Dietary alkyl thiol free radicals (RSS) can be as toxic as reactive oxygen species (ROS)

Spectrophotometric Methods for Measurement of Antioxidant Activity in Food and Pharmaceuticals

In recent years, there has been a growing interest in the application of antioxidants in food and pharmaceuticals due to their association with beneficial health effects against numerous oxidative-related human diseases. The antioxidant potential can be measured by various assays with specific mechanisms of action, including hydrogen atom transfer, single electron transfer, and targeted scavenging activities. Understanding the chemistry of mechanisms, advantages, and limitations of the methods is critical for the proper selection of techniques for the valid assessment of antioxidant activity in specific samples or conditions. There are various analytical techniques available for determining the antioxidant activity of biological samples, including food and plant extracts. The different methods are categorized into three main groups, such as spectrometry, chromatography, and electrochemistry techniques. Among these assays, spectrophotometric methods are considered the most common analytical technique for the determination of the antioxidant potential due to their sensitivity, rapidness, low cost, and reproducibility. This review covers the mechanism of actions and color changes that occur in each method. Furthermore, the advantages and limitations of spectrophotometric methods are described and discussed in this review.

A novel fluorescent probe for the detection of peroxynitrite and its application in acute liver injury model

Realizing the early diagnosis of acute liver injury has become a hotspot in recent years. Since the current indexes are not specific, developing novel probes with new recognition group remains a necessity. In this work, we developed a novel fluorescent probe, NNP, for the detection of ONOO⁻ in acute liver injury (ALI). The in vitro evaluation of NNP indicated the advantages including high sensitivity (LOD = 0.13 μM), rapid response (<25 s), naked-eye (red to yellow), and stability under various pH (4–10) and time (>48 h) conditions. Accordingly, NNP achieved the dose-dependent detection of ONOO⁻ in human hepatic stellate LX-2 cells. Further, in the ALI model mice, NNP could monitor the ONOO⁻ level in the occurrence of ALI in situ (in the liver region) with a steady performance. Subsequent immunohistochemical and imaging studies confirmed that NNP could achieve the detection of endogenous ONOO⁻ in ALI liver tissues. This work introduced a practical implement for the ONOO⁻ detection in ALI as well as a referable example for the establishment of molecular indexes in pre-clinical diagnosis.

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A novel fluorescent probe, NNP, for the detection of ONOO⁻ in acute liver injury model.

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High sensitivity, high selectivity, rapid response and steadiness for over 48 h.

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Applications in human hepatic stellate cell line for cellular imaging of ONOO⁻ level.

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Achieving the detection of endogenous ONOO⁻ in mice and liver tissues.

A three-channel fluorescent probe to image mitochondrial stress

Dual-recognition probes based on one reacting site inevitably encounter competition problems. Here, NPClA, a two-photon fluorescent probe based on a dual-site response for SO2/HOCl, was developed and applied in imaging mitochondrial stress.

Animal Venom Peptides as a Treasure Trove for New Therapeutics Against Neurodegenerative Disorders

BACKGROUND

Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and cerebral ischemic stroke, impose enormous socio-economic burdens on both patients and health-care systems. However, drugs targeting these diseases remain unsatisfactory, and hence there is an urgent need for the development of novel and potent drug candidates.

METHODS

Animal toxins exhibit rich diversity in both proteins and peptides, which play vital roles in biomedical drug development. As a molecular tool, animal toxin peptides have not only helped clarify many critical physiological processes but also led to the discovery of novel drugs and clinical therapeutics.

RESULTS

Recently, toxin peptides identified from venomous animals, e.g. exenatide, ziconotide, Hi1a, and PcTx1 from spider venom, have been shown to block specific ion channels, alleviate inflammation, decrease protein aggregates, regulate glutamate and neurotransmitter levels, and increase neuroprotective factors.

CONCLUSION

Thus, components of venom hold considerable capacity as drug candidates for the alleviation or reduction of neurodegeneration. This review highlights studies evaluating different animal toxins, especially peptides, as promising therapeutic tools for the treatment of different neurodegenerative diseases and disorders.

Antioxidant activity of sulfur and selenium: a review of reactive oxygen species scavenging, glutathione peroxidase, and metal-binding antioxidant mechanisms

It is well known that oxidation caused by reactive oxygen species (ROS) is a major cause of cellular damage and death and has been implicated in cancer, neurodegenerative, and cardiovascular diseases. Small-molecule antioxidants containing sulfur and selenium can ameliorate oxidative damage, and cells employ multiple antioxidant mechanisms to prevent this cellular damage. However, current research has focused mainly on clinical, epidemiological, and in vivo studies with little emphasis on the antioxidant mechanisms responsible for observed sulfur and selenium antioxidant activities. In addition, the antioxidant properties of sulfur compounds are commonly compared to selenium antioxidant properties; however, sulfur and selenium antioxidant activities can be quite distinct, with each utilizing different antioxidant mechanisms to prevent oxidative cellular damage. In the present review, we discuss the antioxidant activities of sulfur and selenium compounds, focusing on several antioxidant mechanisms, including ROS scavenging, glutathione peroxidase, and metal-binding antioxidant mechanisms. Findings of several recent clinical, epidemiological, and in vivo studies highlight the need for future studies that specifically focus on the chemical mechanisms of sulfur and selenium antioxidant behavior.