Folium Ginkgo extract and tetramethylpyrazine sodium chloride injection (Xingxiong injection) protects against focal cerebral ischaemia/reperfusion injury via activating the Akt/Nrf2 pathway and inhibiting NLRP3 inflammasome activation.

CONTEXT: Folium Ginkgo extract and tetramethylpyrazine sodium chloride injection (Xingxiong injection) is a compound preparation commonly used for treating cerebral ischaemia/reperfusion injury in ischaemic stroke in China. However, its potential mechanisms on ischaemic stroke remain unknown. OBJECTIVE: This study explores the potential mechanisms of Xingxiong injection in vivo or in vitro. MATERIALS AND METHODS: Sprague-Dawley (SD) rats were randomly assigned to five groups: the sham (normal saline), the model (normal saline) and the Xingxiong injection groups (12.5, 25 or 50 mL/kg). The rats were subjected to 2 h of middle cerebral artery occlusion (MCAO) followed by reperfusion for 14 d. Xingxiong injection was administered via intraperitoneal (i.p.) injection immediately after ischaemia induction for 14 d. Afterwards, rats were sacrificed at 14 d induced by administration of Xingxiong injection. RESULTS: Xingxiong injection significantly reduces infarct volume (23%) and neurological deficit scores (93%) compared with the MCAO/R group. Additionally, Xingxiong injection inhibits the loss in mitochondrial membrane potential (43%) and reduces caspase-3 level (44%), decreases NOX (41%), protein carbonyl (29%), 4-HNE (40%) and 8-OhdG (41%) levels, inhibits the expression of inflammatory factors, such as TNF-α (26%), IL-1ß (34%), IL-6 (39%), MCP-1 (36%), CD11a (41%) and ICAM-1 (43%). Moreover, Xingxiong injection can increase p-Akt/Akt (35%) and Nrf2 (47%) protein expression and inhibit NLRP3 (42%) protein expression. CONCLUSIONS: Xingxiong injection prevents cerebral ischaemia/reperfusion injury via activating the Akt/Nrf2 pathway and inhibiting NLRP3 inflammasome. These findings provide experimental evidence for clinical use of drugs in the treatment of ischaemic stroke.

Protective effects of Araloside C against myocardial ischaemia/reperfusion injury: potential involvement of heat shock protein 90.

The present study was designed to investigate whether Araloside C, one of the major triterpenoid compounds isolated from Aralia elata known to be cardioprotective, can improve heart function following ischaemia/reperfusion (I/R) injury and elucidate its underlying mechanisms. We observed that Araloside C concentration-dependently improved cardiac function and depressed oxidative stress induced by I/R. Similar protection was confirmed in isolated cardiomyocytes characterized by maintaining Ca2+ transients and cell shortening against I/R. Moreover, the potential targets of Araloside C were predicted using the DDI-CPI server and Discovery Studio software. Molecular docking analysis revealed that Araloside C could be stably docked into the ATP/ADP-binding domain of the heat shock protein 90 (Hsp90) protein via the formation of hydrogen bonds. The binding affinity of Hsp90 to Araloside C was detected using nanopore optical interferometry and yielded KD values of 29 µM. Araloside C also up-regulated the expression levels of Hsp90 and improved cell viability in hypoxia/reoxygenation-treated H9c2 cardiomyocytes, whereas the addition of 17-AAG, a pharmacologic inhibitor of Hsp90, attenuated Araloside C-induced cardioprotective effect. These findings reveal that Araloside C can efficiently attenuate myocardial I/R injury by reducing I/R-induced oxidative stress and [Ca2+ ]i overload, which was possibly related to its binding to the Hsp90 protein.

Convergent synthesis of oligosaccharides on the gram-scale using cetyl thioglycoside based on a hydrophobically assisted switching phase method.

A hydrophobically assisted switching phase (HASP) method is an efficient strategy for the synthesis of carrier-loaded oligosaccharides. We improved this method by using cetyl thioglycoside as the carrier, which made it possible to use the synthetic oligosaccharide block directly as the donor. We applied this improved HASP method in the successful assembly of a gp120-associated nona-mannoside. Our results indicated that the HASP method is an efficient strategy for the synthesis of complex oligosaccharides and glycoconjugates.

[Protective effects and underlying mechanisms of Panax notoginseng saponins against SH-SY5Y cell apoptosis induced by 6-hydroxydopamine].

