Natural products for cancer chemotherapy

Antibacterial and anticancer activities of orphan biosynthetic gene clusters from Atlantis II Red Sea brine pool

BACKGROUND

Cancer and infectious diseases are problematic because of continuous emergence of drug resistance. One way to address this enormous global health threat is bioprospecting the unlikeliest environments, such as extreme marine niches, which have tremendous biodiversity that is barely explored. One such environment is the Red Sea brine pool, Atlantis II Deep (ATII). Here, we functionally screened a fosmid library of metagenomic DNA isolated from the ATII lower convective layer (LCL) for antibacterial and anticancer activities.

RESULTS

Selected clones, 14-7E and 10-2G, displayed antibacterial effects on the marine strain Bacillus sp. Cc6. Moreover, whole cell lysates from 14-7E and 10-2G exhibited decreased cell viability against MCF-7 (39.1% ± 6.6, 42% ± 8.1 at 50% v/v) and U2OS cells (35.7% ± 1.9, 79.9% ± 5.9 at 50% v/v), respectively. By sequencing the insert DNA from 14-7E and 10-2G, we identified two putative orphan biosynthetic gene clusters. Both clusters harbored putative ATP-binding cassette (ABC) transporter permeases and S-adenosylmethionine-related genes. Interestingly, the biosynthetic gene cluster identified on 14-7E is of archaeal origin and harbors a putative transcription factor. Several identified genes may be responsible for the observed antibacterial and anticancer activities. The 14-7E biosynthetic gene cluster may be encoding enzymes producing a specialized metabolite (effect of detected genes involved in C-C bond formation and glycosylation). The bioactivity may also be due to predicted subtilases encoded by this cluster. The 10-2G cluster harbored putative glycosyltransferase and non-ribosomal peptide synthase genes; thus the observed activity of this clone could be caused by a bioactive peptide.

CONCLUSIONS

The ATII LCL prokaryotic metagenome hosts putative orphan biosynthetic gene clusters that confer antibiotic and anticancer effects. Further biochemical studies should characterize the detected bioactive components, and the potential use of 14-7E metabolite for antibiosis and 10-2G metabolite as a selective anti-breast cancer drug.

Two new endophytic Colletotrichum species from Nothapodytespittosporoides in China

Two new endophytic species, Colletotrichumjishouense sp. nov. and. C.tongrenense sp. nov. were isolated from Nothapodytespittosporoides in Guizhou and Hunan provinces, China. Detailed descriptions and illustrations of these new taxa are provided and morphological comparisons with similar taxa are explored. Phylogenetic analysis with combined sequence data (ITS, GAPDH, ACT and TUB2) demonstrated that both species formed distinct clades in this genus. This is the first record of Colletotrichum species from N.pittosporoides in China.

Bioactive molecules from Nocardia: diversity, bioactivities and biosynthesis

Nocardia spp. are catalase positive, aerobic, and non-motile Gram-positive filamentous bacteria. Many Nocarida spp. have been reported as unusual causes of diverse clinical diseases in both humans and animals. Therefore, they have been studied for a long time, primarily focusing on strain characterization, taxonomic classification of new isolates, and host pathophysiology. Currently, there are emerging interests in isolating bioactive molecules from diverse actinobacteria including Nocardia spp. and studying their biosynthetic mechanisms. In addition, these species possess significant metabolic capacity, which has been utilized for generating diverse functionalized bioactive molecules by whole cell biotransformation. This review summarizes the structural diversity and biological activities of compounds biosynthesized or biotransformed by Nocardia spp. Furthermore, the recent advances on biosynthetic mechanisms and genetic engineering approaches for enhanced production or structural/functional modification are presented.

Novel 2-(5-Imino-5H-isoquinolones[3,4-b]quinoxalin-7-ylmethyl)-benzonitrile () and Other Related Derivatives Targeting Colon Cancer Cells: Syntheses and in Vitro Models

Chemotherapy has been shown to be effective in reducing the progression and development of cancer in metastatic patients. However, drug selectivity is still a major issue for most chemotherapeutics. In this study, we synthesized four novel heterocyclic compounds having similarity in structure with quinone systems whereby nitrogen atoms replace the oxygen atoms. The anticancer activity of these compounds (DIQ3-6) was tested against HCT116 human colon cancer cells. We showed that all four heterocycles caused significant reduction in colon cancer cell viability at doses as low as 4 μM, a concentration that was not cytotoxic to normal human FHs74Int intestinal cell lines. Interestingly, these heterocycles inhibited colon sphere formation in 3D cultures at first generation (G₁), mainly because of inhibition of proliferation as evidenced by Ki67 staining. Thus, DIQ3 causes sufficient eradication of the self-renewal ability of the highly resistant cancer stem cells. This study represents the first documentation of the activity of these novel heterocyclic compounds, particularly compound DIQ3, and their potential therapeutic use in targeting colon cancer self-renewal capacity. Our findings provide the basis for proposing these nontoxic and stable compounds for additional testing against cancer.

Microwave-Assisted Extraction of Multiple Trace Levels of Intermediate Metabolites for Camptothecin Biosynthesis in Camptotheca acuminata and Their Simultaneous Determination by HPLC-LTQ-Orbitrap-MS/MS and HPLC-TSQ-MS

Camptothecin (CPT) has strong antitumor activity and is used as an anticancer therapeutic agent. To better understand and decipher the pathway of CPT biosynthesis in Camptotheca acuminata, the main purpose here was focused on creating an effective extraction strategy for a rich intermediate metabolite profile. In the present study, a 70% aqueous acetonitrile was verified as an optimal extraction solvent for microwave-assisted extraction (MAE) of metabolites by spiking experiments. Based on multi-objective optimization, the best extraction conditions of a solid-liquid ratio of 1:20, microwave power of 230 W, and a time of 4 min were achieved using a full factorial 3⁴ experimental design. Crude extracts obtained from the shoot apex of C. acuminata using MAE have been qualitatively profiled by high-performance liquid chromatography coupled with linear ion trap quadrupole-orbitrap mass spectrometry (HPLC-LTQ-Orbitrap-MS/MS) and a HPLC triple quadrupole-MS (HPLC-TSQ-MS) analysis was conducted for their metabolite content in different tissues. CPT, and ten related metabolites and their isomers, including tryptamine, loganic acid, secologanic acid, strictosidinic acid, strictosamide, strictosamide epoxide, strictosamide diol, strictosamide ketolactam, pumiloside, and deoxypumiloside, were detected and tentatively identified. Scanning electron microscopy (SEM) imaging of the shoot apex demonstrated that severe cell disruption was evident after intensified extraction processes. The study showed the difference of metabolite profiles and the enhancement of metabolite content after microwave-pretreated techniques, and the established MAE procedure is an effective methodology to preserve valuable metabolite compounds for analysis.

