The role of endogenous reactive oxygen species in oxymatrine-induced caspase-3-dependent apoptosis in human melanoma A375 cells

Comprehensive review on leucine-rich pentatricopeptide repeat-containing protein (LRPPRC, PPR protein): A burgeoning target for cancer therapy

Leucine-rich pentatricopeptide repeat-containing (LRPPRC), known as the gene mutations that cause Leigh Syndrome French Canadian, encodes a high molecular weight PPR protein (157,905 Da), LRPPRC. LRPPRC binds to DNA, RNA, and proteins to regulate transcription and translation, leading to changes in cell fate. Increasing evidence indicates that LRPPRC plays a pivotal role in various human diseases, particularly cancer in recent years. Here, we review the structure, function, molecular mechanism, as well as inhibitors of LRPPRC. LRPPRC expression elevates in most cancer types and high expression of LRPPRC predicts the poor prognosis of cancer patients. Targeting LRPPRC suppresses tumor progression by affecting several cancer hallmarks, including signal transduction, cancer metabolism, and immune regulation. LRPPRC is a promising target in cancer research, serving as both a biomarker and therapeutic target. Further studies are required to extend the understanding of LRPPRC function and molecular mechanism, as well as to refine novel therapeutic strategies targeting LRPPRC in cancer therapy.

Oxymatrine inhibits melanoma development by modulating the immune microenvironment and targeting the MYC/PD-L1 pathway

Oxymatrine, also known as ammothamnine or oxysophoridine, is a natural compound isolated from Sophora flavescens (in Chinese, Kushen), and many previous researchers have characterized its anti-inflammatory, anti-fibrotic and anti-tumor properties. However, the underlying anti-tumor immunological mechanism of oxymatrine remains elusive. In this study, we carried out experiments both in vitro and in vivo and investigated the anti-tumor effect of oxymatrine to inhibit the proliferation and migration of melanoma B16 cells, while promoting apoptosis. Oxymatrine upregulated CD4+ T, CD8+ T and NKT cells, downregulated Treg cells, promoted TNF-α secretion, and successfully modulated the immune microenvironment and ultimately suppressed melanoma development in subcutaneous tumor models established in mice. Evidence from network pharmacology and RNAseq suggested that possible targets of oxymatrine for melanoma treatment included PD-L1 and MYC. We observed oxymatrine inhibited PD-L1 and MYC expression in melanoma cells via qRT-PCR and western blotting analysis, and found MYC potentially regulated PD-L1 to mediate anti-tumor effects. These findings provide insight into the mechanism by which oxymatrine inhibits melanoma and enhances the anti-tumor immune effect. In summary, our study proposes a novel approach to suppress melanoma by targeting the MYC/PD-L1 pathway using oxymatrine, which may develop into a less toxic and more efficient anti-tumor agent for melanoma treatment.

The nature compound dehydrocrenatidine exerts potent antihepatocellular carcinoma by destroying mitochondrial complexes in vitro and in vivo

Cumulative evidence indicates that mitochondria dysfunction plays an important role in tumour treatment. Given the limited efficacy and toxicity of current mitochondria-targeted drugs, research into effective mitochondria-targeted anticancer agents remains an irresistible general trend. In this study, it was found that dehydrocrenatidine (DEC), a β-carbolin alkaloid isolated from Picrasma quassiodes, displays a promising growth inhibitory effect in vitro and in vivo by inducing apoptosis of hepatocellular carcinoma (HCC) cells. Mechanistically, we provided that the possible target of DEC against HCC cells was determined by isobaric labels for relative and absolute quantification assay and validated them using further experiments. The results suggested that DEC can target and regulate the function of mitochondrial complexes I, III and IV, affecting oxidative phosphorylation and ultimately leading to mitochondrial dysfunction to exert its anti-HCC effects. In addition, the combination of DEC and sorafenib showed a synergistic effect and was also associated with mitochondrial dysfunction. Importantly, DEC did not show significant toxicity in mice. This study provided a new insight into underlying mechanisms in DEC-treated HCC cells, suggesting that DEC might be a mitochondrial targeting lead compound.

