In silico, in vitro screening of antioxidant and anticancer potentials of bioactive secondary metabolites from an endophytic fungus (Curvularia sp.) from Phyllanthus niruri L

The main objective of this research work is to discover novel and efficient phytochemical substances from endophytic fungus found in medicinal plants. Curvularia geniculata L. (C. geniculata L.), an endophytic fungus isolated from Phyllanthus niruri L. (P. niruri L.), was tested against hepatoma cell lines (HepG2) in order to screen their antioxidant and anticancer potentials. The profiling of phytochemicals from the fungal extract was characterized using gas chromatography-mass spectrometry (GC-MS), and molecular docking was done for the identified compounds against one of the potential receptors predominantly present in the hepatocellular carcinoma cell lines. Among the phytochemicals found, 2-methyl-7-phenylindole had the highest binding affinity (- 8.8 kcal mol^-1) for the epidermal growth factor receptor (EGFR). The stability of 2-methyl-7-phenylindole in the EGFR-binding pockets was tested using in silico molecular dynamics simulation. The fungal extract showed the highest antioxidant activity as measured by DPPH, ABTS radical scavenging, and FRAP assays. In vitro cytotoxicity assay of fungal extract demonstrated the concentration-dependent cytotoxicity against HepG2 cells after 24 h, and the IC₅₀ (50% cell death) value was estimated to be 62.23 μg mL^-1. Typical morphological changes such as condensation of nuclei and deformed membrane structures are indicative of ongoing apoptosis. The mitochondria of HepG2 cells were also targeted by the endophytic fungal extract, which resulted in substantial generation of reactive oxygen species (ROS) leading to the destruction of mitochondrial transmembrane potential integrity. These outcomes suggest that the ethyl acetate extract of C. geniculata L. has the potential to be an antioxidant agent and further to be exploited in developing potential anticancer agents.

A systematic review of the therapeutic effects of resveratrol in combination with 5-fluorouracil during colorectal cancer treatment: with a special focus on the oxidant, apoptotic, and anti-inflammatory activities

Purpose

5-fluorouracil (5-FU), an effective chemotherapy drug, is commonly applied for colorectal cancer treatment. Nevertheless, its toxicity to normal tissues and the development of tumor resistance are the main obstacles to successful cancer chemotherapy and hence, its clinical application is limited. The use of resveratrol can increase 5-FU-induced cytotoxicity and mitigate the unwanted adverse effects. This study aimed to review the potential therapeutic effects of resveratrol in combination with 5-FU against colorectal cancer.

Methods

According to the PRISMA guideline, a comprehensive systematic search was carried out for the identification of relevant literature in four electronic databases of PubMed, Web of Science, Embase, and Scopus up to May 2021 using a pre-defined set of keywords in their titles and abstracts. We screened 282 studies in accordance with our inclusion and exclusion criteria. Thirteen articles were finally included in this systematic review.

Results

The in vitro findings showed that proliferation inhibition of colorectal cancer cells in the groups treated by 5-FU was remarkably higher than the untreated groups and the co-administration of resveratrol remarkably increased cytotoxicity induced by 5-FU. The in vivo results demonstrated a decrease in tumor growth of mice treated by 5-FU than the untreated group and a dramatic decrease was observed following combined treatment of resveratrol and 5-FU. It was also found that 5-FU alone and combined with resveratrol could regulate the cell cycle profile of colorectal cancer cells. Moreover, this chemotherapeutic agent induced the biochemical and histopathological changes in the cancerous cells/tissues and these alterations were synergized by resveratrol co-administration (for most of the cases), except for the inflammatory mediators.

Conclusion

The results obtained from this systematic review demonstrated that co-administration of resveratrol could sensitize the colorectal cancer cells to 5-FU treatment via various mechanisms, including regulation of cell cycle distribution, oxidant, apoptosis, anti-inflammatory effects.

