Gold nanoparticles (AuNPs) are finding increased use in therapeutics and imaging. However, their toxic effects still remain to be elucidated. Therefore this study was undertaken to study the biochemical effects of AuNPs on rat brain and identify potential biomarkers of AuNP toxicity. Male Wister rats weighing 150–200 g were injected with 20 μg/kg body weight of 20-nm gold nanoparticles for 3 days through the intraperitoneal route. The rats were killed by carbon dioxide asphyxiation 24 h after the last dose of gold nanoparticle injection. The parameters studied included lipid peroxidation, glutathione peroxidase, 8- hydroxydeoxyguanosine, caspase-3, heat shock protein70, serotonin, dopamine, gamma amino-butyric acid and interferon-γ. In this study AuNPs caused generation of oxidative stress and a decrease of antioxidant enzyme, viz., glutathione peroxidase activity in rat brain. This was accompanied by an increase in 8-hydroxydeoxyguanosine, caspase-3 and heat shock protein70, which might lead to DNA damage and cell death. Gold nanoparticles also caused a significant decrease in the levels of neurotransmitters like dopamine and serotonin, indicating a possible change in the behavior of the treated animals. There was a significant increase in the cerebral levels of IFN-γ in treated animals. This study concludes that AuNPs cause generation of oxidative stress and an impairment of the antioxidant enzyme glutathione peroxidase in rat brain. AuNPs also cause generation of 8-hydroxydeoxyguanosine (8OHdG), caspase-3 and heat shock protein70 (Hsp70), and IFN-γ, which may lead to inflammation and DNA damage/cell death.

Objectives. The present study was carried out to study the protective effects of quercetin andα-lipoic acid alone and in combination against aluminum chloride induced neurotoxicity in rats.Materials and Methods. The study consisted of eight groups, namely, Group 1: control rats, Group 2: rats receiving aluminium chloride 7 mg/kg body weight intraperitoneal route (i.p) for two weeks, Group 3: rats receiving quercetin 50 mg/kg body weight i.p. for two weeks, Group 4: rats receiving quercetin 50 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks, Group 5: rats receivingα-lipoic acid 20 mg/kg body weight i.p. for two weeks, Group 6: rats receiving lipoic acid 20 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks, Group 7: rats receivingα-lipoic acid 20 mg/kg body weight and quercetin 50 mg/kg body weight i.p. for two weeks, and Group 8: rats receivingα-lipoic acid 20 mg/kg body weight and quercetin 50 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks. The animals were killed after 24 hours of the last dose by cervical dislocation.Results. Aluminium chloride treatment of rats resulted in significant increases in lipid peroxidation, protein carbonyl levels, and acetylcholine esterase activity in the brain. This was accompanied with significant decreases in reduced glutathione, activities of the glutathione reductase, and superoxide dismutase. Pretreatment of AlCl₃exposed rats to either quercetin orα-lipoic acid also restored altered lipid peroxidation and superoxide dismutase to near normal levels. Quercetin orα-lipoic acid pretreatment of AlCl₃exposed rats improved the protein carbonyl and reduced glutathione, glutathione reductase, and acetylcholine esterase activities in rat brains towards normal levels. Combined pretreatment of AlCl3 exposed rats with quercetin andα-lipoic acid resulted in a tendency towards normalization of most of the parameters.Conclusions. Quercetin andα-lipoic acid complemented each other in protecting the rat brain against oxidative stress induced by aluminium chloride.

This study identified phytochemicals in Argemone mexicana (A. mexicana) extracts that are responsible for its medicinal properties, and the best solvent for their extraction. The extracts of the stem, leaves, flowers, and fruits of A. mexicana were prepared at low (corresponding to room temperature) and high temperatures (corresponding to the boiling points) in various solvents, viz., hexane, ethyl acetate, methanol, and H₂O. The UV-visible absorption spectra of various phytoconstituents in the isolated extracts were determined through spectrophotometry. Qualitative tests for the screening of phytoconstituents in the extracts were performed to identify various phytochemicals. We identified the presence of terpenoids, alkaloids, cardiac glycosides, and carbohydrates in the plant extracts. The antioxidant and anti-human immunodeficiency virus type 1 reverse transcriptase (anti-HIV-1RT) potential, as well as the antibacterial activity of various A. mexicana extracts were determined. These extracts showed strong antioxidant activities. The extracts exhibited antimicrobial activities against Salmonella typhi, Staphylococcus epidermis, Citrobacter, Neisseria gonorrhoeae, and Shigella flexineri. These extracts significantly inhibited HIV-1 reverse transcriptase activity. The aqueous leaf extract prepared at a temperature equivalent to the boiling point, i.e., 100 °C, was identified to be the most active against pathogenic bacteria and HIV-1 RT.

Aloe vera has been the most useful medicinal herb in the world since ancient times due to its vast biological effects. The presence of high content of bioactive compounds make Aloe vera a promising complementary and alternative agent in disease prevention. The effectiveness of A. vera-based medicines against pesticide toxicity has never been evaluated. It was therefore envisaged to develop an A. vera-based strategy to protect the non-target animals from adverse effects of the pesticides. This article illustrates the ameliorating effect of aqueous extract (AE) of A. vera leaves against the cartap and malathion toxicity. To evaluate the protective impact of A. vera against cartap (Ctp), malathion (Mtn) and a mixture of both pesticides, the animals were divided in eight groups, each containing six rats: Group 1- C (control), Group 2- AE + C, Group 3- Ctp, Group 4- Mtn, Group 5- Ctp + Mtn, Group 6- AE + Ctp, Group 7- AE + Mtn, Group 8- AE + Ctp + Mtn. Wistar rats exposed to Ctp, Mtn and Ctp + Mtn, displayed significant change in body weight. It was observed that the WBC level increased significantly in Mtn and Ctp + Mtn challenged groups. The contents of TNF-α and IL-6 in serum increased expressively in the Ctp, Mtn and Ctp + Mtn challenged groups. Rats treated with Ctp, Mtn and Ctp + Mtn displayed significant alterations in the levels of antioxidative indices (MDA, GSH, GST, GPx, SOD and CAT). Significant alterations were recorded in the activities of AST, ALT, ACP and ALP in Ctp, Mtn and Ctp + Mtn challenged groups. The histopathological results of liver supported the biochemical data. The pre-treatment of rats with the aqueous extract of A. vera leaves significantly protected them from the toxicity of pesticides. These results suggested that A. vera extract may be used as a promising natural agent for the management of pesticide induced toxicity.