Selective induction of apoptosis through activation of caspase-8 in human leukemia cells (Jurkat) by dandelion root extract

Hydroponic Ginseng ROOT Mediated with CMC Polymer-Coated Zinc Oxide Nanoparticles for Cellular Apoptosis via Downregulation of BCL-2 Gene Expression in A549 Lung Cancer Cell Line

The unique and tailorable physicochemical features of zinc oxide nanoparticles (ZnO-NPs) synthesized from green sources make them attractive for use in cancer treatment. Hydroponic-cultured ginseng-root-synthesized ZnO-NPs (HGRCm-ZnO NPs) were coated with O-carboxymethyl chitosan (CMC) polymer, which stabilized and enhanced the biological efficacy of the nanoparticles. Nanoparticles were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy, transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS). The flower-shaped nanoparticles were crystalline in nature with a particle size of 28 nm. To evaluate if these NPs had anti-lung cancer activity, analysis was performed on a human lung carcinoma cell line (A549). HGRCm-ZnO nanoparticles showed less toxicity to normal keratinocytes (HaCaTs), at concentrations up to 20 µg/mL, than A549 cancer cells. Additionally, these NPs showed dose-dependent colony formation and cell migration inhibition ability, which makes them more promising for lung cancer treatment. Additionally, Hoechst and propidium iodide dye staining also confirmed that the NP formulation had apoptotic activity in cancer cells. Further, to evaluate the mechanism of cancer cell death via checking the gene expression, HGRCm ZnO NPs upregulated the BAX and Caspase 3 and 9 expression levels but downregulated Bcl-2 expression, indicating that the nanoformulation induced mitochondrial-mediated apoptosis. Moreover, these preliminary results suggest that HGRCm ZnO NPs can be a potential candidate for future lung cancer treatment.

The potential for traditional Chinese therapy in treating sleep disorders caused by COVID-19 through the cholinergic anti-inflammatory pathway

Since the outbreak of Coronavirus disease (COVID-19) in 2019, it has spread rapidly across the globe. Sleep disorders caused by COVID-19 have become a major concern for COVID-19 patients and recovered patients. So far, there’s no effective therapy on this. Traditional Chinese therapy (TCT) has a great effect on sleep disorders, with rare side effects and no obvious withdrawal symptoms. The cholinergic anti-inflammatory pathway, a neuroregulatory pathway in the central nervous system that uses cholinergic neurons and neurotransmitters to suppress inflammatory responses, has been reported to be associated with sleep disorders and psychiatric symptoms. Many studies have shown that TCT activates the cholinergic anti-inflammatory pathway (CAP), inhibits inflammation, and relieves associated symptoms. Therefore, we believe that TCT may be a potential therapeutic strategy to alleviate sleep disorders induced by COVID-19 through CAP. In this review, we analyzed the relationship between cytokine storm induced by Coronavirus and sleep disorders, explained the influence of CAP on sleep disorders, discussed the TCT’s effect on CAP, and summarized the treatment effect of TCT on sleep disorders. Based on these practical researches and theoretical basis, we propose potential strategies to effectively improve the sleep disorders caused by COVID-19.

The potential of dandelion in the fight against gastrointestinal diseases: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Dandelion (Taraxacum officinale Weber ex F. H. Wigg.), as a garden weed grown globally, has long been consumed as a therapeutic herb. Its folkloric uses include treatments of digestive disorders (dyspepsia, anorexia, stomach disorders, gastritis and enteritis) and associate complex ailments involving uterine, liver and lung disorders.

AIM OF THE STUDY

The present study aims to critically assess the current state of research and summarize the potential roles of dandelion and its constituents in gastrointestinal (GI) -protective actions. A focus is placed on the reported bioactive components, pharmacological activities and modes of action (including molecular mechanisms and interactions among bioactive substances) of dandelion products/preparations and derived active constituents related to GI protection.

MATERIALS AND METHODS

The available information published prior to August 2021 was reviewed via SciFinder, Web of Science, Google Scholar, PubMed, Elsevier, Wiley On-line Library, and The Plant List. The search was based on the ethnomedical remedies, pharmacological activities, bioactive compounds of dandelion for GI protection, as well as the interactions of the components in dandelion with the gut microbiota or biological regulators, and with other ingested bioactive compounds. The key search words were "Taraxacum" and "dandelion".

RESULTS

T. coreanum Nakai, T. mongolicum and T. officinale are the most commonly used species for folkloric uses, with the whole plant, leaves and root of dandelion being used more frequently. GI-protective substances of dandelion include taraxasterol, taraxerol, caffeic acid, chicoric acid, chlorogenic acid, luteolin and its glucosides, polysaccharides, inulin, and β-sitosterol. Dandelion products and derived constituents exhibit pharmacological effects against GI disorders, mainly including dyspepsia, gastroesophageal reflux disease, gastritis, small intestinal ulcer, ulcerative colitis, liver diseases, gallstones, acute pancreatitis, and GI malignancy. The underlying molecular mechanisms may include immuno-inflammatory mechanisms, apoptosis mechanism, autophagy mechanism, and cholinergic mechanism, although interactions of dandelion's constituents with GI health-related biological entities (e.g., GI microbiota and associated biological modulators) or other ingested bioactive compounds shouldn't be ignored.

CONCLUSION

The review reveals some in vivo and in vitro studies on the potential of dandelion derived products as complementary and alternative medicines/therapeutics against GI disorders. The whole herb may alleviate some symptoms related GI immuno-inflammatory basing on the abundant anti-inflammatory and anti-oxide active substances. Dandelion root could be a nontoxic and effective anticancer alternative, owing to its abundant terpenoids and polysaccharides. However, research related to GI protective dandelion-derived products remains limited. Besides the need of identifying bioactive compounds/complexes in various dandelion species, more clinical studies are also required on the metabolism, bioavailability and safety of these substances to support their applications in food, medicine and pharmaceuticals.

Bioactive Compounds from Curcuma amada and Their Effect on Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive blood cancer with limited chemotherapy options and negative patient outcomes. Investigations with bioactive compounds from dietary sources against cancer have increased in the recent years, which highlight the need for novel therapeutic approaches and new anti-leukemic agents possessing higher efficacy and selectivity for AML cells and fewer negative side effects. Bioactive compounds demonstrated the ability to induce cell cycle blockage and apoptosis or autophagy in cancer cells, as well as inhibition of proliferation/migration and tumor progression, etc. Bioactive compounds isolated from dietary sources such as mango ginger show promise for AML treatment. Curcuma amada roots have been used in traditional medicine and showed antioxidant, antimicrobial and anticancer properties. Bioactive molecules isolated from C. amada showed effects on the mitochondrial metabolism and reduced the viability of multiple leukemic cell lines.

Updates and advances on pharmacological properties of Taraxacum mongolicum Hand.-Mazz and its potential applications

As a well-recognized dietary and medicinal plant, Taraxacum mongolicum Hand.-Mazz (TMHM) has been used for making wines, candies, energy drinks, and other functional foods. The TMHM contains a diverse range of active phytoconstituents, including flavonoids, triterpenoids, phenolic acids, sesquiterpene lactones, pigments, coumarins and sterols. Recent pharmacological evidence has revealed multiple biological effects of TMHM, including anti-inflammatory, antioxidant, antibacterial, and gastric-protective effects, which contribute to the ameliorative effects of TMHM on inflammation-associated diseases, constipation, gastric disorders, empyrosis, hyperlipidemia, and swollen carbuncles. Although recent advances have highlighted the potential of TMHM to be applied in the clinical practice, food, and nutraceutical industry, the mechanistic understanding and systematic information on TMHM are still scarce. Here, in this timeline review, we have attempted to compile literary documents on pharmacological potential of TMHM concerning its chemical composition, biological activities, toxicity, and pharmacokinetics to promote further researches on clinical and therapeutic potential of TMHM and its food/nutraceutical applications.