Mitochondria: The metabolic switch of cellular oncogenic transformation

Mitochondria, well recognized as the "powerhouse" of cells, are maternally inherited organelles with bacterial ancestry that play essential roles in a myriad of cellular functions. It has become profoundly evident that mitochondria regulate a wide array of cellular and metabolic functions, including biosynthetic metabolism, cell signaling, redox homeostasis, and cell survival. Correspondingly, defects in normal mitochondrial functioning have been implicated in various human malignancies. Cancer development involves the activation of oncogenes, inactivation of tumor suppressor genes, and impairment of apoptotic programs in cells. Mitochondria have been recognized as the site of key metabolic switches for normal cells to acquire a malignant phenotype. This review outlines the role of mitochondria in human malignancies and highlights potential aspects of mitochondrial metabolism that could be targeted for therapeutic development.

Sophora alopecuroides L.: An ethnopharmacological, phytochemical, and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Sophora alopecuroides L., which is called Kudouzi in China, is a medicinal plant distributed in Western and Central Asia, especially in China, and has been used for decades to treat fever, bacterial infection, heart disease, rheumatism, and gastrointestinal diseases.

AIM OF THE REVIEW

This review aims to provide up-to-date information on S. alopecuroides, including its botanical characterization, medicinal resources, traditional uses, phytochemistry, pharmacological research, and toxicology, in exploring future therapeutic and scientific potentials.

MATERIALS AND METHODS

The information related to this article was systematically collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, Science Direct, Springer, China National Knowledge Infrastructure, published books, PhD and MS dissertations, and other web sources, such as the official website of Flora of China and Yao Zhi website (https://db.yaozh.com/).

RESULTS

A total of 128 compounds, such as alkaloids, flavonoids, steroids, and polysaccharides, were isolated from S. alopecuroides. Among these compounds, the effects of alkaloids, such as matrine and oxymatrine, were extensively studied and developed into new drugs. S. alopecuroides and its active components had a wide range of pharmacological activities, such as anticancer, antiviral, anti-inflammatory, antimicrobial, analgesic, and neuroprotective functions, as well as protective properties against pulmonary fibrosis and cardiac fibroblast proliferation.

CONCLUSIONS

As an important traditional Chinese medicine, modern pharmacological studies have demonstrated that S. alopecuroides has prominent bioactivities, especially on gynecological inflammation and hepatitis B, and anticancer activities. These activities provide prospects for novel drug development for cancer and some chronic diseases. Nevertheless, the comprehensive evaluation, quality control, understanding of the multitarget network pharmacology, long-term in vivo toxicity, and clinical efficacy of S. alopecuroides require further detailed research.

The cytotoxic effect of oxymatrine on basic cellular processes of A549 non-small lung cancer cells

Oxymatrine is the alkaloid derived from the root of Sophora species. This compound is proven to exhibit anti-viral, anti-asthmatic, anti-fibrotic and anti-inflammatory properties. Additionally, oxymatrine is able to promote cancer cells apoptosis and inhibit their proliferation. The aim of this study was to present the influence of oxymatrine on non-small cell lung cancer cells. The results indicate, that this agent induces dose-dependent cell death mainly through ER stress-induced apoptosis pathway. We also suggest that the oxymatrine reduces the metastatic potential by inhibition of the EMT process, as A549 cells treated with chosen doses of the compound were characterized by a decrease in the expression of the N-cadherin, vimentin and the elevation of E-cadherin level. Moreover, the study broadens the knowledge on so far poorly understood aspect of the influence of oxymatrine on the cytoskeleton structure.

Gomesin inhibits melanoma growth by manipulating key signaling cascades that control cell death and proliferation

Consistent with their diverse pharmacology, peptides derived from venomous animals have been developed as drugs to treat disorders as diverse as hypertension, diabetes and chronic pain. Melanoma has a poor prognosis due in part to its metastatic capacity, warranting further development of novel targeted therapies. This prompted us to examine the anti-melanoma activity of the spider peptides gomesin (AgGom) and a gomesin-like homolog (HiGom). AgGom and HiGom dose-dependently reduced the viability and proliferation of melanoma cells whereas it had no deleterious effects on non-transformed neonatal foreskin fibroblasts. Concordantly, gomesin-treated melanoma cells showed a reduced G0/G1 cell population. AgGom and HiGom compromised proliferation of melanoma cells via activation of the p53/p21 cell cycle check-point axis and the Hippo signaling cascade, together with attenuation of the MAP kinase pathway. We show that both gomesin peptides exhibit antitumoral activity in melanoma AVATAR-zebrafish xenograft tumors and that HiGom also reduces tumour progression in a melanoma xenograft mouse model. Taken together, our data highlight the potential of gomesin for development as a novel melanoma-targeted therapy.

