Antitumoral activity of novel 1,4-naphthoquinone derivative involves L-type calcium channel activation in human colorectal cancer cell line

Toxicogenetic profile of the monoterpene alpha-terpineol on normal and tumor eukaryotic cells

Alpha-terpineol is a monoterpene alcohol found in essential oils from medicinal plants with some well-known pharmacological activities and widely used in cosmetics. However, the toxicological effects and additional pharmacological activities need to be clarified. Thus, the study evaluated the toxic, cytotoxic, genotoxic, hemolytic, and oxidative potential of alpha-terpineol in non-clinical bioassays. Different concentrations of alpha-terpineol were used in bioassays, including MTT (50, 100, 200, and 400 μg/mL), Artemia salina (6.25-400 μg/mL), Allium cepa (10, 50, and 100 μg/mL), comet assay (100, 200, and 500 μg/mL), cytokinesis-block micronucleus (100, 250, and 500 μg/mL), confocal microscopy for apoptosis quantification (100 and 500 μg/mL), hemolysis and Saccharomyces cerevisiae central disk test (10, 35, and 75 μg/mL). For the MTT test, alpha-terpineol was more cytotoxic on melanoma murine B16-F10 cells rather than macrophages. For A. salina test, alpha-terpineol showed LC50 of 68.29 and 76.36 μg/mL for 24 h and 48 h of exposure time, respectively. Meanwhile, alpha-terpineol was also cytotoxic to meristematic cells, which revealed inhibition of cellular division and mutagenic action by formation of bridges and delayed anaphases. The compound increased damage index and frequency of damage corroborated by the presence of micronuclei, bridges and nuclear buds at 500 μg/mL, but it caused neither hemolysis, oxidative damage on the S. cerevisiae nor cell death in normal fibroblasts. The findings indicate alpha-terpineol has cytotoxic potential by cytogenetic and molecular mechanisms associated with apoptosis and probable target effects against melanoma cells.

Unlocking the potential of 1,4-naphthoquinones: A comprehensive review of their anticancer properties

Cancer encompasses a group of pathologies with common characteristics, high incidence, and prevalence in all countries. Although there are treatments available for this disease, they are not always effective or safe, often failing to achieve the desired results. This is why it is necessary to continue the search for new therapies. One of the strategies for obtaining new antitumor drugs is the use of 1,4-naphthoquinone as a scaffold in synthetic or natural products with antitumor activity. This review focuses on compiling studies related to the antitumor activity of 1,4-naphthoquinone and its natural and synthetic derivatives over the last 10 years. The work describes the main natural naphthoquinones with antitumor activity and classifies the synthetic naphthoquinones based on the structural modifications made to the scaffold. Additionally, the formation of metal complexes using naphthoquinones as a ligand is considered. After a thorough review, 197 synthetic compounds with potent biological activity against cancer have been classified according to their chemical structures and their mechanisms of action have been described.

Unveiling biological activities of biosynthesized starch/silver-selenium nanocomposite using Cladosporium cladosporioides CBS 174.62

BACKGROUND AND OBJECTIVES

Microbial cells capability to tolerate the effect of various antimicrobial classes represent a major worldwide health concern. The flexible and multi-components nanocomposites have enhanced physicochemical characters with several improved properties. Thus, different biological activities of biosynthesized starch/silver-selenium nanocomposite (St/Ag-Se NC) were assessed.

METHODOLOGY

The St/Ag-Se NC was biosynthesized using Cladosporium cladosporioides CBS 174.62 (C. cladosporioides) strain. The shape and average particle size were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM), respectively. On the other hand, the St/Ag-Se NC effect on two cancer cell lines and red blood cells (RBCs) was evaluated and its hydrogen peroxide (H2O2) scavenging effect was assessed. Moreover, its effects on various microbial species in both planktonic and biofilm growth forms were examined.

RESULTS

The St/Ag-Se NC was successfully biosynthesized with oval and spherical shape and a mean particle diameter of 67.87 nm as confirmed by the HR-TEM analysis. St/Ag-Se NC showed promising anticancer activity toward human colorectal carcinoma (HCT-116) and human breast cancer (MCF-7) cell lines where IC50 were 21.37 and 19.98 µg/ml, respectively. Similarly, little effect on RBCs was observed with low nanocomposite concentration. As well, the highest nanocomposite H2O2 scavenging activity (42.84%) was recorded at a concentration of 2 mg/ml. Additionally, Staphylococcus epidermidis (S. epidermidis) ATCC 12,228 and Candida albicans (C. albicans) ATCC 10,231 were the highly affected bacterial and fungal strains with minimum inhibitory concentrations (MICs) of 18.75 and 50 µg/ml, respectively. Moreover, the noticeable effect of St/Ag-Se NC on microbial biofilm was concentration dependent. A high biofilm suppression percentage, 87.5% and 68.05%, were recorded with S. epidermidis and Staphylococcus aureus (S. aureus) when exposed to 1 mg/ml and 0.5 mg/ml, respectively.

