Anti-Tumor Effect of Pinus massoniana Bark Proanthocyanidins on Ovarian Cancer through Induction of Cell Apoptosis and Inhibition of Cell Migration

Evaluation of graphene oxide, chitosan and their complex as antibacterial agents and anticancer apoptotic effect on HeLa cell line

Cancer and bacterial infection are the most serious problems threatening people's lives worldwide. However, the overuse of antibiotics as antibacterial and anticancer treatments can cause side effects and lead to drug-resistant bacteria. Therefore, developing natural materials with excellent antibacterial and anticancer activity is of great importance. In this study, different concentrations of chitosan (CS), graphene oxide (GO), and graphene oxide-chitosan composite (GO-CS) were tested to inhibit the bacterial growth of gram-positive (Bacillus cereus MG257494.1) and gram-negative (Pseudomonas aeruginosa PAO1). Moreover, we used the most efficient natural antibacterial material as an anticancer treatment. The zeta potential is a vital factor for antibacterial and anticancer mechanism, at pH 3–7, the zeta potential of chitosan was positive while at pH 7–12 were negative, however, the zeta potential for GO was negative at all pH values, which (p < 0.05) increased in the GO-CS composite. Chitosan concentrations (0.2 and 1.5%) exhibited antibacterial activity against BC with inhibition zone diameters of 4 and 12 mm, respectively, and against PAO1 with 2 and 10 mm, respectively. Treating BC and PAO1 with GO:CS (1:2) and GO:CS (1:1) gave a larger (p < 0.05) inhibition zone diameter. The viability and proliferation of HeLa cells treated with chitosan were significantly decreased (p < 0.05) from 95.3% at 0% to 12.93%, 10.33%, and 5.93% at 0.2%, 0.4%, and 0.60% concentrations of chitosan, respectively. Furthermore, CS treatment increased the activity of the P53 protein, which serves as a tumor suppressor. This study suggests that chitosan is effective as an antibacterial and may be useful for cancer treatment.

Tannin extract from maritime pine bark exhibits anticancer properties by targeting the epigenetic UHRF1/DNMT1 tandem leading to the re-expression of TP73

Maritime pine bark is a rich source of polyphenolic compounds and is commonly employed as a herbal supplement worldwide. This study was designed to check the potential of maritime pine tannin extract (MPTE) in anticancer therapy and to determine the underlying mechanism of action. Our results showed that MPTE, containing procyanidin oligomers and lanostane type terpenoids, has an inhibitory effect on cancer cell proliferation through cell cycle arrest in the G2/M phase. Treatment with MPTE also induced apoptosis in a concentration-dependent manner in human cancer cell lines (HeLa and U2OS), as evidenced by the enhanced activation of caspase 3 and the cleavage of PARP along with the downregulation of the antiapoptotic protein Bcl-2. Interestingly, human non-cancerous fibroblasts are much less sensitive to MPTE, suggesting that it preferentially targets cancer cells. MPTE played a pro-oxidant role in cancer cells and promoted the expression of the p73 tumor suppressor gene in p53-deficient cells. It also downregulated the protooncogenic proteins UHRF1 and DNMT1, mediators of the DNA methylation machinery, and reduced the global methylation levels in HeLa cells. Overall, our results show that maritime pine tannin extract can play a favorable role in cancer treatment, and can be further explored by the pharmaceutical industry.

Mechanisms and Advances in Anti-Ovarian Cancer with Natural Plants Component

Ovarian cancer ranks seventh in the most common malignant tumors among female disease, which seriously threatens female reproductive health. It is characterized by hidden pathogenesis, missed diagnosis, high reoccurrence rate, and poor prognosis. In clinic, the first-line treatment prioritized debulking surgery with paclitaxel-based chemotherapy. The harsh truth is that female patients are prone to relapse due to the dissemination of tumor cells and drug resistance. In these circumstances, the development of new therapy strategies combined with traditional approaches is conductive to improving the quality of treatment. Among numerous drug resources, botanical compounds have unique advantages due to their potentials in multitarget functions, long application history, and wide availability. Previous studies have revealed the therapeutic effects of bioactive plant components in ovarian cancer. These natural ingredients act as part of the initial treatment or an auxiliary option for maintenance therapy, further reducing the tumor and metastatic burden. In this review, we summarized the functions and mechanisms of natural botanical components applied in human ovarian cancer. We focused on the molecular mechanisms of cell apoptosis, autophagy, RNA and DNA lesion, ROS damage, and the multiple-drug resistance. We aim to provide a theoretical reference for in-depth drug research so as to manage ovarian cancer better in clinic.

