Effects Of Olive Leaf Extract Research Articles

Effects of Olive Leaf Extracts as Natural Preservative on Retailed Poultry Meat Quality.

Poultry meat is commonly marketed at refrigerated temperatures (2–5 °C). The major concern for retailers and consumers is the quality and safety of refrigerated poultry meat. During the chilling period, poultry meat undergoes too many undesirable changes due to microbial growth that leads to spoilage and economic loss. Therefore, this study was conducted to assess the effects of olive leaf extracts (OLE) used at three concentrations (0.25, 0.5, and 1%) on the sensory attributes, as well as the chemical and microbiological quality of raw poultry meat stored at 4 ± 1 °C for 15 days. The results revealed that the OLE addition reduced microbial growth successfully, and maintained the chemical quality and sensory attributes of poultry meat. Moreover, OLE extended the shelf-life of the poultry meat that held under proper refrigeration conditions up to 15 days compared to the control group, that was completely spoiled by the sixth day of storage. This study concludes that OLE could be used both as a natural antioxidant and an antimicrobial preservative for chilled poultry meat held at refrigerated temperature.

Dietary supplementation of olive leaf extract enhances growth performance, digestive enzyme activity and growth related genes expression in common carp Cyprinus carpio

It is not desirable to use synthetic chemicals as growth promoters in aquaculture. Therefore, phytogenic compounds have been extensively studied in fish diets due to their growth promoter effects. Common carp (Cyprinus carpio) is widely distributed around the world and has been reared in Asia for several centuries. This study was conducted to determine the effects of olive leaf extract (OLE) (0, 0.1, 0.25, 0.50 and 1%) on the growth performance, digestive enzyme activity in the intestine and the expression levels of some growth-related genes in the brain. liver, head kidney and mucsle tissue of common carp C. carpio. At the end of the 60-day feeding period, there was a significant increase in growth performance in the OLE0.1 and OLE0.25 groups. Similar trends have been obtained for digestive enzyme activities such as α-amylase, protease and lipase. Morover, the expression of growth hormone (GH) and insulin-like growth factor I (IGF-I) was regulated by OLE supplemented by up to 0.25% in brain, liver, head kidney and muscle tissue. This study confirms that dietary OLE may enhance the growth performance of the common carp by activating the digestive enzyme activity in the intestine and increase the expression of genes (GH and IGF-I) related with growth in brain, liver, head kidneys and muscle tissue of common carp up to use 0.10% in diets.

Olive leaf extract modulates glycerol-induced kidney and liver damage in rats.

The present study was conducted to examine the protective effect of olive leaf extract (OLE) against glycerol-induced oxidative stress in rats. Sixty male albino rats were used and allocated randomly into four groups, each of 15 rats. Groups (1) and (2) were administered intraperitoneally (i.p.) a single dose of 500μL normal saline and hypertonic glycerol solution (10mL/kg b.wt., 50% v/v, in sterile saline), respectively, followed by a 24-h period of water deprivation. Group (3) was orally given OLE (500mg/kg b.wt.) for 22days and glycerol as mentioned above on the 14th day of OLE administration followed by a 24-h period of water deprivation. Group (4) was administered OLE alone. Five rats from each group were sacrificed and samples were collected 1, 5, and 8days after water deprivation. Alterations in hematobiochemical parameters, renal and hepatic oxidative stress markers, as well as histopathology of the kidney and liver, were evaluated. Glycerol treatment resulted in significant hematological and biochemical alterations as well as significant renal and hepatic oxidative stress. Administration of OLE has significantly ameliorated renal dysfunction, morphological alterations of kidney and liver, and relieved the oxidative stress. These findings show obviously the role of oxidative stress and its relevance to renal dysfunction and suggest the ameliorative impact of OLE in glycerol-induced acute kidney damage in rats, possibly due to its antioxidant properties.

