Effects of Nepeta menthoides aqueous extract on retention and retrieval of memory in mice

Herbal drugs and natural bioactive products as potential therapeutics: A review on pro-cognitives and brain boosters perspectives

Memory, one of the most vital aspects of the human brain, is necessary for the effective survival of an individual. 'Memory' can be defined in various ways but in an overall view, memory is the retention of the information that the brain grasps. Different factors are responsible for the disbalance in the brain's hippocampus region and the acetylcholine level, which masters the memory and cognitive functions. Plants are a source of pharmacologically potent drug molecules of high efficacy. Recently herbal medicine has evolved rapidly, gaining great acceptance worldwide due to their natural origin and fewer side effects. In this review, the authors have discussed the mechanisms and pharmacological action of herbal bioactive compounds to boost memory. Moreover, this review presents an update of different herbs and natural products that could act as memory enhancers and how they can be potentially utilized in the near future for the treatment of severe brain disorders. In addition, the authors also discuss the differences in biological activity of the same herb and emphasize the requirement for a higher standardization in cultivation methods and plant processing. The demand for further studies evaluating the interactions of herbal drugs is mentioned.

Proconvulsant effects of Nepeta menthoides hydro alcoholic extract in different seizure tests: behavioral and biochemical studies

In Iran, both Nepeta menthoides - the endemic species of Nepeta genus - and Lavandula officinalis are known as Ustukhuddoos and used widely as medicinal herbs. In Iranian traditional medicine, Ustukhuddoos has been recommended for several neuronal diseases including depression and epilepsy. While the antiepileptic effects of Lavandula officinalis have been investigated in a number of studies, no reports are available taking into account the effect of Nepeta menthoides on epilepsy. Since convulsion is an important side effect of some medicinal plants, a thorough study of the effects of Nepeta menthoides on epilepsy seems necessary.

This study was designed to investigate the potential anti- or pro-convulsant activity of Nepeta menthoides and its effects on oxidative stress markers. Since an herbal medicine showed opposite effects in two animal models of epilepsy in our laboratory, authers decided to study Nepeta effects through several seizure tests including the intravenous pentylenetetrazol (i.v. PTZ) infusion, the maximal electroshock (MES), acute PTZ and PTZ-kindling tests. These seizure models are generally used for screening pro- or anti-epileptic drugs. Nepeta menthoides (400 mg/kg) significantly reduced the dose of PTZ necessary for clonus seizure induction. Combining either phenytoin (Phen) or Valproate (Val) with Nepeta decreased their antiepileptic effects. Therefore, Nepeta menthoides not only failed to prevent the seizures but also increased sensitivity to them. Nepeta raised brain NO levels in different seizure tests. It seems there is a relation between NO elevation by Nepeta and increased sensitivity to seizures that should be investigated later.

Neuroprotective and Memory-Enhancing Effects of Antioxidant Peptide From Walnut (Juglans regia L.) Protein Hydrolysates

Peptides have been reported to possess interesting biological properties. The present study was designed to evaluate neuroprotective and memory-enhancing effects of antioxidant peptide from walnut ( Juglans regia L.) protein hydrolysates. The neuroprotective effect of walnut peptide (WP) against oxidative stress on PC12 cells was evaluated. And zebrafish was used as the model to corroborate the effect. Its effect on learning and memory of mice using the Morris water maze and the step-down passive avoidance tests were performed. Moreover, the acute toxicity of WP was carried out to assess its safety profile. It was found that WP was able to suppress H2O2-induced cell death in PC12 cells. In the zebrafish model, WP had an obvious neuroprotective effect, and the ratio reached 42% at 222 µg/mL. The mechanism study revealed that WP could inhibit the activity of caspases 3/7 and 8, reduce the mRNA expression levels of Bax and glial cell line-derived neurotrophic factor, and improve the mRNA expression level of brain-derived neurotrophic factor significantly. Besides, the treatment of mice with WP shortened the escape latency and exhibited much longer target time and more crossing times significantly, compared with untreated control groups in the Morris water maze test. Similarly, the step-down passive avoidance test showed that WP could ameliorate memory impairments. The administrated dose (20.1 g/kg body weight [BW]) did not produce mortality or treatment-related adverse effects with regard to BW, general behavior, or relative organ weights of the tested male and female mice. The current results indicated that WP could exert neuroprotective effect, and attenuated learning and memory impairments. These ameliorating effects of WP may be useful for treatment of memory impairment in Alzheimer’s and its related diseases.