Cytochrome c is important in apoptosis of labial glands in primary Sjogren's syndrome

The present study aimed to investigate the expression and effect of cytochrome c (Cytc) in patients with primary Sjogren's syndrome (pSS). In total, 35 newly diagnosed pSS patients and 35 healthy subjects were enrolled in the present study. The mRNA expression levels of Cytc were detected using reverse transcription‑polymerase chain reaction and RT‑quantitative PCR. The expression of the Cytc protein in labial salivary glands was detected by immunohistochemistry and was associated with the integral optical density (IOD) of clinical and laboratory variables. In addition, the content of Cytc in the cytoplasm and mitochondria were examined. The mRNA and protein expression levels of Cytc, and the content of Cytc in the cytoplasm of the pSS patients was increased significantly compared with the healthy controls (P<0.05). The content of Cytc in the mitochondria was significantly decreased compared with the healthy controls (P<0.05). The IOD of Cytc protein levels was positively correlated with immunoglobin G (r=0.8142, P<0.05) and erythrocyte sedimentation rate (r=0.7512, P<0.05). Cytc was upregulated in the pSS patients, indicating the potential role of Cytc in the pathogenesis and development of pSS. Further studies may facilitate the development of targeting this molecular pathway for the treatment of pSS.

Targeting cancer cell mitochondria as a therapeutic approach: recent updates

Mitochondria play a key role in ATP generation, redox homeostasis and regulation of apoptosis. Due to the essential role of mitochondria in metabolism and cell survival, targeting mitochondria in cancer cells is considered as an attractive therapeutic strategy. However, metabolic flexibility in cancer cells may enable the upregulation of compensatory pathways, such as glycolysis to support cancer cell survival when mitochondrial metabolism is inhibited. Thus, compounds capable of both targeting mitochondria and inhibiting glycolysis may be particularly useful to overcome such drug-resistant mechanism. This review provides an update on recent development in the field of targeting mitochondria and novel compounds that impact mitochondria, glycolysis or both. Key challenges in this research area and potential solutions are also discussed.

Oxymatrine suppresses the growth and invasion of MG63 cells by up-regulating PTEN and promoting its nuclear translocation

Studies demonstrated that reduced PTEN levels are associated with poor prognoses of osteosarcoma. The nuclear localization of PTEN is important for its tumor suppressive function. Equally importantly, PTEN is the most significant negative regulator of PI3K/Akt signaling cascade, the constitutively activated pathway in osteosarcoma. In our study MG63 cells and U2OS cells were treated with the indicated concentrations of oxymatrine, in order to find the inhibition of oxymatrine to cells. We found the functions of oxymatrine on proliferation, apoptosis and invasion in cells. Oxymatrine could increase the expression of PTEN and promote its nuclear translocation in MG63 cells. In addition, oxymatrine could induce cell cycle arrest in G1 phase and apoptosis of MG63 cells. The migration and invasion potential of MG63 cells were also markedly inhibited by oxymatrine. Oxymatrine could suppress the growth and invasion of MG63 human osteosarcoma cells by up-regulating PTEN and promoting its nuclear translocation and inhibiting PI3K/Akt signaling pathway.

Oxymatrine inhibits epithelial-mesenchymal transition through regulation of NF-κB signaling in colorectal cancer cells

Oxymatrine, a traditional Chinese herb extracted from Sophora flavescens Ait., displays strong anti-inflammatory and anticancer activities, but how oxymatrine exhibits anticarcinogenic effects in human colorectal cancer (CRC) remains uncertain. The present study aimed to elucidate the exact mechanism by which oxymatrine exhibits anticarcinogenic effects in CRC using the human colon cancer RKO cell line as the experimental model. CRC cells were treated with oxymatrine, and cell proliferation, migration and invasion were examined by colorimetric MTT, Transwell chamber and wound healing assays, respectively. In addition, epithelial-mesenchymal transition (EMT) markers and p65 were assessed by western blot analysis. Our study demonstrated that oxymatrine hindered the proliferation, migration and invasion of the CRC cells. Mechanistically, we found that oxymatrine modulated the expression of EMT markers including E-cadherin, Snail and N-cadherin, and reduced expression of p65 which is crucial to NF-κB activation. In conclusion, our results indicate that oxymatrine reduces the activation of the NF-κB signaling pathway and inhibits CRC invasion by modulating EMT.

