Ebtesam M. Al-Olayan

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.

Naturally Occurring Triggers that Induce Apoptosis-Like Programmed Cell Death in Plasmodium berghei Ookinetes

Several protozoan parasites have been shown to undergo a form of programmed cell death that exhibits morphological features associated with metazoan apoptosis. These include the rodent malaria parasite, Plasmodium berghei. Malaria zygotes develop in the mosquito midgut lumen, forming motile ookinetes. Up to 50% of these exhibit phenotypic markers of apoptosis; as do those grown in culture. We hypothesised that naturally occurring signals induce many ookinetes to undergo apoptosis before midgut traversal. To determine whether nitric oxide and reactive oxygen species act as such triggers, ookinetes were cultured with donors of these molecules. Exposure to the nitric oxide donor SNP induced a significant increase in ookinetes with condensed nuclear chromatin, activated caspase-like molecules and translocation of phosphatidylserine that was dose and time related. Results from an assay that detects the potential-dependent accumulation of aggregates of JC-1 in mitochondria suggested that nitric oxide does not operate via loss of mitochondrial membrane potential. L-DOPA (reactive oxygen species donor) also caused apoptosis in a dose and time dependent manner. Removal of white blood cells significantly decreased ookinetes exhibiting a marker of apoptosis in vitro. Inhibition of the activity of nitric oxide synthase in the mosquito midgut epithelium using L-NAME significantly decreased the proportion of apoptotic ookinetes and increased the number of oocysts that developed. Introduction of a nitric oxide donor into the blood meal had no effect on mosquito longevity but did reduce prevalence and intensity of infection. Thus, nitric oxide and reactive oxygen species are triggers of apoptosis in Plasmodium ookinetes. They occur naturally in the mosquito midgut lumen, sourced from infected blood and mosquito tissue. Up regulation of mosquito nitric oxide synthase activity has potential as a transmission blocking strategy.

In vitro methods for culturing vertebrate and mosquito stages of Plasmodium.

The development of in vitro culture systems for the vertebrate stages of Plasmodium led to major advancements in malaria research. Here we review both improvements made in these techniques and the recent achievement of the in vitro growth of mosquito stages from ookinete to infective sporozoite.

Protective Effect of Fragaria ananassa Crude Extract on Cadmium-Induced Lipid Peroxidation, Antioxidant Enzymes Suppression, and Apoptosis in Rat Testes

Cadmium is a deleterious environmental pollutant that threats both animals and human health. Oxidative stress and elevated levels of reactive oxygen species (ROS) have recently been reported to be the main cause of cellular damage as a result of cadmium exposure. We investigate, here, the protective effect of strawberry crude extracts on cadmium-induced oxidative damage of testes in rats. Four groups (n = 8) of 32 adult male Wistar rats weighing 160–180 g were used. The control group received 0.9% saline solution all over the experimental period (5 days). Group 2 was intraperitoneally injected with 6.5 mg/kg CdCl2. Group 3 was provided only with an oral administration of strawberry methanolic extract (SME) at a dose of 250 mg/kg. Group 4 was treated with SME before cadmium injection with the same mentioned doses. It was shown that cadmium exposure results in a significant decrease in both relative testicular weight and serum testosterone level. Analyzing the oxidative damaging effect of cadmium on the testicular tissue revealed the induction of oxidative stress markers represented in the elevated level of lipid peroxidation (LPO), nitric oxide (NO), and a decrease in the reduced glutathione (GSH) content. Considering cadmium toxicity, the level of the antioxidant enzyme activities including catalase (CAT), superoxide dismutase (SOD2), glutathione peroxidase (GPx1), and glutathione reductase (GR) were markedly decreased. Moreover, gene expression analysis indicated significant upregulation of the pro-apoptotic proteins, bcl-2-associated-X-protein (BAX), and tumor necrosis factor-α (TNFA) in response to cadmium intoxication, while significant downregulation of the anti-apoptotic, B-cell lymphoma 2 (BCL2) gene was detected. Immunohistochemistry of the testicular tissue possessed positive immunostaining for the increased level of TNF-α, but decreased number of proliferating cell nuclear antigen (PCNA) stained cells. Administration of SME debilitated the deleterious effect of cadmium via reduction of both LPO and NO levels followed by a significant enhancement in the gene expression level of CAT, SOD2, GPX1, GR, nuclear factor-erythroid 2-related factor 2 (NFE2L2), heme oxygenase-1 (HMOX1), Bcl-2, and PCNA. In addition, the SME treated group revealed a significant increase in the level of testosterone and GSH accompanied by a marked decrease in the gene expression level of Bax and TNF-α. In terms of the summarized results, the SME of Fragaria ananassa has a protective effect against cadmium-induced oxidative damage of testes.

