Structural diversification of bioactive bibenzyls through modular co-culture leading to the discovery of a novel neuroprotective agent

Bibenzyls, a kind of important plant polyphenols, have attracted growing attention for their broad and remarkable pharmacological activities. However, due to the low abundance in nature, uncontrollable and environmentally unfriendly chemical synthesis processes, these compounds are not readily accessible. Herein, one high-yield bibenzyl backbone-producing Escherichia coli strain was constructed by using a highly active and substrate-promiscuous bibenzyl synthase identified from Dendrobium officinale in combination with starter and extender biosynthetic enzymes. Three types of efficiently post-modifying modular strains were engineered by employing methyltransferases, prenyltransferase, and glycosyltransferase with high activity and substrate tolerance together with their corresponding donor biosynthetic modules. Structurally different bibenzyl derivatives were tandemly and/or divergently synthesized by co-culture engineering in various combination modes. Especially, a prenylated bibenzyl derivative ( 12) was found to be an antioxidant that exhibited potent neuroprotective activity in the cellular and rat models of ischemia stroke. RNA-seq, quantitative RT-PCR, and Western-blot analysis demonstrated that 12 could up-regulate the expression level of an apoptosis-inducing factor, mitochondria associated 3 (Aifm3), suggesting that Aifm3 might be a new target in ischemic stroke therapy. This study provides a flexible plug-and-play strategy for the easy-to-implement synthesis of structurally diverse bibenzyls through a modular co-culture engineering pipeline for drug discovery.

Honokiol alleviated neurodegeneration by reducing oxidative stress and improving mitochondrial function in mutant SOD1 cellular and mouse models of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting both upper and lower motor neurons (MNs) with large unmet medical needs. Multiple pathological mechanisms are considered to contribute to the progression of ALS, including neuronal oxidative stress and mitochondrial dysfunction. Honokiol (HNK) has been reported to exert therapeutic effects in several neurologic disease models including ischemia stroke, Alzheimer's disease and Parkinson's disease. Here we found that honokiol also exhibited protective effects in ALS disease models both in vitro and in vivo. Honokiol improved the viability of NSC-34 motor neuron-like cells that expressed the mutant G93A SOD1 proteins (SOD1-G93A cells for short). Mechanistical studies revealed that honokiol alleviated cellular oxidative stress by enhancing glutathione (GSH) synthesis and activating the nuclear factor erythroid 2-related factor 2 (NRF2)-antioxidant response element (ARE) pathway. Also, honokiol improved both mitochondrial function and morphology via fine-tuning mitochondrial dynamics in SOD1-G93A cells. Importantly, honokiol extended the lifespan of the SOD1-G93A transgenic mice and improved the motor function. The improvement of antioxidant capacity and mitochondrial function was further confirmed in the spinal cord and gastrocnemius muscle in mice. Overall, honokiol showed promising preclinical potential as a multiple target drug for ALS treatment.

Recent advances in pharmacological intervention for prediabetes / 药学学报

Prediabetes is an abnormal condition between normal glucose metabolism and diabetes mellitus. Impaired glucose tolerance (IGT) is an indicator of high-risk state of prediabetes. Positive interventions of IGT, including life style changes and pharmacological intervention, can effectively postpone and reduce the development of prediabetes into type 2 diabetes mellitus, suggesting that IGT is a key point of diabetes prevention. Currently, pharmacological intervention for prediabetes is still at early stage. In this review, we summarizes recent clinical and preclinical studies on pharmacological intervention for prediabetes, and studies in the development of animal models with IGT and the application of new techniques. We also discuss the prospects of drugs for diabetes prevention, especially with the traditional Chinese medicine.

Effect of brazilein on energy metabolism of cerebral ischemia-reperfusion in mice / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate brazilein's role in energy metabolism of cerebral ischemia-reperfusion in mice.</p><p><b>METHOD</b>Fourty mice were randomly divided into the sham group, ischemia group, brazilein 5 mg x kg(-1) group and brazilein 10 mg x kg(-1) group, each with ten cases. Cerebral ischemia model was the built. Mice were injected with brazilein three days before the operation, then they were killed. Cerebrum homogenate was prepared for the detecting of ATP, ADP, AMP and lactic acid by HPLC, expressions of MCT1 and MCT2 in mRNA level by RT-PCR.</p><p><b>RESULT</b>The lactic acid in cerebrum increased sharply 20 minutes after cerebral ischemia and decreased 1 hour after reperfusion, then returned to the normal level 24 hours after reperfusion. The charge of energy decreased significantly at the beginning of the ischemia-reperfusion, and the charge restored 1 hour after reperfusion though it was still much lower than the normal level at the time point of 24 hours. Moreover, MCT1 and MCT2 upregulated accompanied with the increase of lactate, MCT2 mRNA enhanced in brazilein 5 mg x kg(-1) group (P < 0.05) while both the two factors increased in brazilein 10 mg x kg(-1) group (P < 0.01).</p><p><b>CONCLUSION</b>Brazilein might protect neurons by changing the charge of energy.</p>