Quercetin induces apoptosis and necroptosis in MCF-7 breast cancer cells.

OBJECTIVE: This study investigated the quercetin (Que) effects on growth of MCF-7 human cancer breast cell line and its cellular death mechanism. BACKGROUND: Quercetin has been found to be very efficacious against many different types of cancer cells. However, the study is not sufficiently powered to demonastrate anticancer mechanisms. METHODS: MCF-7cells were treated by 50 µM/ ml of Que for 48 hours. MCF-7 cells were also pretreated with 10 Μm ZVAD (apoptosis inhibitor) or 3 mM Nec-1 (necroptosis inhibitor) for evaluation of cell death induced by apoptosis or necroptosis. RESULTS: MTT and clonogenicity assays revealed that the Que induced a significant increase in cell viability and proliferation in presence of Nec-1 in comparison to the presence of ZVAD (p < 0.05). Que also increased apoptosis as revealed by DAPI staining and morphology evaluations. Following Que treatment Bcl-2 expression was significantly decreased while Bax expression was significantly increased. Que in presence of Nec-1 decreased expression of Bax gene, reduced apoptotic index, increased cell viability and proliferation of MCF-7 cells in comparison to absence of Nec-1. MCF-7 cells showed a significantly increased expression of RIPK1 and RIPK3 in response to Que plus ZVAD in comparison to absence of ZVAD. CONCLUSION: Our results revealed that the high Que toxicity for breast cancer cells depends on multiple cell death pathways, which involve mainly necroptosis (Fig. 6, Ref. 21).

Protective effect of pravastatin on doxorubicin-induced hepatotoxicity.

OBJECTIVE: The present study was designed to investigate the possible protection of pravastatin against hepatic oxidative stress and dysfunctions induced by doxorubicin in rats. BACKGROUND: Statins have beneficial effects on oxidative stress and inflammation. METHODS: Male Sprague-Dawley rats were divided into four groups. Control group (received saline orally), Group 2 received pravastatin (20 mg/kg, i.p. for 15 days), Group 3 received single dose doxorubicin (15 mg/kg, i.p.), Group 4 was treated with pravastatin (20 mg/kg, i.p.) daily from 5 days before to 10 days after injection of doxorubicin (15 mg/kg, i.p.). Hepatic toxicity was estimated by biochemical parameters and oxidative stress and histopathological studies. RESULTS: Administration of doxorubicin indicated an increase in ALT, AST, ALP, TG, cholesterol, LDL and total bilirubin levels (p < 0.01). Doxorubicin caused a reduction in HDL and albumin levels (p < 0.01) as well as superoxide dismutase, glutathione peroxidase and catalase activities (p < 0.05) with a concomitant increase in liver malondialdehyde (p < 0.05) and liver damage (p < 0.001). Pravastatin reduced the scale liver injury (p < 0.001) and protected liver functions and other biochemical parameters (p < 0.01). Increase in malondialdehyde level associated with a reduction in antioxidant activities in the doxorubicin group was attenuated by pravastatin treatment (p < 0.05). CONCLUSION: Results indicated that pravastatin has a protective effect on the liver against doxorubicin-induced hepatotoxicity in rats (Tab. 3, Fig. 2, Ref. 34).

Morphometric and stereological assessment of the effects of titanium dioxide nanoparticles on the mouse testicular tissue.

OBJECTIVE: To evaluate the effects of titanium dioxide nanoparticles (TNPs) on morphometric and stereological parameters of mouse testis. BACKGROUND: TNPs are increasingly used in sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. However, the potential toxicity of these nanoparticles is not well understood. METHODS: Experimental Groups (TNP-1, TNP-2 and TNP-3) received one of the following treatments daily for 35 days: 75, 150 and 300 mg/kg TNPs respectively. Right testis from each animal was fixed in bouin's solution for measurement of total volume of testis, total volume of seminiferous tubules, total volume of interstitial tissue and total number of Leydig cells by stereological methods. Seminiferous tubule diameter and seminiferous epithelium height were assessed by morphometrical method. The left testicles were homogenized for measurement of testosterone concentration. RESULTS: There was a significant decrease in the weight of testicles in TNP-3 groups. The stereological and morphometrical parameters were significantly changed in TNP-2 and TNP-3 groups. TNP-2 and TNP-3 groups also showed a significant decrease in testosterone concentrations (p < 0.05). CONCLUSION: This study had demonstrated that TNPs could change stereological and morphometrical parameters of the seminiferous tubules and reduce the number of Leydig cells and testosterone concentration (Tab. 3, Fig. 3, Ref. 35).

Impact of vector-priming on the immunogenicity of a live recombinant Salmonella enterica serovar typhi Ty21a vaccine expressing urease A and B from Helicobacter pylori in human volunteers.

Orally administered recombinant Salmonella vaccines represent an attractive option for mass vaccination programmes against various infectious diseases. Therefore, it is crucial to gather knowledge about the possible impact of preexisiting immunity to carrier antigens on the immunogenicity of recombinant vaccines. Thirteen volunteers were preimmunized with Salmonella typhi Ty21a in order to evaluate the effects of prior immunization with the carrier strain. Then, they received three doses of 1-2 x 10(10) viable organisms of either the vaccine strain S. typhi Ty21a (pDB1) expressing subunits A and B of recombinant Helicobacter pylori urease (n = 9), or placebo strain S. typhi Ty21a (n = 4). Four volunteers were preimmunized and boosted with the vaccine strain S. typhi Ty21a (pDB1). No serious adverse effects were observed in any of the volunteers. Whereas none of the volunteers primed and boosted with the vaccine strain responded to the recombinant antigen, five of the nine volunteers preimmunized with the carrier strain showed cellular immune responses to H. pylori urease (56%). This supports the results of a previous study in non-preimmunized volunteers where 56% (five of nine) of the volunteers showed a cellular immune response to urease after immunisation with S. typhi Ty21a (pDB1).

