Breast Cancer: A Global Concern, Diagnostic and Therapeutic Perspectives, Mechanistic Targets in Drug Development.

Cancer is a complex multifactorial process, unchecked and abrupt division, and cell growth-conventional chemotherapy, along with radiotherapy, is used to treat breast cancer. Due to reduce efficacy and less survival rate, there is a particular need for the discovery of new active anticancer agents. Natural resources such as terrestrial/marine plants or organisms are a promising source for the generation of new therapeutics with improving efficacy. The screening of natural plant extracts and fractions, isolations of phytochemicals, and mechanistic study of those potential compounds play a remarkable role in the development of new therapeutic drugs with increased efficacy. Cancer is a multistage disease with complex signaling cascades. The initial study of screening whole extracts or fractions and later the isolation of secondary compounds and their mechanism of action study gives a clue of potential therapeutic agents for future drug development. The phytochemicals present in extracts/fractions produce remarkable effects due to synergistically targeting multiple signals. In this review, the molecular targets of extracts/ fractions and isolated compounds highlighted. The therapeutic agent's mechanistic targets in drug development focused involves; i) Induction of Apoptosis, ii) modulating cell cycle arrest, iii) Inhibition or suppression of invasion and metastasis and iv) various other pro-survival signaling pathways. The phytochemicals and their modified analogs identified as future potential candidates for anticancer chemotherapy.

Xylocarpus Moluccensis Induces Cytotoxicity in Human Hepatocellular Carcinoma HepG2 Cell Line via Activation of the Extrinsic Pathway.

OBJECTIVE: Liver cancer is one of the most common causes of cancer death, with reduced survival rates. The development of new chemotherapeutic agents is essential to find effective cytotoxic drugs that give minimum side effects to the surrounding healthy tissues. The main objective of the present study was to evaluate the cytotoxic effects and mechanism of cell death induced by the crude and diethyl ether extract of Xylocarpus mouccensis on the human hepatocellular carcinoma cell line. METHODS: The cytotoxicity activity was measured using the MTS assay. The mode of cell death determined by the apoptosis study, DNA fragmentation analysis done by using the TUNEL system. The pathway study or mechanism of apoptosis observed by study caspases 8, 9, 3/7 Glo-caspases method. RESULTS: In this study, the methanol extracts prepared from leaf Xylocarpus mouccensis leaf produced cytotoxicity effect with IC50 (72hr) < 30µg/ml. The IC50 value at 72 hours exerted by diethyl ether extract of Xylocarpus moluccensis leaf was 0.22 µg/ml, which was more cytotoxic than to that of crude methanol extract. The results obtained by the colorimetric TUNEL system suggest that methanol crude extract of Xylocarpus moluccensis (leaf), diethyl ether extract of Xylocarpus moluccensis (leaf) and methanol extract of Xylocarpus granatum (bark) induced DNA fragmentation in the HepG2 cell line. Besides, the caspase-Glo assay demonstrated that diethyl ether leaf extract of Xylocarpus moluccensis triggered apoptotic cell death via activation of caspases -8, and -3/7 However, no visible activation was noticed for caspase -9. Furthermore, TLC indicates the presence of potential metabolites in an extract of Xylocarpus moluccensis. CONCLUSION: Thus, the present study suggests the remarkable potential of active metabolites in the extract of Xylocarpus moluccensis as a future therapeutic agent for the treatment of cancer.
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Acute application of Centella asiatica extract enhanced AMPAR-mediated postsynaptic currents in rat entorhinal cortex.

Centella asiatica is notable for its wide range of biological activities beneficial to human health, particularly its cognitive enhancement and neuroprotective effects. The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors are ionotropic glutamate receptors mediating fast excitatory neurotransmission essential in long-term potentiation widely thought to be the cellular mechanism of learning and memory. The method of whole-cell patch-clamp was used to study the effect of the acute application of Centella asiatica extract on the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-mediated spontaneous excitatory postsynaptic currents in the entorhinal cortex of rat brain slices. The respective low dose of test compounds significantly increased the amplitude of spontaneous excitatory postsynaptic currents while having no significant effects on the frequency. The findings suggested that Centella asiatica extract increased the response of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors at the postsynaptic level, revealing the potential role of Centella asiatica in modulating the glutamatergic responses in the entorhinal cortex of rat brain slices to produce cognitive enhancement effects.

Antihypercholesterolemic and antiatherosclerotic potencies of Pandanus tectorius fruits via increasing scavenger receptor-B1 genes expression and inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity.