Genipin Enhances the Therapeutic Effects of Oxaliplatin by Upregulating BIM in Colorectal Cancer

Despite an increase in the survival rate of patients with cancer owing to the use of current chemotherapeutic agents, adverse effects of cancer therapies remain a concern. Combination therapies have been developed to increase efficacy, reduce adverse effects, and overcome drug resistance. Genipin is a natural product derived from Gardenia jasminoides, which has been associated with anti-inflammatory, anti-angiogenic, and anti-proliferative effects; hypertension; and anti-ischemic brain injuries. However, the enhancement of oxaliplatin sensitivity by genipin remains unexplored. Our study showed that a combination of genipin and oxaliplatin exerts synergistic antitumor effects in vitro and in vivo in colorectal cancer cell lines through the reactive oxygen species (ROS)/endoplasmic reticulum (ER) stress/BIM pathway. Importantly, the combination did not affect normal colon cells. BIM knockdown markedly inhibited apoptosis induced by the combination. In addition, genipin induced ROS by inhibiting superoxide dismutase 3 activity. These findings suggest that genipin may be a novel agent for increasing the sensitivity of oxaliplatin against colorectal cancer. The combination of oxaliplatin and genipin hold significant therapeutic potential with minimal adverse effects.

In vitro and in vivo toxicity assessment of biologically synthesized silver nanoparticles from Elaeodendron croceum

Background The cytotoxic properties of nanoparticles have attracted a great deal of attention in the field of nanoscience and nanotechnology due to their small size and ability to penetrate cellular membranes. Methods The silver nanoparticles were synthesized using Elaeodendron croceum stem bark and characterized. The oral acute toxicity studies were carried out by administration of 500, 1000, 2000 mg/kg body weight to Wister rats in respective groups. An in vitro cytotoxicity assay was evaluated in MDA-MB-231 breast cancer cells using the WST-1 Cell Proliferation assay. The percentage of cell viability after treatment with aqueous extracts of Elaeodendron croceum (ECE) and Elaeodendron croceum silver nanoparticles (ECAgNPs) was compared with that of paclitaxel. Results The in vivo studies revealed that the LD50 was higher than 2000 mg/kg and there was no significant difference (p>0.05) between the treatment groups compared with the control group for mean organ-to-body weight ratio except in the liver and in all hematological parameters except WBC and hematocrit. Similarly, there was no significant difference (p>0.05) for serum electrolytes (Na+, Mg2+ K+, Cl-, and Ca2+), total protein, urea, ɣ-glutamyl transferase (GGT), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP), Alanine aminotransferase (ALT), albumin, total and conjugated bilirubin between the treatment and the control group. However, there were changes in creatinine, urea, and cholesterol. In the in vitro assays, ECE and ECAgNPs showed IC50 values of 70.87±2.99 and 138.8±3.98 µg/mL respectively against MDA-MB-231 cells compared to paclitaxel, which showed an IC50 value of 80 ng/mL. Conclusion The results showed that the LD50 of the ECE and ECAgNPs in Wister rats was determined to be greater than 2000 mg/kg body weight. The aqueous extract also showed more cytotoxic than the ECAgNPs suggesting that the toxic compounds in aqueous extract were involved in the capping of the AgNPs.

Natural product inspired allicin analogs as novel anti-cancer agents

A series of novel analogs of Allicin (S-allyl prop-2-ene-1-sulfinothioate) present in garlic has been synthesized in high yield. Synthesized 23 compounds were evaluated against different breast cancer cells (MDA-MB-468 and MCF-7) and non-cancer cells (WI38). Four compounds (3f, 3h, 3m and 3u) showed significant cytotoxicity against cancer cells whereas nontoxic to the normal cells. Based on the LD₅₀ values and selectivity index (SI), compound 3h (S-p-methoxybenzyl (p-methoxyphenyl)methanesulfinothioate) was considered as most promising anticancer agent amongst the above three compounds. Further bio-chemical studies confirmed that compound 3h promotes ROS generation, changes in mitochondrial permeability transition and induced caspase mediated DNA damage and apoptosis.

Anticancer effect of nor-wogonin (5, 7, 8-trihydroxyflavone) on human triple-negative breast cancer cells via downregulation of TAK1, NF-κB, and STAT3

BACKGROUND

Nor-wogonin, a polyhydroxy flavone, has been shown to possess antitumor activity. However, the mechanisms responsible for its antitumor activity are poorly studied. Herein, we investigated the mechanisms of nor-wogonin actions in triple-negative breast cancer (TNBC) cells.

METHODS

Effects of nor-wogonin on cell proliferation and viability of four TNBC cell lines (MDA-MB-231, BT-549, HCC70, and HCC1806) and two non-tumorigenic breast cell lines (MCF-10A and AG11132) were assessed by BrdU incorporation assays and trypan blue dye exclusion tests. Cell cycle and apoptosis analyses were carried out by flow cytometry. Protein expression was analyzed by immunoblotting.

RESULTS

Nor-wogonin significantly inhibited the growth and decreased the viability of TNBC cells; however, it exhibited no or minimal effects in non-tumorigenic breast cells. Nor-wogonin (40 μM) was a more potent anti-proliferative and cytotoxic agent than wogonin (100 μM) and wogonoside (100 μM), which are structurally related to nor-wogonin. The antitumor effects of nor-wogonin can be attributed to cell cycle arrest via reduction of the expression of cyclin D1, cyclin B1, and CDK1. Furthermore, nor-wogonin induced mitochondrial apoptosis, (as evidenced by the increase in % of cells that are apoptotic), decreases in the mitochondrial membrane potential (ΔΨm), increases in Bax/Bcl-2 ratio, and caspase-3 cleavage. Moreover, nor-wogonin attenuated the expression of the nuclear factor kappa-B and activation of signal transducer and activator of transcription 3 pathways, which can be correlated with suppression of transforming growth factor-β-activated kinase 1 in TNBC cells.

CONCLUSION

These results showed that nor-wogonin might be a potential multi-target agent for TNBC treatment.

3, 9-di-O-substituted coumestrols incorporating basic amine side chains act as novel apoptosis inducers with improved pharmacological selectivity

There is much interest in the use of phytoestrogens such as coumestrol in breast cancer intervention due to their antiestrogenic activity and multiple modes of tumor cell death. However, the clear beneficial effects of naturally occurring estrogen mimetic coumestrol remain controversial due to experimental evidence that it has been shown to stimulate MCF-7 cell proliferation via agonist effect on estrogen receptor at low concentration. Herein, to disconnect the ER interaction and apoptosis-specific mechanism of coumestrol, various 3, 9-di-O-substituted coumestrols (7a-7e) and their furan ring-opened analogs (5a-5e) were synthesized and assessed for antiproliferative properties. Attachment of a dimethylamine-containing side chain to 3-O of coumestrol led to the most promising compound 7e with improved antiproliferative activity (1.7-fold increase) against MCF-7 cells, decreased estrogen activity (>20 times weaker ERα binder) and a novel action to induce apoptosis. Mechanistic studies revealed that 7e is a tubulin polymerization inhibitor, which could arrest cell cycle at G2/M phase and induce apoptosis along with the decrease of mitochondrial membrane potential. In summary, such subtle modifications to the 3, 9-di-hydroxyl groups of coumestrol allow the generation of a novel apoptosis inducer with distinct pharmacological properties, providing an excellent starting point to future development of novel tumor-vascular disrupting agents targeting tubulin.

Zerumbone, a cyclic sesquiterpene, exerts antimitotic activity in HeLa cells through tubulin binding and exhibits synergistic activity with vinblastine and paclitaxel

Objectives

The aim of this study was to elucidate the antimitotic mechanism of zerumbone and to investigate its effect on the HeLa cells in combination with other mitotic blockers.

