P. J. John

Vitamin C in Disease Prevention and Cure: An Overview

The recognition of vitamin C is associated with a history of an unrelenting search for the cause of the ancient haemorrhagic disease scurvy. Isolated in 1928, vitamin C is essential for the development and maintenance of connective tissues. It plays an important role in bone formation, wound healing and the maintenance of healthy gums. Vitamin C plays an important role in a number of metabolic functions including the activation of the B vitamin, folic acid, the conversion of cholesterol to bile acids and the conversion of the amino acid, tryptophan, to the neurotransmitter, serotonin. It is an antioxidant that protects body from free radical damage. It is used as therapeutic agent in many diseases and disorders. Vitamin C protects the immune system, reduces the severity of allergic reactions and helps to fight off infections. However the significance and beneficial effect of vitamin C in respect to human disease such as cancer, atherosclerosis, diabetes, neurodegenerative disease and metal toxicity however remains equivocal. Thus further continuous uninterrupted efforts may open new vistas to understand its significance in disease management.

Organochlorine pesticide residues in wheat and drinking water samples from Jaipur, Rajasthan, India.

The organochlorine pesticide contamination in dietary sources has caused serious threat to the human progeny. The present studywas therefore conducted to evaluate the pesticide contaminationin wheat flour and drinking water from Jaipur City, Rajasthan,India using Gas Chromatograph. All the wheat and water sampleswere found to be contaminated with various organochlorinepesticide residues of DDT and its metabolites, HCH and itsisomers, heptachlor and its expoxide and aldrin. The amount ofpesticide detected in wheat flour was higher than the permissible limitsprescribed by WHO/FAO. In drinking water only a few pesticidesexceeded the permissible limits. Seasonal variations ofpesticides residues were also observed during the study period.

Multi walled carbon nano tubes induced hepatotoxicity in Swiss albino mice

In the present study, multi walled carbon nano tubes (MWCNTs) were synthesized using chemical vapour deposition (CVD) technique. Swiss albino mice were orally administered with single dose of 60 and 100 mg/kg body weight of purified and functionalized MWCNTs suspended in water. The mice were autopsied on 7, 14, 21 and 28 days post exposure. Liver was taken out and part of it fixed in Bouins solution for histopathological examinations. The remaining part was immersed in cold saline, blotted dry, weighed quickly and homogenized in ice cold buffer. The activity of superoxide dismutase (SOD) and catalase (CAT) was immediately measured in the supernatant. The MWCNTs in liver led to pathological changes, including injury to macrophages, cellular swelling, unspecific inflammation, spot necrosis and blood coagulation. Estimation of SOD and CAT showed altered levels in the experimental groups as compared to controls. Therefore, MWCNTs from manufactured and combustion sources in the environment can have adverse effects on human health.

Cytotoxicity, genotoxicity and alteration of cellular antioxidant enzymes in silver nanoparticles exposed CHO cells

The broad applications of silver nanoparticles (Ag NPs) increase human exposure and thus the potential risk associated with their toxicity; therefore, the toxicity of Ag NPs, synthesized by a chemical route was studied using Chinese Hamster Ovary (CHO) cells. A UV-vis absorption maximum at 406 nm confirmed the formation of silver nanoparticles. The average diameter of the silver nanoparticles having spherical shape was found to be about 10.0 ± 1.0 nm by transmission electron microscopy (TEM). For toxicity evaluation, cellular morphology, mitochondrial function (MTT assay), mitochondrial membrane potential, anti-oxidant enzyme assay and comet assay were assessed in CHO cells exposed to various dose concentrations of 25, 50 and 100 μg ml−1 as well as in control cells. Ag NPs caused decreased mitochondrial membrane potential and comparable CAT, SOD, GPx, GST, GR activities as well as total Glutathione level. Comet tail length, tail moment and percent DNA in tail were also found to be increased in a dose dependent manner. In summary, the results suggest that Ag NPs of smaller size at low concentration (25 μg ml−1) cause cytotoxicity by oxidative stress induced apoptosis and damage to DNA and other cellular components.

