Tocopherol Enhances the Antioxidant Defense System and Histomorphometric Parameters in The Gastrointestinal Tract of Rats Treated with Sodium Arsenite.

Arsenic compromises the gastrointestinal integrity and function via the body's anti-oxidative system breakdown.  Hence, this study aimed to investigate the effects of tocopherol on redox imbalance and histoarchitectural alterations in rats' gastrointestinal tract exposed to sodium arsenite. Sodium arsenite and graded doses of tocopherol were administered orally into experimental rats assigned to different groups for four weeks concurrently. Redox status assay was done in homogenized samples by spectrophotometry. Parietal cell mass and mucous cell density (stomach), villus height and crypt depth (ileum), goblet cells count, and crypt depth (colon) were evaluated by histomorphometry. Inflammatory cells infiltration was also assessed using a semi-quantitative procedure. Sodium arsenite caused a significant increase in Malondialdehyde and Myeloperoxidase but, decreased Superoxide dismutase, Catalase, Nitric oxide, Glutathione peroxidase, Glutathione, and Glutathione-S-Transferase. Tocopherol treatment reversed the changes (p<0.05) though not largely dose-dependent. Furthermore, tocopherol annulled sodium arsenite-induced increase in parietal cell mass and decrease in mucous cell density in the stomach, decrease in villus height and villus height/crypt depth ratio in the ileum, and decrease in goblets cells and increase in crypt depth in the colon. Moreover, activated inflammatory cell infiltration by sodium arsenite was mitigated by tocopherol. Sodium arsenite provokes not only marked inflammatory cellular infiltration but a focal loss of glands, hyperplasia of crypts, atrophic villi, and hypertrophy of Peyer's patches in the intestines, which are all lessened with tocopherol treatment.  These findings underscore the anti-oxidative properties of tocopherol as a potent dietary factor against sodium arsenite toxicity in the gastrointestinal tract. Keywords: Tocopherol, arsenic, stomach, ileum, colon.

Persistence of chloroquine-resistant haplotypes of Plasmodium falciparum in children with uncomplicated Malaria in Lagos, Nigeria, four years after change of chloroquine as first-line antimalarial medicine.

BACKGROUND: In Nigeria, despite the change in National malaria drug policy to artemisinin combination therapy (ACT) in 2005 due to widespread chloroquine resistance, chloroquine (CQ) is still widely used in the treatment of malaria because it is cheap, affordable and accessible. The use of ACT for the management of uncomplicated malaria is currently being promoted. The employment of genetic markers to track circulating chloroquine-resistant parasites are useful in elucidating likely poor efficacy of chloroquine, especially in settings where it is not recommended for the treatment of uncomplicated falciparum malaria. This study determined the prevalence of pfcrt haplotypes and point mutations in pfmdr1 genes four years after the change in antimalarial treatment policy from CQ to the ACTs in Lagos, a commercial city in South-West, Nigeria. METHODS: This was a cross sectional study on uncomplicated malaria in children less than 12 years that presented with fever and other symptoms suggestive of malaria. Parasite DNA was extracted from 119 patients out of 251 children who were positive for Plasmodium falciparum by microscopy and amplified. The occurrence of haplotypes was investigated in pfcrt gene using probe-based qPCR and single nucleotide polymorphisms in pfmdr1 gene using nested PCR. RESULTS: One hundred and nine (109) of the 119 children with P falciparum infection (91.6%) harbourd parasites with the mutant pfcrt haplotype (CVIET). Out of this, 4.2% comprised a mixture of genotypes encoding CVMNK and CVIET, while 4.2% had the wild type (CVMNK). Furthermore, the frequency of point mutations in pfmdr1 was 62.2% and 69.0% for codons Y86 and F184 respectively. There were no mutations at codons 1034, 1042 and 1246 of the Pfmdr1 genes. CONCLUSION: The high frequency of the CQ-resistant haplotypes (CVIET) and mutations in Pfmdr1 associated with CQ resistance in P. falciparum among these children suggest that CQ-resistant parasites are still in circulation. Continuous use of chloroquine may continue to increase the level of mutations in pfcrt and pfmdr1genes. There is need to strengthen current case management efforts at promoting ACT use as well as urgently restricting access to chloroquine by the National drug regulatory agency, National Agency for Food Drug Administration and Control (NAFDAC). VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2069472010142303.

