Synthesis, Antiproliferative Activity and Molecular Docking Studies of Novel Doubly Modified Colchicine Amides and Sulfonamides as Anticancer Agents

In-vitro hepatotoxic activity of mitragynine and paynantheine isolated from the leaves of Mitragyna speciosa Korth. (Kratom)

Mitragynine, a primary alkaloid found in kratom leaves has been reported to have a broad range of pharmacological and toxicological properties while its congener, paynatheine has comparatively less information available on these aspects. Mitragynine and its congener, paynantheine, were isolated from the ethanol kratom leaves extract using gravity column chromatography techniques. Our study evaluated the cytotoxicity potential of mitragynine and paynantheine on normal human liver cell line, HL-7702, and human hepatoma cell line, HepG2. Mitragynine exhibited a moderate inhibitory effect on the HepG2 cell line with IC50 value of 42.11 ± 1.31 μM in comparison with vinblastine (IC50: 15.45 ± 0.72 μM) while it showed non-cytotoxic properties towards the HL-7702 cell line with concentrations ranging below 200 μM. In contrast, paynantheine exhibited weak cytotoxic properties towards HepG2 and HL-7702 cell lines. Further comprehensive evaluations of both compounds are needed to establish more details on the cytotoxicity potential of kratom alkaloids.

Optimization of media components for enhanced carotenoid production by Paracoccus marcusii RSPO1 and assessment of their cytotoxicity against A549 and vero cells

In this study, we tried to explore the influence of various tricarboxylic acid (TCA) cycle intermediates on carotenoid production and with a focus on enhancing pigment biosynthesis, we conducted two statistical analysis. In case of TCA intermediates influence on pigment production by Paracoccus marcusii RSPO1; fumaric acid, and malic acid were observed as potent enhancers of pigment biosynthesis. Further, to optimize key media components for enhanced carotenoid production, the Plackett-Burman design was employed encompassing carbon, nitrogen sources, TCA cycle intermediates, and metal salts. The selected factors after Plackett Burman were fine-tuned through Response Surface Methodology and the optimal concentrations that have remarkably elevated carotenoid production were starch-2.24 g/l, MgSO4-0.416 g/l, ZnSO4-0.0157 g/l, and fumaric Acid-16 mM. Further, evaluation of pigment cytotoxicity against normal (Vero) and Non-Small Cell Carcinoma (A549) cells was performed. The resultant IC50 values were quantified as 161.3 µg/ml and 7.623 µg/ml for Vero and A549 cells, respectively. Moreover, a reactive oxygen species (ROS) determination study in A549 cells was done which have shown a noteworthy threefold ROS production in A549 cells through fluorescence spectroscopic observation. This implies that the bacterial carotenoids can act as potent pro-oxidants against cancerous cells while being nontoxic toward normal cells.

A Lipophilic Salt Form to Enhance the Lipid Solubility and Certain Biopharmaceutical Properties of Lapatinib

Lapatinib (LTP) commercially available as lapatinib ditosylate (LTP-DTS) salt is the only drug approved for the treatment of HER-positive metastatic breast cancer. A low and pH-dependent solubility results in poor and variable oral bioavailability, thus driving significant interest in molecular modification and formulation strategies of the drug. Furthermore, due to very high crystallinity, LTP and LTP-DTS have low solubility in lipid excipients, making it difficult to be delivered by lipid-based carrier systems. Thus, the present work reports a new salt form of LTP with a docusate counterion to enhance the pharmaceutical properties of the drug (LTP-DOC). NMR spectra showed a downfield shift of the methylene singlet proton from 3.83 and 4.41 ppm, indicating a lowering of electron density on the adjacent nitrogen atom and confirming the formation of amine-sulfonyl salt through the specified basic nitrogen center located adjacent to the furan ring. PXRD diffractograms of LTP-DOC indicated a reduced crystallinity of the prepared salt. The dissolution, equilibrium solubility, lipid excipient solubility, partitioning coefficient, distribution coefficient, tabletability, and in vitro cytotoxicity of the lipophilic salt of LTP were investigated. The equilibrium solubility data showed that LTP-DOC possesses a pH-independent solubility profile in the pH range of 3.5 to 7.4 with a 3.14 times higher permeability coefficient than commercial ditosylate salt. Furthermore, the prepared LTP-DOC salts showed twice higher log P than the free base and 8 times higher than LTP-DTS. The prepared LTP-DOC was found to have 4- to 9-fold higher solubility in lipid excipients like Capmul MCM C8 and Maisine CC compared to the ditosylate salt. The LTP-DOC salt was tabletable and showed approximately 1.2 times lower dissolution than commercial ditosylate salt, indicating extended-release behavior. A cytotoxicity study of LTP-DOC salt showed an approximately 2.5 times lower IC50 value than the LTP-free base and 1.7 times lower than commercial ditosylate salt with an approximately 3 times higher selectivity index. The investigations strongly indicate a high translational potential of the prepared salt form in maintaining solubility-lipophilicity interplay, enhancing the drug's bioavailability, and developing lipidic formulations.

Transforming microbial pigment into therapeutic revelation: extraction and characterization of pyocyanin from Pseudomonas aeruginosa and its therapeutic potential as an antibacterial and anticancer agent

BACKGROUND

The objectives of the current study were to extract pyocyanin from Pseudomonas aeruginosa clinical isolates, characterize its chemical nature, and assess its biological activity against different bacteria and cancer cells. Due to its diverse bioactive properties, pyocyanin, being one of the virulence factors of P. aeruginosa, holds a promising, safe, and available therapeutic potential.

