml had a mean of 84.6 units. Because of the high standard deviation within each group, estimates of worm burdens in infected individuals using the QC-PCR-ELISA are not recommended. However, we present data indicating that the W. bancrofti QC-PCR-ELISA is a powerful new tool for evaluation of parasitic loads for community-based diagnosis of bancroftian filariasis.

A polymerase chain reaction-based assay for detection of Wuchereria bancrofti in human blood and Culex pipiens

Human blood samples and indoor-resting Culex pipiens were collected in 33 randomly selected houses from different sectors of a village in the Nile Delta of Egypt which was endemic for Wuchereria bancrofti. Blood was also collected from subjects with no history of living in filarial endemic areas. Human blood samples were divided and assessed by both membrane filtration and polymerase chain reaction (PCR). Similarly, mosquito samples were assessed by both dissection and PCR. Blood pools representing each household were tested by PCR. If a pool gave a positive result, then individual blood specimens were also tested by PCR. Of the 33 houses tested, both membrane filtration and blood pools assayed by PCR identified 14 (42.4%) 'infected houses'. PCR detected parasite deoxyribonucleic acid (DNA) in blood pools from an additional 3 households that gave negative results by membrane filtration. Of 178 endemic blood samples tested by membrane filtration, 22 (12.3%) had microfilariae and all were individually positive by PCR. Although microfilaria counts were lower in blood collected during the day than in night-collected blood, the PCR results were consistent, regardless of time of collection. All non-endemic blood samples were negative by PCR. Among the 33 houses rested, mosquito pools assayed by PCR identified 17 (51.5%) as 'infected households'. Of these, 8 houses (47%) contained at least one microfilaraemic resident. One 'infected household' was identified by mosquito dissection. We concluded that PCR is a powerful epidemiological tool for screening villages for the prevalence of W. bancrofti. PCR detection of W. bancrofti DNA in blood-fed mosquitoes could be used initially to locate endemic areas with transmission of bancroftian filariasis. PCR detection of W. bancrofti DNA in blood collected during the day could then be used to assess W. bancrofti infection rates.