Potential Signaling Pathways Involved in the Clinical Application of Oxymatrine

Oxymatrine, an alkaloid component extracted from the roots of Sophora species, has been shown to have antiinflammatory, antifibrosis, and antitumor effects and the ability to protect against myocardial damage, etc. The potential signaling pathways involved in the clinical application of oxymatrine might include the TGF-β/Smad, toll-like receptor 4/nuclear factor kappa-light-chain-enhancer of activated B cells, toll-like receptor9/TRAF6, Janus kinase/signal transduction and activator of transcription, phosphatidylinositol-3 kinase/Akt, delta-opioid receptor-arrestinl-Bcl-2, CD40, epidermal growth factor receptor, nuclear factor erythroid-2-related factor 2/heme oxygenase-1 signaling pathways, and dimethylarginine dimethylaminohydrolase/asymmetric dimethylarginine metabolism pathway. In this review, we summarize the recent investigations of the signaling pathways related to oxymatrine to provide clues and references for further studies on its clinical application. Copyright © 2016 John Wiley & Sons, Ltd.

Silencing of CerS6 increases the invasion and glycolysis of melanoma WM35, WM451 and SK28 cell lines via increased GLUT1-induced downregulation of WNT5A

Ceramide synthases (CerSs) have been shown to regulate numerous aspects of cancer development. CerS6 has been suggested to be involved in cancer etiology. However, little is known concerning the exact effect of CerS6 on the malignant behavior of melanoma, including glycolysis, proliferation and invasion. In the present study, we found that the expression of CerS6 was low in the melanoma cell lines, including WM35, WM451 and SK-28, and the expression level was related to the malignanct behavior of the melanoma cell lines. We constructed overexpression and silencing models of CerS6 in three melanoma cell lines and found that silencing of CerS6 promoted the ability of proliferation and invasion in the melanoma cell lines. Additionally, downregulation of CerS6 upregulated the activity of glycolysis-related enzyme, and enhanced the expression of glycolysis-related genes, including GLUT1 and MCT1. Furthermore, we identified the genes whose expression levels were changed after silencing of CerS6 by gene microarray. The expression of glycolysis-related gene SLC2A1 (also known as GLUT1) was found to be upregulated, while notably WNT5A was downregulated. The altered expression of GLUT1 and WNT5A was verified by qPCR and western blotting. Furthermore, silencing of GLUT1 in the melanoma cells resulted in the increased expression of WNT5A and the decreased ability of invasion and proliferation in the melanoma cells. Collectively, silencing of CerS6 induced the increased expression of GLUT1, which downregulated the expression of WNT5A and enhanced the invasion and proliferation of melanoma cells. Thus, CerS6 may provide a novel therapeutic target for melanoma treatment.

Oxymatrine suppresses proliferation and facilitates apoptosis of human ovarian cancer cells through upregulating microRNA‑29b and downregulating matrix metalloproteinase‑2 expression