Fish Oil, Se Yeast, and Micronutrient-Enriched Nutrition as Adjuvant Treatment during Target Therapy in a Murine Model of Lung Cancer

Despite the effectiveness of primary treatment modalities for cancer, the side effects of treatments, medication resistance, and the deterioration of cachexia after disease progression lead to poor prognosis. A supportive treatment modality to overcome these limitations would be considered a major breakthrough. Here, we used two different target drugs to demonstrate whether a nutraceutical formula (fish oil, Se yeast, and micronutrient-enriched nutrition; NuF) can interfere with cancer cachexia and improve drug efficacy. After Lewis lung cancer (LLC) tumor injection, the C57BL/6 mice were orally administered targeted therapy drugs Iressa and Sutent alone or combined with NuF for 27 days. Sutent administration effectively inhibited tumor size but increased the number of lung metastases in the long term. Sutent combined with NuF had no significant difference in tumor weight and metastasis compare with Sutent alone. However, NuF slightly attenuated metastases number in lung may via mesenchymal marker N-cadherin suppression. NuF otherwise increased epithelial-like marker E-cadherin expression and induce NO-mediated intrinsic apoptotic pathway in tumor cells, thereby strengthening the ability of the targeted therapy drug Iressa for inhibiting tumor progression. Our results demonstrate that NuF can promote the anticancer effect of lung cancer to targeted therapy, especially in Iressa, by inhibiting HIF-1α and epithelial-mesenchymal transition (EMT) and inducing the apoptosis of lung cancer cells. Furthermore, NuF attenuates cancer-related cachectic symptoms by inhibiting systemic oxidative stress.

Dandelion extract relaxes mouse airway smooth muscle by blocking VDLCC and NSCC channels

BACKGROUND

Asthma is one of the main intractable diseases recognized by the international medical community. The current widely used bronchodilators for asthma-β2-adrenal receptor agonists-have limited therapeutic effects, necessitating the development of novel antiasthma drugs with increased efficacy and fewer adverse effects. In this study, we investigated the relaxant effects and underlying mechanism of an ethyl acetate extract from dandelion (EAED) on mouse airway smooth muscle.

METHODS

The effects of EAED on agonist-induced precontraction in mouse airway smooth muscle were evaluated with force measurement. Mouse lung slices were used to study the effects of EAED on bronchial smooth muscle. The intracellular Ca2+ concentration was measured using a calcium imaging system. L-type voltage-dependent calcium channel (VDLCC) and non-selective cationic channel (NSCC) currents were measured by patch-clamp. The lung functions of healthy and asthmatic mouse groups were assessed via the forced oscillation technique.

RESULTS

EAED inhibits acetylcholine-induced sustained contractions of whole airway smooth muscle by inhibiting VDLCCs, NSCCs, and some unknown channels, reduces the agonist-induced increase in the cytosolic free Ca2+ concentration in airway smooth muscle cells, blocks VDLCC and NSCC currents, and relieves the respiratory resistance of healthy and asthmatic mice.

CONCLUSIONS

EAED may have potential beneficial effects on mitigating asthma attacks.

Phytochemicals in Anticancer Drug Development

BACKGROUND

In spite of major technological advances in conventional therapies, cancer continues to remain the leading cause of mortality worldwide. Phytochemicals are gradually emerging as a rich source of effective but safer agents against many life-threatening diseases.

METHODS

Various phytochemicals with reported anticancer activity have been simply categorized into major phytoconstituents- alkaloids, polyphenols, saponins, tannins and terpenoids.

RESULTS

The adverse effects associated with currently available anticancer medications may be overcome by using plant-derived compounds either alone or in combination. Exploration of plant kingdom may provide new leads for the accelerated development of new anticancer agents.

CONCLUSION

Although numerous potent synthetic drugs have been introduced for cancer chemotherapy, yet their serious toxicity concerns to normal cells apart from drug resistance have emerged as the major obstacles for their clinical utility over a prolonged duration of time. Current status and potential of phytochemicals and their derivatives in cancer therapy have been briefly reviewed in the present manuscript.

MR-10 Enhances Men's Health by Improving Endogenous Male Sex Hormone Generation

Although there is a clear need for improving men's health, treatment with suitable natural substances has not yet been well established. Previously, it was reported that MR-10, a novel complex of Korean dandelion and rooibos found by screening many natural products, improved sperm generation and activity. Here, the ability of MR-10 to increase testosterone levels and enhance men's health was tested. Treatment with MR-10 (400 mg/day) for a month significantly increased levels of free testosterone, total testosterone, and the testosterone precursor dehydroepiandrosterone by 22%, 14%, and 32%, respectively, in clinical studies. Also, men's health in terms of mental, physical, and sexual aspects, as determined by using the clinical questionnaires Androgen Deficiency of Aging Men and Aging Males' Symptoms, was improved. Furthermore, the safety of MR-10 was determined by testing levels of prostate-specific antigen, glutamic oxaloacetic transaminase, and glutamic pyruvate transaminase; and the lack of changes due to MR-10 treatment supports the safety of MR-10. In conclusion, this study suggests that MR-10 is a safe and effective natural product improving men's sexual health.

Inhibition of autophagy enhanced cobalt chloride‑induced apoptosis in rat alveolar type II epithelial cells

Hypoxia is a type of cellular stress that may result in apoptosis and autophagy. The molecular mechanisms underlying the association between autophagy and apoptosis remain unclear, particularly in hypoxic conditions. Transmission electron microscope, AO-PI staining, flow cytometry and western blot were used to examine the crosstalk between autophagy and apoptosis in hypoxic conditions. Rat alveolar type II epithelial RLE-6TN cells were cultured in a long-term hypoxic environment established by cobalt (II) chloride. It was demonstrated that autophagy and apoptosis occurred in RLE-6TN cells under hypoxic conditions. Treatment of RLE-6TN cells with the autophagy inhibitor 3-methyladenine increased the generation of reactive oxygen species, mitochondrial damage and hypoxia-induced apoptosis. The expression of caspases, particularly caspase-9, increased and may have participated in these processes. The data indicated that the inhibition of autophagy enhanced apoptosis through the mitochondria-mediated intrinsic pathway. These findings provide important insight into the molecular mechanism of autophagy and apoptosis crosstalk. This may provide new insights into pulmonary disease surveillance, diagnosis and treatment.

Viscum articulatum Burm. f. aqueous extract exerts antiproliferative effect and induces cell cycle arrest and apoptosis in leukemia cells

ETHNOPHARMACOLOGICAL RELEVANCE

Viscum articulatum Burm. f. (leafless mistletoe) has been used in traditional system of medicines in India, China, Taiwan, Cambodia, Laos, and Vietnam, to treat blood-related diseases and various inflammatory and degenerative diseases including cancer. Anticancer activities of some phytomolecules purified from Viscum articulatum Burm. f. have been tested. However scientific evidence for the anticancerous potential of aqueous extract of V. articularum (VAQE) used in traditional medicine is lacking.

AIM OF THE STUDY

To study the antiproliferative and apoptotic effect of VAQE on Jurkat E6.1 and THP1 leukemia cells.

