Essential oil of lemon myrtle (Backhousia citriodora) induces S-phase cell cycle arrest and apoptosis in HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Lemon myrtle (Backhousia citriodora F.Muell.) leaves, whether fresh or dried, are used traditionally in folk medicine to treat wounds, cancers, skin infections, and other infectious conditions. However, the targets and mechanisms related to anti-cancer effect of lemon myrtle are unavailable. In our study, we found that the essential oil of lemon myrtle (LMEO) showed anti-cancer activity in vitro, and we initially explored its mechanism of action.

MATERIALS AND METHODS

We analyzed the chemical compositions of LMEO by GC-MS. We tested the cytotoxicity of LMEO on various cancer cell lines using the MTT assay. Network pharmacology was used also to analyze the targets of LMEO. Moreover, the mechanisms of LMEO were investigated through scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line.

RESULTS

LMEO showed cytotoxicity on various cancer cell lines with values of IC₅₀ 40.90 ± 2.23 (liver cancer HepG2 cell line), 58.60 ± 6.76 (human neuroblastoma SH-SY5Y cell line), 68.91 ± 4.62 (human colon cancer HT-29 cell line) and 57.57 ± 7.61 μg/mL (human non-small cell lung cancer A549 cell line), respectively. The major cytotoxic chemical constituent in LMEO was identified as citrals, which accounted for 74.9% of the content. Network pharmacological analysis suggested that apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1), androgen receptor (AR), cyclin-dependent kinases 1 (CDK1), nuclear factor erythroid 2-related factor 2 (Nrf-2), fatty acid synthase (FASN), epithelial growth factor receptor (EGFR), estrogen receptor 1 (ERα) and cyclin-dependent kinases 4 (CDK4) are potential cytotoxic targets of LMEO. These targets are closely related to cell migration, cycle and apoptosis. Notley, the p53 protein had the highest confidence to co-associate with the eight common targets, which was further confirmed by scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line. LMEO significantly inhibited the migration of HepG2 cells in time-dependent and dose-dependent manner. Moreover, LMEO caused a S-phase blocking on HepG2 cells and promoted apoptosis in the meanwhile. Western blot results indicated that p53 protein, Cyclin A2 and Bax proteins were up-regulated, while Cyclin E1 and Bcl-2 proteins were down-regulated.

CONCLUSION

LMEO showed cytotoxicity in various cancer cell lines in vitro. Pharmacological networks showed LMEO to have multi-component and multi-targeting effects that are related to inhibit migration of HepG2 cells, and affect cell cycle S-phase arrest and apoptosis through modulation of p53 protein.

Determination of biological activities of nanoparticles containing silver and copper in water disinfection with/without ultrasound technique

The final and most crucial step in obtaining clean water is disinfection. More innovative methods of water disinfection have recently been sought. Water disinfection is a promising application for nanoparticles as disinfectants. As a contribution to the literature, biofilm and metal-containing nanoparticles as antiadhesion inhibitors were used in conjunction with ultrasound in this study. The microbroth dilution test was used to reveal the microbiological antibacterial activities of different concentrations of AgNO3 and CuCl2 containing nanoparticles against the Escherichia coli ATCC 25,922 strain, which is an indicator bacterium in water systems. Antibiofilm activities were then investigated using biofilm attachment and biofilm inhibition tests. The inhibitory effect of nanoparticle ultrasonic waves on biofilm contamination was determined using a novel approach. Human keratinocyte cells (HaCaT cell line) were used in cell culture studies after water disinfection, and their cytotoxic effects were demonstrated using the MTT assay. The findings suggest that the nanoparticles utilized might be a viable choice for water disinfection applications. Furthermore, employing ultrasound at low doses with nanoparticles resulted in greater results. One feasible option is to employ nanoparticles to cleanse water without producing cytotoxicity.

New quinones, a sesquiterpene and phenol compounds with cytotoxic activity from the aerial parts of Morinda umbellata L

Eight previously undescribed compounds, two quinones (1-2), one sesquiterpene (3), and five phenol compounds (4-8), including three enantiomers (6a, 7a, and 8a), along with three corresponding known enantiomers (6b-8b) were isolated from the aerial parts of Morinda umbellata L. Their structures were elucidated by 1D and 2D NMR spectroscopy, X-ray diffraction, and experimental and calculated ECD spectra, respectively. Compound 5 was found to have weak cytotoxity, which inhibited the growth of seven human cancer cell lines (A2780, HeLa, MCF-7, BGC-823, H7420, Ketr3 and SW 1990) with IC₅₀ values from 13.3 to 15.1 μM.