The aim of this study is to investigate the protective effects of Panax notoginseng saponins (PNS) against 6-hydroxydopamine(6-OHDA)-induced apoptosis in SH-SY5Y cells and the possible underlying mechanisms. Cell viability was examined by MTT assay. The levels of lactate dehydrogenase(LDH), reactive oxygen species (ROS), malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase(GSH-Px) were measured using the respective assay kits. Apoptosis was measured by TUNEL kit, JC-1 and ROS was measured by staining with fluorescent dyes. The activation of caspase-3 was measured with the caspase-3 assay kit. The expression of nuclear protein Nrf2 and HO-1 were determined by Western blot. PNS had significant protective effects against 6-OHDA-induced apoptosis in SH-SY5Y cells in a time- and dose-dependent manner. PNS could attenuate 6-OHDA-induced suppression of SOD, GAT, GSH-Px (P < 0.01). PNS reduced the level of LDH, decreased the levels of ROS, MDA and increased cell viability and the mitochondrial membrane potential (P < 0.01). PNS also inhibited DNA fragmentation, mitochondrial response and the activation of caspase-3 (P < 0.01). Moreover, PNS pretreatment increased the expression of the nuclear Nrf2 and up-regulate HO-1. The protective effects of PNS could be inhibited by HO-1 inhibitor SnPP. In conclusion, PNS has significant protective effects against 6-OHDA- induced apoptosis in SH-SY5Y cells. The possible mechanisms of PNS are due to PNS-mediated activation of Nrf2, up-regulation of HO-1 and inhibition of oxidative stress.

[Effects of Qizhi Jiangtang capsule on dermal ulcer in type 2 diabetic rats].

The effect of Qizhi Jiangtang vapsule (QJC) on degree of dermal ulcer cicatrization in 2 type diabetic rats was studied. Except the rats for blank group, other male Wistar rats were used to establish type 2 diabetic model by feeding with high sugar and high fat diet for four weeks and intraperitonally injecting with 30 mg•kg⁻¹ streptozotocin (STZ). After that, the rats were divided into balanced groups according to blood sugar, and received corresponding drugs for treatment for 8 weeks. At the end of week 8, 2 cm diameter circular incision was done on the back of rats. After that, the rats were administered continuously for10 days. Area of ulcer surface was detected every two days. After the last administration, wound granulation tissues were cut down to conduct pathological examination and detect the expression of VEGF, PI3K, p-ERK protein in wound tissues. The results showed that compared with the model group, after application of Qizhi Jiangtang capsule (2.24 g•kg⁻¹), the wound was significantly reduced on day 6 and day 10 of wound formation; inflammation reaction on ulcer surface was significantly reduce; Qizhi Jiangtang capsule can increase VEGF expression in the wound tissues of diabetic rats, and inhibit ERK phosphorylation. It can be concluded that Qizhi Jiangtang capsule can promote skin ulcer healing for diabetes rats, and its mechanism may be related to regulating the expression of VEGA and p-ERK proteins.

[Effects of Qizhi Jiangtang capsule on protein expressions of InsR, PI3K, GLUT2 and p-JNK in hepatic tissues of rats with type 2 diabetes].

To observe the hypoglycemic effect of Qizhi Jiangtang capsule in rats with type 2 diabetes, and investigate the preliminary mechanism of its hypoglycemic effect, type 2 diabetes rat models were established by high glucose and high fat combined with small dose of streptozotocin (STZ). After continuous administration for 6 weeks, blood glucose, and glycosylated serum protein (GSP) levels were detected in all of the animals; immunohistochemistry assay was used to detect the number of islet ß cells; Western blot assay was used to detect the protein expression levels of insulin receptor (InsR), phosphoinositide-3 kinases (PI3K), glucose transporter-2 (GLUT2) and phosphorylated Jun N-terminal kinases (p-JNK)in hepatic tissues. The results showed that Qizhi Jiangtang capsule could reduce the blood sugar and GSP levels in serum in animals with type 2 diabetes mellitus, increase the level of insulin in serum and number of islet ß cells, increase the protein expression levels of InsR, PI3K and GLUT2, and reduce the level of p-JNK protein expression. In conclusion, Qizhi Jiangtang capsule has relatively stable hypoglycemic effect, and the mechanism may be associated with increasing the number of islet ß cells and level of insulin in serum, up-regulating the protein expression levels of InsR, PI3K and GLUT2, down-regulating the level of p-JNK protein expression in hepatic tissues, and reducing the level of insulin in hepatic tissues.

