Olive (Olea europaea L.) leaf extract elicits antinociceptive activity, potentiates morphine analgesia and suppresses morphine hyperalgesia in rats

The antioxidant, anti-inflammatory and analgesic activity effect of ethyl acetate extract from the flowers of Syringa pubescens Turcz

ETHNOPHARMACOLOGICAL RELEVANCE

Syringa Pubescens Turcz. (SP), a member of the Oleaceae family, is a species of plant known as Syringa. Flowers, as the medicinal part, are commonly used in the treatment of hepatitis and tonsillitis.

AIM OF THE STUDY

The research was the first to assess the antioxidant and anti-inflammatory potential of different parts of SP flowers (SPF) in vitro. The most promising fraction was ethyl acetate fraction of SP flower (SPFEA). The antioxidant, anti-inflammatory and analgesic activities of SPFEA were further studied, and the chemical components were identified.

METHODS

HPLC was used to identify the major components in various fraction of SPF. DPPH and ABTS + radical scavenging assays as well as FRAP test and β-carotene bleaching test were employed to assess the antioxidant potential of SPF fraction in vitro. The inhibitory effect on NO production in LPS-treated RAW264.7 cells and heat-induced protein denaturation test were used to evaluate the anti-inflammatory potential of SPF fraction. Further analysis of the biological activity of SPFEA was performed. Acute toxicity test was conducted to assess the toxicity of SPFEA. The anti-inflammatory effect was assessed by utilizing xylene induced ear edema model, carrageenan-induced foot edema model and peritonitis model in vivo. The analgesic effect of SPFEA was evaluated using hot plate test, tail immersion test, formaldehyde test as well as acetic acid-induced abdominal writhing pain experiment in vivo. In carrageenan induced foot edema model, ELISA kits were employed to measure levels of inflammation factors (NO, TNF-α, IL-6, COX-2, IL-1β) in foot tissue as well as MDA, CAT, SOD, GSH-PX levels in liver tissue.

RESULTS

HPLC results showed that there were significant differences in bioactive substances among different fractions of SPF, and SPFEA was rich in bioacitve components. Compared with other fractions of SPF, SPFEA exhibited better antioxidant and anti-inflammatory abilities. The 3000 mg/kg SPFEA group in mice had no obvious side effects. The xylene-induced ear edema model, carrageenan-induced foot edema and peritonitis models demonstrated that the SPFEA had significant anti-inflammatory effect. Moreover, inflammation factors including NO, TNF-α, IL-6, COX-2, IL-1β were significantly reduced in SPFEA groups in foot tissue induced by carrageenan. Additionally, SPFEA effectively decreased liver tissue oxidative stress levels (MDA, SOD, GSH-PX and CAT). The bioactivities of SPFEA demonstrated a clear dose-dependent relationship. The results of the hot plate test, tail immersion test, formaldehyde test and acetic acid-induced abdominal writhing pain experiments indicated the SPFEA possessed an excellent analgesic effect, and this effect was in dose-dependent manner.

CONCLUSION

The study provides a scientific foundation for understanding the pharmacological action of SPFEA. It has been indicated that SPFEA has excellent antioxidant, analgesic and anti-inflammatory effects.

An overview of the effect of medicinal herbs on pain

This paper is typically intended to carefully collect and properly review the antinociceptive activities of medicinal plants. In this review article, by searching keywords of medicinal plants, pain, herbal medicine, antinociceptive, phytotherapy in databases of Web of Science, Scopus, Google Scholar, Springer, Wiley, Proquest, PubMed, Nature, Magiran, Emerald, SID, ISI, and some other indexing cites, or traditional books, desired articles were obtained until 2021. The title of medicinal plants was searched diligently in Persian and English. Ultimately, 270 articles were studied. The findings possibly indicated that several medicinal plants are among the most valuable plants that have antinociceptive activities. There efficiently are various antinociceptive compounds in medicinal plants. The antinociceptive activity of these specific compounds may be through their peculiar effects on the opioid system, cholinergic pathways, and stimulation of GABA receptors, with the peripheral and central antinociceptive mechanism. Antiinflammatory processes, inhibition of the synthesis, and the release of arachidonic acid, prostaglandins, phospholipase, nitric oxide, and cyclooxygenase-2 have been reported as analgesic mechanisms of some herbs. In a reasonable conclusion, our review thoughtfully provides a comprehensive summary of present data from some scientific studies on the common herbs with antinociceptive and antiinflammatory activities.