MATERIALS AND METHODS

The aqueous extract of the whole plant of Viscum articulatum Burm. f. was prepared in phosphate buffer saline. In VAQE, total soluble protein was estimated using Bradford's dye-binding assay; flavonoid content was determined using aluminum chloride colorimetric assay; and phenolic content was estimated following Folin-Ciocalteu colorimetric assay. XTT cell viability assay was used to test VAQE induced cytotoxicity in Jurkat E6.1 and THP1 leukemia cells and peripheral blood mononuclear cells (PBMC). The effect of VAQE on cell cycle progression was analyzed by PI staining using flow cytometry. Annexin-V-FITC/PI differential staining method was used for detecting the onset of apoptosis in leukemia cells. Rhodamine 123 dye was used to detect the change in mitochondrial membrane potential (MMP) using flow cytometry. DCF-DA fluorescence dye was used to estimate the level of reactive oxygen species (ROS). The ROS inhibitors were used to evaluate the role of ROS in mediating DNA degradation in VAQE-treated leukemia cells. The molecular mechanisms underlying VAQE induced apoptosis induction was studied by analyzing the expression of anti-apoptotic (Bcl-2) and pro-apoptotic (Bax) proteins, caspase-8 and caspase-3 enzymes using western blot. Diphenylamine (DPA) assay was used to determine the DNA fragmentation and conclusion of apoptosis.

RESULTS

VAQE triggered cytotoxic effect on Jurkat E6.1 (IC₅₀-2.4 µg/ml; 24 h) and THP1 (IC₅₀-1.0 µg/ml; 24 h) cells in a dose- and time-dependent manner. The apoptosis induction and G2/M arrest of the cell cycle are the cause of VAQE-induced cytotoxicity in leukemia cells. The apoptosis in VAQE-treated Jurkat E6.1 and THP1 cells was mediated via a reduction in MMP, elevation of intracellular ROS, decreased expression of the anti-apoptotic (Bcl-2) and increased expression of the pro-apoptotic (Bax) protein, activation of caspase-8 and caspase-3 and DNA fragmentation.

CONCLUSION

VAQE has a high efficacy to exert a cytotoxic effect in Jurkat E6.1 and THP1 cells and to induce apoptosis and G2/M cell cycle arrest. VAQE induces extrinsic pathway of apoptosis in both the leukemia cell lines via disruption of MMP, intracellular ROS imbalance, increased ratio of Bax/Bcl-2, activation of caspase-8, caspase-3 and ROS-mediated DNA fragmentation. The knowledge gained from the outcomes of the study may encourage the identification of novel chemotherapeutic agent from Viscum articulatum Burm. f. to treat leukemia.

Dandelion root extract protects NCM460 colonic cells and relieves experimental mouse colitis

The protective potential of dandelion on acute hepatitis, lung injury and colorectal cancer has recently been revealed. Importantly, ulcerative colitis (UC), a clinically defined inflammatory bowel disease, accelerates the risk of colorectal cancer. However, studies focusing on the activity of dandelion on UC are extremely limited. In the present study, we found that an aqueous extract of dandelion root increases cell viability and decreases apoptosis in dextran sodium sulfate (DSS)-incubated NCM460 human colonic epithelial cells, probably through removing the production of reaction oxygen species and blocking nuclear factor-kappaB signaling. We then examined the anti-colitis efficacy of this extract in an in vivo study. We detected that dandelion root extract efficiently ameliorates progressive acute injury as demonstrated by a reduction in body weight loss, severity scores of disease index and shortened colon length during DSS treatment, as well as reducing the inflammatory conditions and oxidative stress in the colon of DSS-induced mice. Our study clearly demonstrates that dandelion has a strong cytoprotective effect on NCM460 colonocytes and shows powerful defense on an established experimental mouse model of DSS-induced UC. Therefore, dandelion root extract can be an effective anti-colitis complex mixture and can provide a complementary alternative to currently available therapeutic intervention in UC.

Dandelion root extract affects colorectal cancer proliferation and survival through the activation of multiple death signalling pathways

Dandelion extracts have been studied extensively in recent years for its anti-depressant and anti-inflammatory activity. Recent work from our lab, with in-vitro systems, shows the anti-cancer potential of an aqueous dandelion root extract (DRE) in several cancer cell models, with no toxicity to non-cancer cells. In this study, we examined the cancer cell-killing effectiveness of an aqueous DRE in colon cancer cell models. Aqueous DRE induced programmed cell death (PCD) selectively in > 95% of colon cancer cells, irrespective of their p53 status, by 48 hours of treatment. The anti-cancer efficacy of this extract was confirmed in in-vivo studies, as the oral administration of DRE retarded the growth of human colon xenograft models by more than 90%. We found the activation of multiple death pathways in cancer cells by DRE treatment, as revealed by gene expression analyses showing the expression of genes implicated in programmed cell death. Phytochemical analyses of the extract showed complex multi-component composition of the DRE, including some known bioactive phytochemicals such as α-amyrin, β-amyrin, lupeol and taraxasterol. This suggested that this natural extract could engage and effectively target multiple vulnerabilities of cancer cells. Therefore, DRE could be a non-toxic and effective anti-cancer alternative, instrumental for reducing the occurrence of cancer cells drug-resistance.

Taraxacum mongolicum extract induced endoplasmic reticulum stress associated-apoptosis in triple-negative breast cancer cells

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive and deadly breast cancer subtype with limited treatment options. It is necessary to seek complementary strategies for TNBC management. Taraxacum mongolicum, commonly named as dandelion, is a herb medicine with anti-cancer activity and has been utilized to treat mammary abscess, hyperplasia of mammary glands from ancient time in China, but the scientific evidence and action mechanisms still need to be studied.

AIM OF THE STUDY

This study was intended to investigate the therapeutic effect and molecular mechanisms of dandelion extract in TNBC cell line.

METHODOLOGY

Dandelion extract was prepared and purified, and then its chemical composition was determined. Cell viability was evaluated by MTT assay. Analysis of cell apoptosis and cell cycle was assessed by flow cytometry. The expression levels of mRNA and proteins were determined by real-time PCR and Western blotting, respectively. Caspase inhibitor Z-VAD-FMK and CHOP siRNA were used to confirm the cell apoptosis induced by dandelion extract.

RESULTS

Dandelion extract significantly decreased MDA-MB-231cell viability, triggered G2/M phase arrest and cell apoptosis. Concurrently, it caused a markedly increase of cleaved caspase-3 and PARP proteins. Caspase inhibitor Z-VAD-FMK abolished the apoptosis triggered by dandelion extract. The three ER stress-related signals were strongly induced after dandelion treatment, including increased mRNA expressions of ATF4, ATF6, XBP1s, GRP78 and CHOP genes, elevated protein levels of phosphorylated PERK, eIF-2α, IRE1, as well as the downstream molecules of CHOP and GRP78. MDA-MB-231 cells transfected with CHOP siRNA significantly reduced apoptosis induced by dandelion extract. The underlying mechanisms at least partially ascribe to the strong activation of PERK/p-eIF2α/ATF4/CHOP axis.

CONCLUSION

ER stress related cell apoptosis accounted for the anti-cancer effect of dandelion extract, and these findings support dandelion extract might be a potential therapeutic approach to treat TNBC.