Efficient assembly of oligomannosides using the hydrophobically assisted switching phase method.

The hydrophobically assisted switching phase (HASP) method was applied in the assembly of oligomannosides. A new mannosyl donor with high reactivity was selected after a series of optimization studies, which was suitable for the synthesis of oligomannosides via the HASP method. The practicability of the HASP method towards the synthesis of branched oligosaccharides was explored and two branched penta-mannosides were assembled efficiently.

Elatoside C protects against hypoxia/reoxygenation-induced apoptosis in H9c2 cardiomyocytes through the reduction of endoplasmic reticulum stress partially depending on STAT3 activation.

Endoplasmic reticulum (ER) stress-induced apoptosis has been suggested to contribute to myocardial ischemia-reperfusion (I/R) injury. Elatoside C is one of the major triterpenoid compounds isolated from Aralia elata that is known to be cardioprotective. However, its effects on I/R injury to cardiac myocytes have not been clarified. This study aimed to investigate the possible protective effect of Elatoside C against hypoxia/reoxygenation (H/R)-induced H9c2 cardiomyocyte injury and its underlying mechanisms. H9c2 cardiomyocytes were subjected to H/R in the presence of Elatoside C. Our results showed that Elatoside C (25 µM) treatment provided significant protection against H/R-induced cell death, as evidenced by improved cell viability, maintained mitochondrial membrane potential, diminished mitochondrial ROS, and reduced apoptotic cardiomyocytes (P < 0.05). These changes were associated with the inhibition of ER stress-associated apoptosis markers (GRP78, CHOP, Caspase-12 and JNK), as well as the increased phosphorylation of STAT3 and an increased Bcl2/Bax ratio. Moreover, these effects of Elatoside C were prevented by the STAT3 inhibitor Stattic. Taken together, these results suggested that Elatoside C can alleviate H/R-induced cardiomyocyte apoptosis most likely by activating the STAT3 pathways and reducing ER stress-associated apoptosis.

Aconitine-induced Ca2+ overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats.

Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na(+) channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca(2+) in aconitine poisoning. In this study, we explored the importance of pathological Ca(2+) signaling in aconitine poisoning in vitro and in vivo. We found that Ca(2+) overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca(2+) handling proteins demonstrated that aconitine promoted Ca(2+) overload through the expression regulation of Ca(2+) handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca(2+) overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase.

Adaptable synthesis of C-lactosyl glycoclusters and their binding properties with galectin-3.

We report here the syntheses of mono- to tetravalent glycoclusters containing 1-methylene-C-ß-lactose. The 1-methylene-C-ß-lactose moiety has been synthesized from octa-acetyl-ß-lactose using the key carbonyl insertion reaction and linked to a series of alkynlated scaffolds via CuAAC reaction to afford mono- to tetravalent glycoclusters. The binding affinities of the final products to galectin-3 were found in the range of 10-100 µM.

Inhibitory effects of myricitrin on oxidative stress-induced endothelial damage and early atherosclerosis in ApoE-/- mice.

Atherosclerosis (AS) is a state of heightened oxidative stress characterized by lipid and protein oxidation in vascular walls. Oxidative stress-induced vascular endothelial cell (VEC) injury is a major factor in the pathogenesis of AS. Myricitrin, a natural flavonoid isolated from the root bark of Myrica cerifera, was recently found to have a strong antioxidative effect. However, its use for treating cardiovascular diseases, especially AS is still unreported. Consequently, we evaluated the cytoprotective effect of myricitrin on AS by assessing oxidative stress-induced VEC damage. The in vivo study using an ApoE-/-mouse model of AS demonstrated that myricitrin treatment protects against VEC damage and inhibits early AS plaque formation. This effect is associated with the antioxidative effect of myricitrin, as observed in a hydrogen peroxide (H2O2)-induced rat model of artery endothelial injury and primary cultured human VECs. Myricitrin treatment also prevents and attenuates H2O2-induced endothelial injury. Further investigation of the cytoprotective effects of myricitrin demonstrated that myricitrin exerts its function by scavenging for reactive oxygen species, as well as reducing lipid peroxidation, blocking NO release, and maintaining mitochondrial transmembrane potential. Myricitrin treatment also significantly decreased H2O2-induced apoptosis in VECs, which was associated with significant inhibition of p53 gene expression, activation of caspase-3 and the MAPK signaling pathway, and alteration of the patterns of pro-apoptotic and anti-apoptotic gene expression. The resulting significantly increased bcl-2/bax ratio indicates that myricitrin may prevent the apoptosis induced by oxidative stress injury.

