Synergistic Anti-Breast-Cancer Effects of Combined Treatment With Oleuropein and Doxorubicin In Vivo.

CONTEXT: Breast cancer is a leading cause of cancer fatalities among women worldwide. Of the more than 80% of patients who receive adjuvant chemotherapy, approximately 40% relapse. The majority of these patients die of disseminated metastatic disease, which emphasizes the need for new therapeutic strategies. OBJECTIVE: The study intended to investigate the anticancer effects of oleuropein (OL) and doxorubicin (DOX) individually and in combination on breast tumor xenografts and also to evaluate the molecular pathways involved. DESIGN: The research team designed in vivo (animal) and in vitro (cell culture) studies. SETTING: The study was performed in the College of Science of King Saud University in the University Center for Women Students (Riyadh, Saudi Arabia). ANIMALS: The study involved 40 female, nude mice (BALB/c OlaHsd-foxn1). INTERVENTION: The mice were injected subcutaneously with MDA-MB-231 human breast cancer cells. After the growth of tumors, the animals were randomly divided into 4 groups to receive intraperitoneal injections: (1) group 1 (control group)-dimethyl sulfoxide, (2) group 2 (intervention group)-50 mg/kg of OL, (3) group 3 (intervention group)-2.5 mg/kg of DOX, and (4) group 4 (intervention group)-1.5 mg/kg of DOX, immediately followed by 50 mg/kg of OL. The OL was extracted from Manzanillo olive trees (Olea europaea) grown in Tabouk, Saudi Arabia. OUTCOME MEASURES: The measures included the isolation and primary culture of the tumor xenografts, apoptosis analysis by annexin V, cellular lysate preparation, and immunoblotting. RESULTS: The volume of the tumor increased aggressively, reaching 173 mm3 in the control animals in a time-dependent manner. On the other hand, a sharp drop, to 48.7 mm3, in the volume of the tumor was observed with the 2 drugs combined, a more than 3-fold decrease. The effect was mediated through the induction of apoptosis via the mitochondrial pathway. The combined treatment downregulated the antiapoptosis and proproliferation protein, nuclear factor-kappa Β, and its main oncogenic target cyclin D1. Furthermore, it inhibited the expression of BCL-2 and survivin. This inhibition could explain the cooperative suppression of the proliferation of breast tumor xenografts and the induction of apoptosis by the combined effect of the compounds used. CONCLUSIONS: The key findings clearly indicate the synergistic efficacy of DOX with natural and nontoxic OL against breast tumor xenografts.

ADRB3 polymorphism rs4994 (Trp64Arg) associates significantly with bodyweight elevation and dyslipidaemias in Saudis but not rs1801253 (Arg389Gly) polymorphism in ARDB1.

BACKGROUND: In some populations, obesity and body weight related disorders show a correlation with polymorphisms in three subtypes of beta-adrenoceptor (ß1, ß2, and ß3) [ADRB1, ADRB2 and ADRB3] genes. We scanned for the polymorphism of Arg389Gly (rs1801253) in ADRB1 and Trp64Arg (rs4994) in ADRB3 genes in Saudi population to determine association, if any, of these polymorphisms with obesity and related disorders. METHODS: We studied 329 non-related adults (33.1% men and 66.9% women), aged 18-36 years. Anthropometric measurements were recorded, and Body mass index (BMI) and waist/hip ratio were calculated; leptin, insulin, lipidogram, and glucose concentrations were determined. ADRB1 and ADRB3 polymorphisms (Arg389Gly and Trp64Arg, respectively) were screened by DNA sequencing. The subjects were divided into three groups according to BMI: normal weight (BMI < 25 kg/m2), overweight (BMI ≥25.1-29.9 kg/m2) subjects, and obese (≥30 kg/m2). RESULTS: In the age-matched groups of the normal weight, overweight and obese male and female subjects, all anthropometric parameters were found to be significantly higher, and in the obese group, all biochemical parameters were significantly elevated compared to the normal weight controls. The allelic frequency of Gly389 ADRB1 did not differ amongst the three groups, whereas the frequency of Arg64 of ADRB3 gene was significantly higher in the overweight and obese subjects, compared with the normal weight subjects. In addition, subjects carrying Arg64 allele regardless of their BMI had a greater waist and hip circumference, W/H ratio, plasma cholesterol, triglyceride, LDL, leptin, insulin, and glucose level compared to those with the wild-type Trp allele. CONCLUSION: The results of this study have shown a significant association between the Trp64Arg polymorphism in ADRB3 gene and the development of overweight and obesity in Saudi populations. It also has an influence on the levels of lipid, insulin, leptin, and glucose, whereas, Arg389Gly polymorphism in ADRB1 is not associated with overweight, obesity or dyslipidaemias in Saudis.

Leishmanicidal and apoptotic activities of oleuropein on Leishmania major.

BACKGROUND: Leishmania is a unicellular protozoan parasite causing a wide range of human diseases ranging from localized self-healing cutaneous lesions to fatal visceral infections. OBJECTIVE: The aim of the present study is to assess the cytotoxic, anti-proliferative, and apoptotic effects of oleuropein on Leishmania major promastigotes (MHOM/SA/84/JISH) and to compare its effects with the reference drug sodium stibogluconate (pentostam). METHODS: Cytotoxicity and promastigote proliferation were measured using MTT colorimetric assay. Furthermore, the Annexin V/propidium iodide staining technique followed by flow cytometry was used for studying the cell death properties of oleuropein. RESULTS: In the present report we have shown that oleuropein, a pharmacologically safe, natural product of olive leaf, has a potent leishmanicidal effect. Indeed, oleuropein exhibits cytotoxic and anti-proliferative effects against Leishmania major promastigotes. Moreover, oleuropein triggers death through apoptosis, whereas pentostam induces death mainly via necrosis on Leishmania major promastigotes. CONCLUSION: Here we demonstrate for the first time that the non-toxic, natural product oleuropein has apoptotic properties against Leishmania major promastigotes. Further studies are needed to investigate its molecular pathway.

