[Huangdi Anxiao Capsules-containing serum protects cell model from cognitive dysfunction in diabetes via inhibiting NLRP3-mediated pyroptosis].

This study aims to investigate the effects and the molecular mechanism of Huangdi Anxiao Capsules(HDAX)-containing serum in protecting the rat adrenal pheochromocytoma(PC12) cells from diabetes-associated cognitive dysfunction induced by high glucose and whether the mechanism is related to the regulation of NOD-like receptor thermal protein domain associated protein 3(NLRP3)-mediated pyroptosis. The PC12 cell model of diabetes-associated cognitive dysfunction induced by high glucose was established and mcc950 was used to inhibit NLRP3. PC12 cells were randomized into control, model, HDAX-containing serum, mcc950, and HDAX-containing serum+mcc950 groups. Methyl thiazolyl tetrazolium(MTT) assay was employed to determine the viability, and Hoechst 33258/PI staining to detect pyroptosis of PC12 cells. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interleukin-1 beta(IL-1ß) and IL-18. Western blot was employed to determine the protein levels of postsynaptic density protein 95(PSD-95), NLRP3, apoptosis-associated speck-like protein containing a CARD(ASC), gasdermin D(GSDMD), GSDMD-N, and cleaved cysteinyl aspartate specific proteinase-1(caspase-1), and RT-PCR to determine the mRNA levels of NLRP3, ASC, GSDMD, and caspase-1. The immunofluorescence assay was adopted to measure the levels and distribution of NLRP3 and GSDMD-N in PC12 cells. Compared with the control group, the model group showed decreased cell proliferation, increased PI positive rate, down-regulated protein level of PSD-95, up-regulated protein levels of NLRP3, ASC, GSDMD-N, GSDMD, and cleaved caspase-1, up-regulated mRNA levels of NLRP3, ASC, GSDMD, and caspase-1, and elevated levels of IL-1ß and IL-18. Compared with the model group, HDAX-containing serum, mcc950, and the combination of them improved cell survival rate and morphology, decreased the PI positive rate, down-regulated the protein levels of NLRP3, ASC, GSDMD-N, GSDMD, and cleaved caspase-1 and the mRNA levels of NLRP3, ASC, GSDMD, and caspase-1, and promoted the secretion of IL-1ß and IL-18. The findings demonstrated that HDAX-containing serum can inhibit the pyroptosis-mediated by NLRP3 and protect PC12 cells from the cognitive dysfunction induced by high glucose.

Huang-Pu-Tong-Qiao Formula Ameliorates the Hippocampus Apoptosis in Diabetic Cognitive Dysfunction Mice by Activating CREB/BDNF/TrkB Signaling Pathway.

BACKGROUND: Huang-Pu-Tong-Qiao formula (HPTQ), a traditional Chinese medicine (TCM) formula used to improve cognitive impairment. However, the underlying neuroprotective mechanism of HPTQ treated for diabetic cognitive dysfunction (DCD) remains unclear. The purpose of this study was to investigate the neuroprotective mechanism of HPTQ in DCD mice based on molecular docking. METHODS: To investigate the neuroprotective effect of HPTQ in DCD, the Morris water maze (MWM), novel object recognition (NOR) test was used to detect the learning and memory changes of mice; hematoxylin-eosin (HE) staining was used to investigate the damage of hippocampal neurons; the western blot (WB) was used to examine the level of brain-derived neurotrophic factor (BDNF) of hippocampus. To investigate the neuroprotective mechanism of HPTQ in DCD, molecular docking was used to predict the possible target proteins of different active components in HPTQ and then the WB was used to verify the expression of key target proteins in the hippocampus of mice. RESULTS: HPTQ improved the learning and memory ability, hippocampal neuron damage, and the level of BDNF in the hippocampus of the DCD model treated with HFD/STZ for 12 weeks. Besides, the results of molecular docking showed that the main chemical components of HPTQ could be well combined with the targets of Bcl-2-associated X (Bax) and B-cell lymphoma2 (Bcl-2) and caspase-3. The levels of Bax/Bcl-2 protein ratio and caspase-3 increased in the DCD model while the HPTQ inhibited it. In addition, HPTQ restored DCD-induced decline of p-CREB, BDNF, TrkB, and p-Akt in the hippocampus. CONCLUSIONS: These data indicated that HPTQ ameliorates the hippocampus apoptosis in diabetic cognitive dysfunction mice by activating CREB/BDNF/TrkB signaling pathway.

The Regulating Mechanism of Chrysophanol on Protein Level of CaM-CaMKIV to Protect PC12 Cells Against Aß25-35-Induced Damage.