Hepatoprotective Effect of Oleuropein-Rich Extract from Olive Leaves against Cadmium-Induced Toxicity in Mice.

Cadmium (Cd) is a harmful pollutant which mainly affects the liver and kidney. In this work, we investigated the hepatoprotective effects of olive leaf extract based on oleuropein against hepatic cadmium toxicity in mice. Three groups of animals were used: the first one served as the control (C); the second one received intraperitoneal injection of cadmium 2 mg/kg b.w. (CD), administered five times during two weeks; and the third group received the same doses of Cd and simultaneously 16 mg/kg b.w. of oleuropein. Results showed that Cd induced a significant increase in liver injury biomarkers coupled with enhanced lipid peroxidation (MDA) and significant depletion of antioxidants (CAT and SOD). Histological and immunohistochemical analysis confirmed these findings. In fact, we observed a severe central lobular apoptosis and inflammation around central veins. Cotreatment with oleuropein significantly reduced the oxidative damage induced by cadmium. Our findings suggest that oleuropein could be used in the prevention of Cd hepatotoxicity.

Pro‐oxidant and pro‐apoptotic effects of Olive leaf extract on Cancers of Female Reproductive tissues

Modifications in dietary intake and adherence to the Mediterranean diet can importantly increase life expectancy, reduce the risk of developing cancer or chronic diseases and improve the quality of life. Indeed, the study of the antitumor properties of food components is gaining more and more attention. Recently, many studies have demonstrated antiproliferative and antiangiogenic activities of natural aliments such as mangosteen, grape, tomato or chestnut extracts in cancer.Among natural aliments, Olea europaea leaves, oil and fruits have been shown to inhibit proliferation and induce apoptosis in several cancer cells. Among these compounds, polyphenols have been reported to interfere with the initiation, promotion and progression of cancer by affecting tumorigenic cell transformation. Nevertheless, Olive leaves still remain a non‐edible source rich in polyphenols that can play an interesting role in cancer.Breast and ovarian cancers are two of the most frequently diagnosed tumors, and the main and fifth reason of tumor death among females, respectively. In this study, for the first time we investigated the antitumor potential of an Olive Leaf Extract ‐OLE‐ rich in polyphenols (>70% of its content) in MDA‐MB‐231 triple negative breast and OVCAR‐3 ovarian cancer cells.Our results indicate that OLE selectively inhibits MDA‐MB‐231 and OVCAR‐3 cell viability inducing an arrest in S‐phase in MDA‐MB‐231 and in G2/S‐phase in OVCAR‐3 cells, following treatment with OLE at 250 μg/mL and 200 μg/mL in MDA‐MB‐231 and OVCAR‐3 cells respectively for 24h, confirmed by Cyclins B2 and D1 downregulation.We demonstrate that OLE markedly increases apoptotic cell death, investigated by IncuCyte live‐cell Imaging System. Additionally, OLE treatment significantly up regulates the protein levels of cleaved PARP and caspase‐9 in MDA‐MB‐231 and OVCAR‐3 cells.A significant decrease of the mitochondrial mass in terms of MitoTracker Red staining in both cancer cells, together with a reduction of mitochondrial membrane potential, were observed after OLE treatment, using IncuCyte live‐cell Imaging System and fluorescence experiments.Furthermore, OLE treatment resulted in an increased level of intracellular reactive oxygen species (ROS) and mitochondrial superoxide, together with a decreased activity of enzymes such as catalase (CAT) and superoxide dismutase (SOD2), confirming oxidative stress in both MDA‐MB‐231 and OVCAR‐3 cells.These are the first data to demonstrate that OLE exerts a proapoptotic activity on human breast and ovarian cancer cells through ROS generation and mitochondrial impairment, in agreement with recent findings indicating a pro‐oxidant activity of polyphenols in cancer. Therefore, in order to obtain a better quality of life and an increased longevity, OLE might represent an attractive candidate for tumor prevention and drug development against breast and ovarian cancers.Support or Funding InformationThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No 713714. to Reyes Benot DominguezFigure 1