Atherosclerosis is a leading cause of death worldwide. The adverse side effects of currently available drugs urge to find more effective and safe remedial agents. Alternative candidates from natural resources are of great consequence in the emerging of new drugs. Pandanus tectorius (Pandanaceae) was traditionally used in Ayurvedic medicine to cure certain diseases. Thus, the current study conducted to elucidate the potency of P. tectorius fruit as antiatherosclerosis and antihypercholesterolemia agents through the regulation of high density lipoprotein (HDL) receptor (scavenger receptor [SR]-B1) gene expression and 3-hydroxy-3-methylglutaryl coenzyme A reductase reductase (HMGCR) in vitro, respectively. The P. tectorius fruit was noncytotoxic against the HepG2 cell line confirmed by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide assay. The P. tectorius fruit successfully upregulates the SR-B1 gene expression and downregulate the HMGCR. Moreover, an in vivo study showed that P. tectorius has good activity on the upregulation of HDL and subsequently downregulation of total cholesterol level. Moreover, P. tectorius fruit did not show any increase in toxicity biomarkers serum glutamic oxaloacetic transaminase and serum glutamate pyruvate transaminase in vivo. These results found that P. tectorius fruits have potency as the preventive agent for hypercholesterolemia and atherosclerosis via SR-B1 and HMGCR mechanisms of action.

Vitex Rotundifolia Fractions Induced Apoptosis in Human Breast Cancer T-47D Cell Line via Activation of Extrinsic and Intrinsic Pathway.

OBJECTIVE: Breast cancer is the most frequently diagnosed cancer worldwide. The main objective of the present study was to evaluate the cytotoxic effects and mechanism of cell death induced by the extract and fractions of Vitex rotundifolia (leaves) in breast cancer cell line, T-47D. METHODS: The cytotoxicity activity was measured using MTS assay. The mode of cell death was analysed by early (phosphatidylserine externalization) and late apoptosis (DNA fragmentation). The caspases 8, 9, 3/7 and apoptotic proteins bax, bcl-2 study were done by western blot and ELISA method. RESULTS: The methanol extract was found to inhibit 50% growth of T-47D cells at the concentration of 79.43µg/ml respectively after 72hr. From seven fractions, fraction F1, F2 and F3 produced cytotoxicity effects in T-47D cell line with IC50 (72hr) < 30µg/ml. The results obtained by Annexin V/PI apoptosis detection assay and TUNEL assay suggest that active fractions of  Vitex rotundifolia induced early and late apoptosis (DNA fragmentation) in T-47D cell line. Moreover, western blot analysis and Caspase GloTM luminescent assay demonstrated that fractions F2 and F3 triggered apoptotic cell death via activation of caspases -8, -9 and -3/7 and up-regulation of  Bax and down-regulation of Bcl-2 protein.  Furthermore, chemical profiling confirms the presence of potential metabolites (vitexicarpin) in fractions of Vitex rotundifolia. CONCLUSION: Thus, the present study suggests the remarkable potential of active metabolites in fractions of Vitex rotundifolia as future cancer therapeutic agent for the treatment of breast cancer.
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16-Hydroxycembra-1,3,7,11-tetraene, a new Cembrane Diterpene from Malaysian Soft Coral Genus Sarcophyton.

One new cembrane diterpene, 16-hydroxycembra-1,3,7,11-tetraene (1), along with three known compounds, 15-hydroxycembra-1,3,7,11-tetraene (2), sarcophine (3) and sarcophytoxide (4) were isolated from Sarcophyton sp. collected from Karah Island, Terengganu, West Malaysia. Their structures were elucidated based on spectroscopic data. Activities of these compounds against antibacterial resistant clinical bacteria are reported. Only 1 exhibited inhibition against Staphylococcus aureus.

Potent PPARγ Ligands from Swietenia macrophylla Are Capable of Stimulating Glucose Uptake in Muscle Cells.

Numerous documented ethnopharmacological properties have been associated with Swietenia macrophylla (Meliaceae), with its seed extract reported to display anti-hypoglycemic activities in diabetic rats. In the present study, three compounds isolated from the seeds of S. macrophylla were tested on a modified ELISA binding assay and showed to possess PPARγ ligand activity. They were corresponded to PPARγ-mediated cellular response, stimulated adipocyte differentiation but produced lower amount of fat droplets compared to a conventional anti-diabetic agent, rosiglitazone. The up-regulation of adipocytes was followed by increased adipocyte-related gene expressions such as adiponectin, adipsin, and PPARγ. The S. macrophylla compounds also promoted cellular glucose uptake via the translocation of GLUT4 glucose transporter.