Pharmacological Interventions for Opioid-Induced Hyperalgesia: A Scoping Review of Preclinical Trials

BACKGROUND

Opioid analgesics are the most effective pharmacological agents for moderate and severe pain. However, opioid use has several limitations such as opioid-induced hyperalgesia (OIH), which refers to the increased pain sensitivity that occurs once analgesia wears off after opioid administration. Several pharmacological interventions have been suggested for OIH, but the current literature does not provide guidelines on which interventions are the most effective and whether they differ depending on the opioid that induces hyperalgesia. This scoping review aimed to identify and describe all the preclinical trials investigating pharmacological interventions for OIH caused by remifentanil, fentanyl, or morphine as the first step towards evaluating whether the most effective OIH interventions are different for different opioids.

METHODS

Electronic database searches were carried out in Embase, PubMed, and Web of Science. Detailed data extraction was conducted on the eligible trials.

RESULTS

72 trials were eligible for the review. Of these, 27 trials investigated remifentanil, 14 trials investigated fentanyl, and 31 trials investigated morphine. A total of 82 interventions were identified. The most studied interventions were ketamine (eight trials) and gabapentin (four trials). The majority of the interventions were studied in only one trial. The most common mechanism suggested for the interventions was inhibition of N-methyl-D-aspartate (NMDA) receptors.

CONCLUSION

This scoping review identified plenty of preclinical trials investigating pharmacological interventions for OIH. Using the current literature, it is not possible to directly compare the effectiveness of the interventions. Hence, to identify the most effective interventions for each opioid, the interventions must be indirectly compared in a meta-analysis.

Valorizing the usage of olive leaves, bioactive compounds, biological activities, and food applications: A comprehensive review

Olive oil production is a significant source of economic profit for Mediterranean nations, accounting for around 98 percent of global output. Olive oil usage has increased dramatically in recent years, owing to its organoleptic characteristics and rising knowledge of its health advantages. The culture of olive trees and the manufacture of industrial and table olive oil produces enormous volumes of solid waste and dark liquid effluents, involving olive leaves, pomace, and olive oil mill wastewaters. These by-products cause an economic issue for manufacturers and pose major environmental concerns. As a result, partial reuse, like other agronomical production wastes, is a goal to be achieved. Because these by-products are high in bioactive chemicals, which, if isolated, might denote components with significant added value for the food, cosmetic, and nutraceutical sectors, indeed, they include significant amounts of beneficial organic acids, carbohydrates, proteins, fibers, and phenolic materials, which are distributed differently between the various wastes depending on the olive oil production method and table olive agronomical techniques. However, the extraction and recovery of bioactive materials from chosen by-products is a significant problem of their reasonable value, and rigorous detection and quantification are required. The primary aims of this review in this context are to outline the vital bioactive chemicals in olive by-products, evaluate the main developments in extraction, purification, and identification, and study their uses in food packaging systems and safety problems.

Traditional Medicinal Plants as a Source of Inspiration for Osteosarcoma Therapy

Osteosarcoma is one of the most common types of bone cancers among paediatric patients. Despite the advances made in surgery, chemo-, and radiotherapy, the mortality rate of metastatic osteosarcoma remains unchangeably high. The standard drug combination used to treat this bone cancer has remained the same for the last 20 years, and it produces many dangerous side effects. Through history, from ancient to modern times, nature has been a remarkable source of chemical diversity, used to alleviate human disease. The application of modern scientific technology to the study of natural products has identified many specific molecules with anti-cancer properties. This review describes the latest discovered anti-cancer compounds extracted from traditional medicinal plants, with a focus on osteosarcoma research, and on their cellular and molecular mechanisms of action. The presented compounds have proven to kill osteosarcoma cells by interfering with different pathways: apoptosis induction, stimulation of autophagy, generation of reactive oxygen species, etc. This wide variety of cellular targets confer natural products the potential to be used as chemotherapeutic drugs, and also the ability to act as sensitizers in drug combination treatments. The major hindrance for these molecules is low bioavailability. A problem that may be solved by chemical modification or nano-encapsulation.

