Resistance of C57BL/6 Mice to Different Artemisinin-sensitive Strains of PbK173 / 中国实验方剂学杂志

ObjectiveThe tolerance of C57BL/6 mice to artemisinin-sensitive and -resistant strains of Plasmodium berghei （Pb） K173 and the differences in blood parameters， spleen coefficient and spleen structure during infection were compared to explore whether the artemisinin resistance of Pb would aggravate malaria infection. MethodPbK173 artemisinin-sensitive and -resistant strains were tested in parallel. C57BL/6 mice were randomly divided into 1 control group， 4 artemisinin-sensitive strain groups and 4 artemisinin-resistant strain groups by body weight. Each infection group was simultaneously inoculated （ip） with 1×107 infected red blood cells （iRBCs） of sensitive/resistant strain. For the mice in the survival test group， the body weight was recorded every day post infection， and the tail vein blood smear was collected to calculate the Pb infection rate. In the other infection groups， peripheral blood and spleen were collected on 2， 5 and 9 d after infection. Peripheral blood parameters， spleen coefficient， pathological section of spleen and spleen cells were detected in each group. ResultOn 1-3 d after infection， the infection rate of the resistant strain （0.4±0.0， 0.8±0.1， 1.9±0.4）% was always higher than that of the sensitive strain （0.2±0.1， 0.4±0.1， 1.1±0.3）% （P<0.01）. From the 4th d of infection， the infection rate of the two groups gradually approached. The survival period of the sensitive strain group （20.5±1.2） d was shorter than that of the resistant strain group （23.3±1.4） d （P<0.01）. On the 9th d， the white blood cell count of the sensitive strain group （16.2±1.1）×109 cells/L was higher than that of the resistant strain group （10.6±1.8）×109 cells/L （P<0.01）. Flow cytometry analysis of spleen cells showed that the sensitive strain group （3.6±0.4） demonstrated a higher CD4+/CD8+ value than the resistant strain group （2.3±0.2） on the 9th d （P<0.01）. The spleen of C57BL/6 infected mice was gradually enlarged during infection， and on the 9th d， the resistant strain group （3.1±0.1）% showed a higher spleen coefficient than the sensitive strain group （2.7±0.2）% （P<0.01）. In the early stage of C57BL/6 infected mice， the red pulp of spleen was hyperemic and swollen. On the 9th d， the marginal area of the spleen disappeared and the structure of the red and white pulp was destroyed. ConclusionWithout drug treatment， the protective immune responses of peripheral blood and spleen of C57BL/6 mice were more sensitive to PbK173 artemisinin-sensitive strain. The artemisinin-resistant strain of PbK173 bred with mouse-to-mouse blood transmission and increased artemisinin dose exhibited shortened growth period and reduced toxicity.

Effect of Dihydroartemisinin on Oxidative Damage and Energy Metabolism of HepG2 Cells and Its Synergistic Effect with Sorafenib / 中国实验方剂学杂志

Objective:To explore the inhibitory effect of dihydroartemisinin （DHA） on the proliferation of HepG2 cells， elucidate the mechanism from the perspectives of oxidative damage and energy metabolism， and discuss the possibility of combined use of DHA with sorafenib （Sora）. Method:Cell counting kit-8 （CCK-8） assay was used to obtain the 50% inhibitory concentration （IC₅₀） of DHA and Sora on HepG2 and SW480 cells and Chou-Talalay method was used to obtain the combination index （CI） of DHA and Sora. HepG2 cells were classified into the control group， DHA group （10 µmol·L^-1）， Sora group （5 µmol·L^-1）， and DHA + Sora group （DHA 10 µmol·L^-1， Sora 5 µmol·L^-1） and then incubated with corresponding drugs for 8-12 h. Seahorse XF glycolytic rate assay kit and cell mito stress test kit were employed to respectively detect the glycolysis function of cells and oxidative phosphorylation function of mitochondria. DCFH-DA and lipid peroxidation MDA assay kit were separately used to analyze the intracellular levels of reactive oxygen species （ROS） and malondialdehyde （MDA）. Western blot was applied to determine the intracellular levels of heme oxygenase-1 （HO-1） and glutamate-cysteine ligase catalytic subunit （GCLC）. Result:Compared with the control group， DHA alone inhibited the ATP synthesis in mitochondrial oxidative phosphorylation and glycolysis （<italic>P</italic><0.01）， increased the levels of intracellular ROS and MDA （<italic>P<</italic>0.05）， and decreased the levels of HO-1 and GCLC （<italic>P<</italic>0.05） in HepG2 cells. DHA and Sora had synergistic inhibitory effect on proliferation of HepG2 and SW480 cells， with CI < 0.90. The DHA + Sora group showed stronger suppression of ATP synthesis in mitochondrial oxidative phosphorylation and glycolysis （<italic>P</italic><0.01）， higher levels of intracellular ROS and MDA （<italic>P<</italic>0.01）， and lower levels of intracellular antioxidation-related proteins HO-1 and GCLC in HepG2 cells （<italic>P<</italic>0.01） than the DHA group. Conclusion:DHA may increase the level of MDA by reducing HO-1 and GCLC and increasing ROS in HepG2 cells， which results in mitochondria oxidative damage， restricts cell glycolysis and mitochondrial oxidative phosphorylation， and thus finally inhibits the proliferation of HepG2 cells. DHA and Sora have synergistic inhibitory effect on the proliferation of HepG2 and SW480 cells， and the mechanism may be related to the synergistic oxidative damage that affects the mitochondrial electron transport chain and suppresses cell energy metabolism.