Cardamonin, a chalcone, inhibits human triple negative breast cancer cell invasiveness by downregulation of Wnt/β-catenin signaling cascades and reversal of epithelial-mesenchymal transition

Cardamonin (CD), an active chalconoid, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of CD for the treatment of triple negative breast cancer (TNBC) is unclear. This study aims to examine the cytotoxic effects of CD and investigate the underlying mechanism in human TNBC cells. The results show that CD exhibits cytotoxicity by inducing apoptosis and cell cycle arrest in TNBC cells via modulation of Bcl-2, Bax, cyt-C, cleaved caspase-3, and PARP. We find that CD significantly increases expression of the epithelial marker E-cadherin, while reciprocally decreasing expression of mesenchymal markers such as snail, slug, and vimentin in BT-549 cells. In parallel with epithelial-mesenchymal transition (EMT) reversal, CD down regulates invasion and migration of BT-549 cells. CD markedly reduces stability and nuclear translocation of β-catenin, accompanied with downregulation of β-catenin target genes. Using the TopFlash luciferase reporter assay, we reveal CD as a specific inhibitor of the Wnt3a-induced signaling. These results suggest the involvement of the Wnt/β-catenin signaling in the CD-induced EMT reversion of BT-549 cells. Notably, CD restores the glycogen synthase kinase-3β (GSK3β) activity, required for β-catenin destruction via the proteasome-mediated system, by inhibiting the phosphorylation of GSK3β by Akt. These occurrences ultimately lead to the blockage of EMT and the invasion of TNBC cells. Further antitumor activity of CD was tested in 4T1 (TNBC cells) induced tumor and it was found that CD significantly inhibited the tumor volume at dose of 5 mg/kg-treated mice. © 2016 BioFactors, 43(2):152-169, 2017.

The Health Potential of Fruits and Vegetables Phytochemicals: Notable Examples

Fruit and vegetables are essential components of a healthy diet. The World Health Organization (WHO) recommends an intake of five to eight portions (400-600 g) daily of fruits and vegetables to reduce risk of cardiovascular disease, cancer, poor cognitive performance, and other diet-related diseases, as well as for the prevention of micronutrient deficiencies. Much of their potential for disease prevention is thought to be provided by phytochemicals, among which the preventive activity of antioxidants is most well documented. Since numerous meta-studies published indicate variable and often contradictory results about the impact of isolated phytochemicals on health, their consumption as supplements must be carried out with care, because doses may exceed the recommended nutritional intake. Nonetheless, there is a general consensus that whole fruit and vegetable intake is more important in providing health benefits than that of only one of their constituent, because of additive and synergistic effects. This review describes the most recent literature regarding the health benefits of some selected fruits and vegetables. Importantly, since some phytochemicals regulate the same genes and pathways targeted by drugs, diets rich in fruits and vegetables in combination with medical therapies are being considered as novel approaches to treatment. Therefore, phytochemicals in fruits and vegetable might be a promising tool for the prevention and/or amelioration of a wide range of diseases.

Mitochondrial dysfunction rather than mtDNA sequence mutation is responsible for the multi-drug resistance of small cell lung cancer

Small cell lung cancer (SCLC) accounts for ~15% of all lung cancer cases, and chemotherapy has dramatically improved the survival rate of SCLC patients. Yet, the long-term survival rate of this cancer has not improved since multi-drug resistance (MDR) may emerge after chemotherapy. Mitochondrial DNA (mtDNA) mutation-related biological processes, such as energy metabolism and reactive oxygen species (ROS) production, have been considered to be associated with tumorigenesis and drug resistance. It was hypothesized and demonstrated, in the present study, that mitochondrial dysfunction is the reason for the occurrence and progression of SCLC. mtDNA from drug sensitive and drug insensitive cell lines (H446 and H446/CDDP) was sequenced and compared with the revised Cambridge reference sequence (rCRS). The results revealed that there was no difference in the mtDNA sequence from H446 and H446/CDDP cells, but several spot mutations were observed according to that of rCRs. Further evaluation on mitochondrial function revealed that H446 cells synthesized and secreted more lactic acid and ROS compared with that of H446/CDDP cells when challenged by the same dose of cisplatin (P>0.05). In addition, examination of the mitochondrial apoptotic pathway indicated that more Bax, cleaved caspase-3 and cleaved caspase-9 were expressed in H446 cells compared with that of H446/CDDP cells when stimulated by the same dose of cisplatin (P>0.05). In conclusion, the results of the present study revealed that mtDNA mutations were responsible for the tumorigenesis of SLCL, but not associated with the drug sensitivity of SCLC cell lines. On the other hand, varied mitochondrium content‑related mitochondrial dysfunction participated in the MDR of SCLC possibly by affecting the ROS-mediated mitochondrial apoptotic pathway.

Phytoconstituents as apoptosis inducing agents: strategy to combat cancer

Advancement in the field of cancer molecular biology has aided researchers to develop various new chemopreventive agents which can target cancer cells exclusively. Cancer chemopreventive agents have proficiency to inhibit, reverse and delay process of carcinogenesis during its early and later course. Chemopreventive agents can act as antioxidative, antimutagenic/antigenotoxic, anti-inflammatory agents or via aiming various molecular targets in a cell to induce cell death. Apoptosis is a kind of cell death which shows various cellular morphological alterations such as cell shrinkage, blebbing of membrane, chromatin condensation, DNA fragmentation, formation of apoptotic bodies etc. Nowadays, apoptosis is being one of the new approaches for the identification and development of novel anticancer therapies. For centuries, plants are known to play part in daily routine from providing food to management of human health. In the last two decades, diverse phytochemicals and various botanical formulations have been characterized as agents that possess potential to execute cancer cells via inducing apoptosis. Data obtained from the research carried out globally pointed out that natural products are the potential candidates which have capability to combat cancer. In the present review, we surveyed literature on natural products which throws light on the mechanism through which these phytochemicals induce apoptosis in cancer cells.

Resveratrol-4‑O-D‑(2'-galloyl)-glucopyranoside exerts an anticancer effect on leukemia cells via inducing apoptosis

The aim of the present study was to investigate the anticancer effects of resveratrol‑4‑O‑D-(2'‑galloyl)-glucopyranoside (REG) on leukemia and the mechanism underlying its effects. Three leukemia cell lines (HL‑60, Jurkat and U937) were used in this study. A Cell Counting kit‑8 assay was performed to evaluate the anti‑proliferative activity of REG on leukemia cell lines, and flow cytometric analysis was used to detect REG‑induced apoptosis. In addition, western blot analysis was conducted to detect the levels of apoptosis‑related proteins including, cytochrome c, cleaved (c)‑caspases‑3 and ‑9, B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated protein x (Bax). Finally, a HL‑60 cell xenograft model in nude mice was used to evaluate the antitumor effect of REG on leukemia in vivo. The present results indicated that REG can significantly inhibit the proliferation of HL‑60, Jurkat and U937 cell lines in a concentration‑ and time‑dependent manner. The half maximal inhibitory concentration values were 38.4, 49.1 and 48.2 µg/ml for HL‑60, Jurkat and U937 cells, respectively. Furthermore, flow cytometric analysis demonstrated that REG can induce the apoptosis of HL‑60 cells, as well as increase the levels of cytochrome c, c‑caspases‑3 and ‑9, and Bax, as well as downregulate the expression of Bcl‑2. In vivo, REG was found to possess a marked anticancer effect on leukemia. In combination, the present results indicated that REG exerts significant anticancer effects on leukemia in vivo and in vitro through the induction of apoptosis.

Dandelion Extracts Protect Human Skin Fibroblasts from UVB Damage and Cellular Senescence

Ultraviolet (UV) irradiation causes damage in skin by generating excessive reactive oxygen species (ROS) and induction of matrix metalloproteinases (MMPs), leading to skin photoageing. Dandelion extracts have long been used for traditional Chinese medicine and native American medicine to treat cancers, hepatitis, and digestive diseases; however, less is known on the effects of dandelion extracts in skin photoageing. Here we found that dandelion leaf and flower extracts significantly protect UVB irradiation-inhibited cell viability when added before UVB irradiation or promptly after irradiation. Dandelion leaf and flower extracts inhibited UVB irradiation-stimulated MMP activity and ROS generation. Dandelion root extracts showed less action on protecting HDFs from UVB irradiation-induced MMP activity, ROS generation, and cell death. Furthermore, dandelion leaf and flower but not root extracts stimulated glutathione generation and glutathione reductase mRNA expression in the presence or absence of UVB irradiation. We also found that dandelion leaf and flower extracts help absorb UVB irradiation. In addition, dandelion extracts significantly protected HDFs from H₂O₂-induced cellular senescence. In conclusion, dandelion extracts especially leaf and flower extracts are potent protective agents against UVB damage and H₂O₂-induced cellular senescence in HDFs by suppressing ROS generation and MMP activities and helping UVB absorption.