Comparison effects of olive leaf extract and oleuropein compounds on male reproductive function in cyclophosphamide exposed mice

Spermatogenesis is a complicated process in which sperm is susceptible to various chemotherapy drugs such as cyclophosphamide (CP). As olive leaf extract (OLE) and its active ingredient, oleuropein, have variousantioxidant, anti-apoptotic, and anti-inflammatory properties the aim of the present study was to investigate the effects of OLE and oleuropein on male reproductive function focusing antioxidative effects and histological modifications in the testes of CP-exposed mice.In order to do this, 80 NMRI male mice were divided into eight groups including control group, group received CP, group received OLE, group received oleuropein, group received OLE following CP exposure, group received oleuropein following CP exposure, group received OLE plus oleuropein and group received OLE plus oleuropein following CP exposure. In all groups CP (single dose of 100 mg/kg (, OLE (100 mg/kg for consequence 28 days) and oleuropein (100 mg/kg for consequence 28 days) were injected intraperitoneally. Moreover, testis histology, sperm parameters and serum levels of LH, FSH, MDA and antioxidant capacity were investigated. Results showed that CP caused oxidative state and abnormal changes in sperms and testes. Besides, treatments with oleuropein and OLE led to mitigate the harmful effects of CP on the male reproductive system. In conclusion, our findings showed that olive's compounds can diminish the hazardous effects of CP on spermatogenesis in mice.

Comparison of Antiviral Effect of Olive Leaf Extract and Propolis with Acyclovir on Herpes Simplex Virus Type 1

While acyclovir, a nucleoside analogue, is widely used for herpes simplex virus type 1 (HSV-1), emergence of drug-resistant viruses due to frequent usage of this class of medicines, and their toxic side effects require exploring novel active molecules. Despite the studies on developing synthetic molecules in medical sciences and pharmacology, herbs as a natural source of biologically-active compounds remain popular. In this in vitro study, olive leaf extract (OLE) and propolis alone or in combination with acyclovir were investigated for their antiviral efficacy in HSV-1.Toxic doses of OLE, propolis, and dimethyl sulfoxide, propolis diluent, for Hep-2 (ATCC, CCL-23) cells were determined by conventional cell culture. Using "endpoint" method, the viral dose infecting half of the cell culture (TCID50) was calculated, and viral quantity was determined with Spearman-Karber method. Antiviral effects of OLE and propolis on HSV-1 were investigated by conventional cell culture and real-time cell analysis (RTCA). Combinations of the two extracts with one another and with acyclovir were evaluated by RTCA. Active substances prepared at three different dilutions were added to tubes with HSV-1 of logTCID50: 11.5 in descending order starting from the highest non-toxic concentration, and they were left at room temperature for two different durations (one hour and three hours). The aliquots taken from the tubes were cultured in plates containing Hep-2 cells and evaluated after 72 hours. Combinations of extracts and acyclovir at concentrations at least four times lower than the lowest concentration showing antiviral efficacy against HSV-1 were cultured with Hep-2 cells in the e-plates of the xCELLigence RTCA device, measurements were obtained at 30 minute intervals, and data were recorded in real time. In the test with two different durations and at different concentrations of OLE and propolis, antiviral efficacy was observed both with one-hour and three-hour incubation at a concentration of 10 μg/ ml for propolis and 1.2 mg/ml for OLE with RTCA. The duration and concentration of the greatest decrease in viral quantity were in the first one hour and 10 μg/ml for propolis, and in the first one hour and 1.2 mg/ ml for OLE. Combination of propolis and OLE with acyclovir caused no cytopathic effects, and the combination of extracts led to delayed cytopathic effect. According to these results, propolis and OLE, alone and in combinations with acyclovir, have antiviral efficacy against HSV-1. These agents may reduce the dose and side effects of acyclovir in case of co-administration since they exert their effects through a different mechanism than acyclovir,possibly through direct virucidal activity, inhibition of virus internalization or viral inhibition in early stages of replication (inhibition of adsorption/binding of viral particles to the cell). These extracts that do not require conversion to active form have the potential to reduce infectivity in oral lesions, prevent spread, and be used in the topical treatment of acyclovir-resistant HSV infections, particularly in immunocompromised patients. However, in vivo studies should be conducted to determine their medicinal properties and potential toxicities. These results should be supported by further comprehensive studies and the efficacy against other viruses should also be investigated.