METHODS

30 clinical P. aeruginosa isolates were collected from different sources of infections and identified by routine methods, the VITEK 2 compact system, and 16 S rRNA. The phenazine-modifying genes (phzM, phzS) were identified using polymerase chain reaction (PCR). Pyocyanin chemical characterization included UV-Vis spectrophotometry, Fourier Transform Infra-Red spectroscopy (FTIR), Gas Chromatography-Mass Spectrometry (GC-MS), and Liquid Chromatography-Mass Spectrometry (LC-MS). The biological activity of pyocyanin was explored by determining the MIC values against different clinical bacterial strains and assessing its anticancer activity against A549, MDA-MB-231, and Caco-2 cancer cell lines using cytotoxicity, wound healing and colony forming assays.

RESULTS

All identified isolates harboured at least one of the phzM or phzS genes. The co-presence of both genes was demonstrated in 13 isolates. The UV-VIS absorbance peaks were maxima at 215, 265, 385, and 520 nm. FTIR could identify the characteristic pyocyanin functional groups, whereas both GC-MS and LC-MS elucidated the chemical formula C11H18N2O2, with a molecular weight 210. The quadri-technical analytical approaches confirmed the chemical nature of the extracted pyocyanin. The extract showed broad-spectrum antibacterial activity, with the greatest activity against Bacillus, Staphylococcus, and Streptococcus species (MICs 31.25-125 µg/mL), followed by E. coli isolates (MICs 250-1000 µg/mL). Regarding the anticancer activity, the pyocyanin extract showed IC50 values against A549, MDA-MB-231, and Caco-2 cancer cell lines of 130, 105, and 187.9 µg/mL, respectively. Furthermore, pyocyanin has markedly suppressed colony formation and migratory abilities in these cells.

CONCLUSIONS

The extracted pyocyanin has demonstrated to be a potentially effective candidate against various bacterial infections and cancers. Hence, the current findings could contribute to producing this natural compound easily through an affordable method. Nonetheless, future studies are required to investigate pyocyanin's effects in vivo and analyse the results of combining it with other traditional antibiotics or anticancer drugs.

Evaluating the effects of various ethanolic medicinal plant extracts on metastatic breast cancer proliferation, invasion, and expression of a novel potential drug target; CD82 metastatic suppressor protein, and on in vivo angiogenesis using the ex ovo yolk sac membrane (YSM) assay

PURPOSE

Breast cancer metastasis relies on cellular invasion and angiogenesis facilitated by the downregulation of metastatic suppressor proteins like Cluster of Differentiation 82 (CD82). Currently, no medicines target multiple systems to prevent metastatic progression through CD82 upregulation. This study screened for plant extracts displaying effects on cell proliferation, invasion, and CD82 expression in breast cancer cells, and in vivo angiogenesis, and further correlated between the biological activities and effect on CD82 expression.

METHODS

Seventeen ethanolic plant extracts were screened for their effect on cell proliferation (against MDA-MB-231 and MCF-7 breast cancer and Hek293 kidney cells), cell invasion and effect on CD82 expression in metastatic MDA-MB-231 cells. Selected extracts were further evaluated for in vivo anti-angiogenesis.

RESULTS

Extracts displayed varying antiproliferative activity against the different cell lines, and those that showed selectivity indexes (SI) > 0.5 against MDA-MB-231 were selected for anti-invasion evaluation. Buddleja saligna Willd. (BS), Combretum apiculatum Sond. (CA), Foeniculum vulgare, Greyia radlkoferi, Gunnera perpensa and Persicaria senegalensis (Meisn.) Soják (PS) displayed 50% inhibitory concentration (IC50) values of 44.46 ± 3.46, 74.00 ± 4.48, 180.43 ± 4.51, 96.97 ± 2.29, 55.29 ± 9.88 and 243.60 ± 2.69 µg/mL, respectively against MDA-MB-231, and compared to Hek293 showed SI of 0.9, 0.7, 1.4, 1.1, 2.2 and 0.5. Significant invasion inhibition was observed at both 20 and 40 µg/mL for BS (94.10 ± 0.74 and 96.73 ± 0.95%) and CA (87.42 ± 6.54 and 98.24 ± 0.63%), whereas GR (14.91 ± 1.62 and 41 ± 1.78%) and PS (36.58 ± 0.54 and 51.51 ± 0.83%), only showed significant inhibition at 40 µg/mL, and FV (< 5% inhibition) and GP (10 ± 1.03 and 22 ± 1.31%) did not show significant inhibition at both concentrations. Due to the significant anti-invasive activity of BS, CA and PS at 40 µg/mL, these extracts were further evaluated for their potential to stimulate CD82. BS showed significant (p < 0.05) reduction in CD82 at 20 and 40 µg/mL (13.2 ± 2.2% and 20.3 ± 1.5% decrease, respectively), whereas both CA and PS at 20 µg/mL increased (p < 0.05) CD82 expression (16.4 ± 0.8% and 5.4 ± 0.6% increase, respectively), and at 40 µg/mL significantly reduced CD82 expression (23.4 ± 3.1% and 11.2 ± 2.9% decrease, respectively). Using the yolk sac membrane assay, BS (59.52 ± 4.12 and 56.72 ± 3.13% newly formed vessels) and CA (83.33 ± 3.17 and 74.00 ± 2.12%) at both 20 and 40 µg/egg showed significant (p < 0.001) angiogenesis inhibition, with BS showing statistical similar activity to the positive control, combretastatin A4 (10 nmol/egg), whereas PS only displayed significant (p < 0.001) angiogenesis stimulation at 40 µg/egg (120.81 ± 3.34% newly formed vessels).

CONCLUSION

BS exhibits antiproliferative, anti-invasive, and anti-angiogenic activity despite inhibiting CD82, suggesting an alternative mode of action. CA at 20 µg/mL shows moderate anti-invasive and anti-angiogenic potential by stimulating CD82, while at 40 µg/mL it still displays these properties but inhibits CD82, suggesting an additional mode of action. PS, with the least antiproliferative activity, stimulates CD82 and inhibits angiogenesis at 20 µg/mL but inhibits CD82 and increases angiogenesis at 40 µg/mL, indicating CD82 targeting as a major mode of action. Future studies should explore breast cancer xenograft models to assess the extracts' impact on CD82 expression and angiogenesis in the tumor microenvironment, along with isolating bioactive compounds from the extracts.