Olea europea L. Leaves and Hibiscus sabdariffa L. Petals Extracts: Herbal Mix from Cardiovascular Network Target to Gut Motility Dysfunction Application

It is well known that diet and nutrition play a critical role in the etiopathogenesis of many disorders. On the other hand, nutrients or bioactive compounds can specifically target and control various aspects of the mechanism underlying the pathology itself, and, in this context, diseases related to intestinal motility disorders stand out. The Herbal Mix (HM) consisting of Olea europea L. leaf (OEE) and Hibiscus sabdariffa L. (HSE) extracts (13:2) has been proven to be a promising nutraceutical option for many diseases, but its potential in inflammatory-driven gastrointestinal disorders is still unexplored. In this study, HM effects on guinea-pig ileum and colon contractility (induced or spontaneous) and on human iNOS activity, as well as on human colorectal adenocarcinoma Caco-2 cells, were studied. Results showed that the HM can control the ileum and colon contractility without blocking the progression of the food bolus, can selectively inhibit iNOS and possesses a strong pro-apoptotic activity towards Caco-2 cells. In conclusion, the present results suggest that, in some diseases, such as those related to motility disorders, an appropriate nutritional approach can be accompanied by a correct use of nutraceuticals that could help not only in ameliorating the symptoms but also in preventing more severe, cancer-related conditions.

Microbiological and Antioxidant Activity of Phenolic Compounds in Olive Leaf Extract

According to many reports, phenolic compounds isolated from olive leaves have very good biological activities, especially antimicrobial. Presently, the resistance of microorganisms to antibiotics is greater than ever. Therefore, there are numerous recent papers about alternative solutions for inhibiting their influence on human health. Olive leaf is studied as an important source of antimicrobials with low cost and used in medicine. Numerous publications on involving green technologies for isolation of active compounds from olive leaves have appeared over the past few decades. The present review reports on current knowledge of the most isolated phenolic compounds from olive leaf extract as well as methods for their isolation and characterization. This paper uses recent research findings with a wide range of study models to describe the antimicrobial potential of phenolic compounds. It also describes the vast range of information about methods for determination of antimicrobial potential focusing on effects on different microbes. Additionally, it serves to highlight the role of olive leaf extract as an antioxidants and presents methods for determination of antioxidant potential. Furthermore, it provides an overview of presence of enzymes. The significance of olive leaves as industrial and agricultural waste is emphasized by means of explaining their availability, therapeutic and nutritional effects, and research conducted on this field.

Environmental enrichment and pain sensitivity; a study in maternally separated rats

Rodents are highly dependent on maternal care after birth. Maternal separation (MS) is an animal model for studying neglect and abuse. Depriving the pup of such care renders the animal with Hypothalamic-Pituitary-adrenal (HPA) dysfunction and these animals are more susceptible to anxiety and stress as well as poor cognition. These effects are due to abnormal brain development in these animals. We have tried to investigate how maternal separation can affect pain sensation and whether a non-pharmacological intervention such as enriched environment (EE) can restore an abnormal pain sensation. Animals were put into four groups MS, control (CTRL) and MS + EE and CTRL + EE groups that underwent EE after weaning until adulthood. These groups were tested for pain sensitivity with hot plate and tail flick for sensory pain and formalin for affect pain. The results showed that MS rats are more sensitive to pain in the hot plate test and formalin test, however, no significant difference was seen between groups for tail flick test. When MS rats experience EE their pain sensitivity is restored at the behavioral level. Further research is required to see how EE restores pain sensation in MS rats.

What are the consequences of Methylphenidate exposure for maternally separated rats?