Antidiabetic effect of olive leaf extract on streptozotocin-induced diabetes mellitus in experimental animals.

Background: recently, a relationship between diabetic complications and oxidative stress has been emphasized. There have been some studies showing the effect of olive leaf on hyperglycemia and diabetic complications due to its antioxidant properties. In many studies the effect of olive leaf on plasma total antioxidant level has been measured by different methods. Our study represents the first time it has been measured by a new method of total thiol disulfide homeostasis. Aim: chronic exposure to hyperglycemia and hyperlipidemia contributes to the pathogenesis of diabetic complications through oxidative stress mediators. Thiol is one of the most important antioxidant barriers in humans, and thiol disulfide homeostasis is a new oxidative stress marker. We aimed to investigate the effect of olive leaf extract (OLE) obtained from fresh leaves of Olea europaea, var oleaster on diabetic complications through their hypoglycemic and antioxidant effect in diabetic rats. Methods: twenty-eight Wistar albino rats aged 12-13 weeks were used in the study. The rats were divided into a control group (C), a diabetic control group (DC), a diabetic group treated with 200 mg/kg OLE (D+200), and a diabetic group treated with 400 mg/kg OLE (D+400), having 7 rats in each group. The treatment groups received OLE by the gavage method for 21 days. At the end of the study, all rats were sacrificed by cervical dislocation. Blood samples collected from the heart were centrifuged and glucose, total cholesterol, triglyceride, urea, uric acid, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipid hydroperoxide (LOOH) level, and thiol-disulfide homeostasis were determined. The hemoglobin A1c (HbA1c) analysis was performed on complete blood. In addition, a tail flick test and hot plate modeling were performed to indicate pain perception loss. Results: it was observed that OLE had no effect on serum glucose and HbA1c levels. On the contrary, OLE reduced the levels of total cholesterol (p < 0.01), urea (p < 0.01) and hot plate latency (p < 0.01) in a significant manner. Also, OLE showed a tendency to reduce LOOH levels and to increase thiol levels in a dose-dependent manner (p > 0.05). Conclusion: OLE supplementation for 21 days, at the amounts used, cannot protect against hyperglycemia but may be protective against hypercholesterolemia and tissue damage as caused by diabetes mellitus in rats.

Determining Cardiometabolic and Antioxidant Effects of Olive Leaf Extract in Patients with Essential Hypertension

Determining Cardiometabolic and Antioxidant Effects of Olive Leaf Extract in Patients with Essential Hypertension

Effects of Olive Leaf Extract on Prevention of Molecular, Histopathological, and Enzymatic Changes in Chicken Carbon Tetrachloride-Induced Liver Damage.