A Comprehensive Review of Ethnomedicinal Uses, Phytochemistry, Pharmacology, and Toxicity of Prunus africana (Hook. F.) Kalkman from Africa

Prunus africana, a widely utilized medicinal plant in various African ethnic communities, continues to hold significant importance in traditional healing practices. Research has identified phytochemical compounds in this plant, exhibiting diverse pharmacological activities that offer potential for pharmaceutical development. Notably, P. africana is employed in treating various ailments such as wounds, diabetes mellitus, malaria, benign prostatic hyperplasia, chest pain, and prostate cancer. Its pharmacological properties are attributed to a spectrum of bioactive compounds, including tannins, saponins, alkaloids, flavonoids, terpenoids, phytosterols, and fatty acids. Multiple studies have documented the anti-inflammatory, antimicrobial, antiandrogenic, antiangiogenic, antioxidant, antidipeptidyl peptidase-4 activity, analgesic, and astringent properties of P. africana extracts. This review offers a comprehensive compilation of ethnomedicinal applications, phytochemical composition, pharmacological effects, and toxicity assessments of P. africana, serving as a foundation for future preclinical and clinical investigations. By understanding its traditional uses and chemical constituents, researchers can target specific medical conditions with greater precision, potentially expediting the development of safe and effective pharmaceuticals. Moreover, toxicity assessments provide crucial insights into the safety profile of P. africana extracts, ensuring the development of safe pharmaceuticals to treat various diseases.

AM1172 (a hydrolysis-resistant endocannabinoid analog that inhibits anandamide cellular uptake) reduces the viability of the various melanoma cells, but it exerts significant cytotoxic effects on healthy cells: an in vitro study based on isobolographic analysis

BACKGROUND

Despite great advances in our understanding of the impact of cannabinoids on human organism, many of their properties still remain undetermined, including their potential antineoplastic effects. This study was designed to assess the anti-proliferative and cytotoxic effects of AM1172 (a hydrolysis-resistant endocannabinoid analog that inhibits anandamide cellular uptake) administered alone and in combinations with docetaxel (DOCX), paclitaxel (PACX), mitoxantrone (MTX) and cisplatin (CDDP) on various human malignant melanoma A375, FM55P, SK-MEL 28 and FM55M2 cell lines.

MATERIALS

In the MTT, LDH, and BrdU assays, the potency and safety of AM1172 when administered alone and in combinations with DOCX, PACX, MTX, and CDDP were determined.

RESULTS

The isobolographic analysis revealed that combinations of AM1172 with PACX, DOCX, MTX, and CDDP exerted additive interactions, except for a combination of AM1172 with PACX in primary melanoma A375 cell line, for which synergy was observed (*p<0.05). Nevertheless, AM1172 when administered alone produced cytotoxic effects on healthy human melanocytes (HEMa-LP) and human keratinocytes (HaCaT), which unfortunately limits its potential therapeutic utility.

CONCLUSIONS

AM1172 cannot be used separately as a chemotherapeutic drug, but it can be combined with PACX, DOCX, MTX, and CDDP, offering additive interactions in terms of the anti-proliferative effects in various malignant melanoma cell lines.

Green Approach Toward Triazole Forming Reactions for Developing Anticancer Drugs

Compounds containing triazole have many significant applications in the dye and ink industry, corrosion inhibitors, polymers, and pharmaceutical industries. These compounds possess many antimicrobial, antioxidant, anticancer, antiviral, anti-HIV, antitubercular, and anticancer activities. Several synthetic methods have been reported for reducing time, minimizing synthetic steps, and utilizing less hazardous and toxic solvents and reagents to improve the yield of triazoles and their analogues synthesis. Among the improvement in methods, green approaches towards triazole forming biologically active compounds, especially anticancer compounds, would be very important for pharmaceutical industries as well as global research community. In this article, we have reviewed the last five years of green chemistry approaches on click reaction between alkyl azide and alkynes to install 1,2,3-triazole moiety in natural products and synthetic drug-like molecules, such as in colchicine, flavanone cardanol, bisphosphonates, thiabendazoles, piperazine, prostanoid, flavonoid, quinoxalines, C-azanucleoside, dibenzylamine, and aryl-azotriazole. The cytotoxicity of triazole hybrid analogues was evaluated against a panel of cancer cell lines, including multidrug-resistant cell lines.

The effect of environmental stressors on the anticancer potential of Amaranthus hypochondriacus aqueous extracts and fractions

Some Amaranthus species have been shown to have pharmacological properties such as activity against cancer, and it is also used as a traditional herbal medicine in many rural parts of the world. The (3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide assay was used as a screening tool to determine the approximate cell viability inhibitory concentrations of methanol and aqueous crude extracts of Amaranthus spp. The extracts were screened using small-cell lung cancer (H69V), hepatocellular carcinoma (HepG2/C3A) and non-cancerous kidney cells (Vero) cell lines. Viability was assessed following exposure to a series of concentrations of each extract and A. hypochondriacus showed cytotoxicity of 70.55 µg/mL against H69V with a Si index of 1.8. The fractionated aqueous extract of 40 °C-treated A. hypochondriacus under well-watered conditions had a higher viability inhibition on H69V and Vero cell lines compared to the A. caudatus, A. cruentus and A. spinosus crude extracts. In conclusion, A. hypochondriacus could serve as a potential source of anticancer phytoconstituents for drug development.

