Oleuropein protects against ethanol-induced oxidative stress and modulates sperm quality in the rat testis

Oleaster oil (Olea europaea sylvestris) effects on the efficiency of the reproductive system of diet-induced obese male Wistar rats

OBJECTIVES

Obesity is the result of oxidative stress (OS), which appears to be linked to male infertility. Oleaster oil has multiple therapeutic virtues due to its richness in natural bioactive compounds. This study aimed to evaluate the effect of Algerian oleaster oil on the reproductive system effectiveness of diet-induced obese male Wistar rats.

METHODS

The oil was extracted with an oleodoseur from the oleaster fruits. Rats were fed for 28 weeks two diets: a normal diet (NC group, n=8) and a high-fat, high-sucrose diet (HFHS group, n=32). The obese rats in the HFHS group were then split into three groups at random: the HFHS group, which continued to receive the HFHS diet; the HFHS L-OO group; and the HFHS H-OO group, which received for 6 weeks, respectively, in combination with the HFHS diet, oleaster oil at 1.5 and 3 mL/100 g body weight (BW). Then, the animals were sacrificed. Semen and testes were removed for semen analysis, OS, and histopathological evaluation.

RESULTS

The oleaster oil diet induces an improvement in sperm count and viability and a decrease in the percentage of fragmented sperm DNA compared to the group fed the HFHS diet, preserving the testes against OS with a highly significant decrease in testicular MDA. This beneficial effect of oleaster oil on the reproductive efficiency of rats fed the HFHS diet was dose-dependent.

CONCLUSIONS

The results showed that the oil decreased body weight, prevented OS and improved male reproductive indicators in HFHS-fed animals. The potential positive effects of oleaster oil on fertility biomarkers may be attributed to its ability to mitigate OS.

Oleuropein: Chemistry, extraction techniques and nutraceutical perspectives-An update

Olive family (Oleaceae) contains several species among which Olea europaea L. is mostly used for production of olive oils. Various parts of olive tree are rich source of diverse bioactive compounds such as Apigenin, elenolic acid, Hydroxytyrosol, Ligstroside, Oleoside, Oleuropein, Oleuropein aglycone, Tyrosol, etc. Among these, oleuropein, a secoiridoid is predominantly found in olive leaves and young olive fruits of different species of Oleaceae family. Scientists have adopted numerous extraction methods (conventional & latest) to increase the yield of oleuropein. Among these techniques, maceration, soxhlet, microwave-assisted, ultrasonication, and supercritical fluid methods are most commonly employed for extraction of oleuropein. Evidently, this review emphasizes on various in-vitro and in-vivo studies focusing on nutraceutical properties of oleuropein. Available literature highlights the pharmaceutical potential of oleuropein against various diseases such as obesity, diabetes, cardiovascular complications, neurodegenerative diseases, cancer, inflammation, microbial infections, and oxidation. This review will benefit the scientific community as it narrates comprehensive literature regarding absorption, metabolism, bioavailability, extraction techniques, and nutraceutical perspectives associated with oleuropein.

Olive Leaf Extract Attenuates Chlorpyrifos-Induced Neuro- and Reproductive Toxicity in Male Albino Rats

Chlorpyrifos (CPF) is a common organophosphorus insecticide. It is associated with negative consequences such as neurotoxicity and reproductive injury. This study aimed to observe the ability of olive leaf extract to attenuate chlorpyrifos toxicity, which induced neuro- and reproductive toxicity in male albino rats. Olive leaf extract (OLE) exhibits potent antioxidant and antiapoptotic properties. Twenty-two mature male rats were divided into four groups: control (saline), CPF (9 mg/kg), OLE (150 mg/kg), and CPF + OLE. Treatment was administered orally for 80 days. The CPF significantly reduced serum sex hormones, sperm counts and motility, high oxidants (MDA), and depleted antioxidants (GSH, SOD, TAC) in the brain and testes homogenate; additionally, it decreased serum AChE and brain neurotransmitters, increased Bax, decreased Bcl-2, and boosted caspase-3 immune expression in neural and testicular cells. Immunological expression of Ki 67 in the cerebrum, cerebellum, choroid plexus, and hippocampus was reduced, and α-SMA in testicular tissue also decreased. Histopathological findings were consistent with the above impacts. OLE co-administration significantly normalized all these abnormalities. OLE showed significant protection against neural and reproductive damage caused by CPF.