Background: Today, the use of additives such as antibiotics and growth hormones that increase production efficiency in breeding broiler chickens has become inevitable. However, the use of such additives and antibiotics associated with side effects such as liver damage. Oxidative stress occurs due to an imbalance between oxidants and antioxidants. Studies have shown that olive leaves have an antioxidant effect on free radicals. This study was to evaluate the possible effect of olive leaf extract on carbon tetrachloride (CCL4)-induced liver damage (molecular and tissue) and changes of enzymes in chickens. Materials and Methods: A total of 50 chickens were used and classified into5 groups. Treatment groups received 0.5, 1, and 1.5 mg/kg of the olive leaf extract from day 21 of the experiment. Two control groups—healthy and poisoned—did not receive any extract. On the day 35 of the experiment, 1cc of CCL4 was dissolved with olive oil and injected intraperitoneally into the experimental and poisoned control groups. Blood and liver tissue sampling were performed. Results: The histopathology results showed that at high doses of olive leaf extract, the cells and vessels were regularly curable, and sinusoids were healthy. The expression of B-cell lymphoma 2 (BCL2) increased, and that of BH3 interacting domain death agonist (BID )decreased. Enzymatic tests, including serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, showed a reduction in BID expression in the experimental group compared with the control group(P<0.005). Conclusion: We concluded that olive leaf extract boosts the BCL2 —an antiapoptotic gene—and reduces BID —an apoptosis gene—in the liver of chicken. It prevents the liver cells from disintegrating and destroys sinusoids and liver blood vessels. The high doses of the olive leaf extract caused liver resistance to CCL4 toxicity in chicken.

Effects of Olive Leaf Extract on Prevention of Molecular, Histopathological, and Enzymatic Changes in Chicken Carbon Tetrachloride-Induced Liver Damage

Background: Today, the use of additives such as antibiotics and growth hormones that increase production efficiency in breeding broiler chickens has become inevitable. However, the use of such additives and antibiotics associated with side effects such as liver damage. Oxidative stress occurs due to an imbalance between oxidants and antioxidants. Studies have shown that olive leaves have an antioxidant effect on free radicals. This study was to evaluate the possible effect of olive leaf extract on carbon tetrachloride (CCL4)-induced liver damage (molecular and tissue) and changes of enzymes in chickens. Materials and Methods: A total of 50 chickens were used and classified into5 groups. Treatment groups received 0.5, 1, and 1.5 mg/kg of the olive leaf extract from day 21 of the experiment. Two control groupshealthy and poisoneddid not receive any extract. On the day 35 of the experiment, 1cc of CCL4 was dissolved with olive oil and injected intraperitoneally into the experimental and poisoned control groups. Blood and liver tissue sampling were performed. Results: The histopathology results showed that at high doses of olive leaf extract, the cells and vessels were regularly curable, and sinusoids were healthy. The expression of B-cell lymphoma 2 (BCL2) increased, and that of BH3 interacting domain death agonist (BID)decreased. Enzymatic tests, including serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, showed a reduction in BID expression in the experimental group compared with the control group(P&lt;0.005). Conclusion: We concluded that olive leaf extract boosts the BCL2—an antiapoptotic gene—and reduces BID—an apoptosis gene—in the liver of chicken. It prevents the liver cells from disintegrating and destroys sinusoids and liver blood vessels. The high doses of the olive leaf extract caused liver resistance to CCL4 toxicity in chicken. [GMJ.2019;8:e1204]Â

Indirect Chronic Effects of an Oleuropein-Rich Olive Leaf Extract on Sucrase-Isomaltase In Vitro and In Vivo.

Consumption of dietary bioactives is an avenue to enhancing the effective healthiness of diets by attenuating the glycaemic response. The intestinal brush border enzyme sucrase-isomaltase (SI) is the sole enzyme hydrolysing consumed sucrose, and we previously showed the acute effects of olive leaf extract (OLE) on sucrase activity when given together with sugars both in vitro and in vivo. Here we tested whether OLE could affect sucrase expression when pre-incubated chronically, a “priming” effect not dependent on competitive interaction with SI, in both a cell model and a human intervention. Using differentiated Caco-2/TC7 cells, long-term pre-treatment with oleuropein-rich olive leaf extract (OLE) lowered SI mRNA, surface protein and activity, and attenuated subsequent sucrose hydrolysis. Based on these results, a randomised, double-blinded, placebo-controlled, crossover pilot study was conducted. OLE (50 mg oleuropein) was consumed in capsule form 3 times a day for 1 week by 11 healthy young women followed by an oral sucrose tolerance test in the absence of OLE. However this treatment, compared to placebo, did not induce a change in post-prandial blood glucose maximum concentration (Glcmax), time to reach Glcmax and incremental area under the curve. These results indicate that changes in SI mRNA, protein and activity in an intestinal cell model by OLE are not sufficient under these conditions to induce a functional effect in vivo in healthy volunteers.

