Analysis of In Vitro Cyto- and Genotoxicity of Barbatimão Extract on Human Keratinocytes and Fibroblasts.

Barbatimão (Stryphnodendron adstringens, Mart.) is a native Brazilian species used in traditional medicine and some commercial preparations owing to its strong wound-healing activity. However, controversy regarding its use due to safety concerns over the potential genotoxic effect of this plant remains. In order to clarify this issue, the effect of hydroalcoholic extract of barbatimão in vitro on cell viability, DNA damage, and induction of apoptosis in two commercial cell lines of keratinocytes (HaCaT) and fibroblasts (HFF-1) was evaluated. Barbatimão stem bark hydroalcoholic extract (70% ethanol) was obtained and lyophilized for subsequent use in all experiments. The main bioactive molecules quantified by HPLC were gallic acid, caffeic acid, quercetin, catechin, and epigallocatechin gallate (EGCG). Barbatimão (0.024 to 1.99 mg/mL) was found to decrease cellular mortality as compared to the control group. GEMO assay, a noncellular DNA protocol that uses H2O2-exposed calf thymus DNA, revealed not only a genotoxic effect of barbatimão, but also a potential genoprotective action against H2O2-triggered DNA fragmentation. These results indicated that barbatimão at concentrations of 0.49 and 0.99 mg/mL, which are near to the levels found in commercial preparations, exerted an in vitro genoprotective effect on cells by decreasing the levels of DNA oxidation quantified by 8-hydroxy-2'-deoxyguanosine (8-OHdG) and reactive oxygen species (ROS) levels. Gene and protein apoptotic markers, quantified by qRT-PCR (BAX/Bcl-2 genes) and immunoassays (Caspases 3 and 8), respectively, also indicated a decrease in apoptotic events in comparison with control cells. Collectively, the results suggest that barbatimão could exert genoprotective and antiapoptotic effects on human keratinocytes and fibroblasts.

Induction of Apoptosis in HepaRG Cell Line by Aloe-Emodin through Generation of Reactive Oxygen Species and the Mitochondrial Pathway.

BACKGROUND/AIMS: Aloe-emodin (1,8-dihydroxy-3-hydroxymethyl-anthraquinone), an anthraquinone active compounds, is isolated from some traditional medicinal plants such as Rheum palmatum L. and Cassia occidentalis, which induce hepatotoxicity in rats. The aim of this study was to determine potential cytotoxic effects of aloe-emodin on HepaRG cells and to define the underlying mechanism. METHODS: MTT was used to evaluate cell viability. Apoptotic cell death was analyzed via Annexin V-FITC/PI double staining. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were determined by flow cytometry, while the expression of apoptosis-related proteins was determined by Western blot analysis. RESULTS: Treatment with aloe-emodin significantly reduced cell viability and induced apoptosis in HepaRG cells in a dose- and time-dependent manner. It provoked ROS generation and depolarization of MMP in HepaRG cells when compared with controls. Aloe-emodin dose-dependently increased release of mitochondrial cytochrome c, and levels of Fas, p53, p21, Bax/Bcl-2 ratio, as well as activation of caspase-3, caspase-8, caspase-9, and subsequent cleavage of poly(ADP-ribose)polymerase (PARP). It also induced S-phase cell cycle arrest by increasing the expression of p21 and cyclin E proteins while significantly decreasing the expression of cyclin A and CDK2. CONCLUSION: These results suggest that aloe-emodin inhibits cell proliferation and induces apoptosis in HepaRG cells, most probably through a mechanism involving both Fas death pathway and the mitochondrial pathway by generation of ROS. These findings underscore the need for risk assessment of human exposure to aloe-emodin.

Alterations in blood pressure, antioxidant status and caspase 8 expression in cobalt chloride-induced cardio-renal dysfunction are reversed by Ocimum gratissimum and gallic acid in Wistar rats.