Reasearch on lipid metabolism of Plasmodium and antimalarial mechanism of artemisinin / 中国中药杂志

As a unicellular organism, Plasmodium displays a panoply of lipid metabolism pathways that are seldom found together in a unicellular organism. These pathways mostly involve the Plasmodium-encoded enzymatic machinery and meet the requirements of membrane synthesis during the rapid cell growth and division throughout the life cycle. Different lipids have varied synthesis and meta-bolism pathways. For example, the major phospholipids are synthesized via CDP-diacylglycerol-dependent pathway in prokaryotes and de novo pathway in eukaryotes, and fatty acids are synthesized mainly via type Ⅱ fatty acid synthesis pathway. The available studies have demonstrated the impacts of artemisinin and its derivatives, the front-line compounds against malaria, on the lipid metabolism of Plasmodium. Therefore, this article reviewed the known lipid metabolism pathways and the effects of artemisinin and its derivatives on these pathways, aiming to deepen the understanding of lipid synthesis and metabolism in Plasmodium and provide a theoretical basis for the research on the mechanisms and drug resistance of artemisinin and other anti-malarial drugs.

Ferroptosis pathway and its intervention regulated by Chinese materia medica / 中国中药杂志

Ferroptosis is a new form of regulated cell death which is different from apoptosis, necrosis and autophagy, and results from iron-dependent lipidperoxide accumulation. Now, it is found that ferroptosis is involved in multiple physiological and pathological processes, such as cancer, arteriosclerosis, neurodegenerative diseases, diabetes, antiviral immune response, acute renal failure, hepatic and heart ischemia/reperfusion injury. On the one hand, it could be found the appropriate drugs to promote ferroptosis to clear cancer cells and virus infected cells, etc. On the other hand, we could inhibit ferroptosis to protect healthy cells. China has a wealth of traditional Chinese medicine resources. Chinese medicine contains a variety of active ingredients that regulate ferroptosis. Here, this paper reported the research of ferroptosis pathway, targets of its inducers and inhibitors that have been discovered, and the regulatory effects of the discovered Chinese herbs and its active ingredients on ferroptosis to help clinical and scientific research.

Research progress on heme metabolism in intraerythrocytic plasmodium / 中国中药杂志

Heme is a key metabolic factor in all life. Malaria parasite has de novo heme-biosynthetic pathway, however the growth and development of parasite depend on the hemoglobin-derived heme metabolism process during the intraerythrocytic stages, such as the ingestion and degradation of hemoglobin in the food vacuole. The hemoglobin metabolism in the food vesicles mainly includes four aspects: hemoglobin transport and intake, hemoglobin enzymolysis to produce heme, heme polymerization into malarial pigment, and heme transport via the food vacuole. The potential mechanisms of antimalarial drugs,such as chloroquine, artemisinin and atovaquone may be related to this process. The main four aspects of this metabolic process, key metabolic enzymes, effects of antimalarial drugs on the process and their potential mechanism of action would be summarized in this paper, providing ideas for rational use and mechanism exploration of similar drugs.

Protective effects of three phenylallyl compounds from Guizhi decoction ox-LDL-induced oxidative stress injury of human brain microvascular endothelial cells / 中国中药杂志

The main objective of this research is to observe protective effects of three phenylallyl compounds(cinnamyl alcohol,cinnamaldehyde and cinnamic acid)from Guizhi decoction against ox-LDL-induced oxidative stress injury on human brain microvascular endothelial cells(HBMEC).In this study,the toxicity and optimal protective concentration of three phenylallyl compounds from Guizhi decoction were determined by MTT assay.The HBMEC were divided into control group(DMSO),model group(ox-LDL),tert-butylhydroquinone (t-BHQ) group,cinnamyl alcohol group, cinnamaldehyde group and cinnamic acid group.The model group were treated with ox-LDL (50 mg•L⁻¹)for 24 h,other groups were separately treated with t-BHQ, cinnamyl alcohol, cinnamaldehyde and cinnamic acid of 20 μmol•L⁻¹, and exposed to ox-LDL (50 mg•L⁻¹) for 24 h at the same time.The survival rate of HBMEC was detected by MTT assay,reactive oxygen species(ROS) production of injured cells were detected using laser scanning confocal microscope (LSCM),the content of SOD, MDA, eNOS and NO in HBMEC was determined by ELISA, and the expressions of Nrf2 mRNA were detected by quantitative Real-time PCR(qRT-PCR).The results shows that oxidative stress injury of HBMEC could be induced by ox-LDL, the three phenylallyl compounds from Guizhi decoction did not affect morphology and viability of normal HBMEC.Compared with model group, the three phenylallyl compounds from Guizhi decoction could improve the above oxidative stress status and up-regulate Nrf2 mRNA expressions in injured HBMEC(P<0.05, P<0.01) .These findings suggested that the three phenylallyl compounds from Guizhi decoction have certain protective effects against ox-LDL-induced oxidative stress injury on HBMEC(cinnamaldehyde> t-BHQ> cinnamic acid>cinnamyl alcohol),the protective mechanism maybe related to regulation of antioxidant enzymes gene expression in HBMEC by Nrf2.