Effects of Olive Leaf Extract on Metabolic Response, Liver and Kidney Functions and Inflammatory Biomarkers in Hypertensive Patients.

Hypertension is a long-term medical condition in which the blood pressure is gradually elevated. In this project, the effects of olive leaf extract (OLE) were evaluated on metabolic response, liver and kidney functions and also biomarkers of inflammation in hypertensive patients. In this randomized double-blind placebo controlled clinical trial, 60 hypertensive patients, aged 30-60 years old had participated. Patients were randomly assigned into two groups to receive either OLE or placebo tablets for 12 weeks. At the beginning and end of the intervention, metabolic parameters and biomarkers of liver, kidney and inflammation were measured in sera of the participants using available laboratory methods. Compared with the placebo, changes in parameters associated with glucose metabolism were not statistically significant (p>0.05). The OLE tablets did not have significant effect on liver enzymes, total protein, albumin, urea and creatinine (p>0.05), but significantly decreased interleukin-6, interleukin-8 and tumor necrosis factor alpha as inflammatory biomarkers (p<0.05) in OLE group compared to the placebo group. The results concluded that inflammation as a major cause of hypertension was significantly decreased in patients using OLE tablets.

Effect of olive leaf extract combined with Saccharomyces cerevisiae in the fermentation process of table olives.

Yeasts have a great importance in the table olives quality and have been proved more and more as starter cultures. Moreover, the addition of olive leaf extract (OLE) could enhance the nutritional value of table olives, but there are no studies in which added OLE has been combined with yeasts during fermentation. The aim of this work was to determine if the quality and functional value of table olives increases when OLE and a yeast starter are used during a Spanish-style olive fermentation process. Several combinations were used: (1) fermentations trials with OLE combined with a strain of Saccharomyces cerevisiae; (2) fermentations with OLE; (3) control fermentations, with no extract or starter culture. During fermentation performed with the addition of OLE and yeasts, the yeast number remained stable for most of the time, resulting in a slight decrease of yeasts by the end of the process. The phenolic profile of olive flesh and brines of the trials was analysed during the fermentation. The addition of OLE increased the concentration of phenols in olive flesh and brines at the end of the fermentation; in these fermentations, hydroxytyrosol was the most abundant, at around 1700mg/kg in olive flesh and 3500mg/L in brines olive flesh, whereas in the control fermentation the concentrations were around 900mg/kg and 2500mg/L, respectively. In spite of adding OLE, the fermentation resulted in olives without bitterness. We can conclude that yeast inoculation combined with OLE improves safety, nutritional value and other properties of the final product, without affecting its sensorial qualities.

Pro-Apoptotic and Anti-Angiogenesis Effects of Olive Leaf Extract on Spontaneous Mouse Mammary Tumor Model by Balancing Vascular Endothelial Growth Factor and Endostatin Levels

It has been proven that olive associated products such as olive leaf extract (OLE) causes significant reduction in cancer cells viability and proliferation. Female BALB/c adult mice were divided into four groups. Three days prior to oral treatments, tumors were transplanted. First group were treated with distilled water and other three groups were received, respectively, 75, 150, and 225 mg/kg/day of OLE for three weeks. For assessment of anti-angiogenesis and pro-apoptotic effect of OLE on tumor tissue, tumor volume, cell mitosis and apoptosis, and also vascular endothelial growth factor (VEGF) and endostatin levels were assessed. OLE treatment with 150 and 225 mg/kg/day lead to significant reduction in tumor volume and cell mitosis compared with the control group, while the same doses significantly increase tumor cell apoptosis. OLE treatment with 150 mg/kg/day increase endostatin levels, while the same dose did not significantly decrease VEGF levels. The VEGF level is significantly reduced by the treatment with OLE 225 mg/kg/day for three weeks. Although, further studies are needed to clarify anti-angiogenesis and anti-apoptotic mechanism of OLE, consumption of OLE polyphenols after tumor transplantation reduced spontaneous mouse mammary tumor growth.

