Artemisinin mimics calorie restriction to trigger mitochondrial biogenesis and compromise telomere shortening in mice

Blood redistribution preferentially protects vital organs under hypoxic stress in Pelteobagrus vachelli

Blood redistribution occurs in mammals under hypoxia but has not been reported in fish. This study investigated the tissue damage, hypoxia-inducible factor (HIF) activation level, and blood flow changes in the brain, liver, and muscle of Pelteobagrus vachelli during the hypoxia process for normoxia-hypoxia-asphyxia. The results showed that P. vachelli has tissue specificity in response to hypoxic stress. Cerebral blood flow increased with less damage than in the liver and muscle, suggesting that P. vachelli may also have a blood redistribution mechanism in response to hypoxia. It is worth noting that severe hypoxia can lead to a sudden increase in the degree of brain tissue damage. In addition, higher dissolved oxygen levels activate HIF and may have contributed to the reduced damage observed in the brain. This study provides basic data for investigating hypoxic stress in fish.

Artemisinins and their impact on inhibitory neurotransmission

Artemisinin, a major extract of the annual mugwort Artemisia annua, and its semisynthetic derivatives represent state-of-the-art antimalarial drugs. These compounds also target, via poorly understood mechanisms, various mammalian pathways, thereby exhibiting anticancer and immunomodulatory properties. Recently, crystal structures of artemisinins with two mammalian targets were determined, namely, gephyrin, the prime scaffolding protein at inhibitory postsynapses, and pyridoxal kinase, a central metabolic enzyme synthesizing vitamin B6. These structures and corresponding functional studies demonstrate that artemisinins play a dual role in modulating inhibitory synapses, acting on postsynaptic sites by impeding inhibitory neurotransmitter receptor clustering and on presynaptic terminals by limiting the biosynthesis of the inhibitory neurotransmitter γ-aminobutyric acid. These studies pave the way for further investigations of artemisinins as inhibitory neurotransmission modulators in humans.

Does skeletal muscle morphology or functional performance better explain variance in fast gait speed in older adults?

BACKGROUND

Fast gait speed is being increasingly recognized as an important clinical tool in older adults. However, the underlying muscular and functional contributors to fast gait speed performance remain poorly understood.

AIM

We sought to determine predictors of fast gait speed in older adults. We hypothesized that lower-extremity skeletal muscle size and quality would be strong predictors.

METHODS

Ninety community-dwelling older adults (33 men, 57 women; mean ± SD age = 74 ± 6 years) participated. B-mode ultrasonography was used to capture images of the vastus lateralis, rectus femoris, and gastrocnemius in the transverse plane. Each participant performed 30-second chair stand, heel-rise, functional reach, and grip strength tests. Fast gait speed was measured using the NIH Toolbox 4-Meter Walk Test. ImageJ software was used to quantify cross-sectional area (CSA), subcutaneous tissue thickness, and echo intensity. Two separate stepwise regression analyses were performed, one using muscle morphology variables as independent variables, and another including the functional outcomes.

RESULTS

The ultrasound variables exhibited weak-to-moderate correlations with fast gait speed (|r| range = 0.168-0.416). The initial regression analysis indicated that the combination of medial gastrocnemius CSA and subcutaneous tissue thickness explained 22.8% of the variance in fast gait speed. The secondary analysis indicated that 30-second chair stand, heel-rise, and grip strength performance explained 45.5% of the variance.

CONCLUSION

While medial gastrocnemius morphology is important, measures of upper and lower-extremity muscle function are better predictors of fast gait speed. These results highlight a dissociation between skeletal muscle morphology and fast gait speed.

The potential of artemisinins as anti-obesity agents via modulating the immune system

Artemisinin and its derivatives are the most effective antimalarial drugs. Besides anti-malarial activity, artemisinin and its derivatives have displayed wide-spectrum bioactivities such as anti-parasite, anti-tumor, and anti-obesity effects. Obesity is an epidemic worldwide which is a big threat to human health, but there are only a few approved anti-obesity drugs in the world. Also, these drugs are efficient to limited patients partly because their safety and efficacy are questioned. Anti-inflammatory therapies may be valuable in obesity treatment since growing evidence shows chronic metabolic inflammation is implicated in metabolic disease pathogenesis. As artemisinin and its derivatives display effective anti-inflammatory and immunoregulatory properties with less toxicity, it provides an insight for novel drug development in obesity therapeutic strategies via immune-regulatory mechanisms. In this review, the potential of artemisinin and its derivatives to treat various metabolic diseases such as obesity and diabetes is discussed.