Methylphenidate (MPH) abuse is prevalent among youth. Drug abuse results in pain perception. We sought to investigate whether Maternal separation (MS) prone to MPH addiction. The next question was whether MPH abusers with MS differ in pain perception. We investigated the impact of MS on addiction and drug reward as well as pain perception following 5 days of MPH injection in males and females rats. Initially, rats underwent MS protocol of 3 hr daily for 21 days. Conditioned place preference (CPP) test was an attempt to investigate whether MS rats experience more reward with MPH. The protocol consisted of 10 min habituation on Day 1, conditioning on Day 2-Day 6 (5 mg per kg MPH injection in drug compartment and saline in saline compartment with 4 hr gap between injections) and 10 min test on Day 7. Furthermore, using another group, differences in pain perception were investigated after 5 days of daily MPH injection with 5 mg per kg. Sensory pain sensitivity was tested on PND 39 using tail flick and hotplate in MS and control groups with and without MPH exposure. Results indicated that female rats are equally prone to addiction in CPP. On the other hand, MS males experience a higher reward in CPP. In tail flick test, female MS rats exposed to MPH show a lower sensory pain threshold with similar MPH exposure. Experiencing MPH similarly declined hotplate pain perception in MS and controls in the females. Males, on the other hand, did not show any difference in sensory pain tests. According to results one can argue MS is detrimental. MS males experience more reward with MPH, females are equally addiction prone and MS females experience more pain in tail flick. On the other hand pain threshold can decline in hotplate test for both control and MS females that received MPH.

Phenolic composition, antioxidant and antinociceptive activities of Syringa vulgaris L. bark and leaf extracts

Metabolite profile, antioxidant and antinociceptive activities of Syringa vulgaris bark and leaf methanolic extracts were investigated. By means of HPLC-DAD-ESI-TOF and HPLC-DAD-ESI-MS/MS, a total of 33 phenolics were identified, including 15 secoiridoids, 6 phenylpropanoids, 3 flavonoids, 3 lignans and 6 low molecular weight phenols. Validated quantitative analysis show that syringin (2.52%) and rutin (1.13%) are the main phenolic compounds in bark and leaf, respectively. Notable radical scavenging and antinociceptive activities of the bark and leaf extracts were confirmed by in vitro DPPH^● and ABTS^●+ assays and by in vivo hot-plate method in mice, respectively. Our results could lay the scientific basic of future clinical perspectives of lilac bark and leaf.

Synergistic analgesic, anti-pyretic and anti-inflammatory effects of extra virgin olive oil and ibuprofen in different experimental models of albino mice

AIM

Olive oil was used in the past as a remedy for many diseases due to its unlimited benefits in health. This study was carried out to assess the analgesic, anti-pyretic and anti-inflammatory activities of extra virgin olive oil (EVOO) at a dose of 8 mL/kg body weight and to compare it with ibuprofen (IBU) as an individual drug therapy and in combination with two different doses of IBU (therapeutic dose 100 mg/kg and low dose 40 mg/kg), on different animal models in albino mice.

METHOD

A total of 132 adult healthy male Swiss albino mice were used in this study. The analgesic effect was assessed using acetic acid-induced writhing test. The antipyretic effect was evaluated by brewer's yeast-induced pyrexia, while the anti-inflammatory activity was assessed by two different models; the carrageenan-induced paw edema and the carrageenan-induced peritonitis in which the levels of total leukocyte count (TLC), neutrophil count, prostaglandin E2 (PGE2) and interferon gamma (INF-γ) were measured in the peritoneal exudates.

RESULTS

The results revealed significant protection in all the treated groups; however, the combination of EVOO with IBU at its therapeutic dose showed superiority over the two compounds when used separately.

CONCLUSION

Using EVOO with the therapeutic dose of IBU showed synergistic effect in controlling the cardinal signs of acute inflammation rather than using non-steroidal anti-inflammatory drugs alone.

Toxoplasma gondii Infection Promotes Neuroinflammation Through Cytokine Networks and Induced Hyperalgesia in BALB/c Mice

We hypothesized that in Toxoplasma gondii infection, communication among immune cells promotes neuroinflammation through cytokine networks and induces pain sensitivity under conditions of neuropathic pain. The animal model of Toxoplasma infection was established by the intraperitoneal inoculation of 20-25 tissue cysts from Tehran strain of T. gondii to BALB/c mice. Amitriptyline (20 mg/kg, i.p., 1/day) administrated to animals for 7 days before behavioral tests. Pain behavioral tests including tail flick, hot plate, and formalin test were evaluated in all the groups. The mRNA levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were examined by real-time PCR. Results revealed that T. gondii induce hyperalgesia in the infected mice, whereas amitriptyline showed a promising effect against the hyperalgesia induced by Toxoplasma infection. The mRNA levels of the aforementioned cytokines significantly (P < 0.05) increased in the infected mice compared to the uninfected ones. Obtained findings suggested that T. gondii infection could promote neuroinflammation through cytokine networks and induced hyperalgesia in BALB/c mice, whereas amitriptyline as an analgesic drug reverses them.