EVALUATION OF THE RELATIONSHIP BETWEEN VIRULENCE, ANTIBIOTIC RESISTANCE GENES AND DEVELOPMENT OF BIOFILM IN ESCHERICHIA COLI ISOLATED FROM BROILER CHICKEN

A total of 100 diseased broiler chickens of average age 22-28 days old were collected from different farms located in Dakahlia Governorate. All samples were subjected to clinical and postmortem (P.M) examination as well as bacteriological examination for detection of infection. Thus, E. coli was recovered from examined organs of 37 chickens with an incidence rate of 37 % (37 out of 100). Accuratly, 10 E. coli serogroupes were identified in 28 positive samples and the most predominant serogroup were O125 16%, O91 14%, O1 11%, O26 K60 11% & O86 K64 8 & O128 5% & O55 K59 3% & O166 3% & O103 3% and O144 3% and untypable E. coli (24 %). Studying antibiogram resistance pattern of E. coli isolates revealed that all isolates demonstrated multidrug resistence pattern. The highest resistance rates were recorded against Lincomycin (100%) and lowest are Colistin (7.14%) and other tested antibiotics showed variations regarding their resistance patterns. The most predominant serotypes of this study have the ability to form biofilm on the inner wall of the glass. PCR was done for detection of resistant genes (blaTEM and tetA(A)) and virulence genes (csgD, adrA, eaeA and fimH) in the 10 tested isolated serotypes and the results revelead that, 100% and 90% &100%, 90%, 90% and 100% were positive for resistant genes and virulence genes, respectively and investigate the relationship between them was discovered. By studying the effect of Olive Leaf Extract on multidrug resistant isolates, results were revealed that all tested serotypes are sensitive to Olive Leaf Extract (10% conc.).

The effect of olive leaf extract on digestive enzyme inhibition and insulin production in streptozotocin-induced diabetic rats

Olive leaf has natural bioactive compounds, mainly oleuropein, that are widely considered to have potentially beneficial effects on health. This study aimed to evaluate the effects of olive leaf extract (OLE) on the inhibition of carbohydrate digestive enzymes, and immunohistochemical study of insulin in the pancreas of in vivo streptozotocin-induced diabetic rats. Blood glucose levels, insulin, glycated hemoglobin (HbA1c), α-amylase and α-glucosidase activities, and an immunohistochemical study were performed at the end of the experiment. In the OLE treated group, blood glucose levels and HbA1c significantly decreased while insulin levels increased. Besides this, OLE treated group showed remarkable inhibitory activities on α-amylase and α-glucosidase compared with the Acarbose treated group. It was observed that OLE exhibited partial positive immunoreaction for insulin in β-cells through immunohistochemical analysis. Considering that OLE is more tolerable for digestion system compared to acarbose, it may be a better fitoformulation for antidiabetic medications. OLE could offer an additional beneficial effect for the treatment of diabetes.

The Effect of Olive Leaf Extract on Upper Respiratory Illness in High School Athletes: A Randomised Control Trial.