OBJECTIVE: To investigate the neuroprotective effect of chrysophanol (CHR) on PC12 treated with Aß25-35, and the involved mechanism. METHODS: After the establishment of an AD cell model induced by Aß25-35, the cell survival rate was detected by MTT, cell apoptosis was assayed by Hoechst 33342 staining, mRNA expressions of calmodulin (CaM), calcium/calmodulin-dependent protein kinase kinase (CaMKK), calcium/calmodulin-dependent protein kinase IV (CaMKIV) and tau (MAPT; commonly known as tau) were determined by qRT-PCR, and protein levels of CaM, CaMKK, CaMKIV, phospho-CaMKIV (p-CaMKIV), tau and phospho-tau (p-tau) were detected by Western blot analysis. RESULTS: When pretreated with CHR before exposure to Aß25-35, PC12 cells showed that increased cell viability and reduced apoptosis. The qRT-PCR results indicated that the deposition of Aß25-35 triggers a decrease in levels of CaM, CaMKK, CaMKIV, and tau in PC12 cells. In addition, Western blot results also suggested that Aß25-35 decreases the protein expression of CaM, CaMKK, CaMKIV, p-CaMKIV, and the ratio of p-tau to tau in PC12 cells. However, the above effects were significantly alleviated after the treatment of CHR. CONCLUSION: CHR plays a neuroprotective role in AD though decreasing the protein level of CaM-CaMKK-CaMKIV and the expression of p-tau downstream.

Berberine ameliorates rats model of combined Alzheimer's disease and type 2 diabetes mellitus via the suppression of endoplasmic reticulum stress.

This study is aimed to investigate the protective effect against type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) of Berberine (BBR), and the underlying mechanism of action is explored. We established a rat model of combined AD and T2DM and used it to investigate the effect of BBR (150 mg/kg) on the course of these pathologies. The Morris water maze, biochemical analysis, hematoxylin-eosin staining, immunohistochemical study, immunofluorescent staining, TUNEL assay, RT-qPCR and western blot were used to reveal the effect of BBR on blood glucose, lipid changes, hippocampal injuries and cognitive impairment. The results showed that BBR could alleviate memory deficits, restore the disordered arrangement of nerve cells, the damage of neurons, improve TUNEL-positive cells and decrease the elevated levels of fasting blood glucose, triglyceride, total cholesterol and glycosylated serum protein levels in Alzheimer diabetic rats. Moreover, BBR treatment reduces the transcription of mRNAs and expression of proteins related to endoplasmic reticulum (ER) stress. These findings conclude that BBR can protect neurons by inhibiting the pathway of ER stress and thereby play an essential role in the preventive and therapeutic of AD and T2DM.

Quinones as preventive agents in Alzheimer's diseases: focus on NLRP3 inflammasomes.

OBJECTIVES: Alzheimer's disease (AD) is a hidden neurological degenerative disease, which main clinical manifestations are cognitive dysfunction, memory impairment and mental disorders. Neuroinflammation is considered as a basic response of the central nervous system. NLRP3 (Nucleotide-binding domain leucine-rich repeat (NLR) and pyrin domain containing receptor 3) inflammasome is closely related to the occurrence of neuroinflammation. Activation of the NLRP3 inflammasome results in the release of cytokines, pore formation and ultimately pyroptosis, which has demonstrated one of the critical roles in AD pathogenesis. Inhibition of the activity of NLRP3 is one of the focuses of the research. Therefore, NLRP3 represents an attractive pharmacological target, and discovery compounds with good NLRP3 inhibitory activity are particularly important. KEY FINDINGS: Quinones have good neuroprotective effects and prevent AD, which may be related to their regulation of inflammatory response. The molecular docking was used to explore 12 quinones with AD prevention and treatment and NLRP3. Docking results showed that the combination of anthraquinones and NLRP3 were the best, and the top two chemical compounds were Purpurin and Rhein, which are the most promising NLRP3 inhibitors. SUMMARY: These quinones may provide the theoretical basis for finding lead compounds for novel neuroprotective agents.

[Effects of Huangpu Tongqiao Capsules on EGFR-PLCγ signal pathway of hippocampus in rats with Alzheimer's disease].