Spermatoprotective activity of the leaf extract of Psidium guajava Linn.

BACKGROUND: The leaves of Psidium guajava Linn. (guava) contain several natural antioxidants. We therefore designed the present study to evaluate the effect of ethanol extract of guava leaves on gossypol-associated sperm toxicity in Wistar rats. METHODS: Animal groups 1, 2, and 3 (n=6 each) were treated orally with crude cottonseed oil to provide 14 mg/kg/d of free gossypol for 53 d. Besides, groups 1 and 2 rats were supplemented orally with 250 mg/kg/d and 500 mg/kg/d respectively of guava leaf extract (GLE) for the same period. Group 4 animals (control, n=6) received normal saline. RESULTS: No significant difference (P>0.05) occurred in the sperm count of group 1 rats compared to control. In animal group 2, significant increase (P<0.05) in sperm count occurred, as opposed to group 3 animals, where this parameter decreased significantly (P<0.05). Besides, mean values of 78 %, 82 %, 30 %, and 65 % respectively were obtained for sperm motility in animal groups 1, 2, 3, and 4. CONCLUSION: Our findings suggest that ethanol extract of guava leaves possesses beneficial effect on gossypol-associated sperm toxicity, and may therefore enhance male fertility, possibly owing to its rich constituents of natural antioxidants.

Ethanol extract of the leaves of Psidium guajava Linn enhances sperm output in healthy Wistar rats.

Reactive oxygen species (ROS), among other factors, have been implicated in the aetiology of male infertility. Thus, the roles of antioxidants at improving sperm production and quality are being investigated. The present study was designed to assess the effect of the ethanol extract of fresh leaves of Psidium guajava Linn. on the sperm parameters of healthy male Wistar rats. A total of 18 rats, weighing between 108-124 g, were divided into 3 groups of 6 animals each. Animals in groups 1 and 2 were administered 250 mg/kg/d and 500 mg/kg/d of guava leaf extract (GLE) orally for 53 days respectively. Group 3 animals received normal saline. Sperm count increased from 56.2+/-0.3 (x10(6)) in the control to 57.1+/-0.2 (x10(6)) in group 1 animals, and from 56.2+/-0.3 (x10(6)) in the control to 72.3+/-0.4 (x10(6)) in group 2 animals. Similarly, dose-dependent increases in the percentages of motile spermatozoa were observed in GLE-treated animals compared to the control group. These findings suggest that the extracts of the leaves of Psidium guajava Linn. possess beneficial effects on sperm production and quality, and may thus improve the sperm parameters of infertile males with oligospermia and nonobstructive azoospermia.

Polymorphism and virulence factors in the pathogenesis of amoebiasis

Amoebiasis is one of the world's most prevalent infectious diseases of developing world. E. histolytica and E. dispar are two morphologically identical but genetically distinct species. Infection with E. histolytica may be symptomatic and asymptomatic. E. dispar is non-pathogenic. Both innate and acquired immune responses limit amoebic infection while different strains of E. histolytica and its virulence have been described and virulence factors of E. histolytica such as cysteine proteinases; Gal/GalNAc-inhibitable lectin and ameobapore are known to be involved in E.histolytica pathogenesis. Proteolytic enzymes and cysteine proteases facilitate tissue invasion while Gal/GalNAc-inhibitable lectin aids adherence and amoebapores are involved in lysis of target cells. Three new strains of E. histolytica (Rahman; HK-9; and 200: NIH) have been described as well as the previously known strain (HM 1 IMSS). This review highlights the newly described strains and virulent factors involved in the pathogenesis of E. histolytica