Structure-activity relationship of phenylallyl compounds inhibiting PGE2 release in mouse cerebral microvascular endothelial cells induced by IL-1beta / 药学学报

To observe the effects of phenylallyl compounds on prostaglandin E2 (PGE2) release in mouse cerebral microvascular endothelial cells (bEnd. 3) stimulated by IL-1beta, and to analyze their structure-activity relationship. Different concentrations of phenylallyl compounds were added separately, and the content of PGE2 induced by IL-1beta in the culture media was measured by ELISA assay. The 50% inhibitory concentration (IC50) of PGE2 was calculated. Studies showed that phenylallyl compounds could affect the PGE2 release differently in bEnd. 3 cells induced by IL-1beta. Close relationships were shown between the inhibitory activities and the location and number of the substituent groups. In conclusion, phenylallyl compounds exhibited inhibitory activities at different extent on PGE2 release in bEnd. 3 cells stimulated by IL-1beta and presented certain structure-activity relationship.

Effect of Shensu Yin on the expression of toll-like receptors and the downstream signaling components on RAW 264.7 cells / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the influences of Shensu Yin to RAW 264.7 on the expression of TLR3, TLR4 and the factors of the downstream in RAW 264. 7 cells.</p><p><b>METHOD</b>RAW 264.7 cell line was stimulated with Lipopolysaccharide and POLY I: C, respectively, and treated with the drug serum of Shensuyin simultaneously. 24 hours later, collected the supernatant and measured the inflammatory factors TNF-alpha and IFN-beta, extracted mRNA and measured the expression of TLR3, TLR4 and other correlated indexes of the downstream, analyzed and evaluated Shensu Yin's substance basis of pharmacodynamic actions.</p><p><b>RESULT</b>Shensu Yin drug serum depressed the expression of TLR4, MyD88, TRAF-6, TRAM and TRIF mRNA, as a result, it decreased the amount of TNF-alpha and IFN-beta.</p><p><b>CONCLUSION</b>Depressing the expression of TLR3, MyD88, TRAM and TRIF mRNA may be the elementary basis of Shensu Yin to play heat-clearing and detoxicating effect.</p>

Effect of guizhi decoction on PKA and PKC activities of hypothalamus in fever rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the changes of the activity of both protein kinase A and C and the mechanisms of antipyretic action of Guizhi decoction.</p><p><b>METHOD</b>The fever responses were observed after combination injection of H-89 (a selective inhibitor of PKA) and calphostin C (a selective inhibitor of PKC), and oral pretreatment of Guizhi decoction in fever rats induced by an intra-cerebroventricular (icv) injection of an EP3 agonist, and both PKA and PKC activity in hypothalamus were measured in rats pretreated with Guizhi decoction and vehicle using isotopic tracing assay.</p><p><b>RESULT</b>The rise in rat body temperature was inhibited by H-89, Calphostin C, and Guizhi decoction, moreover, pretreatment with Guizhi decoction reduced PKA activity obviously. PKC activity in model rats exhibited a tendency to drop compared with that of control group, Oral administration of Guizhi decoction in large dose inhibited the response significantly, while the low dose of Guzhi decoction has no effect on PKC.</p><p><b>CONCLUSION</b>Both PKA and PKC may participate in the mechanism of fever induction by EP3 agonist. The decrease of PKA and PKC may contribute to the antipyretic action of Guizhi decoction, some isoenzyme of PKC may play a role in the fever production.</p>

Effect of guizhi tang and its active components on the fever induced by EP3 agonist / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of Guizhi Tang and its active components on the fever induced by EP3 receptor agonist sulprostone in rats.</p><p><b>METHOD</b>The rise in body temperature evoked by a LCV(lateral cerebroventricle)-injection of sulprostone was compared with that of sulprostone induced-fever rats pretreated with Guizgi Tang and its active compounds, cinnamaldehyde, cinnamic acid and total glucosides of paeony.</p><p><b>RESULT</b>Pretreatments with Guizhi Tang and cinnamaldehyde inhibited the rise in body temperature induced by sulprostone, while cinnamic acid tended to augment the fever. The sulprostone-induced fever was blocked by an ip pretreatment of total glucosides of paeony even below the basement.</p><p><b>CONCLUSION</b>Present data suggest that interruption with the down-stream events of EP3 receptor may contribute to the antipyretic action of Guizhi Tang, cinnamaldehyde and the total glucosides of paeony, while cinnamic acid may have no such effect.</p>