CONCLUSION

The biosynthesized St/Ag-Se NC showed excellent antioxidant activity, haemocompatibility, and anti-proliferative effect at low concentrations. Also, it exhibited promising antimicrobial and antibiofilm activities.

α-tocopherol as a selective modulator of toxicogenic damage induced by antineoplastic agents cyclophosphamide and doxorubicin

The aim of this study was to determine the oxidative/antioxidative effects, modulatory and selective potential of α-tocopherol (vitamin E) on antineoplastic drug-induced toxicogenetic damage. The toxicity, cytotoxicity and genotoxicity induced by antineoplastic agents cyclophosphamide (CPA) and doxorubicin (DOX) was examined utilizing as models Saccharomyces cerevisiae, Allium cepa, Artemia salina and human peripheral blood mononuclear cells (PBMCs) in the presence of α-tocopherol. For these tests, concentrations of α- tocopherol 100 IU/ml (67mg/ml), CPA 20 µg/ml, DOX 2 µg/ml were used. The selectivity of α-tocopherol was assessed by the MTT test using human mammary gland non-tumor (MCF10A) and tumor (MCF-7) cell lines. Data showed cytoplasmic and mitochondrial oxidative damage induced by CPA or DOX was significantly diminished by α-tocopherol in S. cerevisiae. In addition, the toxic effects on A. salina and cytotoxic and mutagenic effects on A. cepa were significantly reduced by α-tocopherol. In PBMCs, α-tocopherol alone did not markedly affect these cells, and when treated in conjunction with CPA or DOX, α-tocopherol reduced the toxicogenetic effects noted after antineoplastic drug administration as evidenced by decreased chromosomal alterations and lowered cell death rate. In human mammary gland non-tumor and tumor cell lines, α-tocopherol produced selective cytotoxicity with 2-fold higher effect in tumor cells. Evidence indicates that vitamin E (1) produced anti-cytotoxic and anti-mutagenic effects against CPA and DOX (2) increased higher selectivity toward tumor cells, and (3) presented chemoprotective activity in PBMCs.

Sustainable Synthesis, Antiproliferative and Acetylcholinesterase Inhibition of 1,4- and 1,2-Naphthoquinone Derivatives

This work describes the design, sustainable synthesis, evaluation of electrochemical and biological properties against HepG2 cell lines, and AChE enzymes of different substituted derivatives of 1,4- and 1,2-naphthoquinones (NQ). A microwave-assisted protocol was optimized with success for the synthesis of the 2-substituted-1,4-NQ series and extended to the 4-substituted-1,2-NQ family, providing an alternative and more sustainable approach to the synthesis of naphthoquinones. The electrochemical properties were studied by cyclic voltammetry, and the redox potentials related to the molecular structural characteristics and the biological properties. Compounds were tested for their potential anti-cancer activity against a hepatocellular carcinoma cell line, HepG2, using MTT assay, and 1,2-NQ derivatives were found to be more active than their 1,4-NQ homologues (3a-f), with the highest cytotoxic potential found for compound 4a (EC₅₀ = 3 μM). The same trend was found for the inhibitory action against acetylcholinesterase, with 1,2-NQ derivatives showing higher inhibition_50µM than their 1,4-NQ homologues, with 4h being the most potent compound (Inhibition_50µM = 85%). Docking studies were performed for the 1,2-NQ derivatives with the highest inhibitions, showing dual binding interactions with both CAS and PAS sites, while the less active 1,4-NQ derivatives showed interactions with PAS and the mid-gorge region.

Cytotoxic and mutagenic effects of the food additive tartrazine on eukaryotic cells

BACKGROUND

Among the food additives used in the food industry, food dyes are considered the most toxic. For instance, tartrazine (TRZ) is a food colorant commercially available with conflicting data regarding its cytotoxic, genotoxic, and mutagenic effects. Therefore, this study aimed to evaluate the cytotoxic and mutagenic potential of TRZ using different eukaryotic cells (in vitro).

METHODS

This study employed 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), brine shrimp lethality, Allium cepa and Saccharomyces cerevisiae tests. Different concentrations of TRZ and different exposure times were used in this study.

RESULTS

The results demonstrate that TRZ induced a concentration-dependent toxic effect on the test systems. It also exerted cytotoxicity in fibroblasts and human gastric cells. In addition, TRZ showed mutagenic effects on the A. cepa test system. However, its toxicogenic effects may not relate to the oxidizing activity, which was confirmed by the S. cerevisiae test model.

CONCLUSION

Taken together, TRZ exerted toxicogenic effects on the test systems. Therefore, it may be harmful to health, especially its prolonged use may trigger carcinogenesis.