Effect of maternal or post-weaning methyl donor supplementation on growth performance, carcass traits, and meat quality of pig offspring

BACKGROUND

Limited studies have examined links between maternal methyl donor (MET) supplementation and the growth-development characteristics of offspring, and possible underlying mechanisms for such links. This study investigated the effect of maternal or post-weaning MET-supplementation on growth performance, carcass characteristics, and meat quality of the finishing (d 180) offspring. Twenty-four sows were placed on a control (C) or MET-supplemented diet during pregnancy and lactation. Forty-eight female offspring were fed the control or MET-supplemented diet from weaning to 6 months of age, resulting in four study groups (six litters per group): C/C, C/MET, MET/C, and MET/MET.

RESULTS

Maternal MET-supplementation increased average daily gain (ADG), body weight (BW), lean percentage and longissimus dorsi (LD) of the offspring at day 180 (P < 0.05), and upregulated the myosin heavy chain IIx, myogenic differentiation and muscle regulatory factor 4 mRNA levels in the LD muscle (P < 0.05). Meanwhile, offspring from maternal MET-supplementation exhibited a higher pH_24h post mortem and superoxide dismutase activity, a lower L^* _45min , glycolytic potential, malonaldehyde content in the LD muscle, and plasma homocysteine concentration (P < 0.05).

CONCLUSION

Maternal MET-supplementation has a remarkable effect on growth performance, carcass traits, and meat quality of the offspring, which is associated with increased expression levels of myogenic genes and anti-oxidant capacity. © 2018 Society of Chemical Industry.

Olive leaves extract attenuates type II diabetes mellitus-induced testicular damage in rats: Molecular and biochemical study

Diabetes mellitus (DM) has emerged as a public healthcare problem. Sustained hyperglycemia has been linked with many complications including impaired male fertility Olive tree (Olea europaea L.) leaves have been extensively used in traditional remedies worldwide to control blood glucose level in DM. In this study, the beneficial role of olive leaves extract (OLE) was investigated to combat diabetes-induced adverse effect on testicular tissues. Thirty male Wistar rats were divided into 5 equal groups: normal control group, streptozotocin (STZ)-diabetic group and diabetic groups which were given glibenclamide (GLB) or OLE at 250 and 500 mg/kg for 9 weeks to investigate the efficiency of olive leaves extract (OLE) in reducing the deleterious effect of diabetes on the reproductive system of male rats. Rats were checked for serum glucose, insulin, testosterone and gonadotropins. Also, testicular antioxidants, epididymal sperm characteristics and testicular histopathology were assessed. Expression of the testicular steroidogenic enzymes, cholesterol side-chain cleavage enzyme (P450 scc) and 17β-hydroxysteroid dehydrogenase (17β-HSD) was examined. Moreover, androgen receptor and proliferating cell nuclear antigen (PCNA) protein immunohistochemistry were assessed in testes. STZ-induced diabetes significantly increased serum glucose. However, STZ significantly decreased serum levels of insulin, testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH). Marked reductions in testicular antioxidants with elevated malondialdehyde (MDA) parallel with deterioration of the testicular histoarchitecture and epididymal sperm characteristics were recorded. Administration of GLB or OLE (250 and 500 mg/kg) resulted in a significant recovery of the above mentioned parameters in STZ-diabetic rats. Interestingly, OLE shows greater glycemic improvement and testicular protection than GLB with the highest percentage protection exhibited by the OLE high dose. Furthermore, OLE significantly induced testicular steroidogenesis in diabetic rat as evidenced by elevated P450 scc and 17β-HSD mRNA expression. The study proves that OLE possesses a potential protective role against diabetes-induced reproductive disorders, which may be due to its antioxidant activity and its ability to normalize testicular steroidogenesis.