Diabetes mellitus and its management with medicinal plants: A perspective based on Iranian research

ETHNOPHARMACOLOGICAL RELEVANCE

Complementary and alternative medicine has been increasingly used to treat chronic illnesses, such as diabetes mellitus. However, various limitations in terms of their application and efficacies exist. Furthermore, there is still much to be done to discover the right herbal medicine for diabetes.

AIM OF THE STUDY

This paper aims to evaluate previous herbal studies on the management of diabetes mellitus, to address their strengths and weaknesses and propose a general framework for future studies.

APPROACH AND METHODS

Data sources such as PubMed, ScienceDirect, Scopus, SpringerLink, and Wiley were searched, limited to Iran, using 36 search terms such as herbal, traditional, medicine, and phytopharmacy in combination with diabetes and related complications. Reviewed articles were evaluated regarding the use of botanical nomenclature and included information on (1) identity of plants and plant parts used, (2) the processing procedure, and (3) the extraction process. The main outcomes were extracted and then surveyed in terms of the efficacies of herbs in the management of diabetes mellitus. Then a comparative study was performed between Iranian and non-Iranian studies with respect to herbs best studied in Iran.

RESULTS

Of the 82 herbs studied in Iran, only six herbs were endemic and 19 were studied in detail. Although most of the reviewed herbs were found to decrease the level of blood glucose (BG) and/or glycated hemoglobin (HbA1C) in both Iranian and non-Iranian studies, information on their pharmacological mechanisms is scarce. However, the level of HbA1C was measured in a limited number of clinical trials or animal studies. Available information on both short- and long-term use of studied herbs on diabetes related complications and functions of involved organs as well as comorbid depression and/or simultaneous changes in lifestyle is also insufficient. Furthermore, little or no information on their phytochemical, toxicological, and herb-drug interaction properties is available. It is worth noting that the efficacy of the reviewed herbs has been studied scarcely in both humans and animals regarding both Iranian and non-Iranian studies. A significant number of reviewed articles failed to cite the scientific name of herbs and include information on the processing procedure and the extraction process.

CONCLUSIONS

Treatment of diabetes mellitus as a multifactorial disease using herbal medicines requires a comprehensive approach. In order to discover the right herbal medicine for the management of diabetes many other important factors than the levels of BG, HbA1C and insulin should be considered. According to our criteria, all the reviewed herbs suffered from inadequate investigation in human, animal and in vitro models in this respect, whereas they are worth investigating further. However, more research on endemic plants and the traditional history of herbal medicine is warranted. In our opinion, the pharmacological, toxicological, and phytochemical information should be obtained before clinical trials. Furthermore, information such as botanical scientific nomenclature, side effects, and toxicity will improve the quality and validity of publications in herbal research. In particular, designing a database covering all valid information about herbs and/or diseases will decrease unnecessary costs and increase the efficiency of research.

Prophylactic and Therapeutic Effects of Oleuropein on Reperfusion-Induced Arrhythmia in Anesthetized Rat

Background:

This study was conducted to reveal that whether i.v. injection of oleuropein, the most potent polyphenolic antioxidant in olive leaf, has any effect on the magnitude of reperfusion arrhythmia in anesthetized rats or not.

Methods:

Eighty male Wistar rats were divided into 8 groups of 10 each: groups 1 and 5 were assigned as the prophylactic and treatment control groups, groups 2 and 6 as the prophylactic and treatment groups with lidocaine (10 mg/kg), groups 3 and 4 as the prophylactic groups with 10 and 50 mg/kg oleuropein (i.v.), and groups 7 and 8 as the treatment groups with 10 and 50 mg/kg oleuropein (i.v.), respectively. Reperfusion injury was induced by 5-min regional ischemia and 15-min reperfusion of left anterior descending coronary artery. Heart rate, blood pressure, and electrocardiogram were monitored throughout the procedure.