Sesquiterpene coumarins from Ferula samarkandica Korovin and their bioactivity

Phytochemical study on the ethanolic extract of the dried roots of Ferula samarkandica Korovin led to the isolation of nine undiscribed sesquiterpene coumarins, samarcandicins A-I, along with thirteen known sesquiterpene coumarins. Their structures were characterized by detailed spectroscopic analysis including NMR and HR-ESI-MS. Mogoltacin and nevskin exhibited high inhibitory activity against MV-4-11 cell with IC₅₀ values of 3.94 ± 0.06 μM and 3.87 ± 0.10 μM, respectively, and nevskin and feshurin showed high inhibitory activity against mino cell with IC₅₀ values of 1.48 ± 0.06 μM and 7.88 ± 0.60 μM, respectively.

[The cytotoxity of DOP on PC12 cells and it's effect on processing of APP-enzymolysis]

Objective: To study the toxicity of dioctyl phthalate (DOP) on adrenal pheochromocytoma (PC12) cells and its effect on processing of amyloid precursor protein (APP) -enzymolysis. Methods: In vitro experiments, PC12 cells were divided into blank control (CT) , low DOP (DOP1) , medium DOP (DOP2) , high DOP (DOP3) , low DOP+Aβ(25-35) (DOP1+Aβ) , medium DOP+Aβ(25-35) (DOP2+Aβ) , high DOP+Aβ(25-35) (DOP3+Aβ) , Aβ(25-35) (Aβ) , a total of 8 groups, each with 4 samples. The cell viability was measured by MTT assay, the contents of lactate dehydrogenase (LDH) , malondialdehyde (MDA) and nitric oxide (NO) were measured, and cysteine protease 3 (Caspase-3) was determined by Western blot. In the transfection experiment, the hamster ovary (CHO) cells were transfected with APP695 and treated with different concentrations of DOP. They were divided into V-Flag control (V-Flag) , APP695-Flag (APP695) , low DOP (DOP1+APP695) , medium DOP (DOP2+APP695) , high DOP (DOP3+APP695) , a total of 5 groups, each with 4 samples. Enzyme-linked immunosorbent assay (ELISA) was used to determine the content of Aβ(1-40) and the activity of γ-secretase. In vivo experiment, 50 male Kunming mice of SPF grade, weighing (20±2) g, were selected and randomly divided into control, lead (Pb) , low DOP (DOP1＇) , medium DOP (DOP2＇) , high DOP (DOP3＇) consisted of 5 groups, each with 10 mice, continuously gavage for 6 weeks. Morris water maze method was used to detect the effect of different concentrations of DOP on learning and memory in mice, and ELISA method was used to detect β-secretase, γ-secretase activity and Aβ(1-40) content in brain tissue. Results: Compared with the CT group, the cell viabilities of the DOP2 and DOP3 groups were decreased, and the contents of LDH, MDA, and NO were increased, and the differences were statistically significant (P<0.05) . Compared with the CT group, the cell viabilities of DOP1+Aβ, DOP2+Aβ and DOP3+Aβ groups were decreased, the contents of LDH, MDA, NO were increased, the differences were statistically significant (P<0.05) . Compared with the Aβ group, the cell viability of DOP3+Aβ group was decreased, the contents of LDH, MDA, NO were increased, the differences were statistically significant (P<0.05) . Compared with the Aβ group, the contents of LDH and NO in the DOP2+Aβ group were increased, and the differences were statistically significant (P<0.05) . Compared with the CT group, the expression levels of Caspase-3 in the DOP2 and DOP3 groups were increased, and the differences were statistically significant (P<0.05) . Compared with the Aβ group, the expression levels of Caspase-3 in the DOP2+Aβ and DOP3+Aβ groups were increased, and the differences were statistically significant (P<0.05) . Compared with the APP695 group, the contents of Aβ(1-40) and the activities of γ-secretase of the DOP2+APP695 and DOP3+APP695 groups were increased (P<0.05) . Compared with the control group, the activities of β-secretase, γ-secretase and the content of Aβ(1-40) in the brain tissue of DOP3＇group were increased, and the differences were statistically significant (P<0.05) . Compared with the Pb group, the activities of β-secretase, γ-secretase and the content of Aβ(1-40) of the DOP3＇group were increased, and the differences were statistically significant (P<0.05) . Compared with the control group, the target quadrant stay time and the number of crossings in the DOP2＇and DOP3＇groups were reduced, and the differences were statistically significant (P<0.05) . Conclusion: DOP has a certain toxic effect on PC12 cells, causing learning and memory impairment in mice, and may promote the pathological progression of Alzheimer＇s disease.