Circ-ZEB1 promotes PIK3CA expression by silencing miR-199a-3p and affects the proliferation and apoptosis of hepatocellular carcinoma

Background

Although the prognostic outcomes of liver cancer (LC) cases have improved with the advancement in diagnostic technology and treatment methods, the transferability and recurrence of HCC and the 5-year and 10-year survival rates of patients have remained unsatisfactory. As a result, there is a need for more accurate diagnostic indicators that can detect liver cancer early, effectively improving the prognosis of patients. Whole-genome sequencing (WGS) revealed that circ-ZEB1 and PIK3CA are highly expressed in HCC tissues, whereas miR-199a-3p is significantly downregulated in HCC. Multiple databases search and biological analysis revealed that elevated expression of circ-ZEB1 and PIK3CA was related to poor prognosis of HCC. In vitro and in vivo studies revealed that upregulated levels of PIK3CA and circ-ZEB1 were closely associated with HCC proliferation and apoptosis. Based on these results, we believe that circ-ZEB1 and PIK3CA could be used as biomarkers to diagnose and treat patients with HCC. More importantly, circ-ZEB1 can promotes the expression of PIK3CA by silencing miR-199a-3p and affecting the progression of HCC.

Methods and results

Postoperative specimens from 56 patients with HCC who had not undergone chemotherapy from 2015 to 2018 were collected from the Department of Hepatobiliary Surgery, Second Affiliated Hospital of Nanchang University. WGS revealed differential expression of genes in HCC. Furthermore, RT-qPCR detected the expression of circ-ZEB1, miR-199a-3p, and PIK3CA in HCC tissues. MTT, EdU, and plate cloning experiments were conducted to detect cell proliferation, whereas flow cytometry analysis was used to detect apoptosis. FISH was used to co-localize circ-ZEB1 and miR-199a-3p, and biotin-coupled probe pull-down assay was used to detect the specific binding of circ-ZEB1 and miR-199a-3p. The dual-luciferase report assay detected the association of miR-199a-3p with PIK3CA. Western blotting was used to study the expression of PIK3CA protein. Circ-ZEB1 and PIK3CA were upregulated in HCC and predicted a poor prognosis. MiR-199a-3p showed low expression in HCC, whereas downregulation of circ-ZEB1 reduced HCC cell proliferation and promoted cell apoptosis. MiR-199a-3p blocked the effect of circ-ZEB1 on HCC. Circ-ZEB1 served as a biomarker of HCC. Circ-ZEB1 promoted the expression of PIK3CA by silencing miR-199a-3p to affect the progress of HCC.

Conclusions

Circ-ZEB1 promoted the expression of PIK3CA by depleting miR-199a-3p, thereby affecting HCC proliferation and apoptosis.

Prognostic value of maximum standard uptake value, metabolic tumour volume, and total lesion glycolysis of 18F-FDG PET/CT in patients with malignant pleural mesothelioma: a systematic review and meta-analysis

PURPOSE

Present work systematically reviewed relevant literature based on 18F-FDG PET parameters and conducted a meta-analysis to examine the prognostic value of maximal standard uptake value (SUVmax), total lesional glycolysis (TLG), and metabolic tumour volume (MTV) in the prognosis of malignant pleural mesothelioma (MPM).

METHODS

The relevant literature published in English were searched on PubMed, Cochrane Library, and EMBASE databases. We also evaluated the significance of SUVmax, TLG, and MTV in prognosis prediction using pooled hazard ratios (HRs).

RESULTS

The current study comprised 12 primary studies with a total of 1307 MPM cases. According to our results, the pooled HR (95% confidence interval [CI]) of increased SUVmax for overall survival (OS) was 1.30 (95% CI 1.13-1.49, P = 0.000), whereas the increased TLG was 1.81(95% CI 1.25-2.61, P = 0.089). The increased MTV was not significantly related to OS (1.14 [95% CI 0.87-1.50, P = 0.18]).However, study design-stratified subgroup analysis suggested that differences in OS of retrospective and prospective subgroups were statistically significant, and no significant heterogeneity among different studies was observed.

CONCLUSION

Based on the findings from the present work, PET/CT can significantly affect the prognosis prediction in MPM cases. Also, the increased SUVmax and TLG values predict an increased risk of mortality.

Design, synthesis and broad spectrum antibreast cancer activity of diarylindoles via induction of apoptosis in aggressive breast cancer cells

Breast cancer is the second leading cause of cancer deaths in women with significant morbidity and mortality. Present study describes design, synthesis and detailed pharmacology of indole derivatives exhibiting remarkable broad spectrum antiproliferative activity against breast cancer cells. Detailed mechanistic evaluations confirmed induction of G0/G1 arrest, apoptosis induction, loss of mitochondrial integrity, enhanced ROS generation, autophagy, estrogen receptor β-transactivation and increased tubulin polymerization. In in-vivo efficacy studies in rodent model, these indole derivatives induced significant regression in mice mammary tumour on 21 days daily oral dose. Moreover, compounds 19 and 23 were safe in Swiss albino mice in safety studies. These diarylindoles may further be optimized for better efficacy.