Recombinant OprF-OprI as a vaccine against Pseudomonas aeruginosa infections.

A vaccine against Pseudomonas aeruginosa based on recombinant outer membranes has been developed. After intramuscularly injecting into patients with severe burns, antibodies against P. aeruginosa were induced. Vaccination was well tolerated. Intranasal application of the vaccine into volunteers, induced specific s-IgA antibodies. We conclude that the newly developed vaccine may be suitable for protection of the main risk groups of P. aeruginosa infections. In particular, for the protection of burn patients and patients with cystic fibrosis.

Safety and immunogenicity of live recombinant Salmonella enterica serovar Typhi Ty21a expressing urease A and B from Helicobacter pylori in human volunteers.

Helicobacter pylori urease was expressed in the common live typhoid vaccine Ty21a yielding Ty21a(pDB1). Nine volunteers received Ty21a(pDB1) and three control volunteers received Ty21a. No serious adverse effects were observed in any of the volunteers. Ten out of 12 volunteers developed humoral immune responses to the Salmonella carrier as detected by antigen-specific antibody-secreting cells but only two volunteers seroconverted. A total of five volunteers showed responses in one or two out of three assays for cellular responses to the carrier (proliferation, IFN-gamma-secretion, IFN-gamma-ELISPOT). Three of the volunteers that had received Ty21a(pDB1) showed a weak but significant T-cell response to Helicobacter urease, while no volunteer had detectable humoral responses to urease. Ty21a(pDB1) is a suitable prototype to optimize Salmonella-based vaccination for efficient cellular responses that could mediate protective immunity against Helicobacter.

Safety and immunogenicity of an intranasal Pseudomonas aeruginosa hybrid outer membrane protein F-I vaccine in human volunteers.

A hybrid protein [Met-Ala-(His)(6) OprF(190-342)-OprI(21-83)] consisting of the mature outer membrane protein I (OprI) and amino acids 190-342 of OprF of Pseudomonas aeruginosa was expressed in Escherichia coli and purified by Ni(2+) chelate-affinity chromatography. After several studies in healthy volunteers, as well as in patients, had proven the tolerability and immunogenicity of the the OprF-OprI vaccine, after intra-muscular application, we developed an emulgel for intranasal immunization. For this purpose we combined a highly concentrated OprF-I with sodium dodecylsulfate as vehicle and the gel matrix natriumlauryl sulfate. After safety and pyrogenicity evaluations in animals, eight healthy adult human volunteers received the OprF-I gel intranasally three times at 2-week intervals. The vaccination was well tolerated and no side effects were observed. An antibody induction (IgG and IgA) could be detected in the sera. These data support continued clinical investigation of the protection against infections in cystic fibrosis patients and patients prone to P. aeruginosa infections.

A recombinant hybrid outer membrane protein for vaccination against Pseudomonas aeruginosa.

Among the numerous targets which can be used for the development of vaccines against Pseudomonas aeruginosa we focused on the outer membrane proteins OprF and OprI. The C-terminal part of OprF from aa 190 to aa 350 was investigated for its conservation and its localization of B-cell epitopes. A hybrid protein which combines the protective epitopes of OprF and OprI was expressed in E. coli and was proven to be highly protective against an intraperitoneal challenge with P. aeruginosa by active immunization of immunocompromised mice as well as by passive immunization of SCID mice with specific antisera. A purification procedure of the N-terminal His-tagged hybrid antigen was established using immobilized-metal-affinity chromatography. To evaluate its safety and immunogenicity the recombinant protein was purified for the immunization of human volunteers. The OprF/OprI hybrid protein is considered to be a candidate for a vaccine against P. aeruginosa.

Safety and immunogenicity of a Pseudomonas aeruginosa hybrid outer membrane protein F-I vaccine in human volunteers.

A hybrid protein [Met-Ala-(His)6OprF190-342-OprI21-83] consisting of the mature outer membrane protein I (OprI) and amino acids 190 to 342 of OprF of Pseudomonas aeruginosa was expressed in Escherichia coli and purified by Ni2+ chelate-affinity chromatography. After safety and pyrogenicity evaluations in animals, four groups of eight adult human volunteers were vaccinated intramuscularly three times at 4-week intervals and revaccinated 6 months later with either 500, 100, 50, or 20 microg of OprF-OprI adsorbed onto A1(OH)3. All vaccinations were well tolerated. After the first vaccination, a significant rise of antibody titers against P. aeruginosa OprF and OprI was measured in volunteers receiving the 100- or the 500-microg dose. After the second vaccination, significant antibody titers were measured for all groups. Elevated antibody titers against OprF and OprI could still be measured 6 months after the third vaccination. The capacity of the elicited antibodies to promote complement binding and opsonization could be demonstrated by a C1q-binding assay and by the in vitro opsonophagocytic uptake of P. aeruginosa bacteria. These data support the continued development of an OprF-OprI vaccine for use in humans.