Materials and methods

HeLa cells and fluorescence microscopy were used to analyse the effect of zerumbone on cancer cell lines. Cellular internalization of zerumbone was investigated using FITC‐labelled zerumbone. The interaction of zerumbone with tubulin was characterized using fluorescence spectroscopy. The Chou and Talalay equation was used to calculate the combination index.

Results

Zerumbone selectively inhibited the proliferation of HeLa cells with an IC₅₀ of 14.2 ± 0.5 μmol/L through enhanced cellular uptake compared to the normal cell line L929. It induced a strong mitotic block with cells exhibiting bipolar spindles at the IC₅₀ and monopolar spindles at 30 μmol/L. Docking analysis indicated that tubulin is the principal target of zerumbone. In vitro studies indicated that it bound to goat brain tubulin with a Kd of 4 μmol/L and disrupted the assembly of tubulin into microtubules. Zerumbone and colchicine had partially overlapping binding site on tubulin. Zerumbone synergistically enhanced the anti‐proliferative activity of vinblastine and paclitaxel through augmented mitotic block.

Conclusion

Our data suggest that disruption of microtubule assembly dynamics is one of the mechanisms of the anti‐cancer activity of zerumbone and it can be used in combination therapy targeting cell division.

A bacterial DNA repair pathway specific to a natural antibiotic

All organisms possess DNA repair pathways that are used to maintain the integrity of their genetic material. Although many DNA repair pathways are well understood, new pathways continue to be discovered. Here, we report an antibiotic specific DNA repair pathway in Bacillus subtilis that is composed of a previously uncharacterized helicase (mrfA) and exonuclease (mrfB). Deletion of mrfA and mrfB results in sensitivity to the DNA damaging agent mitomycin C, but not to any other type of DNA damage tested. We show that MrfAB function independent of canonical nucleotide excision repair, forming a novel excision repair pathway. We demonstrate that MrfB is a metal-dependent exonuclease and that the N-terminus of MrfB is required for interaction with MrfA. We determined that MrfAB failed to unhook interstrand cross-links in vivo, suggesting that MrfAB are specific to the monoadduct or the intrastrand cross-link. A phylogenetic analysis uncovered MrfAB homologs in diverse bacterial phyla, and cross-complementation indicates that MrfAB function is conserved in closely related species. B. subtilis is a soil dwelling organism and mitomycin C is a natural antibiotic produced by the soil bacterium Streptomyces lavendulae. The specificity of MrfAB suggests that these proteins are an adaptation to environments with mitomycin producing bacteria.

Antrodia cinnamomea induces autophagic cell death via the CHOP/TRB3/Akt/mTOR pathway in colorectal cancer cells

Antrodia cinnamomea, a well-known traditional medicine used in Taiwan, is a potent anticancer drug for colorectal cancer, but the upstream molecular mechanism of its anticancer effects remains unclear. In this study, A. cinnamomea extracts showed cytotoxicity in HCT116, HT29, SW480, Caco-2 and, Colo205 colorectal cancer cells. Whole-genome expression profiling of A. cinnamomea extracts in HCT116 cells was performed. A. cinnamomea extracts upregulated the expression of the endoplasmic reticulum stress marker CHOP and its downstream gene TRB3. Moreover, dephosphorylation of Akt and mTOR as well as autophagic cell death were observed. Gene expression and autophagic cell death were reversed by the knockdown of CHOP and TRB3. Autophagy inhibition but not apoptosis inhibition reversed A. cinnamomea-induced cell death. Finally, we demonstrated that A. cinnamomea extracts significantly suppressed HCT116 tumour growth in nude mice. Our findings suggest that autophagic cell death via the CHOP/TRB3/Akt/mTOR pathway may represent a new mechanism of anti-colorectal cancer action by A. cinnamomea. A. cinnamomea is a new CHOP activator and potential drug that can be used in colorectal cancer treatment.

Molecular targets of curcumin in breast cancer (Review)

Curcumin (diferuloylmethane), an orange‑yellow component of turmeric or curry powder, is a polyphenol natural product isolated from the rhizome of Curcuma longa. For centuries, curcumin has been used in medicinal preparations and as a food colorant. In recent years, extensive in vitro and in vivo studies have suggested that curcumin possesses activity against cancer, viral infection, arthritis, amyloid aggregation, oxidation and inflammation. Curcumin exerts anticancer effects primarily by activating apoptotic pathways in cancer cells and inhibiting pro‑cancer processes, including inflammation, angiogenesis and metastasis. Curcumin targets numerous signaling pathways associated with cancer therapy, including pathways mediated by p53, Ras, phosphatidylinositol‑3‑kinase, protein kinase B, Wnt‑β catenin and mammalian target of rapamycin. Clinical studies have demonstrated that curcumin alone or combined with other drugs exhibits promising anticancer activity in patients with breast cancer without adverse effects. In the present review, the chemistry and bioavailability of curcumin and its molecular targets in breast cancer are discussed. Future research directions are discussed to further understand this promising natural product.

Establishment of in vitro and in vivo anti-colon cancer efficacy of essential oils containing oleo-gum resin extract of Mesua ferrea

Proven the great potential of essential oils as anticancer agents, the current study intended to explore molecular mechanisms responsible for in vitro and in vivo anti-colon cancer efficacy of essential oil containing oleo-gum resin extract (RH) of Mesua ferrea. MTT cell viability studies showed that RH had broad spectrum cytotoxic activities. However, it induced more profound growth inhibitory effects towards two human colon cancer cell lines i.e., HCT 116 and LIM1215 with an IC₅₀ values of 17.38 ± 0.92 and 18.86 ± 0.80 μg/mL respectively. RH induced relatively less toxicity in normal human colon fibroblasts i.e., CCD-18co. Cell death studies conducted, revealed that RH induced characteristic morphological and biochemical changes in HCT 116. At protein level it down-regulated expression of multiple pro-survival proteins i.e., survivin, xIAP, HSP27, HSP60 and HSP70 and up-regulated expression of ROS, caspase-3/7 and TRAIL-R2 in HCT 116. Furthermore, significant reduction in invasion, migration and colony formation potential was observed in HCT 116 treated with RH. Chemical characterization by GC-MS and HPLC methods revealed isoledene and elemene as one the major compounds. RH showed potent antitumor activity in xenograft model. Overall, these findings suggest that RH holds a promise to be further studied for cheap anti-colon cancer naturaceutical development.

The venom of spider Haplopelma hainanum suppresses proliferation and induces apoptosis in hepatic cancer cells by caspase activation in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Spiders and spider venoms have been used in traditional Chinese medicine to treat various ailments for more than 1000 years. For instance, several large spiders have been utilized by the Li People, who mainly live in Hainan Island of China, in their own unique traditional Chinese medicine therapy. Recent studies have indicated that spider venoms may be an important source of bioactive compounds for anti-tumor treatments. However, the specific mechanisms underlying these activities are not yet completely understood.

AIM OF THE STUDY

The present study investigated how the venom of the spider Haplopelma hainanum regulate proliferation and apoptosis in HepG2 cells via the underlying molecular mechanisms.