The protective abilities of the chloroform extract of Ocimum gratissimum (COG) and gallic acid against cobalt chloride (CoCl2) - induced cardiac and renal toxicity were evaluated. Rats were exposed to CoCl2 (350ppm) for 7 days, either alone, or in combination with COG (100 and 200mg/kg) or gallic acid (120mg/kg). CoCl2 given alone, caused significant increases (p<0.05) in oxidative stress parameters (hydrogen peroxide, H2O2 and malondialdehyde, MDA) and increased expression of the apoptotic initiator caspase 8 in the heart and kidneys. There was significant reduction (p<0.05) in reduced glutathione (GSH) in cardiac and renal tissues; reduction in superoxide dismutase (SOD) activity in the kidneys and adaptive increases in Glutathione S-transferase (GST) and catalase (CAT). CoCl2 also produced significant reduction (p<0.05) in systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressures. Oral COG and gallic acid treatment significantly reduced (p<0.05) the levels of H2O2 and MDA; with reduced expression of caspase 8 and restoration of GSH levels, GPx, SOD and CAT activities, howbeit, to varying degrees in the heart and kidneys. COG (200mg/kg) was most effective in restoring the blood pressures in the rats to near control levels. CoCl2-induced histopathological lesions including myocardial infarction and inflammation and renal tubular necrosis and inflammation were effectively ameliorated by the treatments administered. This study provides evidence for the protective roles of O. gratissimum and gallic acid by modulation of CoCl2-induced alterations in blood pressure, antioxidant status and pro-apoptotic caspase 8 in Wistar rats.

Fermented Brown Rice Extract Causes Apoptotic Death of Human Acute Lymphoblastic Leukemia Cells via Death Receptor Pathway.

Mixture of brown rice and rice bran fermented with Aspergillus oryzae, designated as FBRA, has been reported to reveal anti-carcinogenic and anti-inflammatory effects in rodents. Then, to test its potential anti-cancer activity, the aqueous extract was prepared from FBRA powder, and the effect of this extract on human acute lymphoblastic leukemia Jurkat cells was directly examined. The exposure to FBRA extract reduced the cell viability in a concentration- and time-dependent manner. The reduction of the cell viability was accompanied by the DNA fragmentation, and partially restored by treatment with pan-caspase inhibitor. Further studies showed that FBRA extract induced the cleavage of caspase-8, -9, and -3, and decreased Bcl-2 protein expression. Moreover, the expression of tBid, DR5, and Fas proteins was enhanced by FBRA extract, and the pretreatment with caspase-8 inhibitor, but not caspase-9 inhibitor, restored the reduction of the cell viability induced by FBRA extract. These findings suggested that FBRA extract could induce the apoptotic death of human acute lymphoblastic leukemia cells probably through mainly the death receptor-mediated pathway and supplementarily through the tBid-mediated mitochondrial pathway, proposing the possibility that FBRA was a potential functional food beneficial to patients with hematological cancer.

Tanshinone IIA inhibits gastric carcinoma AGS cells through increasing p-p38, p-JNK and p53 but reducing p-ERK, CDC2 and cyclin B1 expression.

Tanshinone IIA (Tan-IIA) is extracted from Danshen (Salviae miltiorrhizae radix). It possesses antitumor activity against a variety of human cancer cells and its induction of apoptosis and inhibition of proliferation of gastric cancer cells are well-documented. However, the molecular mechanisms by which Tan-IIA inhibits gastric cancer have not been well-elucidated. In the present study, we evaluated the cytotoxicity of Tan-IIA against human gastric cancer AGS cells by the (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) MTT assay. The protein expression of tumor necrosis factor-alpha (TNF-α), FAS, p53, p21, cyclin A, cyclin B1, extracellular-related kinase (ERK), phospho extracellular-related kinase (p-ERK), p38, p-p38, Jun-amino-terminal kinase (JNK), phospho Jun-amino-terminal kinase (p-JNK) and ß-actin in AGS cells were measured by western blotting. The cell-cycle distribution was analyzed by flow cytometry. The results showed that Tan-IIA inhibited AGS cells with time- and dose-dependent manners. AGS cells treated with Tan-IIA up-regulated the protein expression of TNFα, FAS, p-p38, p-JNK, p53, p21, caspase-3 and caspase-8 but reduced that of p-ERK, CDC2, cyclin A, and cyclin B1. The results also showed that Tan-IIA dose dependently induced G2/M phase arrest. These findings demonstrate that Tan-IIA can inhibit AGS human gastric cancer cells; one of the molecular mechanisms may be through increasing the protein expression of p-p38 and p-JNK, but decreasing that of p-ERK to induce the activation of p53, followed by increasing the protein expression of p21 to down-regulate CDC2 and cyclin B1 expression which then induces G2/M phase arrest. Another route may be through increasing the protein expression of TNF-α, FAS, caspase-8 and caspase-3 to induce apoptosis.