Growth inhibition of human liver carcinoma HepG2 cells and α-glucosidase inhibitory activity of Murdannia bracteata (C.B. Clarke) Kuntze ex J.K. Morton extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: The juice of the entire fresh herb and infusion of dried sample of Murdannia bracteata are consumed to treat liver cancer and diabetes in Malaysia. However, no scientific evidence of these bioactivities has been reported. MATERIALS AND METHODS: To verify the therapeutic potentials of sequential extracts and infusion of this plant by determining its cytotoxicity against human liver carcinoma HepG2 cells and α-glucosidase inhibitory activity. The cytotoxic activities of the extracts against HepG2 were determined using a methylene blue assay, and an α-glucosidase inhibitory assay was used to assess anti-diabetic activity. The molecular basis of the anti-hepatocellular carcinoma activity of the most active extract was determined using RT-PCR. Chemical profiling of the most active extract was performed using GC-MS and UPLC analyses. RESULTS: The results obtained from the cytotoxic screening revealed the dose-dependent growth inhibition of the HepG2 cells by only the hexane extract, with an EC50 value of 37.17±1.00 µg/ml. The HepG2 cell death was found to be apoptotic in nature and based on the significant biphasic induction of caspase-3, suggesting that the extract inhibited cell growth through a caspase-3-dependent pathway. The hexane extract also displayed α-glucosidase inhibitory activity, with an EC50 of 117.04±2.34 µg/ml. GC-MS analysis revealed that α-tocopherol was the major volatile compound in the hexane extract, and two phenolics (apigenin and caffeic acid derivatives) were detected using UPLC. CONCLUSIONS: Based on various published reports, it could be suggested that α-tocopherol and apigenin derivatives might be involved in the apoptosis-based cytotoxicity of the active extract of this plant against HepG2 carcinoma cells. The effects of this plant in the treatment of diabetes can be related to the presence of α-glucosidase inhibitors, such as the caffeic acid derivative identified in the active extract.

Physalin F from Physalis minima L. triggers apoptosis-based cytotoxic mechanism in T-47D cells through the activation caspase-3- and c-myc-dependent pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Physalin F (a secosteroid derivative), is well recognized as a potent anticancer compound from Physalis minima L., a plant that is traditionally used to treat cancer. However, the exact molecular anticancer mechanism remains to be elucidated. AIM OF THE STUDY: We have recently reported the apoptosis-based cytotoxic effect of the chloroform extract of this plant. Here, we investigated the cytotoxicity and possible cell death mechanism elicited by the active constituent, physalin F on human breast T-47D carcinoma. MATERIALS AND METHODS: Cytotoxic-guided fractionation of the chloroform extract of Physalis minima has led to the isolation of physalin F. The cytotoxicity activity was assayed using MTS assay. The effect of the compound to induce apoptosis was determined by biochemical and morphological observations through DeadEnd Colorimetric and annexin V assays, respectively, and RT-PCR analysis of mRNA expression of the apoptotic-associated genes. RESULTS: Cytotoxicity screening of physalin F displayed a remarkable dose-dependent inhibitory effect on T-47D cells with lower EC50 value (3.60 µg/ml) than the crude extract. mRNA expression analysis revealed the co-regulation of c-myc- and caspase-3-apoptotic genes in the treated cells with the peak expression at 9 and 12h of treatment, respectively. This apoptotic mechanism is reconfirmed by DNA fragmentation and phosphatidylserine externalization. CONCLUSION: These findings indicate that physalin F may potentially act as a chemopreventive and/or chemotherapeutic agent by triggering apoptosis mechanism via the activation of caspase-3 and c-myc pathways in T-47D cells.

The ribosomal protein L19 mRNA is induced by copper exposure in the swordtail fish, Xiphophorus helleri.

Teleosts are useful vertebrate model species for understanding copper toxicity due to the dual entry route for copper intake via the gills and intestine. In this present study, we utilized the differential display reverse transcription-polymerase chain reaction to isolate potential novel hepatic genes induced by sublethal copper exposure in the freshwater swordtail fish, Xiphophorus helleri. Full length cloning of a cDNA fragment induced by copper exposure to 1 µg/ml during 24 h resulted in the positive identification of a hepatic ribosomal protein L19 (RPL19) gene. Further characterization of this gene revealed that its transcriptional expression was dependent on dosage and time of copper exposure. This study describes for the first time the involvement of RPL19 in copper toxicity, probably as a result of increase in ribosome synthesis rate to support activities such as cellular protein translation, transcriptional activation and mRNA stabilization during sublethal copper exposure.

Identification of genes involved in the regulation of 14-deoxy-11,12-didehydroandrographolide-induced toxicity in T-47D mammary cells.