Insights into the Biological Activity and Cytotoxic Mechanism of Epimedium pubigerum

In this work, the phytochemical characterization, biological activity, and cytotoxic mechanism of aerial and rhizome methanol extracts (SME and RME) of Epimedium pubigerum were investigated to demonstrate its potential usage in the treatment of lung cancer. LC-HRMS analysis, total phenolic/flavonoid content assay, DPPH radical scavenging assay, DNA interaction, cytotoxicity, and western blotting were investigated using different methods. Fumaric acid was found to be the most abundant compound in both extracts. SME and RME were cytotoxic on A549 cells concentration-dependently. Also, in vitro scratch assay showed that SME and RME led to a significant anti-migratory effect at 1 mg/mL. Cytochrome c, p53, and caspase 3 expression significantly increased in the presence of RME compared to the control. All of these results claimed that RME might be suggested as a theoretically more effective phytotherapeutic agent for lung cancer compared to the effect seen with the SME.

Repurposing Terfenadine as a Novel Antigiardial Compound

Giardia lamblia is a highly infectious protozoan that causes giardiasis, a gastrointestinal disease with short-term and long-lasting symptoms. The currently available drugs for giardiasis treatment have limitations such as side effects and drug resistance, requiring the search for new antigiardial compounds. Drug repurposing has emerged as a promising strategy to expedite the drug development process. In this study, we evaluated the cytotoxic effect of terfenadine on Giardia lamblia trophozoites. Our results showed that terfenadine inhibited the growth and cell viability of Giardia trophozoites in a time-dose-dependent manner. In addition, using scanning electron microscopy, we identified morphological damage; interestingly, an increased number of protrusions on membranes and tubulin dysregulation with concomitant dysregulation of Giardia GiK were observed. Importantly, terfenadine showed low toxicity for Caco-2 cells, a human intestinal cell line. These findings highlight the potential of terfenadine as a repurposed drug for the treatment of giardiasis and warrant further investigation to elucidate its precise mechanism of action and evaluate its efficacy in future research.

Advances in the Properties of Incomptine A: Cytotoxic Activity and Downregulation of Hexokinase II in Breast Cancer Cell Lines

Breast cancer treatments are limited by the cancer subtype and its selectivity towards tumor cells, hence the importance of finding compounds that increase the survival of healthy cells and target any subtype. Incomptine A (IA) is a sesquiterpene lactone with demonstrated cytotoxic activity. In this study, through in vitro assays, it was observed that IA has similar cytotoxic activity between the subtypes triple negative, HER2+, and luminal A of the breast cancer cell lines. IA cytotoxic activity is higher in cancer than in nontumorigenic cells, and its selectivity index for cancer cells is more than that of the drug doxorubicin. Molecular docking and its in silico comparison with the 2-Deoxyglucose inhibitor suggest that IA could bind to Hexokinase II (HKII), decreasing its expression. Since we did not find changes in the expression of the glycolytic pathway, we suppose that IA could affect the antiapoptotic function of HKII in cancer cells. The IA-HKII union would activate the voltage-gated anion channel 1 (VDAC1), resuming apoptosis. Therefore, we suggest that IA could be used against almost any subtype and that its cytotoxic effect could be due to the reactivation of apoptosis in breast cancer cells.

Disparities in Cisplatin-Induced Cytotoxicity-A Meta-Analysis of Selected Cancer Cell Lines

Cisplatin is a classic anticancer drug widely used as a reference drug to test new metal complex drug candidates. We found an unexpected diversity in cisplatin-related cytotoxicity values, expressed as IC50 (the half-maximal inhibitory concentration) in tumour cell lines, such as MCF-7, HepG2 and HeLa. We reviewed the data published from 2018 to 2022. A total of 41 articles based on 56 in vitro experiments met our eligibility criteria. Using a meta-analysis based on a random effect model, we evaluated the cytotoxicity of cisplatin (IC50) after 48- or 72-h cell exposure. We found large differences between studies using a particular cell line. According to the random effect model, the 95% confidence intervals for IC50 were extremely wide. The heterogeneity of cisplatin IC50, as measured by the I2 index for all cancer cell lines, was over 99.7% at culture times of 48 or 72 h. Therefore, the variability between studies is due to experimental heterogeneity rather than chance. Despite the higher IC50 values after 48 h than after 72 h, the heterogeneity between the two culture periods did not differ significantly. This indicates that the duration of cultivation is not the main cause of heterogeneity. Therefore, the available data is diverse and not useful as a reference. We discuss possible reasons for the IC50 heterogeneity and advise researchers to conduct preliminary testing before starting experiments and not to solely rely on the published data. We hope that this systematic meta-analysis will provide valuable information for researchers searching for new cancer drugs using cisplatin as a reference drug.

Innovative Eco-Friendly Microwave-Assisted Rapid Biosynthesis of Ag/AgCl-NPs Coated with Algae Bloom Extract as Multi-Functional Biomaterials with Non-Toxic Effects on Normal Human Cells

Harmful algal blooms impact human welfare and are a global concern. Sargassum spp., a type of algae or seaweed that can potentially bloom in certain regions of the sea around Thailand, exhibits a noteworthy electron capacity as the sole reducing and stabilizing agent, which suggests its potential for mediating nanoparticle composites. This study proposes an eco-friendly microwave-assisted biosynthesis (MAS) method to fabricate silver nanoparticles coated with Sargassum aqueous extract (Ag/AgCl-NPs-ME). Ag/AgCl-NPs-ME were successfully synthesized in 1 min using a 20 mM AgNO₃ solution without additional hazardous chemicals. UV-visible spectroscopy confirmed their formation through a surface plasmon resonance band at 400-500 nm. XRD and FTIR analyses verified their crystalline nature and involvement of organic molecules. TEM and SEM characterization showed well-dispersed Ag/AgCl-NPs-ME with an average size of 36.43 nm. The EDS results confirmed the presence of metallic Ag⁺ and Cl^- ions. Ag/AgCl-NPs-ME exhibited significant antioxidant activity against free radicals (DPPH, ABTS, and FRAP), suggesting their effectiveness. They also inhibited enzymes (tyrosinase and ACE) linked to diseases, indicating therapeutic potential. Importantly, the Ag/AgCl-NPs-ME displayed remarkable cytotoxicity against cancer cells (A375, A549, and Caco-2) while remaining non-toxic to normal cells. DNA ladder and TUNEL assays confirmed the activation of apoptosis mechanisms in cancer cells after a 48 h treatment. These findings highlight the versatile applications of Ag/AgCl-NPs-ME in food, cosmetics, pharmaceuticals, and nutraceuticals.