Hormetic Effects of Phytochemicals on Health and Longevity

Caloric restriction, intermittent fasting, and exercise activate defensive cellular responses such as autophagy, DNA repair, and the induction of antioxidant enzymes. These processes improve health and longevity by protecting cells and organs against damage, mutations, and reactive oxygen species. Consuming a diet rich in vegetables, fruits, and mushrooms can also improve health and longevity. Phytochemicals such as alkaloids, polyphenols, and terpenoids found in plants and fungi activate the same cellular processes as caloric restriction, fasting, and exercise. Many of the beneficial effects of fruits and vegetables may thus be due to activation of stress resistance pathways by phytochemicals. A better understanding of the mechanisms of action of phytochemicals may provide important insights to delay aging and prevent chronic diseases.

Artemisinin Prevents Glutamate-Induced Neuronal Cell Death Via Akt Pathway Activation

Artemisinin is an anti-malarial drug that has been in use for almost half century. Recently, novel biological effects of artemisinin on cancer, inflammation-related disorders and cardiovascular disease were reported. However, neuroprotective actions of artemisinin against glutamate-induced oxidative stress have not been investigated. In the current study, we determined the effect of artemisinin against oxidative insult in HT-22 mouse hippocampal cell line. We found that pretreatment of artemisinin declined reactive oxygen species (ROS) production, attenuated the collapse of mitochondrial membrane potential induced by glutamate and rescued HT-22 cells from glutamate-induced cell death. Furthermore, our study demonstrated that artemisinin activated Akt/Bcl-2 signaling and that neuroprotective effect of artemisinin was blocked by Akt-specific inhibitor, MK2206. Taken together, our study indicated that artemisinin prevented neuronal HT-22 cell from glutamate-induced oxidative injury by activation of Akt signaling pathway.

Artemisinin: A Panacea Eligible for Unrestrictive Use?

Although artemisinin has been used as anti-malarial drug, accumulating evidence on the extended therapeutic potential of artemisinin emerges. Apart from anti-malaria and anti-tumor, artemisinin can also exert beneficial effects on some metabolic disorders, such as obesity, diabetes, and aging-related diseases. However, whether artemisinin should be applied to treatment of the wide-spectrum diseases is debating. Here, we discuss the predisposition of a raised risk of malarial resistance to artemisinin from consideration of the multi-target and non-specific features of artemisinin.

Combined oridonin with cetuximab treatment shows synergistic anticancer effects on laryngeal squamous cell carcinoma: involvement of inhibition of EGFR and activation of reactive oxygen species-mediated JNK pathway

Epidermal growth factor receptor (EGFR), a transmembrane glycoprotein, is expressed at high levels in a large proportion of laryngeal squamous cell carcinoma (LSCC). Cetuximab (Cet), an anti-EGFR monoclonal antibody, has limited clinical outcome for patients with head and neck squamous cell carcinoma. Our previous studies showed that oridonin (ORI), a natural and safe kaurene diterpenoid isolated from Rabdosia rubescens, inhibited cell growth in HEp-2 cells through inhibition of EGFR phosphorylation. The aim of the present study was to determine whether ORI could improve the anticancer efficacy of Cet on LSCC. We observed that the combination with Cet and ORI synergistically inhibited cell growth associated with Fas-mediated apoptosis and G2/M phase arrest in two LSCC cell lines (HEp-2 and Tu212 cells). Moreover, combination treatment caused cell death associated with suppression of p-EGFR and activation of reactive oxygen species (ROS)-mediated JNK pathway. In nude mice bearing HEp-2 xenografts, ORI plus Cet caused a significant tumor regression through induction of apoptosis and inhibition of proliferation with no side-effect. Together, our findings suggest that the combination of ORI and Cet has the potential to enhance tumor responses and may significantly improve therapeutic outcomes in LSCC.

Integrated Droplet-Based Microextraction with ESI-MS for Removal of Matrix Interference in Single-Cell Analysis

Integrating droplet-based microfluidics with mass spectrometry is essential to high-throughput and multiple analysis of single cells. Nevertheless, matrix effects such as the interference of culture medium and intracellular components influence the sensitivity and the accuracy of results in single-cell analysis. To resolve this problem, we developed a method that integrated droplet-based microextraction with single-cell mass spectrometry. Specific extraction solvent was used to selectively obtain intracellular components of interest and remove interference of other components. Using this method, UDP-Glc-NAc, GSH, GSSG, AMP, ADP and ATP were successfully detected in single MCF-7 cells. We also applied the method to study the change of unicellular metabolites in the biological process of dysfunctional oxidative phosphorylation. The method could not only realize matrix-free, selective and sensitive detection of metabolites in single cells, but also have the capability for reliable and high-throughput single-cell analysis.