Graphene oxide as selective transporter of flavonols for physiological target DNA: A two-color fluorescence approach

Fisetin as a Senotherapeutic Agent: Biopharmaceutical Properties and Crosstalk between Cell Senescence and Neuroprotection

Like other organs, brain functions diminish with age. Furthermore, for a variety of neurological disorders—including Alzheimer’s disease—age is one of the higher-risk factors. Since in many Western countries the average age is increasing, determining approaches for decreasing the effects of aging on brain function is taking on a new urgency. Neuroinflammation and oxidative stress are two convoluted key factors in brain aging and chronic neurodegenerative diseases. The diverseness of factors, causing an age-related decrease in brain functions, requires identifying small molecules that have multiple biological activities that can affect all these factors. One great source of these small molecules is related to polyphenolic flavonoids. Recently, 3,3′,4′,7-tetrahydroxyflavone (fisetin) has been reported as a potent senotherapeutic capable of extending lifespan by reducing peroxidation levels and enhancing antioxidant cell responses. The neuroprotective effects of fisetin have been shown in several in vitro and in vivo models of neurological disorders due to its actions on multiple pathways associated with different neurological disorders. The present work aims to collect the most recent achievements related to the antioxidant and neuroprotective effects of fisetin. Moreover, in silico pharmacokinetics, pharmacodynamics, and toxicity of fisetin are also comprehensively described along with emerging novel drug delivery strategies for the amelioration of this flavonol bioavailability and chemical stability.

Two-color, ultra-sensitive fluorescent strategy for Ochratoxin A detection based on hybridization chain reaction and DNA tweezers

A two-color fluorescent DNA tweezers was developed for ultrasensitive detection of Ochratoxin A (OTA) based on hairpin-locked aptamer and hybridization chain reaction (HCR) amplification strategy. OTA can bind with hairpin-locked aptamer and then trigger the HCR reaction to produce a long double-strand DNA. The side-chains of the long duplex can separately hybridize with the two locker sequences of DNA tweezer, causing the opening of DNA tweezer and the recovery of two-color fluorescent signals. It shows a good linear range from 0.02 to 0.8 ppb with limit of detection of 0.006 ppb for FAM and 0.014 ppb for Cy5, which is beyond the requirement of actual application. In addition, the two-color fluorescent strategy can greatly reduce the false positive rate. It shows excellent performance for detection of OTA in practical food sample.