Biflavones from Platonia insignis Mart. Flowers Promote In Vitro Antileishmanial and Immunomodulatory Effects against Internalized Amastigote Forms of Leishmania amazonensis

Leishmaniasis is an infectious disease that affects millions of people worldwide, making the search essential for more accessible treatments. The species Platonia insignis Mart. (Clusiaceae) has been extensively studied and has gained prominence for its pharmacological potential. The objective of this work was to evaluate the antileishmania activity, cytotoxic effect and activation patterns of macrophages of hydroalcoholic extract (EHPi), ethyl acetate fractions (FAcOEt) and morelloflavone/volkensiflavone mixture (MB) from P. insignis flowers. EHPi, FAcOEt and MB demonstrated concentration-dependent antileishmania activity, with inhibition of parasite growth in all analyzed concentrations. EHPi exhibited maximum effect at 800 μg/mL, while FAcOEt and MB reduced the growth of the parasite by 94.62% at 800 μg/mL. EHPi, FAcOEt and MB showed low cytotoxic effects for macrophages at 81.78, 159.67 and 134.28 μg/mL, respectively. EHPi (11.25 µg/mL), FAcOEt (11.25 and 22.5 µg/mL) and MB (22.5 µg/mL) characterized the increase in lysosomal activity, suggesting a possible modulating effect. These findings open for the application of flowers from a P. insignis flowers and biflavones mixture thereof in the promising treatment of leishmaniasis.

Drug Development in Channelopathies: Allosteric Modulation of Ligand-Gated and Voltage-Gated Ion Channels

Ion channels have been characterized as promising drug targets for treatment of numerous human diseases. Functions of ion channels can be fine-tuned by allosteric modulators, which interact with channels and modulate their activities by binding to sites spatially discrete from those of orthosteric ligands. Positive and negative allosteric modulators have presented a plethora of potential therapeutic advantages over traditionally orthosteric agonists and antagonists in terms of selectivity and safety. This thematic review highlights the discovery of representative allosteric modulators for ligand-gated and voltage-gated ion channels, discussing in particular their identifications, locations, and therapeutic uses in the treatment of a range of channelopathies. Additionally, structures and functions of selected ion channels are briefly described to aid in the rational design of channel modulators. Overall, allosteric modulation represents an innovative targeting approach, and the corresponding modulators provide an abundant but challenging landscape for novel therapeutics targeting ligand-gated and voltage-gated ion channels.

Proapoptotic Effects of triazol-1,4-Naphthoquinones Involve Intracellular ROS Production and MAPK/ERK Pathway in Human Leukemia Cells

BACKGROUND

The natural products constitute an important source of antitumor and cytotoxic agents. Naphthoquinones are effectively quinones present in different plants, with demonstrated anticancer activities. A recent study conducted by our group demonstrated the antileukemic potential of two novel triazol-1,4- naphthoquinones derivatives, PTN (2-(4-Phenyl-1H-1,2,3-triazol-1-yl)-1,4-naphthoquinone) and MPTN (2-[4- (4-Methoxyphenyl)-1H-1,2,3-triazol-1-yl]-1,4-naphthoquinone). Although, the mechanisms underlying the proapoptotic effects of PTN and MPTN have not been fully elucidated so far.

OBJECTIVE

The aim of this study was to evaluate the proapoptotic mechanism of PTN and MPTN in human acute leukemia cells.

METHODS

We used fluorescence microscopy to observe acridine orange and annexin V staining cells. Flow cytometry assay has also been used for ROS quantification, BAX and cytochrome c proteins expression and apoptosis analysis. MTT assay and western blotting technique have been performed as well for MAPK pathway analysis.

RESULTS

By using the acridine orange and annexin V staining with fluorescence microscopy, we have characterized the proapoptotic effects of PTN and MPTN in HL-60 cells involving the intrinsic mitochondrial pathway, since these compounds promoted an increase in the intracellular BAX and cytochrome c protein levels (p<0.05). We further demonstrated that apoptosis induction in HL-60 cells was mediated by increasing intracellular ROS levels via ERK but not p38 MAPKs pathway.

CONCLUSION

Taken together, these results have demonstrated that PTN and MPTN are promising tools for the development of new anti-leukemic drugs.

Toxic, cytogenetic and antitumor evaluations of [6]-gingerol in non-clinical in vitro studies

Gingerol - [6]-gingerol ((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone; [6]-G) - is a phenolic compound with several pharmacological properties. Herein, the aim of the study was to evaluate the toxicogenic effects of [6]-G on Artemia salina nauplii, Allium cepa, HL-60 cell line and Sarcoma 180 (S-180) ascitic fluid cells.For toxic and genotoxic analysis, it was used [6]-G concentrations of 5, 10, 20 and 40 μg mL-1. For cytotoxic evaluation using the MTT test (3- [4,5-dimethyl-thiazol-2-yl] -2,5-diphenyl tetrazolium bromide), serial [6]-G dilutions (1.56-100 μg mL-1) were performed, and S-180, HL-60 and peripheral blood mononuclear cells (PBMC) were treated for 72 h. The IC50 of [6]-G were 1.14, 5.73 and 11.18 μg mL-1 for HL-60, S-180 and PBMC, respectively, indicating a possible selectivity against tumor cell lines. At higher concentrations (>10 μg mL^-1), toxicity and genotoxicity were observed in the A. cepa test, especially at 40 μg mL^-1. Mechanisms indicating apoptosis, such as toxicity, cytotoxicity and nuclear abnormalities (bridges, fragments, delays, loose chromosomes and micronuclei) suggest that [6]-G has potential for antitumor pharmaceutical formulations.