Blood Levels of Organochlorine Pesticide Residues and Risk of Reproductive Tract Cancer Among Women from Jaipur, India

Residues of organochlorine pesticides are integral part of our environment. Because of their strong lipophilic and non-biodegradable nature, organisms at higher trophic levels in the food chain tend to accumulate them. The aim of the present study was to assess the influence of organochlorine pesticides upon the occurrence of reproductive tract cancers in women from Jaipur, India. Blood samples were collected from 150 females. In that group, 100 females suffered from reproductive tract cancers like cervical, uterine, vaginal and ovarian cancers, while the rest did not suffer from cancers or any other major disease and were treated as control group. The collected blood samples were subjected to pesticide extraction and analyzed with the help of gas chromatography. The pesticides detected were benzene hexa chlororide and its isomers, dieldrin, heptachlor, dichloro diphenyl trichloro ethane and its metabolites. The data obtained indicate that the organochlorine pesticide residue levels were significantly higher in all the cancer patients as compared with the control group.

Neurodevelopmental consequences of gestational and lactational exposure to pyrethroids in rats.

Indiscriminate use of pyrethroids has raised serious health related concerns, especially about their effects on children. The present study was designed to assess the developmental neurotoxicity of two pyrethroids; bifenthrin (BIF) and β‐cyfluthrin (CYF) administered at 1/15 of LD50 in rats. Pregnant females were exposed to the test compounds orally throughout gestation and lactation periods. Neonates were weighed and sexed at birth and were observed for any gross abnormality. Growth, viability and weaning indices were calculated during the lactation period. Exposure to both the compounds did not alter the physical developmental parameters viz. eye opening, pinna detachment, and fur appearance. CYF significantly impaired growth and survivability of pups. Behavioral endpoints assessed in neonates (surface righting, pivoting, and negative geotaxis reflex) as well as adults (motor activity and motor coordination) exhibited marked effect of CYF treatment. Administration of BIF to pregnant dams impaired pivoting in neonates. Decreased locomotion in the open‐field and impaired rota‐rod performance were also witnessed in BIF‐exposed animals. Enhanced oxidative stress was seen in corpus striatum, cerebellum, and hippocampus regions of the brain; reduced catalase, superoxide dismutase, and glutathione peroxidase activities were measured in BIF and CYF treated weanlings. Acetylcholinesterase activity was also found to be lowered following administration of both compounds at PND 21. The present results suggest that exposure to pyrethroids during critical periods of growth can induce long term effects on the behavior of animals.

Evaluation of teratogenic potential of cyfluthrin, a synthetic pyrethroid in Swiss albino mice.

A toxicity study was planned to assess the teratogenic potential of cyfluthrin that is widely used as a household insecticide to control mosquitoes, flies and cockroaches. Pregnant Swiss albino mice of one group were orally administered two doses of the pesticide (16 mg/kg and 32 mg/kg body weight) daily during the organogenetic phase (days 5—14) of gestation. The second group received the same two doses daily during the maturation phase (days 14—18) of gestation. The animals receiving the higher dose exhibited burrowing behaviour, which is a characteristic symptom of pyrethroid poisoning. The autopsies were performed on the 18th day of gestation and routine teratological observations were made. No external malformations occurred in any of the fetus. The higher dose significantly reduced the number of live fetuses, litter size and increased the resorption of embryos when administered during organogenesis, while exposure to the pesticide during the maturation phase did not significantly affect the reproductive parameters. During both the phases, the higher dose reduced the maternal weight gain and the average weight of the fetuses. The fetal anomalies observed were reduced ossification of skull bones, widened cranial sutures, short or absent ribs, hydrocephaly of the ventricles, microphthalmia, anophthalmia, pulmonary edema and subcutaneous edema.

