Trilobolide-6-O-isobutyrate from Sphagneticola trilobata acts by inducing oxidative stress, metabolic changes and apoptosis-like processes by caspase 3/7 activation of human lung cancer cell lines.

BACKGROUND: Lung cancer, a chronic and heterogeneous disease, is the leading cause of cancer-related death on a global scale. Presently, despite a variety of available treatments, their effectiveness is limited, often resulting in considerable toxicity and adverse effects. Additionally, the development of chemoresistance in cancer cells poses a challenge. Trilobolide-6-O-isobutyrate (TBB), a natural sesquiterpene lactone extracted from Sphagneticola trilobata, has exhibited antitumor effects. Its pharmacological properties in NSCLC lung cancer, however, have not been explored. PURPOSE: This study evaluated the impact of TBB on the A549 and NCI-H460 tumor cell lines in vitro, examining its antiproliferative properties and initial mechanisms of cell death. METHODS: TBB, obtained at 98 % purity from S. trilobata leaves, was characterized using chromatographic techniques. Subsequently, its impact on inhibiting tumor cell proliferation in vitro, TBB-induced cytotoxicity in LLC-MK2, THP-1, AMJ2-C11 cells, as well as its effects on sheep erythrocytes, and the underlying mechanisms of cell death, were assessed. RESULTS: In silico predictions have shown promising drug-likeness potential for TBB, indicating high oral bioavailability and intestinal absorption. Treatment of A549 and NCI-H460 human tumor cells with TBB demonstrated a direct impact, inducing significant morphological and structural alterations. TBB also reduced migratory capacity without causing toxicity at lower concentrations to LLC-MK2, THP-1 and AMJ2-C11 cell lines. This antiproliferative effect correlated with elevated oxidative stress, characterized by increased levels of ROS, superoxide anion radicals and NO, accompanied by a decrease in antioxidant markers: SOD and GSH. TBB-stress-induced led to changes in cell metabolism, fostering the accumulation of lipid droplets and autophagic vacuoles. Stress also resulted in compromised mitochondrial integrity, a crucial aspect of cellular function. Additionally, TBB prompted apoptosis-like cell death through activation of caspase 3/7 stressors. CONCLUSION: These findings underscore the potential of TBB as a promising candidate for future studies and suggest its viability as an additional component in the development of novel anticancer drugs prototypes.

Larval excretion/secretion of dipters of Lucilia cuprina species induces death in promastigote and amastigote forms of Leishmania amazonensis.

Leishmaniasis is a neglected tropical disease that affects millions of people around the world. Larval excretion/secretion (ES) of the larvae of flies of the Calliphoridae family has microbicidal activity against Gram-positive and Gram-negative bacteria, in addition to some species of Leishmania. Our study aimed at assessing the in vitro efficacy of Lucilia cuprina larval ES against the promastigote and amastigote forms of Leishmania amazonensis, elucidating possible microbicidal mechanisms and routes of death involved. Larval ES was able to inhibit the viability of L. amazonensis at all concentrations, induce morphological and ultrastructural changes in the parasite, retraction of the cell body, roughness of the cytoplasmic membrane, leakage of intracellular content, ROS production increase, induction of membrane depolarization and mitochondrial swelling, the formation of cytoplasmic lipid droplets and phosphatidylserine exposure, thus indicating the possibility of apoptosis-like death. To verify the efficacy of larval ES on amastigote forms, we performed a phagocytic assay, measurement of total ROS and NO. Treatment using larval ES reduced the percentage of infection and the number of amastigotes per macrophage of lineage J774A.1 at all concentrations, increasing the production of ROS and TNF-α, thus indicating possible pro-inflammatory immunomodulation and oxidative damage. Therefore, treatment using larval ES is effective at inducing the death of promastigotes and amastigotes of L. amazonensis even at low concentrations.

Solidagenone acts on promastigotes of L. amazonensis by inducing apoptosis-like processes on intracellular amastigotes by IL-12p70/ROS/NO pathway activation.

BACKGROUND: Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the Leishmania genus. Currently, the treatment has limited effectiveness and high toxicity, is expensive, requires long-term treatment, induces significant side effects, and promotes drug resistance. Thus, new therapeutic strategies must be developed to find alternative compounds with high efficiency and low cost. Solidagenone (SOL), one of the main constituents of Solidago chilensis, has shown gastroprotective, anti-inflammatory and immunomodulatory effects. PURPOSE: This study assessed the in vitro effect of SOL on promastigotes and Leishmania amazonensis-infected macrophages, as well its microbicide and immunomodulatory mechanisms. METHODS: SOL was isolated from the roots of S. chilensis, 98% purity, and identified by chromatographic methods, and the effect of SOL on leishmanicidal activity against promastigotes in vitro, SOL-induced cytotoxicity in THP-1, J774 cells, sheep erythrocytes, and L. amazonensis-infected J774 macrophages, and the mechanisms of death involved in this action were evaluated. RESULTS: In silico predictions showed good drug-likeness potential for SOL with high oral bioavailability and intestinal absorption. SOL treatment (10-160 µM) inhibited promastigote proliferation 24, 48, and 72 h after treatment. After 24 h of treatment, SOL at the IC50 (34.5 µM) and 2 × the IC50 (69 µM) induced several morphological and ultrastructural changes in promastigotes, altered the cell cycle and cellular volume, increased phosphatidylserine exposure on the cell surface, induced the loss of plasma membrane integrity, increased the reactive oxygen species (ROS) level, induced loss of mitochondrial integrity (characterized by an apoptosis-like process), and increased the number of lipid droplets and autophagic vacuoles. Additionally, SOL induced low cytotoxicity in J774 murine macrophages (CC50 of 1587 µM), THP-1 human monocytes (CC50 of 1321 µM), and sheep erythrocytes. SOL treatment reduced the percentage of L. amazonensis-infected macrophages and the number of amastigotes per macrophage (IC50 9.5 µM), reduced TNF-α production and increased IL-12p70, ROS and nitric oxide (NO) levels. CONCLUSION: SOL showed in vitro leishmanicidal effects against the promastigotes by apoptosis-like mechanism and amastigotes by reducing TNF-α and increasing IL-12p70, ROS, and NO levels, suggesting their potential as a candidate for use in further studies on the design of antileishmanial drugs.