The cytotoxic activity of pine needles ethanolic extract of Pinus merkusii on HeLa cell lines

Several efforts have been made to discover new anticancer agents based on natural ingredients. Meanwhile, previous studies have shown that different Pine genus species exhibit cytotoxic activity against various types of cancer cells. This plant is rich in phenolic compounds, especially procyanidins, flavonoids, and phenolic acids. Therefore, this study aims to investigate the in vitro cytotoxicity of Pinus merkusii needles extract on HeLa cancer cell lines. The cytotoxicity assessment was measured using MTT assay and expressed as IC50 value. The results showed that the ethanolic extract poses a dose and time-dependent cytotoxic activity with an IC50 value of 542.5 µg/ml at 48 hours of incubation. Based on this result, Pinus merkusii needles’ ethanolic extract has the potential of a novel candidate for an anticancer agent.

Anti-Inflammatory Activity of Oligomeric Proanthocyanidins Via Inhibition of NF-κB and MAPK in LPS-Stimulated MAC-T Cells

Oligomeric proanthocyanidins (OPCs), classified as condensed tannins, have significant antioxidation, anti-inflammation and anti-cancer effects. This study was performed to investigate the anti-inflammatory effects of OPCs and the mechanism underlying these effects in lipopolysaccharide (LPS)-stimulated bovine mammary epithelial cells (MAC-T). Real-time PCR and ELISA assays indicated that OPC treatment at 1, 3 and 5 μg/ml significantly reduced the mRNA and protein, respectively, of oxidant indicators cyclooxygenase-2 (COX-2) (p < 0.05) and inducible nitric oxide synthase (iNOS) (p < 0.01) as well as inflammation cytokines interleukin (IL)-6 (p < 0.01), IL-1β (p < 0.01) and tumor necrosis factor-α (TNF-α) (p < 0.05) in LPS-induced MAC-T cells. Moreover, OPCs downregulated LPSinduced phosphorylation of p65 and inhibitor of nuclear factor kappa B (NF-κB) (IκB) in the NF-κB signaling pathway (p < 0.01), and they inhibited p65 translocation from the cytoplasm to the nucleus as revealed by immunofluorescence test and western blot. Additionally, OPCs decreased phosphorylation of p38, extracellular signal regulated kinase and c-jun NH₂-terminal kinase in the MAPK signaling pathway (p < 0.01). In conclusion, the anti-inflammatory and antioxidant activities of OPCs involve NF-κB and MAPK signaling pathways, thus inhibiting expression of pro-inflammatory factors and oxidation indicators. These findings provide novel experimental evidence for the further practical application of OPCs in prevention and treatment of bovine mastitis.

Pinus maritima Extract Induces Apoptosis in Human Malignant Melanoma Cells via ROS/Caspase-3 Signaling

Melanoma is the most aggressive type of skin cancer due to its rapid metastasis with a high recurrence rate following conventional therapy. Pine bark extract (PBE) from Pinus maritima contains numerous phenolic compounds and functions as a potent antioxidant. The present study aimed to analyze the potential anticancer properties of PBE on human malignant melanoma A375 cells. The chemical composition of PBE was determined by high-performance liquid chromatography/photodiode array detector. The effects of PBE on cell death, migration, and invasion were determined using xCELLigence Technology real-time cell analysis. Annexin/propidium iodide flow cytometry and Hoechst 33342 staining were conducted to detect cell apoptosis. PBE induced apoptosis and inhibited cell migration and invasion. Cleaved caspase-3 expression and activity were significantly increased ( P < 0.01) in cells treated with PBE compared with control cells. PBE ameliorated hydrogen peroxide (H2O2)-induced reactive oxygen species (ROS) formation. Treatment of the cells with PBE in the presence of H2O2 led to significant ( P < 0.001) reduction of matrix metallopeptidase-9, which is a mediator responsible for advanced melanoma. PBE induces A375 programmed cell death and suppresses cellular invasion by attenuating the ROS-dependent pathway associated with MMP-9 reduction.