20-(s)-ginsenoside Rg3 induces apoptotic cell death in human leukemic U937 and HL-60 cells through PI3K/Akt pathways

Leukemia is currently one of the most deadly diseases. Ginseng has been used in Asian countries for the treatment and prevention of various diseases, including leukemia, but the molecular mechanism of its antileukemia activity has not been well defined. The aim of this study was to explore the effect of 20-(s)-ginsenoside Rg3 on apoptosis in human leukemic U937 and HL-60 cells and the underlying mechanism. We found that 20-(s)-ginsenoside Rg3 reduced cell viability and induced apoptosis in U937 and HL-60 cells. The induction of apoptosis was accompanied by the downregulation of PI3K/Akt family proteins. Moreover, we observed that 20-(s)-ginsenoside Rg3 treatment resulted in activation of caspase-3 and caspase-9. Taken together, our findings suggest for the first time that 20-(s)-ginsenoside Rg3 can promote apoptosis in U937 and HL-60 cells, at least partly through the downregulation of PI3K/Akt family proteins. Moreover, the triggering of caspase-3 and caspase-9 activation mediated apoptotic induction. All these findings collectively demonstrate that the natural compound 20-(s)-ginsenoside Rg3 effectively induces apoptosis in human leukemic cells, which suggests that this compound may play a role in future therapies for leukemia.

Anticancer effect of celastrol on human triple negative breast cancer: possible involvement of oxidative stress, mitochondrial dysfunction, apoptosis and PI3K/Akt pathways

Signaling via the phosphatidylinositol-3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) is crucial for divergent physiological processes including transcription, translation, cell-cycle progression and apoptosis. The aim of work was to elucidate the anti-cancer effect of celastrol and the signal transduction pathways involved. Cytotoxic effect of celastrol was assessed by MTT assay on human triple negative breast cancer cells (TNBCs) and compared with that of MCF-7. Apoptosis induction was determined by AO/EtBr staining, mitochondrial membrane potential by JC-1, Annexin binding assays and modulation of apoptotic proteins and its effect on PI3K/Akt/mTOR pathway by western blotting. Celastrol induced apoptosis in TNBC cells, were supported by DNA fragmentation, caspase-3 activation and PARP cleavage. Meanwhile, celastrol triggered reactive oxygen species production with collapse of mitochondrial membrane potential, down-regulation of Bcl-2 and up-regulation of Bax expression. Celastrol effectively decreased PI3K 110α/85α enzyme activity, phosphorylation of Akt(ser473) and p70S6K1 and 4E-BP1. Although insulin treatment increased the phosphorylation of Akt(ser473), p70S6K1, 4E-BP1, celastrol abolished the insulin mediated phosphorylation. It clearly indicates that celastrol acts through PI3k/Akt/mTOR axis. We also found that celastrol inhibited the Akt/GSK3β and Akt/NFkB survival pathway. PI3K/Akt/mTOR inhibitor, PF-04691502 and mTOR inhibitor rapamycin enhanced the apoptosis-inducing effect of celastrol. These data demonstrated that celastrol induces apoptosis in TNBC cells and indicated that apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway.

The effect of five Taraxacum species on in vitro and in vivo antioxidant and antiproliferative activity

Differences between antioxidant and cytotoxic activities have been found among five Taraxacum species.

Internet claims on dietary and herbal supplements in advanced nephropathy: truth or myth

BACKGROUND

The use of complementary/alternative medicine has garnered rising interest in recent years. Natural products including herbs, vitamins, and minerals are the most popularly consumed. The Internet is a ubiquitous source of information/market for these supplements.

AIM

To systematically evaluate the dietary and herbal supplement recommended for patients with CKD and ESRD on the Internet, and try to distinguish between the claim of the manufacturer and proven scientific data.

METHODS

A questionnaire assessing each website was formulated. Each product ingredient was recorded in the questionnaire by two independent reviewers and statistically analyzed.

RESULTS

Of the 184 websites, 28% claimed to decrease CKD progression, 60% did not advise to consult a doctor before taking the supplement, and >90% did not mention any potential drug interaction, disease interaction, or caution in use during pregnancy or in children. The ten common plant ingredients claiming to be beneficial in kidney diseases were uva ursi, dandelion, parsley, corn silk, juniper, celery, buchu, horsetail, marshmallow, and stinging nettle. In contrast to their claims, these substances were not adequately studied in humans. The available animal studies showed detrimental effects and potential drug interactions with commonly used medications in the CKD/ESRD population.

CONCLUSIONS

Nephrologists need to be cognizant of the lack of substantiated proven benefits of these substances and of the potential adverse effects in the animal models that can translate to the patients. Most importantly, the policy needs to change regarding the regulation of these products to prevent patient harm and misinformation.

Annona muricata leaves induced apoptosis in A549 cells through mitochondrial-mediated pathway and involvement of NF-κB

BACKGROUND

Annona muricata leaves have been reported to have antiproliferative effects against various cancer cell lines. However, the detailed mechanism has yet to be defined. The current study was designed to evaluate the molecular mechanisms of A. muricata leaves ethyl acetate extract (AMEAE) against lung cancer A549 cells.

METHODS

The effect of AMEAE on cell proliferation of different cell lines was analyzed by MTT assay. High content screening (HCS) was applied to investigate the suppression of NF-κB translocation, cell membrane permeability, mitochondrial membrane potential (MMP) and cytochrome c translocation from mitochondria to cytosol. Reactive oxygen species (ROS) formation, lactate dehydrogenase (LDH) release and activation of caspase-3/7, -8 and -9 were measured while treatment. The western blot analysis also carried out to determine the protein expression of cleaved caspase-3 and -9. Flow cytometry analysis was used to determine the cell cycle distribution and phosphatidylserine externalization. Quantitative PCR analysis was performed to measure the gene expression of Bax and Bcl-2 proteins.

RESULTS

Cell viability analysis revealed the selective cytotoxic effect of AMEAE towards lung cancer cells, A549, with an IC50 value of 5.09 ± 0.41 μg/mL after 72 h of treatment. Significant LDH leakage and phosphatidylserine externalization were observed in AMEAE treated cells by fluorescence analysis. Treatment of A549 cells with AMEAE significantly elevated ROS formation, followed by attenuation of MMP via upregulation of Bax and downregulation of Bcl-2, accompanied by cytochrome c release to the cytosol. The incubation of A549 cells with superoxide dismutase and catalase significantly attenuated the cytotoxicity caused by AMEAE, indicating that intracellular ROS plays a pivotal role in cell death. The released cytochrome c triggered the activation of caspase-9 followed by caspase-3. In addition, AMEAE-induced apoptosis was accompanied by cell cycle arrest at G0/G1 phase. Moreover, AMEAE suppressed the induced translocation of NF-κB from cytoplasm to nucleus.

CONCLUSIONS

Our data showed for the first time that the ethyl acetate extract of Annona muricata inhibited the proliferation of A549 cells, leading to cell cycle arrest and programmed cell death through activation of the mitochondrial-mediated signaling pathway with the involvement of the NF-kB signalling pathway.