Results:

blood pressure was significantly decreased by infusion of 50 mg/kg oleuropein in groups 4 and 8, but unlike the lidocaine as a standard anti-arrhythmic drug in groups 2 and 5 had not significant effect on heart rate. The onset of arrhythmia in groups received oleuropein (groups 3, 4, 7, and 8) was significantly delayed. The mortality rate due to irreversible ventricular fibrillation was also significantly reduced in groups 3, 4, 7, and 8. The effect of lidocaine in groups 2 and 5 was more potent than that in oleuropein group.

Conclusion:

These findings indicate that i.v. injection of oleuropein possibly through its antioxidant activity reduces the magnitude of reperfusion-induced arrhythmia.

Traditional Uses, Phytochemistry, and Pharmacology of Olea europaea (Olive)

Aim of the Review. To grasp the fragmented information available on the botany, traditional uses, phytochemistry, pharmacology, and toxicology of Olea europaea to explore its therapeutic potential and future research opportunities. Material and Methods. All the available information on O. europaea was collected via electronic search (using Pubmed, Scirus, Google Scholar, and Web of Science) and a library search. Results. Ethnomedical uses of O. europaea are recorded throughout the world where it has been used to treat various ailments. Phytochemical research had led to the isolation of flavonoids, secoiridoids, iridoids, flavanones, biophenols, triterpenes, benzoic acid derivatives, isochromans, and other classes of secondary metabolites from O. europaea. The plant materials and isolated components have shown a wide spectrum of in vitro and in vivo pharmacological activities like antidiabetic, anticonvulsant, antioxidant, anti-inflammatory, immunomodulatory, analgesic, antimicrobial, antiviral, antihypertensive, anticancer, antihyperglycemic, antinociceptive, gastroprotective, and wound healing activities. Conclusions. O. europaea emerged as a good source of traditional medicine for the treatment of various ailments. The outcomes of phytochemical and pharmacological studies reported in this review will further expand its existing therapeutic potential and provide a convincing support to its future clinical use in modern medicine.

Olive leaf extract inhibits lead poisoning-induced brain injury

Olive leaves have an antioxidant capacity, and olive leaf extract can protect the blood, spleen and hippocampus in lead-poisoned mice. However, little is known about the effects of olive leaf extract on lead-induced brain injury. This study was designed to determine whether olive leaf extract can inhibit lead-induced brain injury, and whether this effect is associated with antioxidant capacity. First, we established a mouse model of lead poisoning by continuous intragastric administration of lead acetate for 30 days. Two hours after successful model establishment, lead-poisoned mice were given olive leaf extract at doses of 250, 500 or 1 000 mg/kg daily by intragastric administration for 50 days. Under the transmission electron microscope, olive leaf extract attenuated neuronal and capillary injury and reduced damage to organelles and the matrix around the capillaries in the frontal lobe of the cerebral cortex in the lead-poisoned mice. Olive leaf extract at a dose of 1 000 mg/kg had the greatest protective effect. Spectrophotometry showed that olive leaf extract significantly increased the activities of superoxide dismutase, catalase, alkaline phosphatase and acid phosphatase, while it reduced malondialdehyde content, in a dose-dependent manner. Furthermore, immunohistochemical staining revealed that olive leaf extract dose-dependently decreased Bax protein expression in the cerebral cortex of lead-poisoned mice. Our findings indicate that olive leaf extract can inhibit lead-induced brain injury by increasing antioxidant capacity and reducing apoptosis.