New azaphilones, phomopsones A-C with biological activities from an endophytic fungus Phomopsis sp. CGMCC No.5416

Three undescribed azaphilones, phomopsones A-C (1-3) and two known azaphilones (4-5) were isolated from the culture of endophytic fungus Phomopsis sp. CGMCC No.5416 from the stems of Achyranthes bidentata. Their structures were determined by spectroscopic analysis (HRESIMS, 1D and 2D NMR), and the absolute configurations were determined by CD spectroscopy. Compounds 2 and 3 showed significant inhibitory activities against HIV-1 with against HIV-1 with IC₅₀ values of 7.6 and 0.5 μmol/L, respectively. Compounds 2 and 3 also displayed moderate cytotoxicity with CC₅₀ values of 3.2-303 μmol/L against A549, MDA-MB-231 and PANC-1 cell lines. Moreover, compound 3 can induce the early apoptosis of PANC-1 cancer cells with the apoptosis rate of 28.54%.

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.

Activated γδ T cells exhibit cytotoxicity and the capacity for viral clearance in patients with acute hepatitis B

γδ T cells are a unique population of lymphocytes that have regulatory roles in patients with chronic hepatitis B (CHB); however, their role in acute hepatitis B (AHB) infection remains unclear. Phenotype and function of γδ T cells were analyzed in 29 AHB patients, 28 CHB patients, and 30 healthy controls (HCs) using immunofunctional assays. Compared with HCs and CHB patients, decreased peripheral and increased hepatic γδ T cells were found in AHB patients. Increased hepatic γδ T cells in AHB patients were attributed to elevated hepatic chemokine levels. Peripheral γδ T cells exhibited highly activated and terminally differentiated memory phenotype in AHB patients. Consistently, peripheral γδ T cells in AHB patients showed increased cytotoxic capacity and enhanced antiviral activity which was further proved in longitudinal study. Activated γδ T cells in AHB patients exhibited increased cytotoxicity and capacity for viral clearance associated with liver injury and the control of infection.

Cytotoxic activity of NN-32 toxin from Indian spectacled cobra venom on human breast cancer cell lines

BACKGROUND

Breast cancer is the most common cancer which causes significant morbidity and mortality among women worldwide. Lack of medical facilities for early detection, therapeutic strategies for treatment and side effects due to pharmacological compounds have encompassed the need for new therapies mostly from natural sources. A lot of components have been identified from different snake venoms as therapeutic agents. A group of polypeptides (60-70 amino acid residues) called cytotoxins or cardiotoxins present in an elapid family of snakes have a wide variety of pharmaceutical actions and have the tendency to damage a wide variety of cells including cancerous cells. The aim of the present study was to evaluate the cytotoxic effect of NN-32 protein toxin purified from Indian Spectacled Cobra venom against human breast cancer cell lines (MCF-7 and MDA-MB-231).

METHODS

The NN-32 toxin was purified by ion exchange chromatography and further by RP-HPLC. The potential anticancer effects of the NN-32 toxin on MCF-7 and MDA-MB-231 cells were evaluated using MTT, anti-proliferation, neutral red (NR) uptake and Lactate Dehydrogenase (LDH) release assay.

RESULTS

The ion exchange chromatography showed various peaks among fraction no. 35 showing cytotoxic activity and this fraction showed a single peak with retention time 3.6 mins by HPLC using C18 column. The NN-32 toxin induced cytotoxicity in MCF-7 and MDA-MB-231 cells with the IC₅₀ value of 2.5 and 6.7 μg/ml respectively. The NN-32 showed significant cytotoxicity to both the cell lines along with low cytotoxicity to MCF-10A (normal breast epithelial) cells. The cytotoxic effect was further confirmed by the anti-proliferative, NR uptake and LDH release assays.

