Insulin Combined with Glucose Improves Spatial Learning and Memory in Aluminum Chloride-Induced Dementia in Rats.

Therapeutic intervention using drugs against Alzheimer disease is curative clinically. At present, there are no reports on the curative role of insulin in chronic models of dementia. We evaluated the curative role of insulin and its combination with glucose in dementia. We also investigated the impact of treatments on blood glucose to correlate with cognitive deficit. Further, we analyzed the interaction of treatments with the cholinergic system and oxidative stress in memory centers (i.e., hippocampus and frontal cortex). The antidementia activity of insulin was assessed against aluminum chloride (AlCl3)-induced dementia in rats. Behavioral parameters (Morris water maze test) along with biochemical parameters (Hippocampus and frontal cortex) such as acetylcholinesterase (AChE), catalase, and glutathione (GSH) levels were assessed to correlate cognitive function with cholinergic transmission and oxidative stress. Rats administered insulin and glucose showed improved cognitive function in the Morris water maze test. The combination corrected the diminished level of antioxidant enzymes such as catalase and GSH in the hippocampus and frontal cortex.Combined administration of insulin and glucose to aluminum-treated rats did not inhibit the aluminum action on the acetylcholinesterase enzyme. No significant changes were observed in blood glucose levels between the treatment groups.

Insulin blocks glutamate-induced neurotoxicity in differentiated SH-SY5Y neuronal cells.

Insulin is a cytokine which promotes cell growth. Recently, a few published reports on insulin in different cell lines support the antiapoptotic effect of insulin. But the reports fail to explain the role of insulin in modulating glutamate-mediated neuronal cell death through excitotoxicity. Thus, we examined the neuroprotective effect of insulin on glutamate-induced toxicity on differentiated SH-SY5Y neuronal cells. Changes in cell viability were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) based assay, while apoptotic damage was detected by acridine orange/ethidium bromide and Hoechst staining. Intracellular reactive oxygen species (ROS) accumulation and morphological alterations were also measured. Treatment with glutamate induced apoptosis, elevated ROS levels and caused damage to neurons. Insulin was able to attenuate the glutamate-induced excitotoxic damage to neuronal cells.

Sesamol prevents doxorubicin-induced oxidative damage and toxicity on H9c2 cardiomyoblasts.

OBJECTIVES: Exposure to toxicants like doxorubicin (Dox) damages cellular components by generating reactive oxygen species (ROS). This can be attenuated using free radical scavengers and/or antioxidants. METHODS: Dox-exposed cardiac myoblasts (H9c2 cells) were treated with sesamol (12.5, 25 and 50 µm), a natural phenolic compound. Intracellular ROS inhibition, cell viability and analysis of antioxidant and biochemical markers such as superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, reduced/oxidized glutathione, lipid peroxidation and protein carbonyl content were performed. The effect of sesamol treatment on the cytotoxic and genotoxic parameters was studied by monitoring the signalling proteins involved in the apoptotic pathway. KEY FINDINGS: Dox triggered cellular and genetic damage by increasing levels of intracellular ROS, thereby decreasing cell viability and increasing apoptosis. Sesamol reversed the cytotoxic and genotoxic effects of Dox. In addition, sesamol attenuated the pro-apoptotic proteins and improved the anti-apoptotic status. Sesamol pre-treatment also alleviated the disturbed antioxidant milieu by preventing ROS production and improving endogenous enzyme levels. CONCLUSIONS: Among the different doses tested, 50 µm of sesamol showed maximum protection against Dox-induced oxidative damage. This reflects the significance of sesamol in ameliorating the deleterious effects associated with cancer chemotherapy.

Pro-healing effects of morin, a natural antioxidant, on normal and dexamethasone-impaired wounds.

BACKGROUND: The aim of the study was to investigate the effects of morin on skin breaking strength, hydroxyproline, lysyl oxidase, DNA and RNA content of experimentally inflicted wounds in rats. METHODS: This study was performed on albino rats of either sex at the Central Animal Research Facility (CARF), Manipal University. RESULTS: Morin showed significant wound contraction on day 7 as compared to control with mean closure of 47.44±6.07% in excision wound model. Granulation tissue breaking strength was significantly increased (p<0.05) in the morin treated group with 180.2±7.94 g when compared to control at 151.2±6.99 g. There was a significant increase in hydroxyproline content with the morin treated group when compared to control with 3.41±0.33 µg/mg of granulation tissue. Similarly, the wound parameters were improved with the morin treated group in dexamethasone delayed healing. CONCLUSIONS: Our results suggest that morin treatment accelerates the healing process delayed by concurrent use of steroids.

Synthesis and evaluation of the antiinflammatory activity of N-[2-(3,5-di-tert-butyl-4-hydroxyphenyl)-4-oxo-thiazolidin-3-yl]-nicotinamide.

A new molecule incorporating nicotinoyl moiety, thiazolidin-4-one ring and 3,5-di-tert-butyl-4-hydroxyphenyl group (a potent antioxidant moiety) was synthesized and evaluated for anti-inflammatory activity in acute as well as chronic phase models of inflammation. The compound exhibited significant anti-inflammatory activity in three experimental models of inflammation, comparable to the positive control drug, ibuprofen (CAS 15687-27-1). It is suggested that besides the hypolipidemic and anti-oxidant potential of the molecule, its anti-inflammatory action could possibly act as an additional mechanism of its hypothesized anti-atherosclerotic activity.