Effects of olive leave extract on metabolic disorders and oxidative stress induced by 2.45 GHz WIFI signals

We investigated the effect of olive leaves extract administration on glucose metabolism and oxidative response in liver and kidneys of rats exposed to radio frequency (RF). The exposure of rats to RF (2.45 GHz, 1h/day during 21 consecutive days) induced a diabetes-like status. Moreover, RF decreased the activities of glutathione peroxidase (GPx, -33.33% and -49.40%) catalase (CAT, -43.39% and -39.62%) and the superoxide dismutase (SOD, -59.29% and -68.53%) and groups thiol amount (-62.68% and -34.85%), respectively in liver and kidneys. Indeed, exposure to RF increased the malondialdehyde (MDA, 29.69% and 51.35%) concentration respectively in liver and kidneys. Olive leaves extract administration (100 mg/kg, ip) in RF-exposed rats prevented glucose metabolism disruption and restored the activities of GPx, CAT and SOD and thiol group amount in liver and kidneys. Moreover, olive leave extract administration was able to bring down the elevated levels of MDA in liver but not in kidneys. Our investigations suggested that RF exposure induced a diabetes-like status through alteration of oxidative response. Olive leaves extract was able to correct glucose metabolism disorder by minimizing oxidative stress induced by RF in rat tissues.

Types of headache and those remedies in traditional persian medicine

The history of headache, as a common neurological complication, goes back to almost 9000 years ago. Many ancient civilizations present references to headaches and the coherent treatment strategies. Accordingly, several documents comprising headache complications embodying precise medical information stem from Traditional Persian Medicine (TPM) that can provide useful opportunities for more comprehensive treatment. We conducted a survey on headache through original important pharmacopeias and other important medical manuscripts of TPM which were written during 9(th) to 19(th) centuries and have derived all headache categories and herbal remedies. An extensive search of scientific data banks, such as Medline and Scopus, has also been exercised to find results relating to the anti-inflammatory, anti-nociceptive, and analgesic effects of denoted medicinal herbs. The concept of headache and treatments in TPM covers over 20 various types of headache and more than 160 different medicinal plants administered for oral, topical, and nasal application according to 1000 years of the subject documents. Nearly, 60% of remarked medicinal herbs have related anti-inflammatory or analgesic effects and some current headache types have similarities and conformities to those of traditional types. Beside historical approaches, there are many possible and available strategies that can lead to development of new and effective headache treatment from medicinal plants so that this study can provide beneficial information on clinical remedies based on centuries of experience in the field of headache which can stand as a new candidate for further investigations.

Endogenous opiates and behavior: 2011

This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).

The neuroprotection effect of pretreatment with olive leaf extract on brain lipidomics in rat stroke model

BACKGROUND

Recent studies suggest that olive extracts suppress inflammation and reduce stress oxidative injury. We have attempted to determine the effect of dietary olive leaf extract (OLE) on brain lipidomics in rat stroke model.

METHODS

Five groups, each consisting of 12 male Wistar rats, were studied. First and second groups (control, and sham) received distilled water, while three treatment groups received oral olive leaf extract (OLE) for 30 days (50, 75 and 100 mg/kg/day, respectively). Two hours after the last dose, each main group was subdivided to Middle cerebral artery occlusion-operated and intact subgroup for assessment of neuropathology (neurologic deficit scores and infarct volume), brain lipid analysis and brain glutathione levels, respectively.

RESULTS

OLE increased the brain cholesterol ester, cholesterol, cerebroside and phosphatidylcholine levels in doses of 50, 75 and 100 mg/kg/day. OLE increased the brain triglyceride levels in doses of 75 and 100 mg/kg/day and OLE reduced the brain ceramide levels in doses of 50, 75 and 100 mg/kg/day in comparison to the control group (p<0.05).

CONCLUSION

Although further studies are needed, it seems that the mechanism of OLE-induced ischemic tolerance in rats is partly associated with changes in brain lipids level.

Antinociceptive activity of carvacrol (5-isopropyl-2-methylphenol) in mice

Objectives

Carvacrol (5-isopropyl-2-methylphenol) is a monoterpenic phenol which is present in the essential oil of oregano and thyme. We have investigated the behavioural effects of carvacrol in animal models of pain, such as acetic acid-induced abdominal constriction, formalin and hot-plate tests in mice. The spontaneous motor activity of animals treated with carvacrol was investigated using open-field and rotarod tests.

Methods

Carvacrol was administered orally, at single doses of 50 and 100 mg/kg while indometacin (5 mg/kg), morphine (7.5 mg/kg) and diazepam (2 mg/kg) were used as standard drugs. Naloxone (1 mg/kg) and l-arginine (150 mg/kg) were used to elucidate the possible antinociceptive mechanism of carvacrol on acetic acid-induced abdominal constriction and formalin tests.