Different packing motifs mediated by weak inter-actions and polymorphism in the crystal structures of five 2-(benzyl-idene)benzosuberone derivatives

The syntheses and crystal structures of five 2-benzyl-idene-1-benzosuberone [1-benzosuberone is 6,7,8,9-tetra-hydro-5H-benzo[7]annulen-5-one] derivatives, viz. 2-(4-meth-oxy-benzyl-idene)-1-benzosuberone, C19H18O2, (I), 2-(4-eth-oxy-benzyl-idene)-1-benzosuberone, C20H20O2, (II), 2-(4-benzyl-benzyl-idene)-1-benzosuberone, C25H22O2, (III), 2-(4-chloro-benzyl-idene)-1-benzosuberone, C18H15ClO, (IV) and 2-(4-cyano-benzyl-idene)-1-benzosuberone, C19H15NO, (V), are described. The conformations of the benzosuberone fused six- plus seven-membered ring fragments are very similar in each case, but the dihedral angles between the fused benzene ring and the pendant benzene ring differ somewhat, with values of 23.79 (3) for (I), 24.60 (4) for (II), 33.72 (4) for (III), 29.93 (8) for (IV) and 21.81 (7)° for (V). Key features of the packing include pairwise C-H⋯O hydrogen bonds for (II) and (IV), and pairwise C-H⋯N hydrogen bonds for (V), which generate inversion dimers in each case. The packing for (I) and (III) feature C-H⋯O hydrogen bonds, which lead to [010] and [100] chains, respectively. Weak C-H⋯π inter-actions consolidate the structures and weak aromatic π-π stacking is seen in (II) [centroid-centroid separation = 3.8414 (7) Å] and (III) [3.9475 (7) Å]. A polymorph of (I) crystallized from a different solvent has been reported previously [Dimmock et al. (1999 ▸) J. Med. Chem. 42, 1358-1366] in the same space group but with a packing motif based on inversion dimers resembling that seen in (IV) in the present study. The Hirshfeld surfaces and fingerprint plots for (I) and its polymorph are com-pared and structural features of the 2-benzyl-idene-1-benzosuberone family of phases are surveyed.

Synthesis and in vitro anticancer evaluation of some fused indazoles, quinazolines and quinolines as potential EGFR inhibitors

derivatives of benzo[g]indazole 5a, b, benzo[h]quinazoline 7, 12a-c, 13a-c and 15a-c and benzo[h]quinoline 17a-c and 19a-c were synthesized from 6-methoxy-3,4-dihydronaphthalen-1(2H)-one (1). Anticancer activity of all the synthesized compounds was evaluated against four cancerous cell lines; HepG2, MCF-7, HCT116 and Caco-2. MCF-7 cells emerged as the most sensitive cell line against the target compounds. All the examined compounds, except 5a and 5b, displayed potent to moderate anticancer activity against MCF-7 cells with an IC₅₀ values ranging from 7.21 to 21.55 µM. In particular, compounds 15c and 19b emerged as the most potent derivatives against EGFR-expressing MCF-7 cells with IC₅₀ values = 7.70 ± 0.39 and 7.21 ± 0.43 μM, respectively. Additionally, both compounds did not display any significant cytotoxicity towards normal BHK-21 fibroblast cells (IC₅₀ value > 200 µM), thereby providing a good safety profile as anticancer agents. Furthermore, compounds 15c and 19b displayed potent inhibitory activity towards EGFR in the sub-micromolar range (IC₅₀ = 0.13 ± 0.01 and 0.14 ± 0.01 μM, respectively), compared to that of Erlotinib (IC₅₀ = 0.11 ± 0.01 μM). Docking studies for 15c and 19b into EGFR active site was carried out to explore their potential binding modes. Therefore, compounds 15c and 19b can be considered as interesting candidates for further development of more potent anticancer agents.