CONCLUSION

The purified toxin NN-32 from Naja naja venom showed cytotoxic activity against MCF-7 (ER+) and MDA-MB-231(ER-) cells in both dose dependent and time dependent manner.

All.: Composition, cytotoxity and possible mechanisms of action

Myracrodruon urundeuva (Engl.) Fr. All., commonly known as "aroeira-do-sertão", is a medicinal plant from Anacardiaceae family. In this study, the chemical composition of M. urundeuva essential oil (MuEO) was evaluated by gas chromatography-mass spectrometry (GC-MS), as well as its anti-Leishmania potential, cytotoxicity, and macrophage activation capability as possible antiprotozoal mechanism of action were assessed. Fourteen compounds were identified, which constituted 94.87% of total oil composition. The most abundant components were monoterpenes (80.35%), with β-myrcene (42.46%), α-myrcene (37.23%), and caryophyllene (4.28%) as the major constituents. The MuEO inhibited the growth of promastigotes (IC₅₀ 205 ± 13.4 μg mL^-1), axenic amastigotes (IC₅₀ 104.5 ± 11.82 μg mL^-1) and decreased percentage of macrophage infection and number of amastigotes per macrophage (IC₅₀ of 44.5 ± 4.37 μg⋅mL^-1), suggesting significant anti-Leishmania activity. The cytotoxicity of MuEO was assessed by MTT test in Balb/c murine macrophages and by human erythrocytes lysis assay and low cytotoxicity for these cells was observed. The CC₅₀ value against macrophages were 550 ± 29.21 μg mL^-1, while cytotoxicity for erythrocytes was around 20% at the highest concentration assessed, with HC₅₀ > 800 μg mL^-1. While MuEO-induced anti-Leishmania activity is not mediated by increases in both lysosomal activity and nitric oxide production in macrophages, the results suggest the antiamastigote activity is associated with an immunomodulatory activity of macrophages due to an increase of phagocytic capability induced by MuEO. Thus, MuEO presented significant activity against Leishmania amazonensis, probably modulating the activation of macrophages, with low cytotoxicity to murine macrophages and human erythrocytes.

TIGIT expression levels on human NK cells correlate with functional heterogeneity among healthy individuals

Human NK cells display extensive phenotypic and functional heterogeneity among healthy individuals, but the mechanism responsible for this variation is still largely unknown. Here, we show that a novel immune receptor, T-cell immunoglobulin and ITIM domain (TIGIT), is expressed preferentially on human NK cells but shows wide variation in its expression levels among healthy individuals. We found that the TIGIT expression level is related to the phenotypic and functional heterogeneity of NK cells, and that NK cells from healthy individuals can be divided into three categories according to TIGIT expression. NK cells with low levels of TIGIT expression show higher cytokine secretion capability, degranulation activity, and cytotoxic potential than NK cells with high levels of TIGIT expression. Blockade of the TIGIT pathway significantly increased NK-cell function, particularly in NK cells with high levels of TIGIT expression. We further observed that the TIGIT expression level was inversely correlated with the IFN-γ secretion capability of NK cells in patients with cancers and autoimmune diseases. Importantly, we propose a novel mechanism that links TIGIT expression with NK-cell functional heterogeneity, and this mechanism might partially explain why individuals have different susceptibilities to infection, autoimmune disease, and cancer.

Synthesis of New N,N'-Bis(5-arylidene-4-oxo-4,5-dihydrothiazolin-2-yl)piperazine Derivatives Under Microwave Irradiation and Preliminary Biological Evaluation

New N,N’-bis(5-arylidene-4-oxo-4,5-dihydrothiazoline-2-yl)diamine derivatives 5 were prepared in two steps from rhodanine and piperazine, or 1,4-bis(3-amino-propyl)piperazine, under microwave reaction conditions with retention of configuration. Some of these compounds were tested for in vitro antiproliferative activities and for their kinase inhibitory potencies towards six kinases (CDK5/p25, GSK3α/β, DYRK1A, DYRK2, CLK1, and CLK2). The compound 5d showed nanomolar activity towards DYRK1A kinase (IC₅₀ = 0.041 μM).