MATERIALS AND METHODS

We treated HepG2 cells with various concentrations of the spider venom (0, 10, 50, 100 and 200 μg/mL) for 48 h, and then analyzed anti-proliferation activity, apoptosis-inducing effects, mitochondrial membrane potential (Δψm) and changes in the pro-apoptotic pathway. The anti-proliferation activity was detected by the MTT assay and Western blotting. Flow cytometry was used to analyze both apoptosis and mitochondrial membrane potential. The key pro-apoptotic molecules in the caspase-3 and -9 dependent mitochondrial pathway, including Bcl2 family, were assessed through realtime PCR, Western blotting and enzymatic test.

RESULTS

Obvious morphological changes induced by the spider venom included decreased cell numbers, shorter cell length and reduced cell adhesion. MTT and Western blotting demonstrated that the spider venom potently suppressed cell proliferation in a dose- and time-dependent manner with IC₅₀ of 126.00 μg/mL for 48 h. In addition, the spider venom caused a reduction in the mitochondrial membrane potential and cytochrome c release from mitochondria to cytoplasm under the participation of Bax. Finally, cytochrome c activated caspase-3 and caspase-9, and induced the apoptosis in the HepG2 cells.

CONCLUSION

The results indicated that the venom of H. hainanum exhibited potent inhibition effects in HepG2 cells through suppressing proliferation, reducing the mitochondrial membrane potential, activating caspase-3 and caspase-9, and inducing the apoptosis through a mitochondrial-dependent pathway.

Apoptosis Induction and Antimigratory Activity of Andrographolide Analog (3A.1)-Incorporated Self-Assembled Nanoparticles in Cancer Cells

Andrographolide analog, namely 19-tert-butyldiphenylsilyl-8,17-epoxy andrographolide (or 3A.1) has been reported to be a potential anticancer agent for several types of cancer. Due to its poor aqueous solubility, 3A.1 was incorporated within self-assembly polymeric nanoparticles made of naphthyl-grafted succinyl chitosan (NSC), octyl-grafted succinyl chitosan (OSC), and benzyl-grafted succinyl chitosan (BSC). These 3A.1-loaded nanoparticles were nanosized (< 200 nm) and spherical in shape with a negative surface charge. 3A.1-loaded nanoparticles were produced using a dropping method, which 40% initial drug adding exhibited the highest entrapment efficiency. The release of 3A.1 from the 3A.1-loaded nanoparticles displayed a delayed release pattern. Under acidic conditions (pH 1.2), there was no free drug release. After the pH was adjusted to 6.8, a high cumulative 3A.1 release was obtained which was dependent on the hydrophobic moieties. These 3A.1-loaded pH-sensitive nanoparticles proved to be beneficial for specifically delivering anticancer drugs to the targeted colon cancer sites. In vitro anticancer activity against HT-29 found that the 3A.1-loaded nanoparticles had significantly lower IC₅₀ than that of the free drug and promoted apoptosis. Additionally, in vitro wound-healing migration on HN-22 revealed that free 3A.1 and the 3A.1-loaded nanoparticles inhibited cell motility compared with untreated cells. These pH-sensitive amphiphilic chitosan nanoparticles may be promising nanocarriers for oral anticancer drug delivery to colorectal cancer cells. Graphical abstract ᅟ.

Attenuation of diethylnitrosamine (DEN) - Induced hepatic cancer in experimental model of Wistar rats by Carissa carandas embedded silver nanoparticles

OBJECTIVE

Hepatic cancer is well known, and leading cancer around the world and remain asymptomatic diseases. Carissa carandas possess anti-proliferative, antioxidant, hepatoprotective property and used in hepatic cancer. The current study deals to evaluate the chemoprotective and therapeutic property of Carissa carandas embedded silver nanoparticles (CCAgNPs) against diethylnitrosamine (DEN) -induced hepatic cancer.

MATERIAL AND METHOD

Wistar rats were divided into six groups and hepatic cancer was induced with diethylnitrosamine at the dose of 200 mg/kg BW. The animals were gastrogavaged with standard drug and CCAgNPs for 16 weeks. Serum biomarkers, haematological profile, antioxidants enzymes, inflammatory markers and membrane bound enzymes were assessed to find the anti-proliferative potential of silver nanoparticles. Histological evaluation and microscopic characterizations were also performed to authenticate the outcomes of the present work.

RESULTS

Biosynthesized CCAgNPs significantly down-regulated the serum marker enzymes of hepatic and non-hepatic parameter, elevated the levels of enzymatic and non-enzymatic antioxidant profile, elevation in membrane bound enzymes and diminish the levels of inflammatory markers (IL-6, TNF-α, and IL-1β) via NF-κB pathway. Histopathological features also showed recovery of a hepatic architecture in cancer-induced rats in a dose-dependent manner.

CONCLUSION

Our consequences established that such plant mediated silver nanoparticles shown a defensive impact against DEN-induced hepatocarcinogenesis, and serves as a better option to ameliorate the clinical results against hepatocellular carcinoma.

Screening for the selective inhibitors of MMP-9 from natural products based on pharmacophore modeling and molecular docking in combination with bioassay experiment, hybrid QM/MM calculation, and MD simulation

Matrix metalloproteinase-9 (MMP-9) has been considered as an attractive target involving cancer therapy. In this study, the 3D QSAR pharmacophore model of MMP-9 inhibitors is built, and its reliability is subsequently validated based on different methods. The built pharmacophore model consists of the four chemical features, including two hydrogen bond acceptors (HBA), one hydrophobic (HY), and one ring aromatic (RA). Among them, both HY and RA are found to be especially important features because they involve the interactions of inhibitors with the S1' pocket of MMP-9, which determines the selectivity of MMP-9 inhibitors. By combining pharmacophore model with molecular docking, the virtual screening is carried out to identify the selective MMP-9 inhibitors from natural products. The four potential selective MMP-9 inhibitors of natural products are found. One of them was used to carry out the bioassay experiment inhibiting MMP-9, and the estimated IC₅₀ value of only 26.94 µM clearly shows its strongly inhibitory activity; besides, both the hybrid quantum mechanics/molecular mechanics (QM/MM) calculation and the molecular dynamics simulation are performed to examine the reliability regarding the binding mode of this inhibitor with MMP-9 active sites predicted by molecular docking. All the screened four natural products are found to well bind with the MMP-9 active sites by different kinds of interactions. Finally, the ADMET properties of screened four natural products are assessed. These screened MMP-9 inhibitors of natural products could be used as the lead compounds to perform structural modifications and optimizations in the future work. Communicated by Ramaswamy H. Sarma.