Synthesis and anti-breast cancer activity of novel indibulin related diarylpyrrole derivatives

BACKGROUND

During recent years, a number of anti-tubulin agents were introduced for treatment of diverse types of cancer. Despite their potential in the treatment of cancer, drug resistance and adverse toxicity, such as peripheral neuropathy, are some of the negative effects of anti-tubulin agents. Among anti-tubulin agents, indibulin was found to cause minimal peripheral neuropathy. Thus far, however, indibulin has not entered clinical usage, caused in part by its poor aqueous solubility and other developmental problems in preclinical evaluation.

OBJECTIVES

With respect to need for finding potent and safe anticancer agents, in our current research work, we synthesized several indibulin-related diarylpyrrole derivatives and investigated their anti-cancer activity.

METHODS

Cell cultur studies were perfomred using the MTT cell viability assay on the breast cancer cell lines MCF-7, T47-D, and MDA-MB231 and also NIH-3 T3 cells as representative of a normal cell line. The activity of some of the synthesized compounds for tubulin interaction was studied using colchicine binding and tubulin polymerization assays. The annexin V-FITC/PI method and flow cytometric analysis were used for studying apoptosis induction and cell cycle distribution.

RESULTS AND CONCLUSION

Two of the synthesized compounds, 4f and 4 g, showed high activity on the MDA-MB231 cell line (IC₅₀ = 11.82 and 13.33 μM, (respectively) and low toxicity on the normal fibroblast cells (IC₅₀ > 100 μM). All of the tested compounds were more potent on T47-D cancer cells and less toxic on NIH-3 T3 normal cells in comparison to reference compound, indibulin. The tubulin polymerization inhibition assay and [³H]colchicine binding assay showed that the main mechanism of cell death by the potent synthesized compounds was not related to an interaction with tubulin. In the annexin V/PI staining assay, the induction of apoptosis in the MCF-7 and MDA-MB231 cell lines was observed. Cell cycle analysis illustrated an increased percentage of sub-G-1 cells in the MDA-MB231 cell line as a further indication of cell death through induction of apoptosis. Graphical abstract Novel Indibulin analogous as anti-breast cancer agents.

Paclitaxel-loaded TPGS enriched self-emulsifying carrier causes apoptosis by modulating survivin expression and inhibits tumour growth in syngeneic mammary tumours

Paclitaxel (PTX) in its commercial products exhibits adverse effects owing to excipients and also has poor oral bioavailability. Present work is directed towards development of tocopheryl polyethylene glycol succinate-assisted self-nanoemulsifying system (SEDDS) for oral delivery of PTX. Box-Behnken design of experiment was employed to optimize PTX-SEDDS and was characterized for droplet size (29.76 ± 2.64 nm), zeta potential (-21.46 ± 2.52 mV), PDI (0.177 ± 0.012), drug content (4.97 ± 0.98 mg), entrapment efficiency (98.33 ± 0.54%) and in vitro drug release (51.03 ± 2.23% PTX at 72 h). PTX-SEDDS exhibited IC₅₀; 1.58 ± 0.12 µM and a 52.46-folds higher cell uptake in MDA-MB-231 cells along with cellular and nuclear morphology changes. Significantly higher G₂M cell cycle arrest, apoptosis, mitochondrial membrane potential disruption and ROS production was exhibited by PTX-SEDDS in comparison to Taxol. Up-regulation of Bax, p21, cleaved-caspase 3, -caspase 9 and down-regulation of Bcl2 and survivin suggested apoptosis via intrinsic pathways. Pharmacokinetic study showed approximately 4-folds higher oral bioavailability of PTX-SEDDS than Taxol. Significant reduction in tumour volume and weight was observed in syngeneic mammary tumour in SD rats. Tumour histopathology and TUNEL assay showed apoptosis in tumour tissue. PTX-SEDDS caused low lung metastasis, and was safe and stable. Conclusively, PTX-SEDDS could be suitable option for oral delivery of PTX.

Activation of autophagy by stress-activated signals as a cellular self-defense mechanism against the cytotoxic effects of MBIC in human breast cancer cells in vitro