Procyanidin Compound (PC) Suppresses Lipopolysaccharide-Induced Cervical Cancer Cell Proliferation Through Blocking the TLR4/NF-κB Pathway

Purpose

Evidence suggested that procyanidin compound (PC) could inhibit the progression of cervical cancer (CC); however, the mechanism still remains unclear. We aimed to study the potential mechanism of PC acting on CC cells.

Patients and Methods

After a 24 hr incubation of lipopolysaccharide (LPS) (1 μg/mL), human CC SiHa and HeLa cells were cultured with various concentrations (20, 40, and 80 μg/mL) of PC for 24 hrs, then the cell viability was detected using Cell Counting Kit-8 (CCK-8). The migration and invasion abilities were assessed by scratch and Transwell assays. Apoptosis and cell cycle were detected using flow cytometry. Real-time quantitative PCR (RT-qPCR) and Western blot were used for expression analysis of the inflammatory cytokines. The pathway components were measured to evaluate the involvement of toll-like receptor 4/nuclear factor kappa-light-chain-enhancer of activated B cells (TLR4/NF-κB) pathway.

Results

PC inhibited the LPS-primed cell viability in a dose-dependent manner. After PC treatment, cell migration and invasion were inhibited, cell number at the G2/M phase was increased. The CC cell apoptosis was triggered through upregulating levels of cleaved caspase-3 and Bax and downregulating the level of B-cell lymphoma 2 protein. A significant reduction was shown in the levels of interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α. Furthermore, a remarkable reduction in the ratio of TLR4 and the p-P65/t-P65 and in the progression of P65 translocation into the nucleus was observed.

Conclusion

Our results revealed that the inhibitory effect of PC on CC cell proliferation relies on the induction of apoptosis and inhibition of inflammatory cytokines.

The potency of chitosan-based Pinus merkusii bark extract nanoparticles as anti-cancer on HeLa cell lines

BACKGROUND AND AIM

Cervical cancer accounts for the fourth as a cause of death from cancer in women worldwide, with more than 85% of events and deaths occurring in developing countries. The main problems of chemotherapy are the lack of selectivity and drug resistance. This study aimed to investigate the signal transduction of chitosan-based Pinus merkusii bark extract nanoparticles (Nano-PMBE) as an anticancer on HeLa cell line.

MATERIALS AND METHODS

Nano-PMBE was prepared based on the ionic gelation method. Its anticancer activities in HeLa cells were investigated through cytotoxicity test, cell cycle, and apoptosis analysis. The expression of p53 and caspase-9 was also observed.

RESULTS

The results showed that Nano-PMBE has a size of 394.3 nm. Meanwhile, the Nano-PMBE was cytotoxic to HeLa cells (IC50 of 384.10 µg/ml), caused G0/G1 phase arrest and cell apoptosis in HeLa cells. Besides, the expression of p53 and caspase-9 has increased.

CONCLUSION

The results showed a notable anticancer effect of Nano-PMBE by arresting the cell cycle and inducing apoptosis in HeLa cells, suggesting that it might have therapeutic potential for cervical cancer. Further research is needed to find out more about the anticancer mechanism of Nano-PMBE in HeLa cells to in vivo and clinical studies.

Analysis of the chemotherapeutic effects of a propadiene compound on malignant ovarian cancer cells