Haloarchaeal carotenoids exert an in vitro antiproliferative effect on human breast cancer cell lines

Oxidative stress has been linked to the onset and progression of different neoplasia. Antioxidants might help prevent it by modulating biochemical processes involved in cell proliferation. Here, the aim was to evaluate the in vitro cytotoxic effect of Haloferax mediterranei bacterioruberin-rich carotenoid extracts (BRCE) (0-100 µg/ml) in six BC cell lines, representative of the intrinsic phenotypes and a healthy mammary epithelium cell line. Cell index values were obtained using xCELLigence RTCA System. Furthermore, cell diameter, viability, and concentration were measured at 12 h, 24 h, and 30 h. We found that BC cells were selectively affected by BRCE (SI > 1, p < 0.005). After 30 h, the population of BC cells exposed to 100 µg/ml was 11.7-64.6% of the control (p = 0.0001-0.0009). Triple-negative cells were significantly affected [MDA-MB-231 (IC₅₀ 51.8 µg/ml, p < 0.0001) and MDA-MB-468 (IC₅₀ 63.9 µg/ml, p < 0.0001)]. Cell size was also reduced after 30 h treatment in 3.8 (± 0.1) µm and 3.3 (± 0.02) µm for SK-BR-3 (p < 0.0001) and MDA-MB-468 (p < 0.0001), respectively. In conclusion, Hfx. mediterranei BRCE exerts a cytotoxic effect on BC cell lines representative of all studied intrinsic subtypes. Furthermore, results obtained for MDA-MB-231 and MDA-MB-468 are very promising, considering the aggressive behaviour of the triple-negative BC subtype.

Computational Analysis and Experimental Testing of the Molecular Mode of Action of Gatastatin and Its Derivatives

Given its critical role in cell mitosis, the tubulin γ chain represents a viable chemotherapeutic target to solve the specificity issues associated with targeting α and β tubulin. Since γ tubulin is overexpressed in glioblastoma multiforme (GBM) and some breast lesions, the glaziovianin A derivative gatastatin, presented as a γ-tubulin-specific inhibitor, could yield a successful therapeutic strategy. The present work aims to identify the binding sites and modes of gatastatin and its derivatives through molecular-docking simulations. Computational binding free energy predictions were compared to experimental microscale thermophoresis assay results. The computational simulations did not reveal a strong preference toward γ tubulin, suggesting that further derivatization may be needed to increase its specificity.

Discovery of novel benzenesulfonamides incorporating 1,2,3-triazole scaffold as carbonic anhydrase I, II, IX, and XII inhibitors

Sulfonamides are among the most promising potential inhibitors for carbonic anhydrases (CAs), which are pharmaceutically relevant targets for treating several disease conditions. Herein, a series of benzenesulfonamides bearing 1,2,3-triazole moiety as inhibitors of human (h) α-CAs (hCAs) were designed using the tail approach. The design method combines a benzenesulfonamide moiety with a tail of oxime and a zinc-binding group on a 1,2,3-triazole scaffold. Among the synthesized derivatives, the naphthyl (6m, K_I of 68.6 nM, S_I of 10.3), and methyl (6a, K_I of 56.3 nM, S_I of 11.7) derivatives (over hCA IX) and propyl (6c, K_I of 95.6 nM, S_I of 2.7), and pentyl (6d, K_I of 51.1 nM, S_I of 6.6) derivatives (over hCA XII) displayed a noticeable selectivity for isoforms hCA I and II, respectively. Meanwhile, derivative 6e displayed a potent inhibitory effect versus the cytosolic isoform hCA I (K_I of 47.8 nM) and tumor-associated isoforms hCA IX and XII (K_Is of 195.9 and 116.9 nM, respectively) compared with the reference drug acetazolamide (AAZ, K_Is of 451.8, 437.2, and 338.9 nM, respectively). Derivative 6b showed higher potency (K_I of 33.2 nM) than AAZ (K_I of 327.3 nM) towards another cytosolic isoform hCA II. Nevertheless, substituting the lipophilic large naphthyl tail to the 1,2,3-triazole linked benzenesulfonamides (6a-n) raised inhibitory effect versus hCA I and XII and selectivity towards hCA I and II isoforms over hCA IX. Evaluation of the cytotoxic potential of the synthesized derivatives was conducted in L929, MCF-7, and Hep-3B cell lines. Several compounds in the series demonstrated significant antiproliferative activity and minimal cytotoxicity. In the molecular docking study, the sulfonamide moiety interacted with the zinc-ion and neatly fit into the hCAs active sites. The extension of the tail was found to participate in diverse hydrophilic and hydrophobic interactions with adjacent amino acids, ultimately influencing the effectiveness and specificity of the derivatives.

Design and Synthesis of 1,3-Diynes as Potent Antifungal Agents against Aspergillus fumigatus

Eugenol and isoeugenol, secondary metabolites isolated from the plant Myristica fragrans have displayed antifungal activities against Aspergillus fumigatus (IC₅₀ 1900 μM). Compounds having conjugated unsaturation have been of great use as antifungals i. e. amphotericin B, nystatin and terbinafine etc. Hence, in the present study, we have designed and synthesised 1,3-diynes by utilizing Glaser-Hay and Cadiot-Chodkiewicz coupling reactions to furnish possible antifungal agents. Synthesis of 1,6-diphenoxyhexa-2,4-diyne derivatives was achieved by Cu(I) catalysed coupling of propargylated eugenol, isoeugenol, guaiacol, vanillin and dihydrogenated eugenol or eugenol in good to excellent yields. All the synthesized compounds were evaluated against pathogenic fungus A. fumigatus. Among all the synthesized compounds, one of the compounds was found to be exhibiting promising antifungal activity with IC₅₀ value of 7.75 μM thereby suggesting that this type of scaffold could pave the way for developing new antifungal agents. The most active compound was found to be low cytotoxic when assayed against L-132 cancer cell line. Effect of the most active compound on ergosterol biosynthesis has also been studied. Also, the most active compound exhibited significant anti-biofilm activity although the concentration was found to be higher than its anti-fungal activity. Morphological changes in the biofilm were remarkable under confocal laser scanning microscopy.