Oxymatrine, an alkaloid extracted from medicinal plants of the genus Sophora, has a wide range of pharmacological effects. Previous studies have revealed that oxymatrine can inhibit proliferation and metastasis of tumor cells through reducing matrix metalloproteinase‑2 (MMP‑2) mRNA expression. However, the expression of MMP‑2 in ovarian cancer is significantly higher than that in normal ovaries. Furthermore, the expression of microRNA‑29b (miR‑29b) in ovarian carcinoma is significantly lower than that in normal ovaries. Therefore, MMP‑2 and miR‑29b are tumor suppressor factors involved in ovarian cancer. To evaluate the anti-cancer effects of oxymatrine the OVCAR‑3 ovary cancer cell line was treated with oxymatrine at the concentrations of 0, 0.5, 1 and 2 mg/ml. Assessment of the proliferation and apoptosis of OVCAR‑3 cells showed that oxymatrine had an inhibitory effect on ovarian cancer cells. Furthermore, oxymatrine decreased the protein levels of MMP‑2 and increased the expression levels of miR‑29b in OVCAR‑3 cells. Through transfection of miR‑29b precursor into OVCAR‑3 cells, it was demonstrated that miR‑29b regulated MMP‑2 expression in OVCAR‑3 cells. In addition, anti‑miR‑29b antibodies were used to verify that the apoptotic effect of oxymatrine was due to upregulating miR‑29b and downregulating MMP‑2 expression. These results showed that oxymatrine suppresses the proliferation and facilitates apoptosis of human ovarian cancer cells through upregulating miR‑29b and downregulating MMP‑2 expression.

Oxymatrine suppresses proliferation and induces apoptosis of hemangioma cells through inhibition of HIF-1a signaling

Oxymatrine (OMT), a natural quinolizidine alkaloid, has been known to have anti-inflammation, anti-anaphylaxis, and chemopreventive effects on various cancer cells. To clarify the underlying role and molecular mechanisms of OMT in human hemangioma (HA), in the present study, we examined the expression of hypoxia-inducible factor-1a (HIF-1a) and vascular endothelial growth factor (VEGF) in different phases of human HA. After HA derived endothelial cells (HDEC) were pretreated with different concentrations of OMT, cell proliferation, apoptosis, and cycle distribution were evaluated by MTT assay and flow cytometry analysis, respectively. The effects of OMT on expression of HIF-1a signaling were determined by real-time PCR and western blot assays. Our results showed that, the expression of HIF-1a and VEGF was significantly increased in proliferating phase HA, but decreased in involuting phase HA. Moreover, OMT in vitro inhibited proliferative activities and induced cell apoptosis and cycle arrest in G0/G1 phase in HA cells with decreased expression of HIF-1a, VEGF, Bcl-2, and CyclinD1, and increased expression of p53. Taken together, our findings suggest that, the expression of HIF-1a and VEGF is increased in proliferating phase HA, and OMT suppresses cell proliferation and induces cell apoptosis and cycle arrest in proliferative phase HA through inhibition of the HIF-1a signaling pathway, suggesting OMT may provide a novel therapeutic strategy for the treatment of HA.

Hibiscus sabdariffa leaf polyphenolic extract induces human melanoma cell death, apoptosis, and autophagy

Melanoma is the least common but most fatal form of skin cancer. Previous studies have indicated that an aqueous extract of Hibiscus sabdariffa leaves possess hypoglycemic, hypolipidemic, and antioxidant effects. In this study, we want to investigate the anticancer activity of Hibiscus leaf polyphenolic (HLP) extract in melanoma cells. First, HLP was exhibited to be rich in epicatechin gallate (ECG) and other polyphenols. Apoptotic and autophagic activities of HLP and ECG were further evaluated by DAPI stain, cell-cycle analysis, and acidic vascular organelle (AVO) stain. Our results revealed that both HLP and ECG induced the caspases cleavages, Bcl-2 family proteins regulation, and Fas/FasL activation in A375 cells. In addition, we also revealed that the cells presented AVO-positive after HLP treatments. HLP could increase the expressions of autophagy-related proteins autophagy-related gene 5 (ATG5), Beclin1, and light chain 3-II (LC3-II), and induce autophagic cell death in A375 cells. These data indicated that the anticancer effect of HLP, partly contributed by ECG, in A375 cells. HLP potentially could be developed as an antimelanoma agent.

Matrine reduces the proliferation and invasion of colorectal cancer cells via reducing the activity of p38 signaling pathway

Matrine has been used in anti-inflammatory and anti-cancer therapies for a long time. However, the anti-metastatic effect and related mechanism(s) in colorectal cancer (CRC) are still unclear. In this study, we investigated whether the administration of matrine could inhibit the proliferation, motility, and invasion of human CRC cells via regulating p38 signaling pathway. Results showed that matrine inhibited migration and invasion of CRC cells in vitro and in vivo. Additionally, after being treated with matrine for 24 h, the expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 as well as proteinase activity in CRC cells were reduced in a dose-dependent manner. Moreover, matrine reduced the phosphorylation level of p38 obviously. Combined treatment with p38 inhibitor (SB203580) and matrine resulted in a synergistic reduction of invasion as well as MMP-2/-9 expression in CRC cells. It was also found that matrine inhibited the proliferation and metastasis of CRC tumor in vivo. In conclusion, p38 signaling pathway may involve in matrine's inhibitory effects on migration and invasion of CRC cells by reducing the expression of MMP-2/-9, suggesting that matrine may be a potential therapeutic agent for CRC.