Induction of specific cytotoxic T lymphocyte responses against hepatitis B virus by hepatitis B virus antigen gene-modified dendritic cells

AIM: To explore whether hepatitis B virus (HBV) antigen gene-modified dendritic cells (DCs) are able to induce a specific cytotoxic T lymphocyte (CTL) response.

METHODS: Three recombinant adenoviruses, Ad-HBs, Ad-HBe and Ad-HBc (carrying HBsAg, HBeAg and HBcAg genes respectively), were prepared and transfected into DCs generated from cord blood. The efficacy of transfection was observed through the expression of enhanced green fluorescent protein (EGFP) in DCs and the expression of HBV antigen were detected by enzyme-linked immunosorbent assay (ELISA). HBV antigen gene-modified DCs were co-cultured with T lymphocytes from cord blood and the proliferation of T cells were detected using mixed lymphocyte reaction (MLR). Lactate dehydrogenase (LDH) release assay was carried out to assess the killing ability of CTL cells against HepG₂22.1.5 cells.

RESULTS: HBV antigen genes were expressed in DCs with a high efficacy by recombinant adenoviral vector. EGFP were observed in 90% transfected DCs and DCs kept their typical forms after transfection. The titers (absorbance) of HBsAg and HBeAg were 0.919 and 0.328, respectively, in the culture supernatant 72 h after transfection. The result of MLR showed that HBV gene-modified DCs effectively stimulated naive T lymphocytes to proliferate. There was no significant difference among Ad-HBs, Ad-HBe, Ad-HBc transfection group and normal group (F = 1.194, P = 0.389). The specific CTL cells generated by HBV antigen gene-modified DCs had obvious cytotoxity against HepG₂22.1.5 cells, and the cytotoxity in Ad-HBs, Ad-HBe, Ad-HBc transfection group was significantly higher than that in normal group (all P < 0.001). The cytotoxity in Ad-HBc transfected group was the strongest.

CONCLUSION: HBV gene-modified DCs are able to effectively stimulate naive T lymphocytes to proliferate and enhance the specific CTL response at the same time, showing its promising future for developing anti-viral vaccine.

In vitro activity of IgY against recombinant VacA protein of Helicobacter pylori

AIM: To explore the physicochemical and biolo-gical properties of IgY extracted from the yolk of hen's egg immunized with recombinant VacA protein of Helicobacter pylori.

METHODS: The purified antigen of recombinant VacA was used to immunize the hens and the VacA-IgY antibody was extracted from the yolk of hen's egg by water dilution methods and then purified by deposition technique with ammonium sulfate. In order to evaluate VacA-IgY heat stability, the titer of VacA-IgY was detected by enzyme-linked immunosorbent assay (ELISA) after being heated for 15 min under different temperatures. VacA-IgY was added into Tris-HCl of different pH values and incubated under a temperature of 37℃ to access its acid stability using ELISA. The competence of anti-pepsin digestion was also measured by ELISA. The VacA⁺H. pylori were co-cultured with Hela cells and VacA-IgY antibody was added to observe its neutralization on the cytotoxity of H. pylori by MTT assay in vitro.

RESULTS: The activity of VacA-IgY was maintained about 50% after water baths (70℃, 15 min). The activity of VacA-IgY seldom changed at pH values 5.0-7.0, but declined rapidly below the pH value 5.0, even absolutely disappeared at pH value 2.0. After incubation with pepsin (pH4.0, 60 kU/L) for 1 h, the activity of VacA-IgY had no changes, and 2 h after incubation, it still maintained over 50%. The VacA-IgY antibody neutralized the cytotoxity of VacA⁺H. pylori in a concentration-dependent manner. VacA⁺H. pylori ultrasonic extracts inhibited 50% proliferation of Hela cells at a concentration of 20 mg/L, while VacA-IgY completely neutralized the cytotoxity of H. pylori at concentrations of 80-320 mg/L (P < 0.01).

CONCLUSION: The VacA-IgY antibody shows a good heat stability, certain acid stability, and competence of anti-pepsin digestion, and can neutralize the cytotoxity of VacA protein of H. pylori effectively in vitro.