Roles of p53 and caspases in induction of apoptosis in MCF- 7 breast cancer cells treated with a methanolic extract of Nigella sativa seeds.

BACKGROUND: Nigella Sativa (NS) is an herb from the Ranunculaceae family that exhibits numerous medicinal properties and has been used as important constituent of many complementary and alternative medicines (CAMs). The ability of NS to kill cancer cells such as PC3, HeLa and hepatoma cells is well established. However, our understanding of the mode of death caused by NS remains nebulous. The objective of this study was to gain further insight into the mode and mechanism of death caused by NS in breast cancer MCF-7 cells. MATERIALS AND METHODS: Human breast cancer cells (MCF-7) were treated with a methanolic extract of NS, and a dose- and time-dependent study was performed. The IC50 was calculated using a Cell Titer Blue® viability assay assay, and evidence for DNA fragmentation was obtained by fluorescence microscopy TUNEL assay. Gene expression was also profiled for a number of apoptosis-related genes (Caspase-3, -8, -9 and p53 genes) through qPCR. RESULTS: The IC50 of MCF-7 cells was 62.8 µL/mL. When MCF-7 cells were exposed to 50 µL/mL and 100 µL/mL NS for 24 h, 48 h and 72 h, microscopic examination (TUNEL assay) revealed a dose- and time-dependent increase in apoptosis. Similarly, the expression of the Caspase-3, -8, -9 and p53 genes increased significantly according to the dose and time. CONCLUSIONS: NS induced apoptosis in MCF-7 cells through both the p53 and caspase pathways. NS could potentially represent an alternative source of medicine for breast cancer therapy.

Arsenic hexoxide enhances TNF-α-induced anticancer effects by inhibiting NF-κB activity at a safe dose in MCF-7 human breast cancer cells.

Arsenic hexoxide (As4O6) has been used in Korean folk remedy for the treatment of cancer since the late 1980s. Evidence suggests that the anticancer effects of As4O6 are different from those of As2O3. Tumor necrosis factor-α (TNF-α) is generally increased in advanced cancer and is closely related to cancer progression, although it has cancer-killing effects. The reason is that TNF-α activates nuclear factor-κB (NF-κB) that is involved in cell proliferation, invasion, drug resistance and metastasis. In the present study, we investigated the effects of As4O6 on NF-κB activity, NF-κB-mediated cellular responses, and NF-κB-regulated gene expressions involved in metastasis at the concentrations of As4O6 where no cytotoxicity was observed. As4O6 suppressed NF-κB activation in both TNF-α-treated and control cells, and also suppressed IκB phosphorylation in a time-dependent manner, suggesting the suppression of NF-κB results, in part, from the inhibition of IκB degradation. We also confirmed the anti-NF-κB activity of As4O6 with synergism with TNF-α by augmenting caspase-8 activation. As4O6 also suppressed NF-κB activation induced by TNF-α, and some of the downstream NF-κB-regulated proteins involved in cancer proliferation, anti-apoptosis and metastasis. In conclusion, the present study demonstrated that As4O6 has anticancer properties by inhibiting NF-κB activation and NF-κB-regulated proteins at least in part through the inhibition of IκB phosphorylation, especially in the conditions of advanced cancer where TNF-α is highly secreted.

Isoquercitrin inhibits the progression of liver cancer in vivo and in vitro via the MAPK signalling pathway.