Piperlongumine, an alkaloid causes inhibition of PI3 K/Akt/mTOR signaling axis to induce caspase-dependent apoptosis in human triple-negative breast cancer cells

The phosphatidylinositol 3-kinase (PI3 K)/Akt/mammalian target of rapamycin (mTOR) signaling axis plays a central role in cell proliferation, growth and survival under physiological conditions. However, aberrant PI3 K/Akt/mTOR signaling has been implicated in many human cancers, including human triple negative breast cancer. Therefore, dual inhibitors of PI3 K/Akt and mTOR signaling could be valuable agents for treating breast cancer. The objective of this study was to investigate the effect of piperlongumine (PPLGM), a natural alkaloid on PI3 K/Akt/mTOR signaling, Akt mediated regulation of NF-kB and apoptosis evasion in human breast cancer cells. Using molecular docking studies, we found that PPLGM physically interacts with the conserved domain of PI3 K and mTOR kinases and the results were comparable with standard dual inhibitor PF04691502. Our results demonstrated that treatment of different human triple-negative breast cancer cells with PPLGM resulted in concentration- and time-dependent growth inhibition. The inhibition of cancer cell growth was associated with G1-phase cell cycle arrest and down-regulation of the NF-kB pathway leads to activation of the mitochondrial apoptotic pathway. It was also found that PPLGM significantly decreased the expression of p-Akt, p70S6K1, 4E-BP1, cyclin D1, Bcl-2, p53 and increased expression of Bax, cytochrome c in human triple-negative breast cancer cells. Although insulin treatment increased the phosphorylation of Akt (Ser473), p70S6K1, 4E-BP1, PPLGM abolished the insulin mediated phosphorylation, it clearly indicates that PPLGM acts through PI3 k/Akt/mTOR axis. Our results suggest that PPLGM may be an effective therapeutic agent for the treatment of human triple negative breast cancer.

Nutraceuticals and regulation of adipocyte life: premises or promises

Obesity is the actual worldwide health threat, that is associated with an increased number of metabolic disorders and diseases. Following the traditional hypothesis stating that in obesity hypertrophic adipocytes trigger the adipose tissue hyperplasia, strategies to treat obesity have increased fat researches of the molecular processes that achieve adipocyte enlargement and formation that finally increase body fat mass. Moreover, a new cell type was recently identified, the "brite" adipocyte that presents a unique gene expression profile of compared to both brown and white adipocytes. Therapies against obesity, targeting these cells and their pathways, would include the induction of lipolysis and apoptosis or the inhibition of differentiation and adipogenesis. However, it should be noted that both the increase of adipocyte size and number take place in association with positive energy balance. According to the adipose tissue expansion hypothesis, adipogenesis could be related with improved metabolic health of obese people, taking back the adipose mass to a traditionally site of lipid storage. Furthermore, new perspectives in fat biology suggest that the conversion of white-to-brown adipocytes and their metabolism could be exploited for the development of therapeutic approaches against obesity-associated diseases and for the regulation of energy balance. Drugs currently available to treat obesity generally have unpleasant side effects. A novel promising approach is the usage of dietary supplements and plant products that could interfere on the life cycle of adipocyte. Here, various dietary bioactive compounds that target different stages of adipocyte life cycle and molecular and metabolic pathways are reviewed.

Apoptogenic activity of ethyl acetate extract of leaves of Memecylon edule on human gastric carcinoma cells via mitochondrial dependent pathway

OBJECTIVE

To evaluate the anti-proliferative and apoptogenic activity of ethyl acetate extract from the leaves of Memecylon edule (EtAc-LME) in MKN-74, NUGC gastric cancer cells and non cancerous gastric mucous cells (GES-1), and to explore the mechanism of EtAc-LME induced apoptosis.

METHODS

The mechanism of EtAc-LME induced apoptosis was explored by analysing the activation of pro-caspases, PARP cleavage, expression of cytochrome-c (Cyt-c) was determined by western blotting, mRNA expression of Bcl-2, Bax by RT-PCR, loss of mitochondrial potential using DiOC6 dye, annexin binding assay and its influence on cell cycle arrest by flow cytometry.

RESULTS

The results indicated that EtAc-LME inhibited the gastric cancer cell growth in dose-dependent manner and cytotoxicity was more towards the gastric cancer cells (NUGC and MKN-74) compared to normal gastric cells (GES-1), suggesting more specific cytotoxicity to the malignant cells. Over expression of Cyt-c and subsequent activation of caspases-3 and down regulation of Bcl-2 and loss in mitochondrial potential in EtAc-LME treated MKN-74 and NUGC cells suggested that EtAc-LME induced apoptosis by mitochondrial dependent pathway.

CONCLUSIONS

The present findings suggest that ethyl acetate extract of Memecylon edule induces apoptosis selectively in gastric cancer cells emphasizing the importance of this traditional medicine for its potential in the treatment of gastric cancer.

Searching in mother nature for anti-cancer activity: anti-proliferative and pro-apoptotic effect elicited by green barley on leukemia/lymphoma cells

Green barley extract (GB) was investigated for possible anti-cancer activity by examining its anti-proliferative and pro-apoptotic properties on human leukemia/lymphoma cell lines. Our results indicate that GB exhibits selective anti-proliferative activity on a panel of leukemia/lymphoma cells in comparison to non-cancerous cells. Specifically, GB disrupted the cell-cycle progression within BJAB cells, as manifested by G2/M phase arrest and DNA fragmentation, and induced apoptosis, as evidenced by phosphatidylserine (PS) translocation to the outer cytoplasmic membrane in two B-lineage leukemia/lymphoma cell lines. The pro-apoptotic effect of GB was found to be independent of mitochondrial depolarization, thus implicating extrinsic cell death pathways to exert its cytotoxicity. Indeed, GB elicited an increase of TNF-α production, caspase-8 and caspase-3 activation, and PARP-1 cleavage within pre-B acute lymphoblastic leukemia Nalm-6 cells. Moreover, caspase-8 and caspase-3 activation and PARP-1 cleavage were strongly inhibited/blocked by the addition of the specific caspase inhibitors Z-VAD-FMK and Ac-DEVD-CHO. Furthermore, intracellular signaling analyses determined that GB treatment enhanced constitutive activation of Lck and Src tyrosine kinases in Nalm-6 cells. Taken together, these findings indicate that GB induced preferential anti-proliferative and pro-apoptotic signals within B-lineage leukemia/lymphoma cells, as determined by the following biochemical hallmarks of apoptosis: PS externalization, enhanced release of TNF-α, caspase-8 and caspase-3 activation, PARP-1 cleavage and DNA fragmentation Our observations reveal that GB has potential as an anti-leukemia/lymphoma agent alone or in combination with standard cancer therapies and thus warrants further evaluation in vivo to support these findings.

A novel cysteine-rich antifungal peptide ToAMP4 from Taraxacum officinale Wigg. flowers

A novel peptide named ToAMP4 was isolated from Taraxacum officinale Wigg. flowers by a combination of acetic acid extraction and different types of chromatography: affinity, size-exclusion, and RP-HPLC. The amino acid sequence of ToAMP4 was determined by automated Edman degradation. The peptide is basic, consists of 41 amino acids, and incorporates three disulphide bonds. Due to the unusual cysteine spacing pattern, ToAMP4 does not belong to any known plant AMP family, but classifies together with two other antimicrobial peptides ToAMP1 and ToAMP2 previously isolated from the dandelion flowers. To study the biological activity of ToAMP4, it was successfully produced in a prokaryotic expression system as a fusion protein with thioredoxin. The recombinant peptide was shown to be identical to the native ToAMP4 by chromatographic behavior, molecular mass, and N-terminal amino acid sequence. The peptide displays broad-spectrum antifungal activity against important phytopathogens. Two ToAMP4-mediated inhibition strategies depending on the fungus were demonstrated. The results obtained add to our knowledge on the structural and functional diversity of AMPs in plants.