Resveratrol inhibits the proliferation of human melanoma cells by inducing G1/S cell cycle arrest and apoptosis

Resveratrol (Res), a natural plant extract, is an effective inducer of cell apoptosis and cell cycle arrest in multiple carcinoma cell types, which has been demonstrated by its ability to inhibit the proliferation of multiple human tumor cells in vitro. Although Res possesses chemopreventive properties against several types of cancer, the molecular mechanism underlying its anticancer activity remains to be fully elucidated. The present study demonstrated that Res induced cell cycle arrest and inhibited the proliferation of human melanoma A375 (IC50=23 µM after 48 h; P<0.05) and SK-MEL-31 (IC50=15 µM after 48 h; P<0.05) cells. Western blot analysis demonstrated that Res induced the apoptosis of human melanoma A375 and SK-MEL-31 cells by upregulating the expression of Bcl-2-associated X protein and B-cell lymphoma 2, possibly via the p53 pathway and activation of caspase-9 and caspase-3.

Neuroprotection induced by N-acetylcysteine and selenium against traumatic brain injury-induced apoptosis and calcium entry in hippocampus of rat

Neurodegeneration associated with acute central nervous system injuries and diseases such as spinal cord injury and traumatic brain injury (TBI) are reported to be mediated by the regulation of apoptosis and oxidative stress through Ca(2+) influx. The thiol redox system antioxidants, such as N-acetylcysteine (NAC) and selenium (Se), display neuroprotective activities mediated at least in part by their antioxidant and anti-inflammatory properties. However, there are no reports on hippocampal apoptosis, cytosolic reactive oxygen species (ROS), or Ca(2+) values in rats with an induced TBI. Therefore, we tested the effects of Se and NAC administration on apoptosis, oxidative stress, and Ca(2+) influx through TRPV1 channel activations in the hippocampus of TBI-induced rats. The 32 rats were divided into four groups: control, TBI, TBI + NAC, and TBI + Se groups. Intraperitoneal administrations of NAC and Se were performed at 1, 24, 48, and 72 h after TBI induction. After 3 days, the hippocampal neurons were freshly isolated from the rats. In cytosolic-free Ca(2+) analyses, the neurons were stimulated with the TRPV1 channel agonist capsaicin, a pungent compound found in hot chili peppers. Cytosolic-free Ca(2+), apoptosis, cytosolic ROS levels, and caspase-3 and -9 activities were higher in the TBI group than control. The values in the hippocampus were decreased by Se and NAC administrations. In conclusion, we observed that NAC and Se have protective effects on oxidative stress, apoptosis, and Ca(2+) entry via TRPV1 channel activation in the hippocampus of this TBI model, but the effect of NAC appears to be much greater than that of Se. They are both interesting candidates for studying the amelioration of TBIs.

Oxymatrine attenuates diabetes-associated cognitive deficits in rats

AIM

Oxymatrine (OMT) is the major quinolizidine alkaloid extracted from the root of Sophora flavescens Ait (the Chinese herb Kushen) and exhibits diverse pharmacological actions. In this work we investigated the effects of OMT on diabetes-associated cognitive decline (DACD) in a rat model of diabetes and explored the mechanisms of action.

METHODS

Male Wistar rats were injected with streptozotocin (65 mg/kg, ip) once to induce diabetes. The rats were then treated with vehicle or OMT (60 or 120 mg/kg per day, ip) for 7 weeks. Memory function was assessed using Morris water maze test. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), NF-κB p65 unit, TNF-α, IL-1β and caspase-3 in the cerebral cortex and hippocampus were quantified.