Huangpu Tongqiao Capsules(HPTQC), with the functions of invigorating Qi and kidney, eliminating phlegm and removing blood stasis, have the effect of treating Alzheimer's disease(AD), but its mechanism needs further exploration. To explore the relationship between the therapeutic mechanism of HPTQC on Alzheimer's disease and EGFR-PLCγ signal pathway, 40 healthy male SD rats were selected and divided into 4 groups randomly: sham operation group(sham), model group(model), HPTQC group(HPTQC), and nimodipine group(NMP). AD rat model was established by intraperitoneal injection of D-galactose combined with an intracerebral injection of amyloid-ß peptide(25-35). After 28 days of administration, Morris water maze test and HE staining showed that the learning and memory ability of AD rats were significantly decreased(P<0.01), and hippocampal neurons were obviously da-maged. However, HPTQC could improve the learning and memory ability of AD rats(P<0.05) and reduce the damage of hippocampal neurons. Immunofluorescence test results showed that the expression levels of EGFR and p-Tau in hippocampal CA1 region of AD rats were significantly increased(P<0.01), and HPTQC could reduce the expression of EGFR and p-Tau in hippocampus of AD rats(P<0.01). Western blot results showed that the protein expression levels of EGFR, PLCγ, IP3 R and p-Tau in hippocampus of AD rats were significantly increased(P<0.01), and HPTQC could reduce the protein expression of EGFR, PLCγ, IP3 R and p-Tau in AD rats(P<0.05). RT-PCR results showed that the mRNA levels of EGFR, PLCγ, IP3 R and Tau in hippocampus of AD rats were significantly increased(P<0.01), and HPTQC could reduce the mRNA levels of EGFR, PLCγ, IP3 R and Tau in AD rats(P<0.05). The results indicate that HPTQC can improve the learning and memory ability of AD rats, and its mechanism of action may be related to regulating EGFR-PLCγ signal pathway.

[Effect of total flavonoids in Scutellaria barbata in mediating autophagy in tumor cells via PI3K/AKT/mTOR pathway].

To investigate the effect of the total flavonoids in Scutellaria barbata(TF-SB) against autophagy in tumor cells in vivo, and further determine whether the mechanism is correlated with the PI3K/AKT/mTOR pathway, which lead to autophagy-induced tumor cell death. Melanoma-bearing mice were prepared and divided into control group, rapamycin group (Rap 1.5 mg•kg⁻¹), and high, middle and low-dose TF-SB (200, 100, 50 mg•kg⁻¹) groups. The groups were given drugs once a day for successively 11 days. The inhibitory effect of TF-SB on the growth of melanoma was determined by measuring tumor volume and tumor inhibition rate. TUNEL method was used to detect the apoptosis of tumor cells to further verify the antitumor activity of TF-SB. The protein expressions of LC3-Ⅰ and LC3-Ⅱ were detected by Western blot, and the relative expression of LC3-Ⅱ was calculated based on LC3-Ⅱ/LC3-Ⅰ. In addition, the effect of TF-SB on autophagy of tumor cells, the underlying molecular mechanism of TF-SB in inducing autophagy and PI3K/AKT/mTOR pathway marker protein phosphorylation were also studied. According to the results, TF-SB effectively inhibited melanoma growth in mice, reduced tumor volume, increased the tumor inhibition rate, and significantly increased tumor cell apoptosis index and the ratio of LC3-Ⅱ/LC3-I (P<0.05, P<0.01 or P<0.001). The protein expressions of p-PI3K, p-AKT and p-mTOR were also suppressed dramatically compared with those in control group (P<0.05, P<0.01 or P<0.001). In conclusion, the total flavonoids in S. barbata could inhibit the growth of melanoma in vivo by inducing autophagy and apoptosis of tumor cells, which may be correlated with suppression of PI3K/AKT/mTOR pathway.

[Total flavonoids in Scutellaria barbata prevents NLRP3 inflammasome expression in tumor cells by affecting autologous pathway].

This paper was aimed to investigate the relationship between autophagy and NLRP3 inflammasome activation by studying the effect oftotal flavonoids in Scutellaria barbata (TF-SB) on autophagy in tumor cells and NLRP3 inflammasome, and to provide experimental evidence for further study of the anti-tumor mechanism of TF-SB. Mielanoma models were established by inoculating B16-F1 cell line to mice, and then were randomly divided into 5 groups (n=10 in each group): model control, positive control control(Rap, 1.5 mg•kg⁻¹), and TF-SB low, middle and high groups (50, 100 and 200 mg•kg⁻¹). Meanwhile, healthy C57BL/6J mice were used as normal control group (n=10). The drugs were given once daily for 2 weeks consecutively. Thirty minutes after last treatment, the determinations at endpoint were performed; pathological changes of tumor tissue were evaluated by using HE staining; protein expressions of LC3-II/LC3-I or NLRP3inflammasome/caspase-1/IL-1ß and IL-18 in tumor tissues were detected by using Western-blot; and serum levels of IL-1ß and IL-18 were detected by using Elisa kit. The results showed that the tumor cells in model group showed obvious atypia and malignant proliferation; the invasion of tumor tissue was significantly reduced, the tumor necrosis area was significantly increased, and the inflammatory reaction was significantly alleviated in positive control group and various TF-SB groups. As compared with model control group, LC3-II/LC3-I was significantly increased, while NLRP3/caspase-1/IL-1ßand IL-18 protein expressions were significantly decreased in positive control group and TF-SB groups. Serum IL-1ß and IL-18 levels in model control group were found higher than those in control group (P<0.001), but they were significantly lowered in positive control group and TF-SB groups (P<0.05, P<0.01 or P<0.001). Taken together, total flavonoids in S. barbata could effectively alter the tumor growth micro-environment by inhibiting the expression of NLRP3 inflammasome, and its anti-tumor effect may be associated with the induction of tumor cell autophagy.