Epithelial ovarian cancer is most lethal in female reproductive carcinomas owing to the high chemoresistance and metastasis, so more efficient therapeutic agents are terribly needed. A propadiene compound: 1-phenylpropadienyl phosphine oxide (PHPO), was employed to test the chemotherapeutic efficacy against ovarian cancer cell lines. MTT assay showed that PHPO displayed a much lower IC50 than cisplatin and paclitaxel, while combination treatment of cells with PHPO + cisplatin induced more apoptosis than with PHPO + paclitaxel or with cisplatin + paclitaxel (p < 0.05). Animal assays demonstrated that subcutaneous tumor growth was highly inhibited by PHPO + cisplatin, compared with that inhibited by PHPO or by cisplatin treatment alone, indicating PHPO and cisplatin may have synergistic effects against ovarian cancer growth. We also found that PHPO induced few side effects on animals, compared with cisplatin. Mechanistic studies suggested that treatment of cells with PHPO or with PHPO + cisplatin differentially inhibited the PI3K/Akt, MAPK and ATM/Chk2 pathways, which consequently suppressed the anti-apoptotic factors Bcl-xL, Bcl-2 and XIAP, but activated the pro-apoptotic factors Bad, Bax, p53, caspase 9, caspase 8, caspase 7 and PARP. Taken together, PHPO may induce cell apoptosis through multiple signal pathways, especially when used along with cisplatin. Therefore, PHPO may be explored as a prospective agent to effectively treat ovarian cancer.

TGF-β2-induced EMT is dampened by inhibition of autophagy and TNF-α treatment

Hepatocellular carcinoma (HCC) typically develops in a chronic inflammatory setting causal to release of a plethora of growth factors and cytokines. However, the molecular effect of these cytokines on HCC progression is poorly understood. In this study, we exposed HCC cells to TGF-β2 (Transforming Growth Factor-β2), which resulted in a significant elevation of EMT (Epithelial to Mesenchymal Transition) like features. Molecular analysis of EMT markers showed an increase at both RNA and protein levels upon TGF-β2 administration along with up-regulation of TGF-β-induced Smad signaling. Induction of EMT was associated with a simultaneous increase in reactive oxygen species (ROS) and cytostasis of TGF-β2-treated cells. Importantly, quenching of ROS resulted in a significant promotion of TGF-β2-induced EMT. Furthermore, cells treated with TGF-β2 also showed an enhanced autophagic flux. Interestingly, inhibition of autophagy by chloroquine-di-phosphate (CQDP) or siRNA-mediated ablation of ATG5 drastically inhibited TGF-β2-induced EMT. Autophagy inhibition significantly increased ROS levels promoting apoptosis. It was further observed that pro-inflammatory cytokine like, TNF-α (Tumor Necrosis Factor-α) can antagonize TGF-β2-induced response by down-regulating autophagy, increasing ROS levels and thus inhibiting EMT in HCC cells. This inhibitory effect of TNF-α is serum-independent. Transcriptomic analysis through RNA sequencing was further performed which validated that TGF-β2-induced autophagic genes are inhibited by TNF-α treatment suppressing EMT. Our study suggests that autophagy plays a pro-metastatic role facilitating EMT by regulating ROS levels in HCC cells and TNF-α can suppress EMT by inhibiting autophagy. We provide unique mechanistic insights into the role of TGF-β2 in HCC cells, along with appropriate cues to effectively control the disease.

Castanea sativa Mill. bark extract exhibits chemopreventive properties triggering extrinsic apoptotic pathway in Jurkat cells

Background

Chemoprevention represents the possibility to prevent, stop or reverse the cancerogenetic process. In this context the interest towards natural extracts and botanical drugs has constantly grown due to their phytochemical content. Castanea sativa Mill. (CSM) extracts showed to exert positive effect in the prevention/counteraction of chronic/degenerative diseases, therefore, we evaluated the potential chemopreventive effect of CSM bark extract.

Methods

Flow cytometry (FCM) analyses of Jurkat cells treated with CSM bark extract (0–500 μg·mL⁻¹) for 24–72 h allowed evaluating its cytotoxicity and ability to induce apoptosis through the intrinsic or extrinsic pathways. Moreover, to evaluate CSM bark extract selectivity towards cancer cells, its cytotoxic and pro-apoptotic effect was also evaluated in human peripheral blood lymphocytes (PBL).

Results

CSM bark extract induced apoptosis in Jurkat cells in a dose- and time- dependent manner activating the extrinsic pathways as evidenced by the increase of activated caspase-8 positive cells. Moreover, IC₅₀ calculated after 24 h treatment resulted 304 and 128 μg·mL⁻¹ in PBL and Jurkat cells respectively.