The protective properties of melatonin against aluminium‐induced neuronal injury

Aluminium (Al) toxicity is closely linked to the pathogenesis of Alzheimers disease (AD). This experimental study investigated the neuroprotective effect of melatonin (Mel; 10 mg/kg bwt) on aluminium chloride (AlCl3; 34 mg/kg bwt) induced neurotoxicity and oxidative stress in rats. Adult male albino Wistar rats were injected with AlCl3 for 7 days. The effect on brain structure, lipid peroxidation (LPO), nitric oxide (NO) levels, glutathione (GSH) content, antioxidant enzymes (SOD, CAT, GPx and GR), apoptotic proteins (Bax and Bcl‐2) and an apoptotic enzyme (caspase‐3) was investigated. No apparent changes occurred following the injection of melatonin. Melatonin pretreatment of the AlCl3‐administered rats reduced brain damage, and the tissues appeared like those of the control rats. Compared to treatment with AlCl3, pretreatment with melatonin decreased LPO and NO levels and increased the GSH content and antioxidant enzyme activity. Moreover, melatonin increased the levels of the anti‐apoptotic protein, Bcl‐2, decreased the levels of the pro‐apoptotic protein, Bax, and inhibited caspase‐3 activity. Therefore, our results indicate that melatonin may provide therapeutic value against aluminium‐induced oxidative stress and histopathological alternations in the rat brain and that these effects may be related to anti‐apoptotic and antioxidant activities.

Neuroprotective Effects of Citrus reticulata in Scopolamine-Induced Dementia Oxidative Stress in Rats

The purpose of the study was to evaluate the potential effects of Citrus reticulate (mandarin) peel methanolic extract (MPME) on memory dysfunction in rats. Memory impairment was produced by scopolamine (1.4 mg/kg, intraperitoneally injected). Brain acetylcholinesterase enzyme (AChE) activity was measured to assess the central cholinergic activity. This study also investigated the effect of scopolamine on norepinephrine, dopamine and serotonin content in rat hippocampus, striatum and cerebral cortex. In addition, the levels of brain lipid peroxidation (LPO), nitric oxide (NO) and glutathione (GSH) were estimated to assess the degree of oxidative stress. Scopolamine administration induced a significant impairment of central cholinergic activity in rats, as indicated by a marked increase in AChE activity. The impairment of the cholinergic system was associated with a significant alternation in brain monoamines. Scopolamine administration also caused oxidant damage (elevation in LPO and NO and reduction in GSH levels). Pretreatment of MPME (250 mg/kg, orally administered) significantly reduced scopolamine-induced alternation in brain monoamines with an attenuation of scopolamine-induced rise in brain AChE activity and brain oxidative stress. It is concluded that administration of mandarin peel extract, demonstrating antioxidant activity, may be of value for dementia exhibiting elevated brain oxidative status.

The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (F. ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds.

Anti-Leishmanial Activity (In Vitro and In Vivo) of Allicin and Allicin Cream Using Leishmania major (Sub-strain Zymowme LON4) and Balb/c Mice

Background Leishmania is a unicellular protozoan parasite that produces several human diseases, ranging from localized self-healing cutaneous lesions to deadly visceral infections. Objective The effect of allicin on the growth of Leishmania major (L. major) promastigotes was evaluated under in vitro conditions. Moreover, the efficacy of a topical allicin cream was examined in BALB/c (Bagg albino, laboratory-bred strain of the House Mouse) mice with cutaneous leishmanial lesions compared to the currently used drug, sodiumstibogluconate (pentostam). Methods Cytotoxiciy and promastigote proliferation were measured. Different concentrations (50, 100, 150, and 200 μM) of liquid allicin were tested on L. major promastigotes twice: after 24 and 48 hours using an MTT colorimetric assay. In the in vivo condition, the efficacies of allicin cream and liquid allicin at two concentrations (0.15 μM/mouse and 0.30 μM/mouse) were evaluated. Serum factors of the control and treated groups were tested to evaluate the toxic effects of allicin on the liver and kidney. Results Allicin at a concentration of 50 μM inhibited the growth of Leishmania promastigotes. Topical application of allicin cream reduced lesion sizes in mice. No significant differences in biochemical analysis were observed between the control and treated groups. Conclusions Allicin has antileishmanial effects under in vitro and in vivo conditions and may be used in clinical applications.

The beneficial effect of Cape gooseberry juice on carbon tetrachloride-induced neuronal damage

OBJECTIVE Cape gooseberry (Physalis peruviana L.) belongs to the Solanaceae family. Physalis has many medicinal properties however, the beneficial effect of physalis in protecting against neurotoxins has not yet been evaluated. This experimental study investigated the protective effect of physalis juice against the oxidative damage induced by carbon tetrachloride (CCl4) in the rat brain. METHODS The degrees of protection by physalis in brain tissues were evaluated by determining the brain levels of lipid peroxidation, nitric oxide, glutathione content and antioxidant enzyme activities (superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase and glutathione reductase), after CCl4) induction in the presence or absence of physalis. Adult male albino Wistar rats were divided into 4 groups, Group I served as the control group, Group II was intraperitoneally treated with 2 ml CCl4)/kg bwt for 12 weeks, Group III was supplemented with physalis juice via the drinking water for 12 weeks, Group IV was supplemented with physalis juice and was intraperitoneally injected weekly with CCl4). RESULTS Treatment with CCl4) was significantly associated with a disturbance in the oxidative status in the brain tissues; this was marked by a significant (p<0.05) elevation in the lipid peroxidation and nitric oxide levels with a concomitant reduction in glutathione content compared to the control, along with a remarkable reduction in antioxidant enzymes. The administration of physalis along with CCl4) juice significantly (p<0.05) alleviated the changes in enzymatic antioxidant activity when compared to the CCl4) treated group. Furthermore, physalis juice supplemention inhibited apoptosis, as indicated by the increase of Bcl-2 immunoreactivity in brain tissue. CONCLUSION Our results suggest that physalis juice could be effective in preventing neurotoxicity and the neuroprotective effect of physalis might be mediated via antioxidant and anti-apoptosis activities.