Golden berry-derived 4β-hydroxywithanolide E for selectively killing oral cancer cells by generating ROS, DNA damage, and apoptotic pathways

Background

Most chemotherapeutic drugs for killing cancer cells are highly cytotoxic in normal cells, which limits their clinical applications. Therefore, a continuing challenge is identifying a drug that is hypersensitive to cancer cells but has minimal deleterious effects on healthy cells. The aims of this study were to evaluate the potential of 4β-hydroxywithanolide (4βHWE) for selectively killing cancer cells and to elucidate its related mechanisms.

Methodology and Principal Findings

Changes in survival, oxidative stress, DNA damage, and apoptosis signaling were compared between 4βHWE-treated oral cancer (Ca9-22) and normal fibroblast (HGF-1) cells. At 24 h and 48 h, the numbers of Ca9-22 cells were substantially decreased, but the numbers of HGF-1 cells were only slightly decreased. Additionally, the IC₅₀ values for 4βHWE in the Ca9-22 cells were 3.6 and 1.9 µg/ml at 24 and 48 h, respectively. Time-dependent abnormal increases in ROS and dose-responsive mitochondrial depolarization can be exploited by using 4βHWE in chemotherapies for selectively killing cancer cells. Dose-dependent DNA damage measured by comet-nuclear extract assay and flow cytometry-based γ-H2AX/propidium iodide (PI) analysis showed relatively severer damage in the Ca9-22 cells. At both low and high concentrations, 4βHWE preferably perturbed the cell cycle in Ca9-22 cells by increasing the subG1 population and arrest of G1 or G2/M. Selective induction of apoptosis in Ca9-22 cells was further confirmed by Annexin V/PI assay, by preferential expression of phosphorylated ataxia-telangiectasia- and Rad3-related protein (p-ATR), and by cleavage of caspase 9, caspase 3, and poly ADP-ribose polymerase (PARP).

Conclusions/Significance

Together, the findings of this study, particularly the improved understanding of the selective killing mechanisms of 4βHWE, can be used to improve efficiency in killing oral cancer cells during chemoprevention and therapy.

Improvement of andropause symptoms by dandelion and rooibos extract complex CRS-10 in aging male

Many aging male suffer various andropause symptoms including loss of physical and mental activities. This study evaluated the putative alleviative effects of CRS-10 dandelion and rooibos extract complex (CRS-10) on the symptoms of andropause. The survival rate of TM3 Leydig cells (TM3 cells) treated with CRS-10 was measured based on typical physiological stress. After daily intake of CRS-10 for 4 weeks, the level of testosterone, physical activity and both the number and activity of sperm in older rats (18 weeks) were measured. Furthermore, thirty males were surveyed with AMS (Aging Males' Symptoms) questionnaire after intake of 400 mg of CRS-10. Overall, CRS-10 protected TM3 cells from serum restriction and oxidative stress via activation of ERK and Akt pathways. The level of testosterone and activation of spermatogenesis in rats were significantly enhanced. In addition, physical locomotion was markedly improved. Daily intake of 400 mg of CRS-10 improved the quality of life among agingmale respondents, according to a clinical survey using the AMS. The results indicate the potential of CRS-10 as a safe and efficacious natural substance for reducing or alleviating andropause symptoms.

Selective induction of apoptosis and autophagy through treatment with dandelion root extract in human pancreatic cancer cells

OBJECTIVES

Pancreatic cancer has a 100% mortality rate; the aim of this study is to evaluate the efficacy of dandelion root extract (DRE) in inducing apoptosis and autophagy in aggressive and resistant pancreatic cancer cells.

METHODS

The effect of DRE was evaluated using WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate) assay. Apoptotic cell death was confirmed by nuclear condensation by Hoechst staining and externalization of phosphatidylserine to the outer leaflet of the plasma membrane by Annexin-V binding assay. Loss of mitochondrial membrane potential was observed using the JC-1 (5,5',6, 6'-tetrachloro-1,1',3,3' tetraethylbenzimidazolylcarbocyanine iodide) dye. The induction of autophagy was detected using a monodansylcadaverine assay and this was confirmed by immunofluorescence for light chain 3-II.

RESULTS

BxPC-3 and PANC-1 pancreatic cells were sensitive to aqueous DRE. This extract induces selective apoptosis in a dose- and time-dependent manner. Dandelion root extract caused the collapse of the mitochondrial membrane potential, leading to prodeath autophagy. Normal human fibroblasts were resistant at similar doses.

CONCLUSIONS

We demonstrate that DRE has the potential to induce apoptosis and autophagy in human pancreatic cancer cells with no significant effect on noncancerous cells. This will provide a basis on which further research in cancer treatment through DRE can be executed.

The peptide derived from the Ig-like domain of human herpesvirus 8 K1 protein induces death in hematological cancer cells

BACKGROUND

Although significant progress has been made in the treatment of lymphomas, many lymphomas exhibit resistance to cell death, suggesting a defective Fas signaling, which remains poorly understood. We previously reported that cells expressing the K1 protein of human herpesvirus 8 (HHV-8) resist death through the complex formation of the Ig-like domain of K1 with Fas. Recently, we investigated whether peptides derived from the Ig-like domain of the K1 protein may affect cell death.

METHODS

K1 positive and negative cell lines were incubated with the K1-derived peptides, and cell death (apoptotic and necrotic) was assessed by flow cytometry and LDH assay. Activation of caspases was assessed by fluorometric assay and flow cytometry. Fas receptor-independent, peptide-mediated cell killing was tested in the Fas-resistant Daudi cell line and Jurkat cell clones deficient in caspase-8 and FADD functionality. Activation of TNF receptors I and II was blocked by pre-incubation with corresponding blocking antibodies. The effect of the K1 peptide in vivo was tested in a mouse xenograft model.

RESULTS

We observed that the peptide S20-3 enhanced cell death in K1-positive BJAB cells and HHV-8 positive primary effusion lymphoma (PEL) cell lines. Similar effects of this peptide were observed in B-cell lymphoma and T-lymphoblastic leukemia cells without K1 expression but not in normal human peripheral blood mononuclear cells. A single intratumoral injection of the S20-3 peptide decreased the growth of Jurkat xenografts in SCID mice. The mechanism of tumor cell death induced by the S20-3 peptide was associated with activation of caspases, but this activity was only partially inhibited by the pan-caspase inhibitor z-VAD. Furthermore, the K1 peptide also killed Fas-resistant Daudi cells, and this killing effect was inhibited by pre-incubation of cells with antibodies blocking TNFRI.

CONCLUSION

Taken together, these findings indicate that the S20-3 peptide can selectively induce the death of malignant hematological cell lines by Fas- and/or TNFRI-dependent mechanisms, suggesting the K1-derived peptide or peptidomimetic may have promising therapeutic potential for the treatment of hematological cancers.

Diverse biological activities of dandelion

Dandelion (Taraxacum officinale Weber) is a member of the Asteraceae (Compositae) family, native to Europe but widely distributed in the warmer temperate zones of the Northern Hemisphere. Dandelion and its parts are habitually consumed as plant foods in several areas of the world, where they are also employed in phytotherapy. Indeed, dandelion contains a wide array of phytochemicals whose biological activities are actively being explored in various areas of human health. In particular, emerging evidence suggests that dandelion and its constituents have antioxidant and anti-inflammatory activities that result in diverse biological effects. The present review provides a comprehensive analysis of the constituents of dandelion, an assessment of the pharmacological properties of dandelion, and a description of relevant studies that support the use of dandelion as a medicinal plant.