We recently reported that methyl 2-(-5-fluoro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (MBIC) is a microtubule targeting agent (MTA) with multiple mechanisms of action including apoptosis in two human breast cancer cell-lines MCF-7 and MDA-MB-231. In the present study, investigation of early molecular events following MBIC treatment demonstrated the induction of autophagy. This early (<24 h) response to MBIC was characterized by accumulation of autophagy markers; LC3-II, Beclin1, autophagic proteins (ATGs) and collection of autophagosomes but with different variations in the two cell-lines. MBIC-induced autophagy was associated with generation of reactive oxygen species (ROS). In parallel, an increased activation of SAPK/JNK pathway was detected, as an intersection of ROS production and induction of autophagy. The cytotoxic effect of MBIC was enhanced by inhibition of autophagy through blockage of SAPK/JNK signaling, suggesting that MBIC-induced autophagy, is a possible cellular self-defense mechanism against toxicity of this agent in both breast cancer cell-lines. The present findings suggest that inhibition of autophagy eliminates the cytoprotective activity of MDA-MB-231 and MCF-7 cells, and sensitizes both the aggressive and non-aggressive human breast cancer cell-lines to the cytotoxic effects of MBIC.

Structural studies of (E)-2-(benzylidene)-1-tetralone derivatives: crystal structures and Hirshfeld surface analysis

Crystal structures are reported from data collected at 100 K of (E)-2-(X-benzylidene)-1-tetralone (2: X=3-O2N; 3: X=4-O2N; 5: X=4-HO; 6: X=4-Me2N; 7: 4-NC), (E)-2-(X-benzylidene)-6-MeO-1-tetralone, 8, and (E)-2-(X-benzylidene)-5-MeO-1-tetralone 9. Also reported herein are the Hirshfeld surface calculations for these compounds as well as those of (E)-2-(X-benzylidene)-1-tetralone (1: X=H; 4: X=4-MeO), whose structures were previously reported. The molecules are not planar as shown by the dihedral angles of 45.66(5)–69.78(5)° between the phenyl groups and by the puckered cyclohexenyl rings. A common feature of the molecular conformations is the C–H···O1(carbonyl) intramolecular hydrogen bond. The carbonyl oxygen atom plays significant roles in the interactions in all compounds baring compound 8. However, there is no consistent set of intermolecular interaction in this group of compounds. Intermolecular interactions present in each compound are some of the O–H···O, C–H···A (A=O, N or π), A–O···π (A=C or N) and π···π interactions. The only compound exhibiting a classical O–H···O hydrogen bond is compound 5. C–H···π interactions are found in all compounds, and while π···π interactions are present in compounds 2, 3, 7 and 9, no consistent type of stacking arrangement is shown. The Hirshfeld surface calculations, while generally concurring with the intermolecular interactions indicated by PLATON analyses, also reveal short interactions, which fall below the PLATON cut-off parameters.

Structural studies of (E)-2-(benzylidene)- 2,3-dihydro-1H-inden-1-one derivatives: crystal structures and Hirshfeld surface analysis

Crystal structures are reported of (E)-2-(4-hydroxybenzylidene)-2,3-dihydro-1H-inden-1-one, 1, (E)-2-(4-dimethylaminobenzylidene)-2,3- dihydro-1H-inden-1-one, 2, (E)-2-(4-cyanobenzylidene)-2,3-dihydro-1H-inden-1-one, 3, and monoclinic-(E)- 2-(3-nitrobenzylidene)-2,3-dihydro-1H-inden-1-one, monoclinic-4, all from data collected at 100 K and (E)-2-(4-hydroxy-3,5-dimethylbenzylidene)-2,3-dihydro-1H-indan-1-one, 6, from data collected at 299 K. An earlier triclinic form of 4 has been reported. Also reported herein are the Hirshfeld suface calculations for these five compounds, as well as that of 2-(4-methoxybenzylidene)-2,3-dihydro-1H-inden-1-one, 5,whose crystal structure has been previously reported. The three rings in each of the compounds, 1–4 and 6, are essentially planar, including the five-membered ring containing a formally hydridized sp3 atom. The molecules exhibit slight deviations from overall planarity as shown by the dihedral angles, >8.15(6)° between the 2,3-dihydro-1H-inden-1-one fragments and the phenyl fragments. The main intermolecular interactions in compounds 1 and are classical O–H···O1(carbonyl) hydrogen bonds. The carbonyl oxygen atom in compounds 1–4 are involved in non-classical C–H···O intermolecular hydrogen bonds. Intermolecular C–H---π interactions are present in 2, 3 and 6, while π···π are present in 2–4 and 6. As noted in the structure determinations of these compounds, different π···π motifs are possible. The Hirshfeld surface calculations, while generally concurring with the intermolecular interactions indicated by PLATON analyses, also reveal significant interactions, which fall below the PLATON radar.