Conclusions

Our data suggest that CSM bark extract might be considered an interesting potential anti-cancer agent, since it induces apoptosis in cancer cells without appreciable cytotoxic effects on non-transformed cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1756-6) contains supplementary material, which is available to authorized users.

Recent Advances in Anticancer Activities and Drug Delivery Systems of Tannins

Tannins, polyphenols in medicinal plants, have been divided into two groups of hydrolysable and condensed tannins, including gallotannins, ellagitannins, and (-)-epigallocatechin-3-gallate (EGCG). Potent anticancer activities have been observed in tannins (especially EGCG) with multiple mechanisms, such as apoptosis, cell cycle arrest, and inhibition of invasion and metastases. Furthermore, the combinational effects of tannins and anticancer drugs have been demonstrated in this review, including chemoprotective, chemosensitive, and antagonizing effects accompanying with anticancer effect. However, the applications of tannins have been hindered due to their poor liposolubility, low bioavailability, off-taste, and shorter half-life time in human body, such as EGCG, gallic acid, and ellagic acid. To tackle these obstacles, novel drug delivery systems have been employed to deliver tannins with the aim of improving their applications, such as gelatin nanoparticles, micelles, nanogold, liposomes, and so on. In this review, the chemical characteristics, anticancer properties, and drug delivery systems of tannins were discussed with an attempt to provide a systemic reference to promote the development of tannins as anticancer agents.

Pinus massoniana bark extract inhibits migration of the lung cancer A549 cell line

The bark of Pinus massoniana is a traditional Chinese medicine for the treatment of various health disorders. Previous studies have demonstrated that P. massoniana bark extract (PMBE) may induce the apoptosis of hepatoma and cervical cancer cells. However, whether PMBE is able to inhibit the migration of lung cancer cells requires further investigation. In the current study, the effects of PMBE on the viability of human lung cancer A549 cells were detected using an MTT assay. The migration of lung cancer cells following exposure to PMBE were quantified using wound healing and Transwell assays, respectively. The expression levels of matrix metalloproteinase (MMP)-9 were determined using western blotting. The results revealed that PMBE significantly inhibited the growth of the lung cancer cells. In addition, the wound closure rate and the migration of the lung cancer cells were suppressed by PMBE. Furthermore, the expression levels of MMP-9 were reduced. These findings indicated that PMBE is able to restrict the migration and invasion of lung cancer cells, and that PMBE may serve as a novel therapeutic agent for patients with metastatic lung cancer in the future.

Neuroprotective effects of polydatin against mitochondrial-dependent apoptosis in the rat cerebral cortex following ischemia/reperfusion injury

The neuroprotective effect of polydatin (PD) against hemorrhagic shock-induced mitochondrial injury has been described previously, and mitochondrial dysfunction and apoptosis were reportedly involved in ischemic stroke. In the present study the neuroprotective effect of PD in preventing apoptosis was evaluated following induction of focal cerebral ischemia by middle cerebral artery occlusion (MCAO) in rats. PD (30 mg/kg) was administered by caudal vein injection 10 min prior to ischemia/reperfusion (I/R) injury. 24 h following I/R injury, ameliorated modified neurological severity scores (mNSS) and reduced infarct volume were observed in the PD treated group. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Annexin V/propidium iodide assays demonstrated the anti-apoptotic effect of PD in the ischemic cortex. In addition, PD improved I/R injury‑induced mitochondrial dysfunction, reflected by morphological observations and measurements of mitochondrial membrane potential and intracellular ATP measurement. Western blot analysis revealed an increase in B‑cell lymphoma 2 apoptosis regulator (Bcl-2) expression, and a decrease in Bcl‑2‑associated protein X apoptosis regulator expression in the PD group in comparison with the vehicle treated group. PD treatment also prevented the release of cytochrome c from mitochondria into the cytoplasm, and blunted the activities of caspase‑9 and caspase‑3. Furthermore, PD treatment decreased the levels of reactive oxygen species in neurons isolated from the ischemic cortex. The findings of this study, therefore, suggest that PD has a dual effect, ameliorating both oxidative stress and mitochondria‑dependent apoptosis, making it a promising new therapy for the treatment of ischemic stroke.