Efficient syntheses and anti-cancer activity of xenortides A-D including ent/epi-stereoisomers

A one-pot, two-step, total synthesis of naturally occurring xenortides A, B, C and D, (Xens A-D) isolated from the bacterium Xenorhabdus nematophila, and an entire complementary set of stereoisomers, has been achieved. Compounds were synthesized utilizing an isocyanide-based Ugi 4-CR followed by facile N-Boc deprotection. The reaction sequence took advantage of the chiral pool of N-Boc protected amino acids (l-Leu/Val and d-Leu/Val) with aryl isocyanides, phenyl acetaldehyde and methylamine giving the desired Xens A-D (A and B >98% ee) and all subsequent stereoisomers in reasonable yields upon deprotection followed by separation of diastereomers. Also, detailed mechanistic insights for diastereoselectivity of (-)-Xen A, as a model in the Ugi 4-CR, has been described. Moreover, for the first time, this focused library was screened for cytotoxicity against a panel of epithelial cancer cell lines as well as normal cell lines with an MTT proliferation assay. The structure-activity relationship (SAR) study demonstrated that tryptamides Xen B and D were more active than phenylethylamides Xen A and C. Furthermore, (-)-Xen B (IC50 = 19-25 μM) and ent-(+)-Xen D (IC50 = 21-26 μM) gave the highest cytotoxicity and they were also found to be non-toxic toward normal cells. Importantly, the SAR results indicate that the stereochemistry at C8 and C11 in (-)-Xen B and ent-(+)-Xen D play a critical role in cytotoxic activity.

Optimization of the Cytotoxic Activity of Three Streptomyces Strains Isolated from Guaviare River Sediments (Colombia, South America)

Three Streptomyces strains isolated from Guaviare sediments (Colombia, South America) with cytotoxic activity against prostate cancer (PC3), breast cancer (MDA-MB-231), and lung cancer (A549) line cells were studied. The present investigation reveals the enhancement of the cytotoxic activity evaluating different values of pH, carbon sources (sucrose, glucose, xylose, maltose, and starch), and nitrogen sources (malt extract, yeast extract, meat extract, peptone, and potassium nitrate). Based on the response surface methodology, the isolates Streptomyces aburaviensis (73) had the maximum activity for lung cancer (IC50= 25.00 ± 1.86 ppm) with 4% of yeast extract, 3% of starch, and a pH value of 7. Streptomyces gramineus (386) had the maximum activity against prostate cancer (IC50= 6.14 ± 2.07 ppm) with 5% of malt extract, 3% of glucose, and a pH value of 6. Finally, Streptomyces psammoticus (519) had the maximum activity against breast cancer (IC50= 35.53 ± 2.71 ppm) with 1% of yeast extract, 4% of starch, and a pH 8. The results suggest that the ethyl acetate extracts from isolates Streptomyces aburaviensis (73), Streptomyces gramineus (386), and Streptomyces psammoticus (519) have a potential for use in pharmaceuticals as cytotoxic agents.

Carbon nanotubes in the delivery of anticancer herbal drugs

Cancer is estimated to be a significant health problem of the 21st century. The situation gets even tougher when it comes to its treatment using chemotherapy employing synthetic anticancer molecules with numerous side effects. Recently, there has been a paradigm shift toward the adoption of herbal drugs for the treatment of cancer. In this context, a suitable delivery system is principally warranted to deliver these herbal biomolecules specifically at the tumorous site. To achieve this goal, carbon nanotubes (CNTs) have been widely explored to deliver anticancer herbal molecules with improved therapeutic efficacy and safety. This review uniquely expounds the biopharmaceutical, clinical and safety aspects of different anticancer herbal drugs delivered through CNTs with a cross-talk on their outcomes. This review will serve as a one-stop-shop for the readers on various anticancer herbal drugs delivered through CNTs as a futuristic delivery device.

Lupeol alters ER stress-signaling pathway by downregulating ABCG2 expression to induce Oxaliplatin-resistant LoVo colorectal cancer cell apoptosis

Colorectal cancer (CRC) is one of the most common cancers and causes of cancer-related death. There are several first-line chemotherapeutic drugs used to treat CRC. Oxaliplatin (OXA) is an alkylating cytotoxic agent that is usually combined with other chemotherapeutic drugs to treat stage II and stage III CRC. However, cancer cells commonly acquire multidrug resistance (MDR), which is a major obstruction to cancer treatment. Recent studies have shown that natural components from traditional Chinese medicine or foods that have many biological functions may be new adjuvant therapies in clinical trials. We challenged LoVo CRC cell lines with OXA in a dose-dependent manner to create an OXA-resistant model. The expression of ABCG2 was significantly higher, and levels of endoplasmic reticulum (ER) stress markers were lower than those Parental cells. However, Lupeol, which is found in fruits and vegetables, has been shown to have bioactive properties, including anti-tumor properties that are relevant to many diseases. In our study, Lupeol downregulated cell viability and activated cell apoptosis. Moreover, Lupeol decreased the expression of ABCG2 and activated ER stress to induce OXA-resistant cell death. Importantly, the anti-tumor effect of Lupeol in OXA-resistant cells was higher than that of LoVo Parental cells. In addition, we also confirmed our results with a xenograft animal model, and the tumor size significantly decreased after Lupeol injections. Our findings show that Lupeol served as a strong chemoresistant sensitizer and could be a new adjuvant therapy method for chemoresistant patients.

Therapeutic potential of patupilone in epithelial ovarian cancer and future directions

Ovarian cancer is the most lethal gynecologic malignancy worldwide with extremely poor patient prognosis. Elucidation of the detailed mechanisms of action of drugs targeting this cancer type is necessary to optimize treatment efficacy. Epothilones, a new class of microtubule-stabilizing anticancer drugs, show strong cytotoxic properties in vitro and in vivo and are additionally effective in taxane-resistant cells. In this report, we focus on inhibitors of microtubule depolymerization, taxanes, and the novel antimicrotubule agents, epothilones. Current knowledge regarding the effects of epothilone B on ovarian tumor cell metabolism is reviewed, along with recent advances in therapeutic strategies, such as novel agents and biologic drug combinations containing epothilone that target aberrant pathways in ovarian cancer.

Endophytic Fungi-Alternative Sources of Cytotoxic Compounds: A Review

Cancer is a major cause of death worldwide, with an increasing number of cases being reported annually. The elevated rate of mortality necessitates a global challenge to explore newer sources of anticancer drugs. Recent advancements in cancer treatment involve the discovery and development of new and improved chemotherapeutics derived from natural or synthetic sources. Natural sources offer the potential of finding new structural classes with unique bioactivities for cancer therapy. Endophytic fungi represent a rich source of bioactive metabolites that can be manipulated to produce desirable novel analogs for chemotherapy. This review offers a current and integrative account of clinically used anticancer drugs such as taxol, podophyllotoxin, camptothecin, and vinca alkaloids in terms of their mechanism of action, isolation from endophytic fungi and their characterization, yield obtained, and fungal strain improvement strategies. It also covers recent literature on endophytic fungal metabolites from terrestrial, mangrove, and marine sources as potential anticancer agents and emphasizes the findings for cytotoxic bioactive compounds tested against specific cancer cell lines.

Marine Invertebrate Natural Products that Target Microtubules

Marine natural products as secondary metabolites are a potential major source of new drugs for treating disease. In some cases, cytotoxic marine metabolites target the microtubules of the eukaryote cytoskeleton for reasons that will be discussed. This review covers the microtubule-targeting agents reported from sponges, corals, tunicates, and molluscs and the evidence that many of these secondary metabolites are produced by bacterial symbionts. The review finishes by discussing the directions for future development and production of clinically relevant amounts of these natural products and their analogues through aquaculture, chemical synthesis, and biosynthesis by bacterial symbionts.