Biochemical and pathophysiological improvements in rats with thioacetamide induced-hepatocellular carcinoma using aspirin plus vitamin C

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death, so we should be concerned and look for effective/less-harmful treatments than chemotherapeutics already clinically in application. Aspirin works well ''in conjunction'' with other therapies for HCC since aspirin can boost the sensitivity of anti-cancer activity. Vitamin C also was shown to have antitumor effects. In this study, we examined the anti-HCC activities of synergistic combination (aspirin and vitamin C) vs. doxorubicin on HCC-bearing rats and hepatocellular carcinoma (HepG-2) cells.

METHODS

In vitro, we evaluated IC₅₀ and selectivity index (SI) using HepG-2 and human lung fibroblast (WI-38) cell lines. In vivo, four rat groups were used: Normal, HCC (intraperitoneally (i.p.) administered 200 mg thioacetamide/kg/twice a week), HCC + DOXO (HCC-bearing rats i.p. administered 0.72 mg doxorubicin (DOXO)/rat/once a week), and HCC + Aspirin + Vit. C (i.p. administered vitamin C (Vit. C) 4 g/kg/day after day concomitant with aspirin 60 mg/kg/orally day after day). We evaluated biochemical factors [aminotransferases (ALT and AST), albumin, and bilirubin (TBIL) spectrophotometrically, caspase 8 (CASP8), p53, Bcl2 associated X protein (BAX), caspase 3 (CASP3), alpha-fetoprotein (AFP), cancer antigen 19.9 (CA19.9), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) using ELISA], and liver histopathologically.

RESULTS

HCC induction was accompanied by significant time-dependent elevations in all measured biochemical parameters except the p53 level significantly declined. Liver tissue architecture organization appeared disturbed with cellular infiltration, trabeculae, fibrosis, and neovascularization. Following drug medication, all biochemical levels significantly reversed toward normal, with fewer signs of carcinogenicity in liver tissues. Compared to doxorubicin, aspirin & vitamin C therapy ameliorations were more appreciated. In vitro, combination therapy (aspirin & vitamin C) exhibited potent cytotoxicity (HepG-2 IC₅₀ of 17.41 ± 1.4 µg/mL) and more excellent safety with a SI of 3.663.

CONCLUSIONS

Based on our results, aspirin plus vitamin C can be considered reliable, accessible, and efficient synergistic anti-HCC medication.

Naturally Occurring Functional Ingredient from Filamentous Thermophilic Cyanobacterium Leptolyngbya sp. KC45: Phytochemical Characterizations and Their Multiple Bioactivities

Cyanobacteria are rich in phytochemicals, which have beneficial impacts on the prevention of many diseases. This study aimed to comprehensively characterize phytochemicals and evaluate multifunctional bioactivities in the ethanolic extract of the cyanobacterium Leptolyngbya sp. KC45. Results found that the extract mainly contained chlorophylls, carotenoids, phenolics, and flavonoids. Through LC-ESI-QTOF-MS/MS analysis, 38 phenolic compounds with promising bioactivities were discovered, and a higher diversity of flavonoids was found among the phenolic compounds identified. The extract effectively absorbed the harmful UV rays and showed high antioxidant activity on DPPH, ABTS, and PFRAP. The extract yielded high-efficiency inhibitory effects on enzymes (tyrosinase, collagenase, ACE, and α-glucosidase) related to diseases. Interestingly, the extract showed a strong cytotoxic effect on cancer cells (skin A375, lung A549, and colon Caco-2), but had a much smaller effect on normal cells, indicating a satisfactory level of safety for the extract. More importantly, the combination of the DNA ladder assay and the TUNEL assay proved the appearance of DNA fragmentation in cancer cells after a 48 h treatment with the extract, confirming the apoptosis mechanisms. Our findings suggest that cyanobacterium extract could be potentially used as a functional ingredient for various industrial applications in foods, cosmetics, pharmaceuticals, and nutraceuticals.

Evaluating the Potential Anticancer Properties of Salvia triloba in Human-Osteosarcoma U2OS Cell Line and Ovarian Adenocarcinoma SKOV3 Cell Line

Salvia triloba (S. triloba) is an herb inherently linked to traditional medicine systems in the Eastern Mediterranean region. There is minimal experimental evidence however, regarding the anticancer effects of S. triloba in both osteosarcoma and ovarian cancer. In this study, we investigated the effects of crude (macerated) S. triloba ethanol and acetone leaf extracts on viability, migratory ability, and the expression of genes regulating these activities in U2OS and SKOV3 cells using MTT assay, scratch-wound healing/trans-well migration assay, and RT-qPCR respectively. MTT assay results indicated that the acetone extract significantly reduced both U2OS and SKOV3 cell viability with half-maximal inhibitory concentrations (IC50) of 54.51 ± 1.10 µg/mL and 75.96 ± 1.0237 µg/mL respectively; these concentrations further displayed negligible hemolytic activity. The combination of acetone extract (19 µg/mL) and paclitaxel (0.787 µg/mL) displayed synergy and reduced SKOV3 cell viability by over 90%. Additionally, the trans-well migration assay illustrated that the acetone extract (IC50) inhibited both U2OS and SKOV3 cell migration by more than 50%. Moreover, S. triloba acetone extract significantly downregulated the steady-state mRNA expression of key genes involved in driving select cancer hallmarks. Four fractions were generated from the acetone extract by thin layer chromatography (TLC), and the obtained retention factors (Rf) (ranging from 0.2 to 0.8) suggested a mixture of high and moderately polar compounds whose bioactivities require further investigation. In addition, FTIR measurements of the extract revealed peaks corresponding to OH, aliphatic CH, and ester groups suggesting the presence of phenolic compounds, terpenes, and polysaccharides. Altogether, these results suggest that S. triloba possesses potential therapeutic compounds that inhibit cell proliferation and migration, and modulate several genes involved in osteosarcoma and ovarian carcinoma progression.