The neuroprotective effects of hydro-alcoholic extract of olive (Olea europaea L.) leaf on rotenone-induced Parkinson's disease in rat

Parkinson's disease (PD) is an age-related disease in which dopaminergic neurons in the nigrostriatal pathway are destroyed, resulting in movement and behavioral problems. Oxidative stress and the generation of reactive oxygen species play key roles in neurodegenerative diseases, such as PD. Rotenone (ROT) is a common pesticide that induces oxidative stress. Olive leaves extract (OLE) has antioxidant and neuroprotective effects. Thus, the aim of this study was to investigate the neuroprotective effects of OLE on ROT-induced oxidative stress in the midbrain of a rat model of PD. Ninety-six Wistar rats were randomly divided into the following 6 groups (n = 16 rats/group): Control, Sham, ROT, and 3 ROT + OLE (75, 150, and 300 mg/kg/daily) groups. ROT (2.5 mg/kg/48 h) was injected subcutaneously, and vehicle or OLE was orally administered for 30 days. The animals were then sacrificed, and their brains were removed. Biochemical measures, including the levels of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and malondialdehyde (MDA), and the number of tyrosine hydroxylase (TH)-positive neurons were determined, and behavioral (rotarod and hanging) tests were conducted. The balance and muscle strength of the OLE (150 and 300 mg/kg)-treated groups were significantly improved. Treatment with OLE prevented the increases in the levels of MDA, significantly improved the SOD, CAT, and GPx levels in the midbrain, and prevented the depletion of the TH-positive neurons. These findings suggested that OLE has neuroprotective properties and that it might be useful for preventing the death of dopaminergic neurons in patients with PD.

Oleuropein attenuates cognitive dysfunction and oxidative stress induced by some anesthetic drugs in the hippocampal area of rats

The present study was designed to evaluate the antioxidant effects of oleuropein against oxidative stress in the hippocampal area of rats. We used seven experimental groups as follows: Control, Propofol, Propofol-Ketamine (Pro.-Ket.), Xylazine-Ketamine (Xyl.-Ket.), and three oleuropein-pretreated groups (Ole.-Pro., Ole.-Pro.-Ket. and Ole.-Xyl.-Ket.). The oleuropein-pretreated groups received oleuropein (15 mg/kg body weight as orally) for 10 consecutive days. Propofol 100 mg/kg, xylazine 3 mg/kg, and ketamine 75 mg/kg once as ip was used on the 11th day of treatment. Spatial memory impairment and antioxidant status of hippocampus were measured via Morris water maze, lipid peroxidation marker, and antioxidant enzyme activities. Spatial memory impairment and lipid peroxidation significantly increased in Xyl.-Ket.-treated rats in comparison to the control, propofol, Ole.-Pro. and Ole.-Pro.-Ket. groups. Oleuropein pretreatment significantly reversed spatial memory impairment and lipid peroxidation in the Ole.-Xyl.-Ket. group as compared to the Xyl.-Ket.-treated rats. There was no significant difference between the control and the propofol group in lipid peroxidation and spatial memory status. Superoxide dismutase and catalase activities both significantly decreased in Xyl.-Ket.-treated rats when compared to the control, propofol, Ole.-Pro., Ole.-Pro.-Ket., and Ole.-Xyl.-Ket. groups. In contrast, glutathione peroxidase activity in Xyl.-Ket.-treated rats significantly increased as compared to the control, propofol, Pro.-Ket., Ole.-Pro., and Ole.-Pro.-Ket. groups. We concluded that xylazine in combination with ketamine is an oxidative anesthetic drug and oleuropein pretreatment attenuates cognitive dysfunction and oxidative stress induced by anesthesia in the hippocampal area of rats. We also confirmed the antioxidant properties of propofol as a promising antioxidant anesthetic agent.

Oleuropein and hydroxytyrosol protect from bisphenol A effects in livers and kidneys of lactating mother rats and their pups'

Bisphenol A (BPA) is a chemical found in hard plastics and the coatings of food and drinks cans which can behave in a similar way to estrogen and other hormones in the human body. This study aimed to evaluate the significance of the treatment with oleuropein and hydroxytyrosol olive leaves rich extracts in reducing functional perturbations and oxidative stress arising from BPA treatment in livers and kidneys of lactating mother rats and their pups'. For this, four groups of lactating mothers were used: controls (group A), treated with bisphenol A (group B), treated with bisphenol A and oleuropein (group C) and with bisphenol A and hydroxytyrosol (group D). As results, we had found, in BPA treated group, either in mothers or in their pups', a significant decrease in morphological parameters, in catalase activity and in total antioxidant capacity associated to an increase in malondialdehyde levels in livers and kidneys. For these rats, the histological aspect showed, also, deep changes. Indeed, we had observed, in livers, hepatocellular necrosis associated to leucocytes infiltration and in kidneys tubular and glomerular necrosis. The co-treatments with BPA and oleuropein (group C) or with BPA and hydroxytyrosol (group D) ameliorate all morphological, biochemical and histological parameters as compared to BPA treated group B. The analysis of BPA and its derivatives with LC-MS/MS showed changes in their localizations between serum, livers or kidneys in all studied groups. In conclusion, the present study demonstrates the hepato-protective and reno-protective effects of oleuropein and hydroxytyrosol olive leaves extracts from BPA and its derivates toxicity.