Effects of Nano‐Graphene Oxide on Testis, Epididymis and Fertility of Wistar Rats

Nanoscale graphene oxide (NGO) has great potential in biomedicine by the virtue of its facile functionalization and tunable characteristics. Toxicity assessments have therefore become essential prior to its biomedical applications. This study examined the effects of NGO exposure on male reproductive function of adult Wistar rats. Rats were exposed intraperitoneally to three increasing doses, namely low‐dose (0.4 mg/kg BW), mid‐dose (2.0 mg/kg BW) and high‐dose (10.0 mg/kg BW) of NGO. Repeated exposure of NGO for 15 and 30 days resulted in decreased epididymal sperm counts and elevated sperm abnormalities. Percentage of motile sperms was also significantly reduced due to the exposure. Activities of SOD, GPx and malondialdehyde concentration in the testes increased in a dose‐specific manner. Results of the study demonstrated that high‐dose of NGO resulted in considerable histological damage to testicular tissue which included atrophy of seminiferous tubules with reduction in germinal epithelium, germ cell loss and vacuolization. Low and mid‐doses of NGO were not associated with sperm dysfunction or testis damage. Withdrawal of treatment for 30 days demonstrated significant recovery potential. Histology of epididymis and male fertility potential were not affected due to the NGO exposure. These findings are important for assessment of the risk involved in manufacturing, use and processing of the graphene oxide‐based materials towards male reproductive function.

Tartrazine induced neurobiochemical alterations in rat brain sub-regions

Tartrazine is a synthetic lemon yellow azo dye primarily used as a food coloring. The present study aimed to screen the neurobiochemical effects of Tartrazine in Wistar rats after administering the Acceptable Daily Intake (ADI) level. Tartrazine (7.5 mg/kg b.w.) was administered to 21 day old weanling rats through oral gavage once daily for 40 consecutive days. On 41st day, the animals were sacrificed and brain sub regions namely, frontal cortex, corpus striatum, hippocampus and cerebellum were used to determine activities of anti-oxidant enzymes viz. Superoxide Dismutase (SOD), Catalase (CAT), Glutathione-Stransferase (GST), Glutathione Reductase (GR) and Glutathione Peroxidase (GPx) and levels of lipid peroxides using Thio-barbituric Acid Reactive Substance (TBARS) assay. Our investigation showed a significant decrease in SOD and CAT activity, whereas there occurred a decline in GST and GR activity with an increase in GPx activity to counteract the oxidative damage caused by significantly increased levels of lipid peroxides. The possible mechanism of this oxidative damage might be attributed to the production of sulphanilc acid as a metabolite in azofission of tartrazine. It may be concluded that the ADI levels of food azo dyes adversely affect and alter biochemical markers of brain tissue and cause oxidative damage.

Effects of hydroxyl-functionalized multiwalled carbon nanotubes on sperm health and testes of Wistar rats

Carbon nanotubes (CNTs) are promising candidates for various applications including biomedical purposes. Owing to their remarkable physical, mechanical, electrical and chemical properties, CNTs have become an area of intense research and industrial activity in recent years. Therefore, toxicity and risk assessment studies are becoming increasingly important. The present study was designed to assess the effects of hydroxyl-functionalized multiwalled CNTs (OH-f MWCNTs) on sperm health and testes of adult Wistar rats. Animals were treated with different doses of OH-f MWCNTs (0.4, 2.0 and 10.0 mg/kg) along with a control group receiving only vehicle. Assessments after 15 alternate intraperitoneal doses revealed dose-related adverse effects on many endpoints tested. Results of the study showed significant impairment of sperm health at 2.0 and 10.0 mg/kg. Histology of testes demonstrated degeneration of germinal epithelium and loss of germ cells in the treatment groups. The exposure resulted in increased oxidative stress in testes in a dose-dependent manner. The findings of the study demonstrate that CNTs are potentially harmful for male reproductive health.