Mechanistic Insights and Docking Studies of Phytomolecules as Potential Candidates in the Management of Cancer

BACKGROUND

Cancer is a leading risk of death globally. According to the World Health Organization, it is presently the second most important disease that causes death in both developing and developed countries. Remarkable progress has been made in the war against cancer with the development of numerous novel chemotherapy agents. However, it remains an immense challenge to discover new efficient therapeutic potential candidates to combat cancer.

OBJECTIVES

The majority of the currently used anticancer drugs are of natural origins, such as curcumin, colchicine, vinca alkaloid, paclitaxel, bergenin, taxols, and combretastatin. Concerning this, this review article presents the structure of the most potent molecules along with IC50 values, structure-activity relationships, mechanistic studies, docking studies, in silico studies of phytomolecules, and important key findings on human cancer cell lines.

METHODS

A viewpoint of drug design and development of antiproliferative agents from natural phytomolecules has been established by searching peer-reviewed literature from Google Scholar, PubMed, Scopus, Springer, Science Direct, and Web of Science over the past few years.

RESULTS

Our analysis revealed that this article would assist chemical biologists and medicinal chemists in industry and academia in gaining insights into the anticancer potential of phytomolecules.

CONCLUSION

In vitro and in silico studies present phytomolecules, such as curcumin, colchicine, vinca alkaloids, colchicine, bergenin, combretastatin, and taxol encompassing anticancer agents, offerings abundant sanguinity and capacity in the arena of drug discovery to inspire the investigators towards the continual investigations on these phytomolecules. It is extremely expected that efforts in this track will strengthen and grant some budding cancer therapeutics candidates in the near future.

Cytotoxic effect, enzyme inhibition, and in silico studies of some novel N-substituted sulfonyl amides incorporating 1,3,4-oxadiazol structural motif

Abstract

The acetylcholinesterase and carbonic anhydrase inhibitors (AChEIs and hCAIs) remain key therapeutic agents for many bioactivities such as anti-Alzheimer and antiobesity antiepileptic, anticancer, antiinfective, antiglaucoma, and diuretic effects. Here, it has been attempted to discover novel multi-target AChEIs and hCAIs that are highly potent, orally bioavailable, may be brain penetrant, and have higher effectiveness at lower doses than tacrine and acetazolamide. After detailed investigations both in vitro and in silico, novel N-substituted sulfonyl amide derivatives (6a–j) were determined to be highly potent inhibitors for AChE and hCAs (K_Is are in the range of 23.11–52.49 nM, 18.66–59.62 nM, and 9.33–120.80 nM for AChE, hCA I, and hCA II, respectively). Moreover, according to the cytotoxic effect studies, such as the ADME-Tox, cortex neuron cells, and neuroblastoma SH-SY5Y cell line, compounds 6a, 6d, and 6h, which are the most potent representative versus the target enzymes, were identified as orally bioavailable, highly selective, and brain preferentially distributed AChEIs and hCAIs. The docking studies revealed precise binding modes between 6a, 6d, and 6h and hCA II, hCA I, and AChE, respectively. The results presented here might provide a solid basis for further investigation into more potent AChEIs and hCAIs.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11030-022-10422-8.

A New Insight into Toxicity of Colchicine Analogues by Molecular Docking Analysis Based on Intestinal Tight Junction Protein ZO-1

Colchicine (COL) is a well-known plant alkaloid long used for medical purposes due to the selective anti-inflammatory effect on acute gouty arthritis. It is also a kind of mitosis toxin with strong inhibitory effects of cell division and is therefore being applied to the treatment of various cancers. However, this product shows a variety of adverse effects that are significantly correlated with the dosage and have attracted much attention. For the first time, the present work obtained a new insight into the gastrointestinal toxicity of colchicine analogues by molecular docking analysis, which was based on the 3D structure of intestinal tight junction protein ZO-1 and the ligand library containing dozens of small-molecule compounds with the basic skeleton of COL and its metabolites. The binding energy and mode of protein–ligand interaction were investigated to better understand the structure–toxicity relationships of COL analogues and the mechanism of action as well. Cluster analysis clearly demonstrated the strong correlation between the binding energy and toxicity of ligand molecules. The interaction mode further revealed that the hydrogen bonding (via the C-7 amide or C-9 carbonyl group) and hydrophobic effect (at ring A or C) were both responsible for ZO-1-related gastrointestinal toxicity of COL analogues, while metabolic transformation via phase I and/or phase II reaction would significantly attenuate the gastrointestinal toxicity of colchicine, indicating an effective detoxication pathway through metabolism.

Synthesis of thiocolchicine amine derivatives and evaluation of their antiproliferative activity

A series of 22 amine analogs of thiocolchicine were synthesized using the reductive amination reaction. The antiproliferative activities of these compounds were tested against four tumor cell lines as well as one normal cell line. The tested analogs exhibited IC₅₀ values in the nanomolar range accompanied by high selectivity indexes, and most importantly, they were able to break the drug resistance of the human colon adenocarcinoma resistant cell line (LoVo/DX). Also, a correlation between the antiproliferative activity and physicochemical properties of the novel compounds has been found.