The plant histaminase: a promising enzyme with antioxidant properties versus histamine release in isoprenaline-induced myocardial infarction in rats

The present study was designed to evaluate possible protective effects of purified histaminase from Lathyrus sativus L. seedling on the myocardial injuries upon isoprenaline-induced myocardial infarction in rats. In this regard, blood histamine concentration, creatine kinase-MB (CK-MB) activity, antioxidant status, and histopathological changes of the hearts were measured. A total of 40 adult male Sprague-Dawley rats were divided into five equal groups and treated in the following order: control (normal saline), isoprenaline (isoproterenol 110 mg/kg BW), Isopren.-H1 (isoprenaline plus histaminase 80 U/kg BW), Isopren.-H2 (isoprenaline plus histaminase 120 U/kg BW), and Isopren.-H3 (isoprenaline plus histaminase 160 U/kg BW). Myocardial infarction was manifested by a significant elevation in the level of CK-MB and histopathological findings in isoprenaline group when compared to controls. In contrast, histaminase pretreatment at dose of 160 U/kg prevented isoprenaline-induced histamine release and significantly decreased CK-MB activity as well as histopathological changes in Isopren.-H3 group. A significant increase in the catalase (CAT) and superoxide dismutase (SOD) activities was also observed by histaminase treatment in Isopren.-H2 and Isopren.-H3 groups. Although the activity of glutathione peroxidase (GPx) increased significantly to suppress oxidative stress in isoprenaline group, it was not able to prevent lipid peroxidation (as shown by TBARS concentration) in the heart of rats. In conclusion, the plant-originated histaminase presented as a promising enzyme with antioxidant properties against histamine release and myocardial infarction in rats, and it seems be a suitable therapeutic agent for future clinical trials in humans.

Effects of pretreatment with single-dose or intermittent oxygen on Cisplatin-induced nephrotoxicity in rats

Background:

Renal injury is the main side effect of cisplatin (CP), an anticancer drug. It has been shown that pretreatment with single-dose oxygen (0.5 to six hours) could reduce CP-induced renal toxicity in rats.

Objectives:

The present study aimed to compare the effects of pretreatment with single-dose and intermittent O₂ on CP-induced nephrotoxicity.

Materials and Methods:

Adult male rats were allocated to seven groups (eight rats in each group). The rats were kept in normal air or hyperoxic environment (O₂, 80%) for either a single six-hour period or intermittent six hours per day for seven days and then were subjected to intraperitoneal injection of saline or CP (5 mg/kg) at 48 hours, 72 hours, or seven days after exposure to O₂. Three days after CP (or Saline) injection, renal function tests, renal tissue injury scores, and cleaved Caspase-3 and Bax/Bcl-2 genes expression (as markers of renal cell apoptosis) were assessed.

Results:

Treatment with the 6-hour single-dose O₂ reduced renal injury significantly when CP was administrated 48 hours after O₂ pretreatment. Pretreatment with intermittent seven days of six hours per day had no protective effects and even relatively worsened renal injury when CP was injected 48 hours or 72 hours after the last session of O₂ pretreatment. The beneficial effects of pretreatment with O₂ on renal structure and function were seen if CP was administrates seven days after pretreatment with intermittent O₂.

Conclusions:

The pattern of pretreatment with O₂ could change this potential and highly protective strategy against CP-induced nephropathy to an ineffective or even mildly deteriorating one. Therefore, O₂ administration before CP injection to patients with cancer, for therapeutic purposes or as a preconditioning approach, should be performed and investigated with caution until exact effects of different protocols has been determined in human.