Trans-chalcone induces death by autophagy mediated by p53 up-regulation and ß-catenin down-regulation on human hepatocellular carcinoma HuH7.5 cell line.

BACKGROUND: Hepatocellular Carcinoma (HCC) is extremely aggressive and presents low rates of response to the available chemotherapeutic agents. Many studies have focused on the search for alternative low-cost natural compounds with antiproliferative potential that selectively respond to liver cancer cells. PURPOSE: This study assessed the in vitro direct action of trans-chalcone (TC) on cells of the human HCC HuH7.5 cell line. METHODS: We subjected the HuH7.5 tumor cells to TC treatment at increasing concentrations (12.5-100 µM) for 24 and 48 h. Cell viability was verified through MTT and 50% inhibitory concentration of cells (IC50 23.66 µM) was determined within 48 h. We quantified trypan blue proliferation and light microscopy, ROS production, mitochondrial depolarization and autophagy, cell cycle analysis, and apoptosis using Muse® cell analyzer and immunocytochemical markings of p53 and ß-catenin. RESULTS: Data showed an effective dose- and time-dependent TC-cytotoxic action at low micromolar concentrations without causing toxicity to non-cancerous cells, such as erythrocytes. TC-treatment caused mitochondrial membrane damage and cell cycle G0/G1 phase arrest, increasing the presence of the p53 protein and decreasing ß-catenin, in addition, to inducing cell death by autophagy. Additionally, TC decreased the metastatic capacity of HuH7.5, which affected the migration/invasion of this type of cell. CONCLUSION: In vitro TC activity in the human HCC HuH7.5 tumor cell line is shown to be a potential molecule to develop new therapies to repair the p53 pathway and prevent the overexpression of Wnt/ß-catenin tumor development inducing autophagy cell death and decreasing metastatic capacity of HuH7.5 cell line.

Caffeic acid has antipromastigote activity by apoptosis-like process; and anti-amastigote by TNF-α/ROS/NO production and decreased of iron availability.

BACKGROUND: Leishmaniasis is a disease caused by protozoan parasites of the Leishmania genus whose current treatment has high cost, highly toxic, and difficult administration, which makes it very important to find alternative natural compounds of high efficiency and low cost. PURPOSE: This study assessed the in vitro effect of caffeic acid (CA) on promastigotes and L. amazonensis-infected macrophages. METHODS: Evaluation of the in vitro leishmanicidal activity of CA against promastigotes and L. amazonensis infected peritoneal macrophages, as well its microbicide mechanisms. RESULTS: CA 12.5-100 µg/ml were able to inhibit promastigotes proliferation at all tested periods. The IC50, 12.5 µg/ml, also altered promastigote cell morphology and cell volume accompanied by loss of mitochondrial integrity, increase in reactive oxygen species (ROS) production, phosphatidylserine exposure, and loss of plasma membrane integrity - characterizing the apoptosis-like process. Moreover, CA reduced the percentage of infected macrophages and the number of amastigotes per macrophages increasing TNF-α, ROS, NO and reducing IL-10 levels as well as iron availability. CONCLUSION: CA showed in vitro antipromastigote and antiamostigote by increasing oxidant and inflammatory response important to eliminate the parasite.

Grandiflorenic acid promotes death of promastigotes via apoptosis-like mechanism and affects amastigotes by increasing total iron bound capacity.

BACKGROUND: American tegumentary leishmaniasis (ATL) is a zoonotic disease caused by protozoa of the genus Leishmania. The high toxicity, high costs and resistance of some strains to current drugs has prompted the search for therapeutic alternatives for the management of this disease. Sphagneticola trilobata is a plant that has diterpenes as main constituents, including grandiflorenic acid (GFA) that has antiinflammatory, antiprotozoal, antibacterial and antinociceptive activity. PURPOSE: The aim of our study was to determine the effect of GFA on both the promastigotes and the amastigotes of Leishmania amazonensis. METHODS: Isolation by chromatographic methods and chemical identification of GFA, then evaluation of the in vitro leishmanicidal activity of this compound against Leishmania amazonensis promastigotes and L. amazonensis infected peritoneal Balb/c macrophages, as well its action and microbicide mechanisms. RESULTS: GFA treatment significantly inhibited the proliferation of promastigotes. This antiproliferative effect was accompanied by morphological changes in the parasite with 25 nM GFA. Afterwards, we investigated the mechanisms involved in the death of the protozoan; there was an increase in the production of reactive oxygen species (ROS), phosphatidylserine exposure, permeabilization of the plasma membrane and decreased mitochondrial depolarization. In addition, we observed that the treatment caused a reduction in the percentage of infected cells and the number of amastigotes per macrophage, without showing cytotoxicity in low doses to peritoneal macrophages and sheep erythrocytes. GFA increased IL-10 and total iron bound to transferrin in infected macrophages. Our results showed that GFA treatment acts on promastigote forms through an apoptosis-like mechanism and on intracellular amastigote forms, dependent of regulatory cytokine IL-10 modulation with increase in total iron bound to transferrin. CONCLUSION: GFA showed in vitro antileishmanial activity on L. amazonensis promastigotes forms and on L. amazonensis-infected macrophages.