Hypervalent iodine mediated para-selective fluorination of anilides.

A metal-free method for the direct regioselective fluorination of anilides has been developed. In the presence of bis(tert-butylcarbonyloxy)iodobenzene (PhI(OPiv)(2)) and hydrogen fluoride-pyridine, the para-fluorination products of anilides were obtained in moderate to good yields. Because of its operational safety and the use of readily available reagents, this new procedure provides facile access to a variety of para-fluorinated anilides.

[Protect effects and the underlying mechanisms of myricitrin against vascular endothelial cells apoptosis induced by oxidative stress].

This study is to report the study of protective effects of myricitrin against oxidative stress-induced apoptosis of vascular endothelial cells and the investigation of the possible mechanisms of action of myricitrin. The model of H2O2-induced apoptosis of vascular endothelial cells was used to determine the protective effects of myricitrin. The levels of LDH, MDA and the activities of SOD, NO were measured using the respective kits. The H2O2-induced apoptosis of vascular endothelial cells was detected using MTT reduction, TUNEL assay, JC-1 and ROS staining. The activation of Caspase-3 was also measured by fluorometry. The expression of apoptosis-related proteins was determined with Western blotting assay. Myricitrin had significant protective effects against H2O2-induced apoptosis of vascular endothelial cells in a time- and dose-dependent manner. The results show that myricitrin could attenuate H2O2-induced decrease in the activities of SOD (P < 0.01). Myricitrin could decrease the levels of LDH, MDA and increase cell viability and the mitochondrial membrane potential (P < 0.01). Myricitrin had protective effects in a dose-dependent manner between 32 micromol x L(-1) to 64 micromol x L(-1). Myricitrin pretreatment could attenuate H2O2-induced increase of p-ERK. Moreover, myricitrin pretreatment could up-regulate the expression of the anti-apoptotic protein Bcl-2, down-regulate the expression of the pro-apoptotic protein Bax, and decrease the expression of Caspase-3, 9. In conclusion, myricitrin had significant protective effects against H2O2-induced apoptosis of vascular endothelial cells. Myricitrin can enhance the activities of anti-oxidative enzymes and decrease the production of free radicals. The possible mechanisms of action of myricitrin are due to myricitrin-mediated inhibition of phosphorylation of the apoptosis signaling pathways-related kinase ERK, up-regulation of the expression of the anti-apoptotic protein, and down-regulation of the expression of the pro-apoptotic protein.

Oxidative stress suppression by luteolin-induced heme oxygenase-1 expression.

Luteolin, a flavonoid that exhibits antioxidative properties, exerts myocardial protection effects. However, the underlying molecular mechanisms are not yet fully understood. To investigate the effects of luteolin on myocardial injury protection and its possible mechanisms, a myocardial injury model was established with intragastric administration of 4 mg/kg isoproterenol (ISO) to male Sprague-Dawley rats (200-220 g) daily for 2 days. We found that pretreatment of luteolin (160, 80 and 40 mg/kg, i.g., respectively) daily for 15 days can prevent ISO-induced myocardial damage, including decrease of serum cardiac enzymes, improvement electrocardiography and heart vacuolation. Luteolin also improved the free radical scavenging and antioxidant potential, suggesting one possible mechanism of luteolin-induced cardio-protection is mediated by blocking the oxidative stress. To clarify the mechanisms, we performed the in vitro study by hydrogen peroxide (H(2)O(2))-induced cytotoxicty model in H9c2 cells. We found that luteolin pretreatment prevented apoptosis, increased the expression of heme oxygenase-1 (HO-1), and enhanced the binding of Nrf2 to the antioxidant response element, providing an adaptive survival response against H(2)O(2)-derived oxidative cytotoxicity. The addition of Znpp, a selective HO-1 competitive inhibitor, reduced the cytoprotective ability of luteolin, indicating the vital role of HO-1 on these effects. Luteolin also activated Akt and ERK, whereas the addition of LY294002 and U0126, the pharmacologic inhibitors of PI3K and ERK, attenuated luteolin-induced HO-1 expression and cytoprotective effect. Taken together, the above findings suggest that luteolin protects against myocardial injury and enhances cellular antioxidant defense capacity through the activation of Akt and ERK signal pathways that leads to Nrf2 activation, and subsequently HO-1 induction.