14-Deoxy-11,12-didehydroandrographolide is one of the principle compounds of the medicinal plant, Andrographis paniculata Nees. This study explored the mechanisms of 14-deoxy-11,12-didehydroandrographolide-induced toxicity and non-apoptotic cell death in T-47D breast carcinoma cells. Gene expression analysis revealed that 14-deoxy-11,12-didehydroandrographolide exerted its cytotoxic effects by regulating genes that inhibit the cell cycle or promote cell cycle arrest. This compound regulated genes that are known to reduce/inhibit cell proliferation, induce growth arrest and suppress cell growth. The growth suppression activities of this compound were demonstrated by a downregulation of several genes normally found to be over-expressed in cancers. Microscopic analysis revealed positive monodansylcadaverine (MDC) staining at 8h, indicating possible autophagosomes. TEM analysis revealed that the treated cells were highly vacuolated, thereby suggesting that 14-deoxy-11,12-didehydroandrographolide may cause autophagic morphology in these cells. This morphology may be correlated with the concurrent expression of genes known to affect lysosomal activity, ion transport, protein degradation and vesicle transport. Interestingly, some apoptotic-like bodies were found, and these bodies contained multiple large vacuoles, suggesting that this compound is capable of eliciting a combination of apoptotic and autophagic-like morphological characteristics.

Swietenia macrophylla extract promotes the ability of Caenorhabditis elegans to survive Pseudomonas aeruginosa infection.

ETHNOPHARMACOLOGICAL RELEVANCE: Swietenia macrophylla or commonly known as big leaf mahogany, has been traditionally used as an antibacterial and antifungal agent. AIM OF THE STUDY: The unwanted problem of antibiotic resistance in many bacterial species advocates the need for the discovery of the new anti-infective drugs. Here, we investigated the anti-infective properties of Swietenia macrophylla with an assay involving lethal infection of Caenorhabditis elegans with the opportunistic human pathogen Pseudomonas aeruginosa. MATERIALS AND METHODS: Using a slow killing assay, Caenorhabditis elegans was challenged with an infective strain of Pseudomonas aeruginosa (PA14). The ability of Swietenia macrophylla seed ethyl acetate extract to promote the survival of infected worms was assessed by comparing the percentage of survival between extract treated and non-treated worm populations. The effect of Swietenia macrophylla towards PA14 growth, Caenorhabditis elegans feeding rate and degree of PA14 colonization in the worm gut was also evaluated. Lastly, using a fluorescent transgenic Caenorhabditis elegans strain and real time PCR, the effect of Swietenia macrophylla on the expression of lys-7, an immune response gene was also investigated. RESULTS: Our results demonstrate the ability of Swietenia macrophylla seed ethyl acetate extract in rescuing Caenorhabditis elegans from fatal PA14 infection. Consequently, we showed that the extract promotes the survival without exhibiting any bactericidal effect or perturbation of Caenorhabditis elegans feeding rate. We also showed that Swietenia macrophylla was able to restore the initially repressed lys-7 level in PA14 infected Caenorhabditis elegans. CONCLUSION: Swietenia macrophylla extract is able to enhance the ability of Caenorhabditis elegans to survive PA14 infection without directly killing the pathogen. We further showed that the extract boosted the expression of a gene pivotal for innate immunity in Caenorhabditis elegans. Collectively, these findings strongly suggest the presence of compounds within Swietenia macrophylla seed that either reduces Pseudomonas aeruginosa virulence and/or enhance host resistance.

Cytotoxic, apoptotic and anti-α-glucosidase activities of 3,4-di-O-caffeoyl quinic acid, an antioxidant isolated from the polyphenolic-rich extract of Elephantopus mollis Kunth.