Bidesmosidic betulin saponin bearing L-rhamnopyranoside moieties induces apoptosis and inhibition of lung cancer cells growth in vitro and in vivo

Betulin has a wide range of biological and pharmacological properties with its anticancer activity attracting most of the attention as it offers a possible alternative treatment to chemotherapy. However, betulin’s in vivo biological effectiveness is limited by its poor solubility. As such, we synthesized polar glycosylated derivatives to increase its hydrosolubility and enhance its pharmacological properties. Among these synthesized compounds, 28-O-α-l-rhamnopyranosylbetulin 3β-O-α-l-rhamnopyranoside (Bi-L-RhamBet) was assessed for its cytotoxic effects against a suite of lung cancer cell lines. We also investigated its mechanism of action using an A549 lung cancer cell line. Our results showed that Bi-L-RhamBet exhibited potent cytotoxic activity toward lung cancer cell lines including A549, NCI-H2087, NCI-H522, NCI-H1993 NCI-H1755, and LLC1 having IC₅₀ values ranging from 2.9 to 5.9 μM. Moreover, Bi-L-RhamBet (50 mg/kg) significantly inhibited tumor growth with a treatment-to-control ratio (T/C) of 0.54 and a tumor growth inhibition rate of 46% at day 18 (p < 0.05). Microscopic observations of A549 cells, double stained with acridine orange and ethidium bromide, showed apoptotic features. Bi-L-RhamBet induced activation of pro-apoptotic caspases 8, 9, and 3/7 as well as causing DNA fragmentation. Moreover, a marked increase in mitochondrial ROS (mROS) was coupled with a reduction of mitochondrial potential. Interestingly, the presence of mitochondrial electron transport chain (ETC) inhibitors, including rotenone, malonate, and antimycin A, reduced mROS production, and the activation of caspases suggesting that Bi-L-RhamBet disturbs the ETC. Finally, dichloroacetate, a pyruvate dehydrogenase kinase inhibitor potentiated the cytotoxicity of Bi-L-RhamBet against A549 cells. Taken together, these data suggest that Bi-L-RhamBet can induce apoptotic cell death via disturbance of mitochondrial electron transfer chain, reduced ROS production, and decreased membrane potential.

Molecular targets and anti-cancer potential of escin

Escin is a mixture of triterpenoid saponins extracted from the horse chestnut tree, Aesculus hippocastanum. Its potent anti-inflammatory and anti-odematous properties makes it a choice of therapy against chronic venous insufficiency and odema. More recently, escin is being actively investigated for its potential activity against diverse cancers. It exhibits anti-cancer effects in many cancer cell models including lung adenocarcinoma, hepatocellular carcinoma and leukemia. Escin also attenuates tumor growth and metastases in various in vivo models. Importantly, escin augments the effects of existing chemotherapeutic drugs, thereby supporting the role of escin as an adjunct or alternative anti-cancer therapy. The beneficial effects of escin can be attributed to its inhibition of proliferation and induction of cell cycle arrest. By regulating transcription factors/growth factors mediated oncogenic pathways, escin also potentially mitigates chronic inflammatory processes that are linked to cancer survival and resistance. This review provides a comprehensive overview of the current knowledge of escin and its potential as an anti-cancer therapy through its anti-proliferative, pro-apoptotic, and anti-inflammatory effects.

Dendrimers in combination with natural products and analogues as anti-cancer agents

For the first time, an overview of dendrimers in combination with natural products and analogues as anti-cancer agents is presented. This reflects the development of drug delivery systems, such as dendrimers, to tackle cancers. The most significant advantages of using dendrimers in nanomedicine are their high biocompatibility, good water solubility, and their entry - with or without encapsulated, complexed or conjugated drugs - through an endocytosis process. This strategy has accelerated over the years in order to develop nanosystems as nanocarriers, to decrease the intrinsic toxicity of anti-cancer agents, to decrease the drug side effects, to increase the efficacy of the treatment, and consequently to improve patient compliance.

Next-Generation Plant Metabolic Engineering, Inspired by an Ancient Chinese Irrigation System

Specialized secondary metabolites serve not only to protect plants against abiotic and biotic challenges, but have also been used extensively by humans to combat diseases. Due to the great importance of medicinal plants for health, we need to find new and sustainable ways to improve the production of the specialized metabolites. In addition to direct extraction, recent progress in metabolic engineering of plants offers an alternative supply option. We argue that metabolic engineering for producing the secondary metabolites in plants may have distinct advantages over microbial production platforms, and thus propose new approaches of plant metabolic engineering, which are inspired by an ancient Chinese irrigation system. Metabolic engineering strategies work at three levels: introducing biosynthetic genes, using transcription factors, and improving metabolic flux including increasing the supply of precursors, energy, and reducing power. In addition, recent progress in biotechnology contributes markedly to better engineering, such as the use of specific promoters and the deletion of competing branch pathways. We propose that next-generation plant metabolic engineering will improve current engineering strategies, for the purpose of producing valuable metabolites in plants on industrial scales.

Dendrimers in combination with natural products and analogues as anti-cancer agents

Overview of the use of dendrimers in combination with encapsulated and conjugated natural products and analogues as anti-cancer agents.

Dendrimers in combination with natural products and analogues as anti-cancer agents

Overview of the use of dendrimers in combination with encapsulated and conjugated natural products and analogues as anti-cancer agents.

A novel agent exerts antitumor activity in breast cancer cells by targeting mitochondrial complex II

The mitochondrial respiratory chain, including mitochondrial complex II, has emerged as a potential target for cancer therapy. In the present study, a novel conjugate of danshensu (DSS) and tetramethylpyrazine (TMP), DT-010, was synthesized. Our results showed that DT-010 is more potent than its parental compounds separately or in combination, in inhibiting the proliferation of MCF-7 and MDA-MB-231 cells by inducing cytotoxicity and promoting cell cycle arrest. It also inhibited the growth of 4T1 breast cancer cells in vivo. DT-010 suppressed the fundamental parameters of mitochondrial function in MCF-7 cells, including basal respiration, ATP turnover, maximal respiration. Treatment with DT-010 in MCF-7 and MDA-MB-231 cells resulted in the loss of mitochondrial membrane potential and decreased ATP production. DT-010 also promoted ROS generation, while treatment with ROS scavenger, NAC (N-acetyl-L-cysteine), reversed DT-010-induced cytotoxicity. Further study showed that DT-010 suppressed succinate-induced mitochondrial respiration and impaired mitochondrial complex II enzyme activity indicating that DT-010 may inhibit mitochondrial complex II. Overall, our results suggested that the antitumor activity of DT-010 is associated with inhibition of mitochondrial complex II, which triggers ROS generation and mitochondrial dysfunction in breast cancer cells.