KI-catalyzed imidation of sp3 C-H bond adjacent to amide nitrogen atom.

We have developed a new KI-catalyzed method for the imidation of an sp(3) C-H bond adjacent to an amide nitrogen atom by using TBHP (tert-butyl hydroperoxide, 70% aqueous solution) as the oxidant. This novel procedure tolerated air and moisture and provided a series of novel products in moderate to excellent yields under mild conditions.

Assembly of homolinear α(1→2)-linked nonamannoside on ionic liquid support.

An improved method for the synthesis of large and complex oligosaccharides on ionic liquid (IL) support was developed. A strategy to attach the acceptor on IL using a more stable ether linker was used to prevent undesirable decomposition and side products. A "dissolution-evaporation-precipitation" purification procedure was also developed by combining the advantages of precipitation and solid-liquid extraction to reduce mechanical loss and purification time. This approach was successfully used for the rapid assembly of ionic liquid supported homolinear α(1→2)-linked nonamannoside in 25.2% overall yield within 28.5 h.

Active cobalt catalyst for the cleavage of benzyl ether.

An improved method for the deprotection of benzyl ethers using a catalytic amount of Co(2)(CO)(8) in the presence of Me(2)PhSiH and CO (1 atm) is described. The deprotection reaction is compatible with double bond or sulfur-containing substrates. The method also tolerates other functional groups, such as Ac, Piv, and Bz, and shows potential selectivity in perbenzylated monosaccharides.

Notoginsenoside R1 activates the NAMPT-NAD+-SIRT1 cascade to promote postischemic angiogenesis by modulating Notch signaling.

Nicotinamide phosphoribosyltransferase (NAMPT) maintains mitochondrial function and protects against cerebral ischemic injury by improving energy metabolism. Notoginsenoside R1 (R1), a unique constituent of Panax notoginseng, has been shown to promote the proliferation and tube formation of human umbilical vein endothelial cells. Whether R1 has proangiogenesis on the activation of NAMPT in ischemic stroke remains unclear. The purpose of this study was to investigate the pharmacodynamic effect and mechanism of R1 on angiogenesis after ischemic stroke. We used male Sprague-Dawley (SD) rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). R1 was administered via intraperitoneal (i.p.) injection immediately after ischemia induction. The promotion of R1 on angiogenesis were detected by immunofluorescence staining, 3D stereoscopic imaging and transmission electron microscopy detection. HBMEC cells were pretreated with different concentrations of R1 for 12 h before oxygen-glucose deprivation/reoxygenation (OGD/R) exposure. Afterward, scratch assay, EdU staining and tube formation were determined. Western blot analyses of proteins, including those involved in angiogenesis, NAMPT-SIRT1 cascade, VEGFR-2, and Notch signaling, were conducted. We showed that R1 significantly restored cerebral blood flow, improved mitochondrial energy metabolism and promoted angiogenesis. More importantly, incubation with 12.5-50 µM R1 significantly increased the migration, proliferation and tube formation of HBMECs in vitro. The promotion of R1 on angiogenesis were associated with the NAMPT-NAD+-SIRT1 cascade and Notch/VEGFR-2 signaling pathway, which was partially eliminated by inhibitors of NAMPT and SIRT1. We demonstrated that R1 promotes post-stroke angiogenesis via activating NAMPT-NAD+-SIRT1 cascade. The modulation of Notch signaling and VEGFR-2 contribute to the post-stroke angiogenesis. These findings offer insight for exploring new therapeutic strategies for neurorestoration via R1 treatment after ischemic stroke.

Xuesaitong injection (lyophilized) combined with aspirin and clopidogrel protect against focal cerebral ischemic/reperfusion injury in rats by suppressing oxidative stress and inflammation and regulating the NOX2/IL-6/STAT3 pathway.