Key findings

The results showed that carvacrol produced significant inhibitions on nociception in the acetic acid-induced abdominal constriction, formalin and hot-plate tests. In the open-field and rotarod tests carvacrol did not significantly impair the motor performance. The effect of the highest dose of carvacrol in mice in the acetic acid-induced abdominal constriction and formalin tests were not reversed by naloxone or l-arginine.

Conclusions

Based on these results, it has been suggested that carvacrol presents antinociceptive activity that may not act through the opioid system nor through inhibition of the nitric oxide pathway.

Ethanolic extract of Aconiti Brachypodi Radix attenuates nociceptive pain probably via inhibition of voltage-dependent Na⁺ channel

Aconiti Brachypodi Radix, belonging to the genus of Aconitum (Family Ranunculaceae), are used clinically as anti-rheumatic, anti-inflammatory and anti-nociceptive in traditional medicine of China. However, its mechanism and influence on nociceptive threshold are unknown and need further investigation. The analgesic effects of ethanolic extract of Aconiti Brachypodi Radix (EABR) were thus studied in vivo and in vitro. Three pain models in mice were used to assess the effect of EABR on nociceptive threshold. In vitro study was conducted to clarify the modulation of the extract on the tetrodotoxin-sensitive (TTX-S) sodium currents in rat's dorsal root ganglion (DRG) neurons using whole-cell patch clamp technique. The results showed that EABR (5-20 mg/kg, i.g.) could produce dose-dependent analgesic effect on hot-plate tests as well as writhing response induced by acetic acid. In addition, administration of 2.5-10 mg/kg EABR (i.g.) caused significant decrease in pain responses in the first and second phases of formalin test without altering the PGE₂ production in the hind paw of the mice. Moreover, EABR (10 µg/ml -1 mg/ml) could suppress TTX-S voltage-gated sodium currents in a dose-dependent way, indicating the underlying electrophysiological mechanism of the analgesic effect of the folk plant medicine. Collectively, our results indicated that EABR has analgesic property in three pain models and useful influence on TTX-S sodium currents in DRG neurons, suggesting that the interference with pain messages caused by the modulation of EABR on TTX-S sodium currents in DRG neurones may explain some of its analgesic effect.

Olive (Olea europaea L.) leaf extract attenuates early diabetic neuropathic pain through prevention of high glucose-induced apoptosis: in vitro and in vivo studies

AIM OF STUDY

Since the leaves of olive have been recommended in the literature as a remedy for the treatment of diabetes and they also contain antioxidant agents, we decided to investigate the possible effects of olive leaf extract (OLE) on in vitro and in vivo models of diabetic pain neuropathy.

MATERIALS AND METHODS

The high glucose-induced cell damage in naive and NGF-treated Pheochromocytoma (PC12) cells and streptozotocin-induced diabetic rats were used. Tail-flick test was used to access nociceptive threshold. Cell viability was determined by MTT assay. Biochemical markers of neural apoptosis were evaluated using immunoblotting.

RESULTS

We found that elevation of glucose (4 times of normal) sequentially increases functional cell damage and caspase-3 activation in NGF-treated PC12 cells. Incubation of cells with OLE (200, 400 and 600 μg/ml) decreased cell damage. Furthermore, the diabetic rats developed neuropathic pain which was evident from decreased tail-flick latency (thermal hyperalgesia). Activated caspase 3 and Bax/Bcl2 ratio were significantly increased in spinal cord of diabetic animals. OLE treatment (300 and 500 mg/kg per day) ameliorated hyperalgesia, inhibited caspase 3 activation and decreased Bax/Bcl2 ratio. Furthermore, OLE exhibited potent DPPH free radical scavenging capacity.

CONCLUSION

The results suggest that olive leaf extract inhibits high glucose-induced neural damage and suppresses diabetes-induced thermal hyperalgesia. The mechanisms of these effects may be due, at least in part, to reduce neuronal apoptosis and suggest therapeutic potential of olive leaf extract in attenuation of diabetic neuropathic pain.