Nepeta menthoides Boiss. & Buhse, an endemic species in Iran: A review of traditional uses, phytochemistry and pharmacology

Nepeta menthoides Boiss & Buhse is one of the endemic species in Iran. Named Ostokhodus, it is almost used as substitute of the Lavandula stoechas –the original Ostokhodus- in traditional Persian medicine (TPM) over the time and widely used for the management of some ailments such as anxiety, depression, dementia and chronic pain. The aim of this study is to review the pharmacological and phytochemical evidence on Nepeta menthoides for the assessment of the recommended traditional indications of this herb. In this review, all the relevant articles that met our inclusion criteria [English or Persian articles, having full text, evaluating therapeutic effects of N. menthoides and dated mainly from the year 1980 to 2018] were included by searching studies in PubMed, Scopus, Google Scholar, Web of Science, and SID. The search terms were "Nepeta menthoides, "Ostokhodus". Triterpenes and monoterpenes were the most chemicals reported from essential oil of N. menthoides. Several pharmacological properties via in vitro, in vivo and clinical studies have been reported including antioxidant, anti-inflammatory, anti-nociceptive, antidepressant and anxiolytic, anticholinesterase, neuroprotective, memory enhancing, anti-Alzheimer’s disease, anticancer and effect on opioid dependence. Some proposed traditional indications of this herb in TPM books are in accordance with pharmacological evidence like anti-nociceptive, anti-seizure, anti-Alzheimer’s disease, memory enhancing, neuroprotective, antidepressant, anxiolytic activity and anti-infective properties. Although some properties in TPM, such as anti-tussive and gastrotonic effects are not supported by scientific evidence, they need more investigations.

New candidates for treatment and management of carpal tunnel syndrome based on the Persian Canon of Medicine

Carpal tunnel syndrome (CTS) is defined as a compressing median mononeuropathy. CTS is one of the major costly debilitating diseases of the hand. Although CTS is a relatively recent concept in current medicine, some evidences show that medieval physicians in Persian medicine (PM) such as Avicenna were familiar with it. The PM textbook written by Avicenna, the Canon of Medicine, defines the anatomy of carpal tunnel and median nerve, as well as mononeuropathy; it also offers suggestions for the prevention and treatment of carpal tunnel syndrome (called as Vaja al-asab and Khadar) in the chapter of nerve diseases. The book describes not only symptoms including pain, paresthesia, hypoesthesia, tingling, and numbness, but also its etiology such as nerve compression (entrapment neuropathy); nonphysical reasons such as disturbed balance among the four body humors; alteration in the nerve's temperament (Mizaj) that prevents the transmission of nerve impulses; and the others such as nutrition, mental condition, sleep, weather condition, body movements, and proper disposal of body waste. Furthermore, the book suggests a lifestyle modification method based on six factors and 10 prescriptions composed with 85 natural products that are not actively used for CTS treatment in modern times. The medicinal suggestions for CTS in the Canon of Medicine will be good candidates for discovering new treatments besides providing historical significance to the various insights considered 1000 years ago.

Prevention of morphine dependence and tolerance by Nepeta menthoides was accompanied by attenuation of Nitric oxide overproduction in male mice

ETHNOPHARMACOLOGICAL RELEVANCE

Repeated administration of morphine for chronic pain leads to dependence and tolerance that limits clinical usage. Nepeta menthoides is commonly known as Iranian Ustukhuddoos and are administered in traditional medicine for gastrodynia, bone pain, blood depurative and restlessness.

AIMS OF STUDY

To investigate the effects of Nepeta menthoides on expression and acquisition of morphine dependence and tolerance in mice with regard to oxidative stress.

MATERIALS AND METHODS

Morphine dependence in mice was developed by administration of gradually increasing doses of morphine twice daily for 7 consecutive days. In experimental groups, administration of Nepeta menthoides (200 and 400mg/kg), methadone and their combination were performed 60min prior to each morphine injection (for acquisition) or the last injection of morphine on test day (for expression). Morphine tolerance was measured by the tail-immersion test before and after the administration of a single dose of morphine (100mg/kg; i.p.) on the test day (8th day). Morphine dependence was also evaluated by counting the number of jumps after the injection of naloxone (5mg/kg; i.p.).

RESULTS

Nepeta menthoides, similar to methadone, significantly prevented the development (but not the expression) of morphine dependence, tolerance, and potentiated morphine antinociception and also reduced (23.23±1.15) Nitric oxide (NO) overproduction (35.23±3.36) (in compared with naloxone group (6.3±0.52)). However, single and repeated application of the extract could not change high single-dose morphine analgesia.

CONCLUSION

It appears that Nepeta menthoides and methadone prevented morphine dependence and tolerance, partly through inhibition of the NO overproduction.