[Effects of sapindus saponins on inflammatory response mediated by Ang II/p38MAPK pathway and cardiac hypertrophy in spontaneously hypertensive rats].

OBJECTIVE: To investigate the effects of sapindus saponins on myocardial inflammation mediated by Ang II/ p38MAPK signal pathway and cardiac hypertrophy in spontaneously hypertensive rats. And also to explore the correlation of cardiac hypertrophy and inflammation. METHOD: Thirty-two 16-week-old spontaneously hypertensive rats (SHR) were randomly divided into four groups, one with placebo as model group, one with captopril tablets (27 mg x kg(-1)) as positive control, one with low-dose sapindus saponins (27 mg x kg(-1)), one with high-dose (108 mg x kg(-1)). And another eight healthy Wistar-Kyoto strain (WKY) rats were used as the normal group. The animals were treated for eight weeks, and the indicators detected were as follows: (1) left ventricular mass index (LVMI); (2) the content of Ang II and hs-CRP in plasma were determined by ELISA; (3) the protein expression of AT1R and VEGF were determined by immunohistochemical method; (4) the protein expression of p-p38MAPK in myocardial cells was determined by Western blot. RESULT: Sapindus saponins reduced LVMI, and blocked the expression level of Ang II, AT1R, p-p38MAPK, VEGF and hs-CRP in myocardial tissue. Vs the SHR model group, there were significant differences (P < 0.05 or P < 0.01). CONCLUSION: Our findings suggested that sapindus saponins could inhibited cardiac hypertrophy, the possible mechanisms may be related to the inhibition on inflammatory response mediated by Ang II/p38MAPK pathway.

[Research of sapindus saponins on endothelial function in spontaneously hypertensive rats].

OBJECTIVE: To investigate the regulation on endothelial function of sapindus saponins in spontaneously hypertensive rats by studying the reactivity on different vasoconstrictor and dilator, and the content of the active substances. METHOD: Forty 16-week-old spontaneously hypertensive rats were randomly divided into five groups, one with placebo as model group, one with captopril tablets (27 mg x kg(-1)) as positive control, one with low-dose sapindus saponins (27 mg x kg(-1)), one with medium-dose (54 mg x kg(-1)), one with high-dose (108 mg x kg(-1)). And another eight healthy Wistar-Kyoto strain (WKY) rats were used as the normal group. The animals were treated for eight weeks, and the indicators to be detected were as follows: (1) the response of thoracic aorta on different vasoconstrictors Ang II (1 x 10(-9) -1 x 10(-5) mol x L(-1)), PE (1 x 10(-8) 1 x 10(-4) mol x L(-1)), KCl (20 -120 mmol x L(-1)); (2) the endothelium-dependent or non-endothelium-dependent vasodilation response of thoracic aorta on Ach (1 x 10-(10)-1 x 10(-5) mol x L(-1)) or SNP (1 x 10(-8)-1 x 10(-3) mol x (L(-1); (3) the content of NO, 6-KPG1alpha, ET-1 and TXB2 in serum was determined by Elisa. RESULT: In SHR model group, the response of thoracic aorta on Ang II, PE and KCl was increased, the endothelium-dependent vasodilation on Ach was reduced, but the effects on SNP was not obvious, the content of ET-1 and TXB2 was increased, and the content of NO and 6-KPG1alpha was reduced, Vs the normal control group, there were significant differences (P < 0.05 or P < 0.01); in the treatment groups, the response of thoracic aorta on Ang II, PE and KCl was reduced, the endothelium-dependent vasodilation of thoracic aorta on Ach was improved, the content of ET-1 and TXB2 was reduced, and the content of NO and 6-KPG1alpha was increased, Vs the SHR model group, there were significant differences (P < 0.05 or P < 0.01). CONCLUSION: Our findings suggested that sapindus saponins protected the endothelial function in SHR, the mechanisms were relevant to the protection of endothelial function.