Purification and differential biological effects of ginger-derived substances on normal and tumor cell lines

This study describes an optimization of [6]-, [8]- and [10]-gingerol isolation and purification in semi-preparative HPLC scale and their anti-proliferative activity. The gingerols purification was carried out in HPLC system using a Luna-C₁₈ and the best mobile phase evaluated was MeOH/H₂O (75:25, v/v). This new methodology for the gingerols isolation was very effective, since considerable amounts (in the range of milligrams) with a good purity degree (∼98%) were achieved in 30 min of chromatographic run. [6]-, [8]- and [10]-Gingerol purified by this methodology inhibited the proliferation of MDA-MB-231 tumor cell line with IC₅₀ of 666.2±134.6 μM, 135.6±22.6 μM and 12.1±0.3 μM, respectively. These substances also inhibited human fibroblasts (HF) cell proliferation, however in concentrations starting from 500 μM. In conclusion, our results demonstrate an optimization of gingerols isolation and their specific anti-proliferative activities against tumor cells, suggesting their use as important models for drug design in an attempt to develop new compounds with fewer side effects when compared to conventional chemotherapy.

Efficient induction of extrinsic cell death by dandelion root extract in human chronic myelomonocytic leukemia (CMML) cells

Background

Chronic Myelomonocytic Leukemia (CMML) is a heterogeneous disease that is not only hard to diagnose and classify, but is also highly resistant to treatment. Available forms of therapy for this disease have not shown significant effects and patients rapidly develop resistance early on in therapy. These factors lead to the very poor prognosis observed with CMML patients, with median survival duration between 12 and 24 months after diagnosis. This study is therefore centered around evaluating the selective efficacy of a natural extract from dandelion roots, in inducing programmed cell death in aggressive and resistant CMML cell lines.

Methodology/Principal Findings

To confirm the induction of programmed cell death in three human CMML cell lines, nuclear condensation and externalization of the phosphatidylserine, two main characteristics of apoptosis, were detected using Hoechst staining and annexin-V binding assay. The induction of another mode of cell death, autophagy, was determined using a monodansylcadaverine (MDC) stain, to detect the formation of autophagy vacuoles. The results from this study indicate that Dandelion Root Extract (DRE) is able to efficiently and selectively induce apoptosis and autophagy in these cell lines in a dose and time dependent manner, with no significant toxicity on non-cancerous peripheral blood mononuclear cells. More importantly, we observed early activation of initiator caspase-8, which led to mitochondrial destabilization and the induction of autophagy, suggesting that DRE acts through the extrinsic pathway of apoptosis. The inability of DRE to induce apoptosis in dominant-negative FADD cells, confirms the mechanism of action of DRE in in vitro models of CMML.

Conclusion

The results from this study indicate that natural products, in particular Dandelion Root Extract, have great potential, as non-toxic and effective alternatives to conventional modes of chemotherapy available today.

Selective cytotoxicity against human osteosarcoma cells by a novel synthetic C-1 analogue of 7-deoxypancratistatin is potentiated by curcumin

The natural compound pancratistatin (PST) is a non-genotoxic inducer of apoptosis in a variety of cancers. It exhibits cancer selectivity as non-cancerous cells are markedly less sensitive to PST. Nonetheless, PST is not readily synthesized and is present in very low quantities in its natural source to be applied clinically. We have previously synthesized and evaluated several synthetic analogues of 7-deoxypancratistatin, and found that JC-TH-acetate-4 (JCTH-4), a C-1 acetoxymethyl analogue, possessed similar apoptosis inducing activity compared to PST. In this study, notoriously chemoresistant osteosarcoma (OS) cells (Saos-2, U-2 OS) were substantially susceptible to JCTH-4-induced apoptosis through mitochondrial targeting; JCTH-4 induced collapse of mitochondrial membrane potential (MMP), increased reactive oxygen species (ROS) production in isolated mitochondria, and caused release of apoptosis inducing factor (AIF) and endonuclease G (EndoG) from isolated mitochondria. Furthermore, JCTH-4 selectively induced autophagy in OS cells. Additionally, we investigated the combinatory effect of JCTH-4 with the natural compound curcumin (CC), a compound found in turmeric spice, previously shown to possess antiproliferative properties. CC alone had no observable effect on Saos-2 and U-2 OS cells. However, when present with JCTH-4, CC was able to enhance the cytotoxicity of JCTH-4 selectively in OS cells. Such cytotoxicity by JCTH-4 alone and in combination with CC was not observed in normal human osteoblasts (HOb) and normal human fetal fibroblasts (NFF). Therefore, this report illustrates a new window in combination therapy, utilizing a novel synthetic analogue of PST with the natural compound CC, for the treatment of OS.

Anti-influenza virus effect of aqueous extracts from dandelion

BACKGROUND

Human influenza is a seasonal disease associated with significant morbidity and mortality. Anti-flu Traditional Chinese Medicine (TCM) has played a significant role in fighting the virus pandemic. In TCM, dandelion is a commonly used ingredient in many therapeutic remedies, either alone or in conjunction with other natural substances. Evidence suggests that dandelion is associated with a variety of pharmacological activities. In this study, we evaluated anti-influenza virus activity of an aqueous extract from dandelion, which was tested for in vitro antiviral activity against influenza virus type A, human A/PR/8/34 and WSN (H1N1).

RESULTS

Results obstained using antiviral assays, minigenome assay and real-time reverse transcription-PCR analysis showed that 0.625-5 mg/ml of dandelion extracts inhibited infections in Madin-Darby canine kidney (MDCK) cells or Human lung adenocarcinoma cell line (A549) of PR8 or WSN viruses, as well as inhibited polymerase activity and reduced virus nucleoprotein (NP) RNA level. The plant extract did not exhibit any apparent negative effects on cell viability, metabolism or proliferation at the effective dose. This result is consistent with the added advantage of lacking any reported complications of the plant's utility in traditional medicine over several centuries.

CONCLUSION

The antiviral activity of dandelion extracts indicates that a component or components of these extracts possess anti-influenza virus properties. Mechanisms of reduction of viral growth in MDCK or A549 cells by dandelion involve inhibition on virus replication.

Inhibitory effect of aqueous Dandelion extract on HIV-1 replication and reverse transcriptase activity

BACKGROUND

Acquired immunodeficiency syndrome (AIDS), which is caused by the human immunodeficiency virus (HIV), is an immunosuppressive disease that results in life-threatening opportunistic infections. The general problems in current therapy include the constant emergence of drug-resistant HIV strains, adverse side effects and the unavailability of treatments in developing countries. Natural products from herbs with the abilities to inhibit HIV-1 life cycle at different stages, have served as excellent sources of new anti-HIV-1 drugs. In this study, we aimed to investigate the anti-HIV-1 activity of aqueous dandelion extract.

METHODS

The pseudotyped HIV-1 virus has been utilized to explore the anti-HIV-1 activity of dandelion, the level of HIV-1 replication was assessed by the percentage of GFP-positive cells. The inhibitory effect of the dandelion extract on reverse transcriptase activity was assessed by the reverse transcriptase assay kit.

RESULTS

Compared to control values obtained from cells infected without treatment, the level of HIV-1 replication and reverse transcriptase activity were decreased in a dose-dependent manner. The data suggest that dandelion extract has a potent inhibitory activity against HIV-1 replication and reverse transcriptase activity. The identification of HIV-1 antiviral compounds from Taraxacum officinale should be pursued.

CONCLUSIONS

The dandelion extract showed strong activity against HIV-1 RT and inhibited both the HIV-1 vector and the hybrid-MoMuLV/MoMuSV retrovirus replication. These findings provide additional support for the potential therapeutic efficacy of Taraxacum officinale. Extracts from this plant may be regarded as another starting point for the development of an antiretroviral therapy with fewer side effects.