Liver cancer is a malignant tumour with high morbidity and fatality rates that is common worldwide. At present, the clinical approaches to treating primary liver cancer include partial hepatectomy, systemic or local chemotherapy, radiotherapy, radiofrequency ablative surgery and liver transplantation. However, all of these approaches have shortcomings, including poor prognosis and numerous side-effects. A large number of studies have proven that many effective ingredients in traditional Chinese medicine, particularly the flavonoid compounds extracted from plants, have achieved breakthroughs in terms of enhancing the effects and reducing the toxicity of chemotherapy and radiotherapy, preventing tumour metastasis and relapse after surgery, alleviating the clinical symptoms of advanced tumours, improving the quality of life of the patient with tumours and extending patient long­term survival. The purpose of the present study was to investigate the impact of isoquercitrin, the flavonoid from Bidens bipinnata L. extract, on the progression of liver cancer and to achieve a deeper understanding of the biological characteristics of isoquercitrin's involvement in the progression of liver cancer. In the in vitro experiments, isoquercitrin was found to strongly inhibit the proliferation of human liver cancer cells, promote the apoptosis of human liver cancer cells, and block the cell cycle in the G1 phase. Isoquercitrin activated caspase-3, -8 and -9, inhibited the expression level of ERK and p38MAPK protein phosphorylation, and promoted the phosphorylation of JNK. Additionally, isoquercitrin reduced the expression level of PKC in human liver cancer cells. In the in vivo experiments, isoquercitrin was also found to significantly inhibit the growth of transplanted tumours in nude mice. The present study confirmed that isoquercitrin could inhibit the progression of human liver cancer in vivo and in vitro, and the molecular mechanism of isoquercitrin may be closely associated with the MAPK and PKC signalling pathways.

The selective cytotoxicity elicited by phytochemical extract from Senecio graveolens (Asteraceae) on breast cancer cells is enhanced by hypoxia.

Breast cancer is the second cause of cancer­related deaths in woman and the incidence of the disease has increased worldwide, in part due to improvements in early detection. Several drugs with anticancer effects have been extracted from plants in the last 20 years, many of which are particularly effective against breast cancer cells. In particular, we have become interested in the ethanolic extract from Senecio graveolens (synonym of S. nutans), a plant commonly called Chachacoma, in an effort to isolate compounds that could demonstrate cytotoxic effects on breast cancer cells. Senecio (Asteraceae) is the largest gender in Chile comprising approximatly 200 species. These herbs inhabit areas over 3,500 meters above the sea level in the Andes Mountains. S. graveolens is commonly used by local communities for its medicinal properties, particularly its capacity to ameliorate high-altitude-associated sickness. The cytotoxic effect of the alcoholic extract from S. graveolens, as well as its most abundant compound 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone, were tested in the breast cancer cell lines ZR-75-1, MCF-7 and MDA-MB­231, and non-tumorigenic MCF-10F cells. We show that the phytochemical extract was able to induce cytotoxicity in cancer cells but not in MCF-10F. Importantly, this effect was enhanced under hypoxic conditions. However, 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone, the main compound, did not by itself show an effective anticarcinogenic activity in comparison to the whole extract. Interestingly, the cytotoxic effect of the phytochemical extract was dependent on the basal MnSOD protein expression. Thus, cytotoxicity was increased when MnSOD levels were low, but resistance was evident when protein levels were high. Additionally, the crude extract seems to trigger cell death by a variety of processes, including autophagy, apoptosis and necrosis, in MCF-7 cells. In summary, S. graveolens extract possess anticancer activity displaying a specific cytotoxic effect on cancer cells, thus serving as a potential source of phytochemical compounds for cancer treatment.

Alteration of Bax/Bcl-2 ratio contributes to Terminalia belerica-induced apoptosis in human lung and breast carcinoma.

The objective of the present study was to assess the in vitro anticancer activity of 70% methanolic extract of Terminalia belerica (TBME) against human lung (A549) and human breast (MCF-7) carcinoma and its possible mechanism. TBME showed significant cytotoxicity to both A549 and MCF-7 cells, whereas, no cytotoxicity was found in non-malignant WI-38 cells. Flow cytometric analysis was then performed and 100 µg/ml of TBME was selected as the effective concentration inducing apoptosis in A549 and MCF-7. At this concentration, TBME caused DNA fragmentation pattern of apoptosis. Furthermore, mechanism of apoptosis induction was demonstrated using western blotting and Bax/Bcl-2 ratio in both types of the cells was found increased, which leads to the activation of caspase cascade along with the cleavage of PARP. These results suggested that TBME is able to induce anticancer effects on both lung and breast cancer cell lines through the modulation of Bcl-2 family proteins.