Evaluation of Apoptosis and Autophagy Inducing Potential of Berberis aristata, Azadirachta indica, and Their Synergistic Combinations in Parental and Resistant Human Osteosarcoma Cells

Cancer is a multifactorial disease and hence can be effectively overcome by a multi-constituently therapeutic strategy. Medicinal plant extracts represent a perfect example of such stratagem. However, minimal studies have been done till date that portray the effect of extraction techniques on the phyto-constituent profile of plant extracts and its impact on anticancer activity. In the present study, we have evaluated the anticancer potential of methanolic extracts of Berberis aristata root and Azadirachta indica seeds prepared by various extraction techniques in human osteosarcoma (HOS) cells. Soxhlation extract of B. aristata (BAM-SX) and sonication extract of A. indica (AIM-SO) were most effective in inducing apoptosis in parental drug sensitive, as well as resistant cell type developed by repeated drug exposure. Generation of reactive oxygen species and cell cycle arrest preceded caspase-mediated apoptosis in HOS cells. Interestingly, inhibition of autophagy enhanced cell death suggesting the cytoprotective role of autophagy. Combination studies of different methanolic extracts of BAM and AIM were performed, among which, the combination of BAM-SO and AIM-SO (BAAISO) was found to show synergism (IC₅₀ 10.27 µg/ml) followed by combination of BAM-MC and AIM-MC (BAAIMC) with respect to other combinations in the ratio of 1:1. BAAISO also showed synergism when it was added to cisplatin-resistant HOS cells (HCR). Chromatographic profiling of BAM-SX and AIM-SO by high performance thin layer chromatography resulted in identification of berberine (R_f 0.55), palmitine (R_f 0.50) in BAM-SX and azadirachtin A (R_f 0.36), azadirachtin B (R_f 0.56), nimbin (R_f 0.80), and nimbolide (R_f 0.43) in AIM-SO. The cytotoxic sensitivity obtained can be attributed to the above compounds. Our results highlight the importance of extraction technique and subsequent mechanism of action of multi-constituential B. aristata and A. indica against both sensitive and drug refractory HOS cells.

Anticancer effects of methanol extract of Myrmecodia platytyrea Becc. leaves against human hepatocellular carcinoma cells via inhibition of ERK and STAT3 signaling pathways

Myrmecodia platytyrea Becc., a member of the Rubiaceae family, is found throughout Southeast Asia and has been traditionally used to treat cancer. However, there is limited pharmacological information on this plant. We investigated the anticancer effects of the methanol extract of Myrmecodia platytyrea Becc. leaves (MMPL) and determined the molecular mechanisms underlying the effects of MMPL on metastasis in human hepatocellular carcinoma (HCC) cells. MMPL dose-dependently inhibited cell migration and invasion in SK‑Hep1 and Huh7 cells. In addition, MMPL strongly suppressed the enzymatic activity of matrix metalloproteinases (MMP‑2 and MMP‑9). Diminished telomerase activity by MMPL resulted in the suppression of both telomerase activity and telomerase-associated gene expression. The levels of urokinase-type plasminogen activator receptor (uPAR) expression as well as the phosphorylation levels of signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated kinase (ERK) were also attenuated by MMPL. The above results collectively suggest that MMPL has anticancer effects in HCC and that MMPL can serve as an effective therapeutic agent for treating human liver cancer.

Mechanisms of cancer cell killing by sea cucumber-derived compounds

The aim of cancer therapy is to specifically eradicate tumor cells while causing minimal damage to normal tissues and minimal side-effects. Because of this, the use of natural substances with low toxicity is a good option. Sea cucumbers are one of many potential marine animals that contain valuable nutrients and medicinal properties. The medicinal value of sea cucumbers is attributed to the presence of bioactive agents with promising biological and pharmacological properties that include cytotoxic activity, induction of apoptosis, cell cycle arrest, inhibition of tumor growth, anti-metastatic and anti-angiogenic properties, and inhibition of drug resistance. This review discusses the mechanisms of cancer cell death induced by sea cucumber-derived compounds with regard to exploring the potential use of these marine natural products for cancer therapy.

A review of Tunisian medicinal plants with anticancer activity

Cancer is a major public health problem in the world. The use of the medicinal plants in cancer prevention and management is frequent in Africa, especially in Tunisia, and it is transmitted from generation to generation within cultures. Many previous studies showed that a wide range of Tunisian medicinal plants exerted cytotoxic and anticancer activity. A comprehensive review was conducted to collect information from scientific journal articles, including indigenous knowledge researches, about Tunisian medicinal plants used for the prevention and management of cancer. The aim of this review article is to provide the reader with information concerning the importance of Tunisian medicinal plants in the prevention and management of cancer and to open the door for the health professionals and scientists working in the field of pharmacology and therapeutics to produce new drug formulations to treat different types of cancer.

Harmine suppresses the proliferation and migration of human ovarian cancer cells through inhibiting ERK/CREB pathway

Ovarian cancer is the most lethal gynaecological cancer and the sixth most common cause of cancer related death among Western women. Recent studies show that harmine, a small-molecular β-carboline alkaloid present in medicinal plants, displayed obvious anticancer effects in several cancer cells. However, the effect of harmine on ovarian cancer is not well understood. In the present study, the effect of harmine on the cell proliferation and migration of ovarian cancer SKOV-3 cells and the underlying mechanism were investigated. Our results indicated that harmine significantly suppressed the proliferation of SKOV-3 cells in a dose-dependent manner. Interestingly, it also inhibited the epidermal growth factor (EGF)-induced proliferation of SKOV-3 cells. Moreover, the migration of SKOV-3 cells was markedly inhibited by harmine treatment. Further study showed that harmine inhibited not only the basal phosphorylation level of extra-cellular signal-regulated kinase 1/2 (ERK1/2) and cyclic adenosine monophosphate response element-binding protein (CREB) but also EGF-induced ERK1/2 and CREB phosphorylation. Finally, harmine significantly suppressed the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP) family MMP-2, and MMP-9. In conclusion, our data revealed that harmine inhibited the proliferation and migration of SKOV-3 cells, which might be mediated by ERK/CREB pathway. These findings elucidate that harmine may act as a potential therapeutic drug for ovarian cancer treatment.

A homomeric geranyl diphosphate synthase-encoding gene from Camptotheca acuminata and its combinatorial optimization for production of geraniol in Escherichia coli

Geranyl diphosphate (GPP), the unique precursor for all monoterpenoids, is biosynthesized from isopentenyl diphosphate and dimethylallyl diphosphate via the head-to-tail condensation reaction catalyzed by GPP synthase (GPPS). Herein a homomeric GPPS from Camptotheca acuminata, a camptothecin-producing plant, was obtained from 5'- and 3'-rapid amplification of cDNA ends and subsequent overlap extension and convenient PCR amplifications. The truncate CaGPPS was introduced to replace ispA of pBbA5c-MevT(CO)-MBIS(CO, ispA), a de novo biosynthetic construct for farnesyl diphosphate generation, and overexpressed in Escherichia coli, together with the truncate geraniol synthase-encoding gene from C. acuminata (tCaGES), to confirm CaGPPS-catalyzed reaction in vivo. A 24.0 ± 1.3 mg L^-1 of geraniol was produced in the recombinant E. coli. The production of GPP was also validated by the direct UPLC-HRMS^E analyses. The tCaGPPS and tCaGES genes with different copy numbers were introduced into E. coli to balance their catalytic potential for high-yield geraniol production. A 1.6-fold increase of geraniol production was obtained when four copies of tCaGPPS and one copy of tCaGES were introduced into E. coli. The following fermentation conditions optimization, including removal of organic layers and addition of new n-decane, led to a 74.6 ± 6.5 mg L^-1 of geraniol production. The present study suggested that the gene copy number optimization, i.e., the ratio of tCaGPPS and tCaGES, plays an important role in geraniol production in the recombinant E. coli. The removal and addition of organic solvent are very useful for sustainable high-yield production of geraniol in the recombinant E. coli in view of that the solubility of geraniol is limited in the fermentation broth and/or n-decane.