RESULTS

The diabetic rats exhibited markedly reduced body weight and increased plasma glucose level. The memory function of the rats assessed using Morris water maze test showed significant reduction in the percentage of time spent in the target quadrant and the number of times crossing the platform, coupled with markedly prolongation of escape latency and mean path length. Moreover, the rats showed oxidative stress (significantly increased MDA, decreased SOD and reduced GSH levels), as well as significant increases of NF-κB p65 unit, TNF-α, IL-1β and caspase-3 levels in the cerebral cortex and hippocampus. Chronic treatment with OMT dose-dependently reversed these behavioral, biochemical and molecular changes in the diabetic rats. However, the swimming speed had no significant difference among the control, diabetic and OMT-treated diabetic rats.

CONCLUSION

Chronic treatment with OMT alleviates diabetes-associated cognitive decline in rats, which is associated with oxidative stress, inflammation and apoptotic cascades.

Andrographolide sensitizes the cytotoxicity of human colorectal carcinoma cells toward cisplatin via enhancing apoptosis pathways in vitro and in vivo

Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, has been shown to suppress the growth and invasion of human colorectal carcinoma (CRC) Lovo cells, and trigger apoptosis in vitro. The potential of Andro as a chemotherapeutic agent in CRC was evaluated by investigating its cytotoxic effects as a single agent or in coadministration with cisplatin (CDDP). Andro potentiated the cytotoxic effect of CDDP in Lovo cells through apoptosis. The molecular mechanism for these favorable cellular response was further investigated by analyzing the apoptotic profiles, protein levels, and mRNA expression patterns of several key genes after treatments of Andro or/and CDDP. Molecular results indicated that the effect of Andro alone might be mediated via both intrinsic and extrinsic apoptotic pathways in Lovo cells. The addition of Andro to CDDP induced synergistic apoptosis, which could be corroborated to the changes in protein and mRNA levels of Bax and Bcl-2, and the increased Fas/FasL association in these cells, resulting in increased release of cytochrome c, and activation of caspases. Pretreatment of Nok-1 monoclonal antibody, a Fas signaling inhibitor, or Bax inhibitor peptide V5 repressed the Andro-induced cleavage of procaspase and the sensitization to CDDP-induced apoptosis. Finally, the combination therapy of Andro with CDDP was evidenced by its synergistic inhibition on the growth of Lovo cells in xenograft tumor studies. The results indicate that Andro, in combination with chemotherapeutics, is likely to represent a potential therapeutic strategy for CRC.

Down-regulation of nicotinamide N-methyltransferase induces apoptosis in human breast cancer cells via the mitochondria-mediated pathway

Nicotinamide N-methyltransferase (NNMT) has been found involved in cell proliferation of several malignancies. However, the functional role of NNMT in breast cancer has not been elucidated. In the present study, we showed that NNMT was selectively expressed in some breast cancer cell lines, down-regulation of NNMT expression in Bcap-37 and MDA-MB-231 cell lines by NNMT shRNA significantly inhibited cell growth in vitro, decreased tumorigenicity in mice and induced apoptosis. The silencing reciprocal effect of NNMT was confirmed by over-expressing NNMT in the MCF-7 and SK-BR-3 breast cancer cell lines which lack constitutive expression of NNMT. In addition, down-regulation of NNMT expression resulted in reducing expression of Bcl-2 and Bcl-xL, up-regulation of Bax, Puma, cleaved caspase-9, cleaved caspase-3 and cleaved PARP, increasing reactive oxygen species production and release of cytochrome c from mitochondria, and decreasing the phosphorylation of Akt and ERK1/2. These data suggest that down-regulation of NNMT induces apoptosis via the mitochondria-mediated pathway in breast cancer cells.

Antiangiogenic effects of oxymatrine on pancreatic cancer by inhibition of the NF-κB-mediated VEGF signaling pathway

Oxymatrine, the main alkaloid component in the traditional Chinese herbal medicine Sophora japonica (Sophora flavescens Ait), has been reported to have antitumor properties. However, the mechanisms of action in human pancreatic cancer are not well established to date. In the present study, we investigated the antiangiogenic effects of oxymatrine on human pancreatic cancer as well as the possible mechanisms involved. The results of the cell viability assay showed that treatment of PANC-1 pancreatic cancer cells with oxymatrine resulted in cell growth inhibition in a dose- and time-dependent manner. To investigate the possible mechanisms involved in these events, we performed western blotting and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The results revealed that oxymatrine decreased the expression of angiogenesis-associated factors, including nuclear factor κB (NF-κB) and vascular endothelial growth factor (VEGF). Finally, the antiproliferative and antiangiogenic effects of oxymatrine on human pancreatic cancer were further confirmed in pancreatic cancer xenograft tumors in nude mice. In conclusion, our studies for the first time suggest that oxymatrine has potential antitumor effects on pancreatic cancer via suppression of angiogenesis, probably through regulation of the expression of the NF-κB-mediated VEGF signaling pathway.