Induction of G2/M phase cell cycle arrest and apoptosis by ginsenoside Rf in human osteosarcoma MG­63 cells through the mitochondrial pathway.

Ginsenosides, extracted from the traditional Chinese herb ginseng, are a series of novel natural anticancer products known for their favorable safety and efficacy profiles. The present study aimed to investigate the cytotoxicity of ginsenoside Rf to human osteosarcoma cells and to explore the anticancer molecular mechanisms of ginsenoside Rf. Five human osteosarcoma cell lines (MG-63, OS732, U-2OS, HOS and SAOS-2) were employed to investigate the cytotoxicity of ginsenoside Rf by MTT and colony forming assays. After treatment with ginsenoside Rf, MG-63 cells which were the most sensitive to ginsenoside Rf, were subjected to flow cytometry to detect cell cycle distribution and apoptosis, and nuclear morphological changes were visualized by Hoechst 33258 staining. Caspase-3, -8 and -9 activities were also evaluated. The expression of cell cycle markers including cyclin B1 and Cdk1 was detected by RT-PCR and western blotting. The expression of apoptotic genes Bcl-2 and Bax and the release of cytochrome c were also examined by western blotting. Change in the mitochondrial membrane potential was observed by JC-1 staining in situ. Our results demonstrated that the cytotoxicity of ginsenoside Rf to these human osteosarcoma cell lines was dose-dependent, and the MG-63 cells were the most sensitive to exposure to ginsenoside Rf. Additionally, ginsenoside Rf induced G2/M phase cell cycle arrest and apoptosis in MG-63 cells. Furthermore, we observed upregulation of Bax and downregulation of Bcl-2, Cdk1 and cyclin B1, the activation of caspase-3 and -9 and the release of cytochrome c in MG-63 cells following treatment with ginsenoside Rf. Our findings demonstrated that ginsenoside Rf induces G2/M phase cell cycle arrest and apoptosis in human osteosarcoma MG-63 cells through the mitochondrial pathway, suggesting that ginsenoside Rf, as an effective natural product, may have a therapeutic effect on human osteosarcoma.

Methanol extract of the ethnopharmaceutical remedy Smilax spinosa exhibits anti-neoplastic activity.

Plants have been the source of several effective drugs for the treatment of cancer and over 60% of anticancer drugs originate from natural sources. Therefore, extracts of the rhizome of Smilax spinosa, an ethnomedicinal plant from Guatemala which is used for the treatment of inflammatory conditions, were investigated regarding their anti-neoplastic activities. By using several solvents the methanol extract was by far the most potent against HL60 cell proliferation (50% inhibition at 60 µg/ml). Furthermore, fractionation of this extract yielded fraction F2, which exhibited enforced pro-apoptotic activity, and activated CYP1A1. Proteins that are relevant for cell cycle progression and apoptosis, as well as proto-oncogenes were investigated by western blotting. This revealed that the methanol extract increased the levels of p21 and this may have caused cell cycle attenuation. The derivative fraction F2 induced apoptosis through the intrinsic pathway, which correlated with the inhibition of Stat3 phosphorylation and concomitant induction of caspase 9, then caspase 8 and caspase 3. In summary, the methanol extract and the derivative fraction F2 of S. spinosa showed anti-neoplastic effects in HL-60 cells and CYP1A1 activation in estrogen receptor-positive MCF-7 breast cancer cells but not in estrogen-negative MDA-MB231 breast cancer cells. Based on our data Smilax spinosa may be a promising source for novel anticancer agents.

The effect of the PQ1 anti-breast cancer agent on normal tissues.