Carpatizine, a novel bridged oxazine derivative generated by non-enzymatic reactions

Carpatizine (1), a new bridged oxazine derivative, was isolated from a marine-derived Streptomyces strain SNE-011. The structure was fully determined by spectroscopic analysis, ECD calculations and chemical methods. A plausible non-enzymatic reaction mechanism from daryamide D leading to carpatizine was presented, which was confirmed by chemical transformation.

Two likely targets for the anti-cancer effect of indole derivatives from cruciferous vegetables: PI3K/Akt/mTOR signalling pathway and the aryl hydrocarbon receptor

Diets containing high quantities of plant foods are linked with a decreased likelihood of incidence of cancer. Several common plant-based dietary components exert effects on DNA methylation levels, and can positively influence genome stability and the transcription of tumor suppressors and oncogenes. Indole-3-carbinol (I3C) is a substance present in vegetables of the Brassicaeae family, especially broccoli, white cabbage, Brussels sprouts and cauliflower. The in vivo biological effects of I3C are ascribed to a series of oligomeric products (including 3,3'-diindolylmethane), developed under acidic conditions. I3C is one of the many natural products and bioactive compounds found in foods which have recently received much attention for its potential effects in cancer prevention and treatment. In vitro studies report that I3C suppresses the proliferation of different tumor cells, including those isolated from breast, prostate, endometrium, and colon cancers. I3C resulted to be a potent in vivo chemopreventive agent for certain hormone-dependent cancers, including breast and cervical cancer. However, the mechanisms underlying these effects are not well defined. In this review, we have analysed recent literature on the use of indole derivatives against various forms of cancer, and have identified the main signalling pathways involved in their anti-cancer effect as PI3K/Akt/mTOR and the aryl hydrocarbon receptor.

Cross-Kingdom Regulation of Putative miRNAs Derived from Happy Tree in Cancer Pathway: A Systems Biology Approach

MicroRNAs (miRNAs) are well-known key regulators of gene expression primarily at the post-transcriptional level. Plant-derived miRNAs may pass through the gastrointestinal tract, entering into the body fluid and regulate the expression of endogenous mRNAs. Camptotheca acuminata, a highly important medicinal plant known for its anti-cancer potential was selected to investigate cross-kingdom regulatory mechanism and involvement of miRNAs derived from this plant in cancer-associated pathways through in silico systems biology approach. In this study, total 33 highly stable putative novel miRNAs were predicted from the publically available 53,294 ESTs of C. acuminata, out of which 14 miRNAs were found to be regulating 152 target genes in human. Functional enrichment, gene-disease associations and network analysis of these target genes were carried out and the results revealed their association with prominent types of cancers like breast cancer, leukemia and lung cancer. Pathways like focal adhesion, regulation of lipolysis in adipocytes and mTOR signaling pathways were found significantly associated with the target genes. The regulatory network analysis showed the association of some important hub proteins like GSK3B, NUMB, PEG3, ITGA2 and DLG2 with cancer-associated pathways. Based on the analysis results, it can be suggested that the ingestion of the C. acuminata miRNAs may have a functional impact on tumorigenesis in a cross-kingdom way and may affect the physiological condition at genetic level. Thus, the predicted miRNAs seem to hold potentially significant role in cancer pathway regulation and therefore, may be further validated using in vivo experiments for a better insight into their mechanism of epigenetic action of miRNA.

Novel hybrids of natural β-elemene bearing isopropanolamine moieties: Synthesis, enhanced anticancer profile, and improved aqueous solubility

A series of novel β-elemene isopropanolamine derivatives were synthesized and evaluated for their antitumor activity. The results indicated that all of the compounds showed stronger antiproliferative activities than β-elemene as well as improved aqueous solubility. In particular dimer 6q showed the strongest cytotoxicity against four tumor cell lines (SGC-7901, HeLa, U87 and A549) with IC₅₀ values ranging from 4.37 to 10.20μM. Moreover, combination of 6q with cisplatin exhibited a synergistic effect on these cell lines with IC₅₀ values ranging from 1.21 to 2.94μM, and reversed the resistance of A549/DPP cells with an IC₅₀ value of 2.52μM. The mechanism study revealed that 6q caused cell cycle arrest at the G2 phase and induced apoptosis of SGC-7901 cells through a mitochondrial-dependent apoptotic pathway. Further in vivo study in H22 liver cancer xenograft mouse model validated the antitumor activity of 6q with a tumor inhibitory ratio (TIR) of 60.3%, which was higher than that of β-elemene (TIR, 49.1%) at a dose of 60mg/kg. Altogether, the potent antitumor activity of 6qin vitro and in vivo warranted further preclinical investigation for potential anticancer chemotherapy.

Microbial metabolites in nutrition, healthcare and agriculture

Microorganisms are a promising source of an enormous number of natural products, which have made significant contribution to almost each sphere of human, plant and veterinary life. Natural compounds obtained from microorganisms have proved their value in nutrition, agriculture and healthcare. Primary metabolites, such as amino acids, enzymes, vitamins, organic acids and alcohol are used as nutritional supplements as well as in the production of industrial commodities through biotransformation. Whereas, secondary metabolites are organic compounds that are largely obtained by extraction from plants or tissues. They are primarily used in the biopharmaceutical industry due to their capability to reduce infectious diseases in human beings and animals and thus increase the life expectancy. Additionally, microorganisms and their products inevitably play a significant role in sustainable agriculture development.

LFG-500, a newly synthesized flavonoid, induces apoptosis in human ovarian carcinoma SKOV3 cells with involvement of the reactive oxygen species-mitochondria pathway

Ovarian cancer is the main cause of gynecologic malignancy-related mortality in women. Therefore, the disease requires improvements in treatment options and in the potency of chemotherapeutic drugs. The study of apoptosis in tumor cells is an important field for cancer therapy and cancer molecular biology. It has recently been established that LFG-500, a new synthesized flavonoid with a piperazine and benzyl group substitution, has strong anticancer activity. However, its exact molecular mechanism is not fully understood. The present study aimed to examine the effects of LFG-500 on human ovarian cancer SKOV3 cells, as well as to identify its underlying mechanisms. The data showed that LFG-500 inhibited the growth of SKOV3 cells in a concentration-dependent manner. It was found that LFG-500 induced apoptosis in SKOV3 cells, detected by DAPI staining and an Annexin V/PI double-staining assay. Moreover, LFG-500 reduced caspase-3 protein expression and increased the Bcl-2-associated X protein/B-cell lymphoma 2 protein ratio. Further findings revealed that LFG-500 treatment resulted in reactive oxygen species (ROS) accumulation and loss of mitochondrial transmembrane potential. Collectively, these results demonstrated that LFG-500 efficiently induced apoptosis in SKOV3 cells, an event possibly associated with the trigging of the mitochondrial apoptotic pathway through ROS accumulation. Therefore, LFG-500 shows potential as a potent anticancer agent for the treatment of ovarian cancer.