Saponins isolated from Asparagus induce apoptosis in human hepatoma cell line HepG2 through a mitochondrial-mediated pathway

OBJECTIVE

Many scientific studies have shown that Asparagus officinalis has an antitumour effect and enhances human immunity, but the active components and the antitumour mechanisms are unclear. We investigated the effects of saponins isolated from Asparagus on proliferation and apoptosis in the human hepatoma cell line HepG2.

METHODS

HepG2 cells were treated with varying concentrations of Asparagus saponins at various times. Using mtt and flow cytometry assays, we evaluated the effects of Asparagus saponins on the growth and apoptosis of HepG2 cells. Transmission electron microscopy was used to observe the morphology of cell apoptosis. Confocal laser scanning microscopy was used to analyze intracellular calcium ion concentration, mitochondrial permeability transition pore (mptp), and mitochondrial membrane potential (mmp). Spectrophotometry was applied to quantify the activity of caspase-9 and caspase-3. Flow cytometry was used to investigate the levels of reactive oxygen species (ros) and pH, and the expressions of Bcl2, Bax, CytC, and caspase-3, in HepG2 cells.

RESULTS

Asparagus saponins inhibited the growth of HepG2 cells in a dose-dependent manner. The median inhibitory concentration (IC(50)) was 101.15 mg/L at 72 hours. The apoptosis morphology at 72 hours of treatment was obvious, showing cell protuberance, concentrated cytoplasm, and apoptotic bodies. The apoptotic rates at 72 hours were 30.9%, 51.7%, and 62.1% (for saponin concentrations of 50 mg/L, 100 mg/L, 200 mg/L). Treatment with Asparagus saponins for 24 hours increased the intracellular level of ros and Ca(2+), lowered the pH, activated intracellular mptp, and decreased mmp in a dose-dependent manner. Treatment also increased the activity of caspase-9 and caspase-3, downregulated the expression of Bcl2, upregulated the expression of Bax, and induced release of CytC and activation of caspase-3.

CONCLUSIONS

Asparagus saponins induce apoptosis in HepG2 cells through a mitochondrial-mediated and caspase-dependent pathway, suggesting that they may be a potent agent for the treatment of hepatocellular carcinoma.

Laminarin induces apoptosis of human colon cancer LOVO cells through a mitochondrial pathway

Many scientific studies have shown that laminarin has anti-tumor effects, but the anti-tumor mechanism was unclear. The purpose of this study was to investigate the effect of laminarin on the induction of apoptosis in human colon cancer LOVO cells and the molecular mechanism involved. LOVO cells were treated with different concentrations of laminarin at different times. Morphology observations were performed to determine the effects of laminarin on apoptosis of LOVO cells. Flow cytometry (FCM) was used to detect the level of intracellular reactive oxygen species (ROS) and pH. Laser scanning confocal microscope (LSCM) was used to analyze intracellular calcium ion concentration, mitochondrion permeability transition pore (MPTP) and mitochondrial membrane potential (MMP). Western blotd were performed to analyze the expressions of Cyt-C, Caspase-9 and -3. The results showed the apoptosis morphology, which showed cell protuberance, concentrated cytoplasm and apoptotic bodies, was obvious after 72 h treatment. Laminarin treatment for 24 h increased the intracellular level of ROS and Ca²⁺; decreased pH value; activated intracellular MPTP and decreased MMP in dose-dependent manners. It also induced the release of Cyt-C and the activation of Caspase-9 and -3. In conclusion, laminarin induces LOVO cell apoptosis through a mitochondrial pathway, suggesting that it could be a potent agent for cancer prevention and treatment.