Gap junctions are intercellular channels connecting adjacent cells, allowing cells to transport small molecules. The loss of gap junctional intercellular communication (GJIC) is one of the important hallmarks of cancer. Restoration of GJIC is related to the reduction of tumorigenesis and increase in drug sensitivity. Previous reports have shown that PQ1, a quinoline derivative, increases GJIC in T47D breast cancer cells, and subsequently attenuates xenograft breast tumor growth. Combinational treatment of PQ1 and tamoxifen can lower the effective dose of tamoxifen in cancer cells. In this study, the effects of PQ1 were examined in normal C57BL/6J mice, evaluating the distribution, toxicity, and adverse effects. The distribution of PQ1 was quantified by high-performance liquid chromatography and mass spectrometry. The expressions of survivin, caspase-8, cleaved caspase-3, aryl hydrocarbon receptor (AhR), and gap junction protein, connexin 43 (Cx43), were assessed using western blot analysis. Our results showed that PQ1 was absorbed and distributed to vital organs within 1 h and the level of PQ1 decreased after 24 h. Furthermore, PQ1 increased the expression of survivin, but decreased the expression of caspase-8 and caspase-3 activity. Interestingly, the expression of AhR increased in the presence of PQ1, suggesting that PQ1 may be involved in the AhR-mediated response. Previously, PQ1 caused an increase in Cx43 expression in breast cancer cells; however, PQ1 induced a decrease in Cx43 in normal tissues. Hemotoxylin and eosin staining of the tissues showed no histological change between the treated and the untreated organs. Our studies indicate that the administration of PQ1 by an oral gavage can be achieved with low toxicity to normal vital organs.

The novel proapoptotic activity of nonnatural enantiomer of Lentiginosine.

D-(-)-Lentiginosine [(-)-4], the nonnatural enantiomer of the iminosugar indolizidine alkaloid L-(+)-lentiginosine, acts as apoptosis inducer on tumor cells of different origin, in contrast to its natural enantiomer. Although D-(-)-4 exhibited a proapoptotic activity towards tumor cells at level lower than the chemotherapeutic agent, SN38, it was less proapoptotic towards normal cells and less cytotoxic. Apoptosis induced by D-(-)-4 was caspase-dependent, as shown by the increased expression and activity of caspase-3 and -8 in treated cells, and by inhibition following treatment with the pan caspase inhibitor, ZVAD-FMK. This study highlighted how a natural iminosugar alkaloid and its synthetic enantiomer, which were simply known for their inhibition against a fungal glucoamylase, could behave in a complete different way when tested towards cell growth and death of cells of different origin.

[Comparative study of that synergistic effect of cisplatin combined with compound herbal medicinal prescription for tonic quality and activating blood circulation is on SKOV3 cell proliferation and apoptosis].

OBJECTIVE: To investigate the synergistic effects on cell apoptosis and growing restriction of SKOV3 cells by the combination of compound herbal medicinal prescription (CHMP) with cisplatin (DDP). METHODS: Cisplatin and two CHMP for tonic quality(CHMP1) and activating blood circulation (CHMP2), which was medicated serum, were prepared and used to treat the human ovarian carcinoma cell line SKOV3. By serum pharmacologic method, the growth and apoptosis of SKOV3 cell were observed at different time points(24,48,72, 96 h) with different concentrations of medicated serum. Coefficient of drug interaction (CDI) between CHMP, and CHMP2 was studied by MTT method. The effects of control group(A group),CHMP1 group(B group),CHMP2 group (C group), DDP group(D group), CHMP1 + DDP group(E group), CHMP2 + DDP group(Fgroup)to SKOV3 cell were studied by flow cytometry; and the cell apoptosis was observed by agarose electrophoresis; the expressions of TNFR1, caspase-8 on each group were analyzed by Western blot method. RESULTS: Synergistic effects were found between herbal medicinal mixtures and DDP, Restraining rate of SKOV3 and CHMP serum concentration was not in a dose-dependent manner as DDP was. CDI between CHMPI and CHMPS was found to be significant difference (CDI of CHMP1, CHMP2 and DDPwas 0.66, 0.58 respectively). It showed that the combined treatment was able to get better effect than single drug treatment. The performed agarose electrophoresis revealed the extracted DNA to show a typical ladder patterns for cell apoptosis. The analysis results of western blot showed the increased expressions of TNFR1 and caspase-8 after combined using of medicine, which were accord to the rates of apoptosis. CONCLUSIONS: CHMP drug granules show the synergistic effects with DDP, and the suppressing functions in the course of cell proliferation, and the inducing effect on apoptosis of human ovarian carcinoma cell line SKOV3 in vitro. And this mechanism is showed to be sponsored by the activation of TNFR1 and Caspase-8.