Genotyping of Toxoplasma gondii from Rats (Rattus rattus) in Riyadh, Saudi Arabia.

Toxoplasma 3 main clonal lineages are designated as type I, II, and III; however, atypical and mixed genotypes were also reported. This study was conducted for detection of Toxoplasma gondii genotypes in rats (Rattus rattus) in Riyadh region, Saudi Arabia. PCR test on T. gondii B1 gene was conducted on ELISA IgM positive samples for confirmation of the infection. However, genetic analysis of the SAG2 locus was performed to determine T. gondii genotypes using PCR-RFLP technique. PCR test on T. gondii B1gene showed that 22 (81.5%) out of the 27 ELISA IgM positive samples have T. gondii DNA. Genotypic analysis shows that, of the total 22 PCR positive samples, only 13 (59.1%) were of type II, 7 (31.8%) were of type III, and 2 (9.1%) were of an unknown genotype. It is obvious that the prevalence of both type II and III is high in rats. No reports have been available on T. gondii genotypes among rats in Riyadh region, and only little is known about its seroprevalence in rats. Future studies on T. gondii genotypes in rats using multi-locus markers is needed in Riyadh region, Saudi Arabia for better understanding of T. gondii pathogenesis and treatment in humans and animals.

Olive oil oleuropein has anti-breast cancer properties with higher efficiency on ER-negative cells.

Breast cancer constitutes a major health problem for women worldwide. However, its incidence varies between populations and geographical locations. These variations could be diet-related, since there are several carcinogenic compounds in the modern diet, while natural products contain various anti-cancer elements. Several lines of evidence indicate that, in addition to their clear preventive effect, these compounds could also be used as therapeutic agents. In the present report we have shown that oleuropein, a pharmacologically safe natural product of olive leaf, has potent anti-breast cancer properties. Indeed, oleuropein exhibits specific cytotoxicity against breast cancer cells, with higher effect on the basal-like MDA-MB-231 cells than on the luminal MCF-7 cells. This effect is mediated through the induction of apoptosis via the mitochondrial pathway. Moreover, oleuropein inhibits cell proliferation by delaying the cell cycle at S phase and up-regulated the cyclin-dependent inhibitor p21. Furthermore, oleuropein inhibited the anti-apoptosis and pro-proliferation protein NF-κB and its main oncogenic target cyclin D1. This inhibition could explain the great effect of oleuropein on cell proliferation and cell death of breast cancer cells. Therefore, oleuropein warrants further investigations to prove its utility in preventing/treating breast cancer, especially the less-responsive basal-like type.

Oleuropein induces anti-metastatic effects in breast cancer.

Breast cancer causes death due to distant metastases in which tumor cells produce matrix metalloproteinase (MMP) enzymes which facilitate invasion. Oleuropein, the main olive oil polyphenol, has anti-proliferative effects. This study aimed to investigate the effect of oleuropein on the metastatic and anti-metastatic gene expression in the MDA human breast cancer cell line. We evaluated the MMPs and TIMPs gene expression by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in treated and untreated cells. This study demonstrated that OL may induce anti-metastatic effects on human breast cancer cells. We found that TIMP1,-3, and -4 were over-expressed after all periods of incubation in treated cancer cells compared to untreated cells, while MMP2 and MMP9 genes were down-regulated, at least initially. Treatment of breast cancer cells with oleuropein could help in prevention of cancer metastasis by increasing the TIMPs and suppressing the MMPs gene expressions.

Curcumin inhibits the Sonic Hedgehog signaling pathway and triggers apoptosis in medulloblastoma cells.

Medulloblastoma is an aggressive primary brain tumor that arises in the cerebellum of children and young adults. The Sonic Hedgehog (Shh) signaling pathway that plays important roles in the pathology of this aggressive disease is a promising therapeutic target. In the present report we have shown that curcumin has cytotoxic effects on medulloblastoma cells. Curcumin suppressed also cell proliferation and triggered cell-cycle arrest at G(2)/M phase. Moreover, curcumin inhibited the Shh-Gli1 signaling pathway by downregulating the Shh protein and its most important downstream targets GLI1 and PTCH1. Furthermore, curcumin reduced the levels of beta-catenin, the activate/phosphorylated form of Akt and NF-kappaB, which led to downregulating the three common key effectors, namely C-myc, N-myc, and Cyclin D1. Consequently, apoptosis was triggered by curcumin through the mitochondrial pathway via downregulation of Bcl-2, a downstream anti-apoptotic effector of the Shh signaling. Importantly, the resistant cells that exhibited no decrease in the levels of Shh and Bcl-2, were sensitized to curcumin by the addition of the Shh antagonist, cyclopamine. Furthermore, we have shown that curcumin enhances the killing efficiency of nontoxic doses of cisplatin and gamma-rays. In addition, we present clear evidence that piperine, an enhancer of curcumin bioavailability in humans, potentiates the apoptotic effect of curcumin against medulloblastoma cells. This effect was mediated through strong downregulation of Bcl-2. These results indicate that curcumin, a natural nontoxic compound, represents great promise as Shh-targeted therapy for medulloblastomas.