BACKGROUND: Combination of aspirin (ASA) and clopidogrel (CLP) [dual antiplatelet therapy (DAPT)] has been limited in reducing early recurrent stroke events. Xuesaitong injection (lyophilized) (XST) made of total saponins from P. notoginseng, which significantly improves cerebral circulation and has been widely used in clinical applications for decades to treat and prevent ischemic stroke. Here, we confirmed the protective effect and mechanism of XST combined with DAPT (XST+ASA+CLP) on cerebral ischemia/reperfusion injury, exploring their better pharmacological action for clinical patients. METHODS: Sprague-Dawley rats (SD rats) (n=9 in each group) were randomly assigned to three groups and pretreated with XST, ASA+CLP, or XST+ASA+CLP for 7 days. Then rats were subjected to 2 h of middle cerebral artery occlusion (MCAO) followed by reperfusion for 24 h. Therapeutic effect of XST+ASA+CLP was measured by infarct volume, neurological behavior and regional cerebral blood flow (rCBF). Inhibition of neuronal apoptosis and glial cells was determined by immunofluorescent staining. We studied the protein levels of neurotrophic factors, neuroplasticity-related factors, oxidative stress indicators and inflammatory factors by ELISA assay. RESULTS: XST+ASA+CLP group showed significant reduction in infarct volumes and neurological deficit scores. XST+ASA+CLP group also had higher levels in rCBF and synaptic growth, and showed remarkable inhibition of microglia and astrocytes activation and the neuronal apoptosis. In addition, XST+ASA+CLP group had lower levels of NADPH, protein carbonyl, 4-hydroxynonenal (4-HNE), 8-hydroxydeoxyguanosine (8-OHdG) and several inflammatory cytokines. Moreover, XST+ASA+CLP group also had lower levels of NOX2, inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and p-STAT3/STAT3. CONCLUSIONS: These results demonstrate that a combination of XST, ASA, and CLP effectively protected rats against middle cerebral artery occlusion/reperfusion (MCAO/R) injury by suppressing the NOX2/IL-6/ STAT3 pathway. These novel findings provide theoretical basis and experimental evidence for the rationality of clinical combined use of drugs in the treatment of ischemic stroke.

Cassane diterpenoid derivative induces apoptosis in IDH1 mutant glioma cells through the inhibition of glutaminase in vitro and in vivo.

BACKGROUND: Glioblastoma multiforme (GBM) is the most frequent, lethal and aggressive tumour of the central nervous system in adults. The discovery of novel anti-GBM agents based on the isocitrate dehydrogenase (IDH) mutant phenotypes and classifications have attracted comprehensive attention. PURPOSE: Diterpenoids are a class of naturally occurring 20-carbon isoprenoid compounds, and have previously been shown to possess high cytotoxicity for a variety of human tumours in many scientific reports. In the present study, 31 cassane diterpenoids of four types, namely, butanolide lactone cassane diterpenoids (I) (1-10), tricyclic cassane diterpenoids (II) (11-15), polyoxybutanolide lactone cassane diterpenoids (III) (16-23), and fused furan ring cassane diterpenoids (IV) (24-31), were tested for their anti-glioblastoma activity and mechanism underlying based on IDH1 mutant phenotypes of primary GBM cell cultures and human oligodendroglioma (HOG) cell lines. RESULTS: We confirmed that tricyclic-type (II) and compound 13 (Caesalpin A, CSA) showed the best anti-neoplastic potencies in IDH1 mutant glioma cells compared with the other types and compounds. Furthermore, the structure-relationship analysis indicated that the carbonyl group at C-12 and an α, ß-unsaturated ketone unit fundamentally contributed to enhancing the anti-glioma activity. Studies investigating the mechanism demonstrated that CSA induced oxidative stress via causing glutathione reduction and NOS activation by negatively regulating glutaminase (GLS), which proved to be highly dependent on IDH mutant type glioblastoma. Finally, GLS overexpression reversed the CSA-induced anti-glioma effects in vitro and in vivo, which indicated that the reduction of GLS contributed to the CSA-induced proliferation inhibition and apoptosis in HOG-IDH1-mu cells. CONCLUSION: Therefore, the present results demonstrated that compared with other diterpenoids, tricyclic-type diterpenoids could be a targeted drug candidate for the treatment of secondary IDH1 mutant type glioblastoma through negatively regulating GLS.