[Study on synergistic anti-tumor effect of Shuangdan Capsules combined with 5-FU on hepatocellular carcinoma cells Huh-7 and xenograft mice].

This paper discussed the synergistic anti-tumor effect of Shuangdan Capsules combined with 5-fluorouracil(5-FU) on human liver cancer cell line Huh-7 and tumor bearing mice. The effects of Shuangdan Capsules combined with 5-FU on the activity and vascular endothelial growth factor(VEGF) receptor protein expression of Huh-7 cells were investigated, and the effects of drug combination on tube formation of HUVEC cell were also verified. In addition, the mice model of Huh-7 was established to observe the anti-tumor effect of drug combination and the distribution of tumor blood flow in tumor bearing mice by using molecular imaging. HPLC analysis showed that Shuangdan Capsules mainly consisted of danshensusodium, protocatechuic aldehyde, paeoniflorin, rosmarinic acid, alkannic acid, salvianolic acid B, and paeonol. In MTT experiment, the inhibition rate of Shuangdan Capsules(20 mg·L~(-1)) and 5-FU(1 µmol·L~(-1)) on Huh-7 cells was 60%, and the CI value was 0.59, suggesting that these two drugs had synergistic anti-hepatoma cells effect. The expression of VEGF receptor in Huh-7 cells was inhibited by the combination of these two drugs. In addition, the process of HUVEC was slow, and the number, length and area of the lumen branches decreased significantly. In vivo, Shuangdan Capsules combined with 5-FU inhibited the growth and prolongation of survival of Huh-7 cells in subcutaneous transplanted tumor nude mice; serum expression of CD31 and VEGF in nude mice were decreased, while caspase-3 was increased. Meanwhile, the drug combination significantly inhibited the expressions of MMP2 and VEGF in tumor tissues. Ultrasound showed that Shuangdan Capsules combined with 5-FU also inhibited tumor angiogenesis and reduced blood flow of tumor tissue. The results showed that Shuangdan Capsules combined with 5-FU may inhibit tumor angiogenesis by inhibiting VEGF and MMP2 expressions, thereby blocking tumor growth.

PI3K/Akt signaling pathway is involved in the neurotrophic effect of senegenin.

Neurodegenerative diseases are frequently associated with the loss of synapses and neurons. Senegenin, extracted from the Chinese herb Polygala tenuifolia Willd, was previously found to promote neurite outgrowth and neuronal survival in primary cultured rat cortical neurons. The aim of the present study was to investigate the underlying mechanisms of senegenin-induced neurotrophic effects on rat cortical neurons. Primary cortical rat neurons were treated with various pharmacological antagonists and with or without senegenin, and subjected to MTT and western blot analysis to explore the effects of senegenin on cell survival as well as the activation of signaling pathways. Neurite outgrowth and neuronal survival induced by senegenin were significantly inhibited by A2A receptor antagonist ZM241385 and specific phosphoinositide-3 kinase (PI3K) inhibitor LY294002, but not by tropomyosin receptor kinase A receptor inhibitor K252a, mitogen-activated protein kinase kinase inhibitor PD98059 or protein kinase C inhibitor GÖ6976. Furthermore, senegenin enhanced the phosphorylation of Akt, which was blocked by LY294002. The present study revealed that the PI3K/Akt signaling pathway may be involved in the neurotrophic effects of senegenin.

Neuroprotective effects of methyl 3,4-dihydroxybenzoate against H2O2-induced apoptosis in RGC-5 cells.

In the present study, we investigated the protective effect of methyl 3,4-dihydroxybenzoate (MDHB) against H2O2-induced apoptosis in RGC-5 cells. The RGC-5 cells were cultured in plates for 24 h, which were then pretreated with dimethyl sulfoxide, different concentrations of MDHB, or probucol for 12 h prior to addition of 300 µM H2O2 for 24 h. The cell viability was detected by MTT assay. The rate of apoptosis, level of lipid peroxidation, and mitochondrial membrane potential (MMP) were detected by flow cytometry. Western blot analysis was also used to measure the expression level of Bcl-2, Bax, caspase 9, and caspase 3 proteins in H2O2-treated RGC-5 cells. Our study showed that the cell viability of RGC-5 cells significantly decreased after treatment with 300 µM H2O2 for 24 h, but MDHB (8, 16, 32 µM) increased RGC-5 cell survival, suppressed the rate of apoptosis, scavenged reactive oxygen species, and restored MMP. MDHB also obstructed H2O2-induced apoptosis by regulating the expression of Bcl-2 and Bax, as well as suppressing the activation of caspase 9 and caspase 3. Our results showed that MDHB is an effective neuroprotective compound that mitigates oxidative stress and inhibits apoptosis in RGC-5 cells.

Methyl 3,4-dihydroxybenzoate protects primary cortical neurons against Aß25₋35-induced neurotoxicity through mitochondria pathway.

Amyloid-ß peptides (Aß), which can aggregate into oligomers or fibrils in neurons, play a critical role in the pathogenesis of Alzheimer's disease (AD). Methyl 3,4-dihydroxybenzoate (MDHB), a phenolic acid compound, has been reported to have antioxidative and neurotrophic effects. The present study investigated the neuroprotective effects of MDHB against Aß-induced apoptosis in rat primary cortical neutons. The primary cortical neurons were pretreated with different concentrations of MDHB for 24 hr, then incubated with 10 µM Aß25-35 for 24 hr. The results showed that Aß25-35 could induce neurotoxicity as evidenced by the decreased cell viability and the increased apoptotic rate. In parallel, Aß25-35 significantly increased the reactive oxygen species accumulation and decreased mitochondrial membrane potential. However, pretreatment of the primary cortical neurons with MDHB could effectively suppress these cellular events caused by Aß25-35 exposure. In addition, MDHB could increase the level of Bcl-2, decrease the level of Bax, and inhibit the activation of caspase-9 and caspase-3 in Aß25-35 -treated primary cortical neurons. All these results were beneficial in their protective effect against Aß-induced neurotoxicity. Our results suggest that MDHB has a neuroprotective effect that provides a pharmacological basis for its clinical use in the treatment of AD.

Phosphorylation of Akt is involved in protocatechuic acid-induced neurotrophic activity.

OBJECTIVE: To investigate the mechanisms underlying protocatechuic acid (PCA)-induced neurotrophic effects on cultured cortical neurons. METHODS: The mRNA expression of microtubule-associated protein 2 (MAP2) and brain-derived neurotrophic factor (BDNF) were measured by real-time quantitative PCR (qPCR). Subsequently, antagonists were used to study the signaling pathways activated by PCA and western blotting was used to detect the phosphorylation level of kinase-related protein. RESULTS: The mRNA expression of MAP2 and BDNF were upregulated in neurons treated with PCA compared with vehicle control. PCA-induced neurite outgrowth and neuronal survival in cultured cortical neurons were significantly inhibited by ZM241385 (an A(2A) receptor antagonist) and LY294002 (a PI3K inhibitor), but not by K252a (a TrkA receptor antagonist), GÖ6976 (a protein kinase C inhibitor) and PD98059 (a MEK inhibitor). PCA enhanced the phosphorylation of Akt, which could be blocked by LY294002. CONCLUSION: The PI3K/Akt signaling pathway might play an important role in the neurotrophic activity of PCA.