Protective activities of ellagic acid and urolithins against kidney toxicity of environmental pollutants: A review

Oxidative stress and inflammation are two possible mechanisms related to nephrotoxicity caused by environmental pollutants. Ellagic acid, a powerful antioxidant phytochemical, may have great relevance in mitigating pollutant-induced nephrotoxicity and preventing the progression of kidney disease. This review discusses the latest findings on the protective effects of ellagic acid, its metabolic derivatives, the urolithins, against kidney toxicity caused by heavy metals, pesticides, mycotoxins, and organic air pollutants. We describe the chelating, antioxidant, anti-inflammatory, antifibrotic, antiautophagic, and antiapoptotic properties of ellagic acid to attenuate nephrotoxicity. Furthermore, we present the molecular targets and signaling pathways that are regulated by these antioxidants, and suggest some others that should be explored. Nevertheless, the number of reports is still limited to establish the efficacy of ellagic acid against kidney damage induced by environmental pollutants. Therefore, additional preclinical studies on this topic are required, as well as the development of well-designed clinical trials.     

Bidirectional Association Between Sleep Quality and Low Back Pain in Older Adults: A Longitudinal Observational Study

ObjectiveTo investigate the bidirectional relationship by determining whether baseline sleep quality predicts pain intensity and whether baseline pain intensity predicts sleep quality in older individuals with chronic low back pain (LBP).DesignA prospective longitudinal cohort study with a 6-month follow-up period.SettingCommunity.ParticipantsOlder adults with LBP aged 60 years or older (N=215).InterventionNot applicable.Main Outcome MeasuresData collection occurred at baseline and at 6 months. Pain intensity and sleep quality were measured in both time points of assessment using the numeric pain rating scale (range, 0-10) and the Pittsburg Sleep Quality Index. At baseline, we also collected information on demographic anthropometric variables, cognitive status, depression, and comorbidities. Multivariable linear regression analyses adjusted for potential covariates were performed.ResultsA total of 215 individuals with LBP were recruited. Poor sleep quality at baseline predicted high pain intensity at 6 months (β coefficient, 0.18; 95% confidence interval [CI], 0.07-0.30). High pain intensity at baseline predicted poor sleep quality 6 months later (β coefficient, 0.14; 95% CI, 0.01-0.26).ConclusionOur findings give some support to the bidirectional relationship between pain and sleep quality in older individuals with LBP. This bidirectional relationship may be used as prognostic information by clinicians when managing patients with LBP.     

Mitochondrial dysfunction from malathion and chlorpyrifos exposure is associated with degeneration of GABAergic neurons in Caenorhabditis elegans

Toxicity resulting from off-target effects, beyond acetylcholine esterase inhibition, for the commonly used organophosphate (OP) insecticides chlorpyrifos (CPS) and malathion (MA) was investigated using Saccharomyces cerevisiae and Caenorhabditis elegans model systems. Mitochondrial damage and dysfunction were observed in yeast following exposure to CPS and MA, suggesting this organelle is a major target. In the C. elegans model, the mitochondrial unfolded protein response pathway showed the most robust induction from CPS and MA treatment among stress responses examined. GABAergic neurodegeneration was observed with CPS and MA exposure. Impaired movement observed in C. elegans exposed to CPS and MA may be the result of motor neuron damage. Our analysis suggests that stress from CPS and MA results in mitochondrial dysfunction, with GABAergic neurons sensitized to these effects. These findings may aid in the understanding of toxicity from CPS and MA from high concentration exposure leading to insecticide poisoning.