Novel Double-Modified Colchicine Derivatives Bearing 1,2,3-Triazole: Design, Synthesis, and Biological Activity Evaluation

A series of 1,4-disubstituted 1,2,3-triazoles having 10-demethoxy-10-N-methylaminocolchicine core were designed and synthesized via the Cu(I)-catalyzed "click" reaction and screened for their in vitro cytotoxicity against four cancer cell lines (A549, MCF-7, LoVo, LoVo/DX) and one noncancerous cell line (BALB/3T3). Indexes of resistance (RI) and selectivity (SI) were also determined to assess the potential of the analogues to break drug resistance of the LoVo/DX cells and to verify their selectivity toward killing cancer cells over normal cells. The compounds with an ester or amide moiety in the fourth position of 1,2,3-triazole of 10-N-methylaminocolchicine turned out to have the greatest therapeutic potential (low IC₅₀ values and favorable SI values), much better than that of unmodified colchicine or doxorubicin and cisplatin. Thus, they make a valuable clue for the further search for a drug having a colchicine scaffold.

Synthesis and antiproliferative screening of novel doubly modified colchicines containing urea, thiourea and guanidine moieties

A new series of 10-demethoxy-10-methylaminocolchicines bearing urea, thiourea or aguanidine moieties at position C7 has been designed, synthesized and evaluated for in vitro anticancer activity against different cancer cell lines (A549, MCF-7, LoVo, LoVo/DX). The majority of the new derivatives were active in the nanomolar range and were characterized by lower IC₅₀ values than cisplatin or doxorubicin. Two ureas (4 and 8) and thioureas (19 and 25) were found to be good antiproliferative agents (low IC₅₀ values and high SI) and could prove to be promising candidates for further research in the field of anticancer drugs based on the colchicine skeleton.

Recent advances in research of colchicine binding site inhibitors and their interaction modes with tubulin

Microtubules have been a concerning target of cancer chemotherapeutics for decades, and several tubulin-targeted agents, such as paclitaxel, vincristine and vinorelbine, have been approved. The colchicine binding site is one of the primary targets on microtubules and possesses advantages compared with other tubulin-targeted agents, such as inhibitors of tumor vessels and overcoming P-glycoprotein overexpression-mediated multidrug resistance. This study reviews and summarizes colchicine binding site inhibitors reported in recent years with structural studies via the crystal structures of complexes or computer simulations to discover new lead compounds. We are attempting to resolve the challenge of colchicine site agent research.

An insight into the anticancer potential of carbamates and thiocarbamates of 10-demethoxy-10-methylaminocolchicine

Colchicine shows very high antimitotic activity, therefore, it is used as a lead compound for generation of new anticancer agents. In the hope of developing novel, useful drugs with more favourable pharmacological profiles, a series of doubly modified colchicine derivatives has been designed, synthesized and characterized. These novel carbamate or thiocarbamate derivatives of 10-demethoxy-10-methylaminocolchicine have been tested for their antiproliferative activity against four human cancer cell lines. Additionally, their mode of action has been evaluated as colchicine binding site inhibitors, using molecular docking studies. Most of the tested compounds showed greater cytotoxicity (IC₅₀ in a low nanomolar range) and were characterized by a higher selectivity index than standard chemotherapeutics such as cisplatin and doxorubicin as well as unmodified colchicine. Their pharmacological use in cancer therapy could possibly be accomplished with lower dosages and result in less acute toxicity problems than in the case of colchicine. In addition, we present a QSAR model for predicting the antiproliferative activity of doubly modified derivatives for two tumour cell lines.

Interdimeric Curvature in Tubulin-Tubulin Complexes Delineates the Microtubule-Destabilizing Properties of Plocabulin

Plocabulin is a novel microtubule (MT) destabilizer agent with potent antineoplastic activity. This compound binds to the maytansine site at the longitudinal interface between tubulin dimers and exerts a hinge-like effect that disrupts normal microtubule assembly. Plocabulin has emerged as a valuable model for the rational design of novel MT destabilizers because of its unique structural and mechanistic features. To make progress on this matter, detailed molecular-level understanding of the ligand-protein interactions responsible for plocabulin association and the conformation and energetic effects arising from plocabulin binding on the longitudinal interaction between tubulin dimers must be provided. In this work, fully atomistic MD simulations and MM/GBSA binding free-energy calculations were used to examine the association of plocabulin to one or two tubulin dimers in longitudinal arrangement. Our results revealed that plocabulin binding is favored by the addition of a second tubulin dimer and that this ligand promotes the assembly of curved tetrameric arrangements with strengthened longitudinal interdimeric interactions compared to ligand-free systems. The applicability of these findings to the rational discovery of novel MT destabilizers was tested using MD and MM/GBSA calculations as filtering tools to narrow the results of virtual screening among an FDA-approved drug database. Our results confirmed that tight-binding ligands do not necessarily exert the expected conformational and energetic effects on longitudinal tubulin-tubulin interactions, which is a matter to consider in future design strategies.

New Series of Double-Modified Colchicine Derivatives: Synthesis, Cytotoxic Effect and Molecular Docking

Colchicine is a well-known anticancer compound showing antimitotic effect on cells. Its high cytotoxic activity against different cancer cell lines has been demonstrated many times. In this paper we report the syntheses and spectroscopic analyses of novel colchicine derivatives obtained by structural modifications at C7 (carbon-nitrogen single bond) and C10 (methylamino group) positions. All the obtained compounds have been tested in vitro to determine their cytotoxicity toward A549, MCF-7, LoVo, LoVo/DX, and BALB/3T3 cell lines. The majority of obtained derivatives exhibited higher cytotoxicity than colchicine, doxorubicin and cisplatin against the tested cancerous cell lines. Additionally, most of the presented derivatives were able to overcome the resistance of LoVo/DX cells. Additionally, their mode of binding to β-tubulin was evaluated in silico. Molecular docking studies showed that apart from the initial amides 1 and 2, compound 14, which had the best antiproliferative activity (IC₅₀ = 0.1–1.6 nM), stood out also in terms of its predicted binding energy and probably binds best into the active site of βI-tubulin isotype.