Rheumatoid arthritis (RA) is an autoimmune inflammatory disease, affecting almost 1% of world population. Although the exact cause of RA is not known but the complex interaction between inflammatory mediators like tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2) and nitric oxide (NO) is accountable for cartilage destruction in joints. Gold is used for arthritis treatment since long without knowing its mechanism of action. Hence, the present study was designed to assess antiarthritic activity of nanogold (AuNGs) in collagen-induced arthritic (CIA) rat model by virtue of decreasing inflammatory mediators and oxidative stress. After induction CIA rats were treated with AuNGs in phosphate buffer at a dose of 20 μg/kg body weight for 20 days and found a significant decrease in the level of inflammatory mediators like TNF-α, IL-1β, COX-2 and transcription factor NF-kB (Nuclear factor-kB), which was found to be elevated in CIA rats. Additionally imbalance in oxidant and antioxidant status were determined and perceived that AuNGs remarkably attenuates the imbalance in level of antioxidant and oxidant near to normal. In consistent to biochemical results, mRNA expression of NF-kB, TNF-α, COX-2, and iNOS were also up-regulated in CIA rats, which were considerably down regulated by AuNGs treatment. These findings were positively correlated with the histological results of joints, displayed reduced inflammation and bone erosion in treated group. This study demonstrates the ability of AuNGs to ameliorate production of inflammatory mediators and oxidative stress in CIA rats. Induction of arthritis in rats showed increased inflammation, which activate the transcription factor NF-kB through activation of of IkB kinases (IKK) and ubiquination/proteosome degradation of IKB and transportation of activated NF-kB from cytoplasm to nucleus. In nucleus activated NF-kB bind to the promoter region of target gene and up regulate the production of pro-inflammatory cytokines, COX-2 and other inflammatory mediators that leads to cartilage destruction. AuNGs inhibit the activation of NF-kB and other inflammatory mediators and attenuate inflammation and cartilage destruction. COX-2: cyclooxygenase-2; IKK: IkB kinases; IKB: I Kappa B; IL-1β: interleukin-6; IL-6: interleukin-6; iNOS: inducible nitric oxide synthase; NF-kB: nuclear transcription factor kappa B; ROS: reactive oxygen species; TNF-α: tumour necrosis factor-alpha. Graphical Abstract

Alzheimer’s disease (AD) is an age-related progressive neurodegenerative disorder, characterized by the deposition of amyloid-β within the brain parenchyma resulting in a significant decline in cognitive functions. The pathophysiological conditions of the disease are recognized by the perturbation of synaptic function, energy and lipid metabolism. In Addition deposition of amyloid plaques also triggers inflammation upon the induction of microglia. Peroxisome proliferatoractivated receptors (PPARs) are ligand-activated transcription factors known to play important role in the regulation of glucose absorption, homeostasis of lipid metabolism and are further known to involved in repressing the expression of genes related to inflammation. Therefore, agonists of this receptor represent an attractive therapeutic target for AD. Recently, both clinical and preclinical studies showed that use of Peroxisome proliferator-activated receptor gamma (PPARγ) agonist improves both learning and memory along with other AD related pathology. Thus, PPARγ signifies a significant new therapeutic target in treating AD. In this review, we have shed some light on the recent progress of how, PPARγ agonist selectively modulated different cellular targets in AD and its amazing potential in the treatment of AD.

Microalgae have been recognized as one of the most efficient microorganisms to remediate industrial effluents. Among microalgae diatoms are silica shelled unicellular eukaryotes, found in all types of water bodies and flourish very well even in wastewater. They have their silica cell wall made up of nano arrayed pores arranged in a uniform fashion. Therefore, they act as smart nanocontainers to adsorb various trace metals, dyes, polymers, and drugs which are hazardous to human as well to aquatic life. The beautiful nanoarchitecture in diatoms allows them to easily bind to ligands of choice to form a nanocomposite structure with the pollutants which can be a chemical or biological component. Such naturally available diatom nanomaterials are economical and highly sensitive compared to manmade artificial silica nanomaterials to help in facile removal of the toxic pollutants from wastewater. This review is thus focused on employing diatoms to remediate various pollutants such as heavy metals, dyes, hydrocarbons detected in the wastewater. It also includes different microalgae as biosensors for determination of pollutants in effluents and the perspectives for nanotechnological applications in the field of remediating pollutants through microalgae. The review also discusses in length the hurdles and perspectives of employing microalgae in wastewater remediation.