ETHNOPHARMACOLOGICAL RELEVANCE: The decoction of the whole plant of Elephantopus mollis Kunth. is traditionally consumed to treat various free radical-mediated diseases including cancer and diabetes. AIM OF THE STUDY: This study was initiated to determine whether the most effective antioxidant compound isolated from the whole plant of Elephantopus mollis can also contribute to its claimed traditional values as anticancer and antidiabetes agents. MATERIALS AND METHODS: An active antiradical phenolic compound (3,4-di-O-caffeoyl quinic acid) was isolated from the methanol extract (with the highest in polyphenolic content) and their antioxidant activities were compared using four different assays, that are DPPH, FRAP, metal chelating, and ß-carotene bleaching tests. The compound was also evaluated for its cytotoxic activity, apoptotic induction and anti-glucosidase efficacies using methylene blue, DeadEnd™ assay and α-glucosidase assays, respectively. RESULTS: The compound acted as a greater primary antioxidant than its methanol extract, by having higher ferric reducing activity (EC(50) 2.18±0.05 µg/ml), ß-carotene bleaching activity (EC(50) 23.85±0.65 µg/ml) and DPPH scavenging activity (EC(50) 68.91±5.44µg/ml), whereas the methanol extract exhibited higher secondary antioxidant activity as a metal chelator with lower EC(50) value (49.39±3.68 µg/ml) than the compound. Cytotoxicity screening of this compound exhibited a remarkable dose-dependent inhibitory effect on NCI-H23 (human lung adenocarcinoma) cell lines (EC(50) 3.26±0.35 µg/ml) and was found to be apoptotic in nature based on a clear indication of DNA fragmentation. This compound also displayed a concentration-dependent α-glucosidase inhibition with EC(50) 241.80±14.29 µg/ml. CONCLUSIONS: The findings indicate the major role of 3,4-di-O-caffeoyl quinic acid to antioxidant capacities of Elephantopus mollis extracts. The compound also exerted apoptosis-mediated cytotoxicity and α-glucosidase inhibitory effects and is thus a promising non toxic agent in treating cancer and type 2 diabetes mellitus.

Cytotoxic Activities of Physalis minima L. Chloroform Extract on Human Lung Adenocarcinoma NCI-H23 Cell Lines by Induction of Apoptosis.

Physalis minima L. is reputed for having anticancer property. In this study, the chloroform extract of this plant exhibited remarkable cytotoxic activities on NCI-H23 (human lung adenocarcinoma) cell line at dose- and time-dependent manners (after 24, 48 and 72 h of incubation). Analysis of cell-death mechanism demonstrated that the extract exerted apoptotic programed cell death in NCI-H23 cells with typical DNA fragmentation, which is a biochemical hallmark of apoptosis. Morphological observation using transmission electron microscope (TEM) also displayed apoptotic characteristics in the treated cells, including clumping and margination of chromatins, followed by convolution of the nuclear and budding of the cells to produce membrane-bound apoptotic bodies. Different stages of apoptotic programed cell death as well as phosphatidylserine externalization were confirmed using annexin V and propidium iodide staining. Furthermore, acute exposure to the extract produced a significant regulation of c-myc, caspase-3 and p53 mRNA expression in this cell line. Due to its apoptotic effect on NCI-H23 cells, it is strongly suggested that the extract could be further developed as an anticancer drug.

Growth arrest and induction of apoptotic and non-apoptotic programmed cell death by, Physalis minima L. chloroform extract in human ovarian carcinoma Caov-3 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The decoction of the whole plant of Physalis minima L. is traditionally consumed to treat cancer. Its anticancer property has been previously verified (using in vitro cytotoxicity assays) against NCI-H23 lung, CORL23 lung and MCF7 breast cancer cell lines but the mechanism underlying the anticancer potency towards ovarian carcinoma cells remain unclear. AIM OF THE STUDY: The present study is aimed to systematically determine the cytotoxicity and possible cell death mechanism elicited by the chloroform extract of Physalis minima in human ovarian Caov-3 carcinoma. MATERIALS AND METHODS: Cytotoxicity of the extract was measured using the methylene blue assay. The mechanism of cell death was determined using four independent methods, namely DeadEnd assay to label the DNA fragmentation nuclei cells, RT-PCR analysis to determine the mRNA expression level of three apoptotic genes (c-myc, p53 and caspase-3 genes), Transmission Electron Microscope (TEM) analysis to describe the ultra structural characteristics and annexin V and propidium iodide staining to confirm the types and stages of cell deaths. RESULTS: Cytotoxicity screening of the extract on Caov-3 cells exhibited concentration- and time-dependent inhibitory effects. A combination of apoptotic and autophagic programmed cell death was detected. The apoptotic characteristic was initially determined by DNA fragmentation followed by the expression of c-myc and p53 genes that was much earlier than caspase-3. Apoptotic ultra structural changes (including clumping and magination of chromatin, blebbing and convolution of nucleus membrane and formation of apoptotic bodies) and autophagy (Type II non-apoptotic programmed cell death) with distinct vacuolated morphology were detected in TEM analysis. The existence of these programmed cell deaths was then corroborated using annexin V and propidium iodide staining. CONCLUSIONS: The chloroform extract of Physalis minima exerted anticancer effect due to a combination of apoptotic and autophagic cell death mechanisms on Caov-3 cells. The induction of these programmed cell deaths was mediated via c-myc, p53 and caspase-3 dependent pathway. The results could provide a valuable insight in cancer therapy.