Upper respiratory illness (URI) has a major impact on both training and competition in an athletic setting. High school athletes are a sub-category who have reported higher illness rates than professional and sub-elite high school athletes of the same sport. Olive leaf extract (OLE) is an over-the-counter supplement that contains polyphenols, notably oleuropein and hydroxytyrosol, that have antiviral, antibacterial, anti-inflammatory and antioxidant properties that may reduce URI rates. Thirty-two high school students who play sport for the elite team at their school were recruited to a randomised controlled trial and allocated to a daily placebo or OLE (extent equivalent to 20 g of olive leaf, containing 100 mg oleuropein) supplementation for nine weeks during their competitive season. Twice weekly measures of wellbeing, training load and respiratory illness (sporting upper respiratory illness (SUPPRESS) questionnaire) were recorded at trainings, meetings or games. There was no significant difference in illness incidence (odds ratio (OR): 1.02 (95% confidence interval (CI) 0.21–4.44)), but there was a significant 28% reduction in sick days (OR: 0.72 (95% CI 0.56–0.93) p-value = 0.02) when supplemented with OLE. The dietary intakes of the athletes were sub-optimal with regard to immune support. OLE supplementation over a season did not significantly reduce URI incidence, but did decrease duration in high school athletes, potentially aiding return to play.

The Effects of Olive Leaf Extract on The Testis, Sperm Quality and Testicular Germ Cell Apoptosis in Male Rats Exposed to Busulfan.

BackgroundBusulfan (BU) has a destructive effect on the male reproductive system. The goal of this study was to assess the effects of olive leaf extract (OLE) as a source of antioxidants and phenolic compounds, on BU-induced damages in rat testes.Materials and MethodsIn this experimental study, 40 male Wistar rats were randomly divided into 5 groups. The control group (CTL) received a single intraperitoneal (i.p.) injection of dimethyl sulfoxide (DMSO), followed by oral administration of distilled water for 5 weeks. In BU group, BU (10 mg/kg) was administrated i.p. once. In co- treatment groups, first, received BU (10 mg/kg, a single i.p. injection) then, OLE was administrated orally at different doses of 250 mg/kg (BU+OLE 250), 500 mg/kg (BU+OLE 500) and 750 mg/kg (BU+OLE 750), for 5 weeks. Next, blood and sperm samples were collected. The left testis was removed to investigate testicular parameters and apop- tosis by using H&E and TUNEL staining, respectively. All data were analyzed by SPSS software and a P<0.05 was considered significant.ResultsThere was a significant decline in sperm viability (P=0.017), number of primary spermatocyte (PS) (P=0.001) and Leydig cells (P=0.023) in the BU group versus the CTL group. OLE at three doses could repair these defects ver- sus BU group. Increases in apoptotic spermatogonia cells (SG) due to BU were significantly reduced by OLE 250 and 500 mg/kg (P<0.01). A reduction in germinal epithelium height and an increase in apoptotic SG were observed in BU+OLE 750 group vs. other groups (P<0.01) and alkaline phosphatase (ALP) was at the highest level, also Aspartate aminotransferase (AST) increased markedly vs. CTL (P=0.024).ConclusionOral administration of OLE at the doses of 250 and 500 mg/kg could be helpful in ameliorating BU- induced toxicity in rat testes, while OLE 750 mg/kg not only did not cause positive effects, but also could exacerbate the harmful effects.

Inhibitory Effect of Olive Leaf Extract on Obesity in High-fat Diet-induced Mice.

The rapid increase in the number of people who are overweight or obese, which increases the risk of diseases and health problems, is becoming an important issue. Herein, we investigated whether olive leaf extract (OLE) has potent anti-obesity effects in high-fat induced mouse models. C57BL/6 mice were randomized into normal control, high-fat diet (HFD), HFD with OLE, and HFD with garcinia groups and administered experimental diets for 12 weeks. Body weight and food intake were measured once per week and obesity-related biomarkers were evaluated in the serum and adipose tissue. OLE significantly suppressed weight gain, food efficiency ratio, visceral fat accumulation, and serum lipid composition in HFD-induced mice. Furthermore, the expression of adipogenesis- and thermogenesis-related molecules was decreased in the OLE-treated group. OLE prevents obesity development by regulating the expression of molecules involved in adipogenesis and thermogenesis.