The Aqueous Crude Extracts of Montanoa frutescens and Montanoa grandiflora Reduce Immobility Faster Than Fluoxetine Through GABAA Receptors in Rats Forced to Swim

Chemical characterization, anti-struvite crystal, anti-inflammatory, analgesic, and antidepressant activities of Papaver rhoeas L. root and leaf extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Papaver rhoeas L. (P. rhoeas) is used to treat a wide range of pathologies. But there is no data on the anti-struvite, anti-inflammatory, analgesic, and anti-depressant effects of root and leaf extracts from this medicinal plant.

AIM OF THE STUDY

This study aimed to chemically characterize and determine the antidepressant, analgesic, anti-inflammatory, and anti-struvite activities of the root extract (RE) and leaf extract (LE) of P. rhoeas, a wild plant.

MATERIALS AND METHODS

The extraction of secondary metabolites and phytochemical screening were carried out using standard methods. The anti-struvite effect of our samples was assessed by Fourier transform infrared spectroscopy (FT-IR) and microscopic observation. For the anti-inflammatory impact, we used the carrageenan-induced paw edema technique in rats. To assess the analgesic effect of the extracts, we recorded the resulting abdominal contraction after intraperitoneal (IP) acetic acid injection. Finally, we assessed the antidepressant effect by conducting the Forced Swimming Test (FST).

RESULTS

Phytochemical screening results revealed the presence of phenols, flavonoids, saponins, tannins, coumarins, terpenoids, and alkaloids. Extraction results confirmed that our extracts were rich in secondary metabolites. Both P. rhoeas extracts limited struvite crystal development by reducing the size and number of crystals, as indicated by FT-IR analysis and microscopic observation. Additionally, the anti-struvite effects of the LE sample were greater than those of the RE sample. The results of the anti-inflammatory capacity of our extracts demonstrate the maximum inhibition of carrageenan-induced edema following 6 h (T6) of injection, ranging from 72.73 ± 7.7% for LE (400 mg/kg) to 95.45 ± 6.42% for the RE sample (400 mg/kg). On the other hand, the results for analgesic activity showed that the number of abdominal contractions in rats treated with RE and LE ranged from 11 ± 1.73 for RE (400 mg/kg) to 18 ± 1.50 for LE (200 mg/kg), while that of aspirin was 10.33 ± 0.57. Furthermore, the FST results show that the immobility time in rats treated with RE and LE varied from 91.98 ± 4.24 s for LE-treated rats (300 mg/kg) to 123.54 ± 7.83 s for RE-treated rats (150 mg/kg).

CONCLUSION

Based on these results, the roots and leaves of the studied plant can be considered a significant source of biologically active molecules for use in the pharmaceutical industry.

Papaver rhoeas L. stem and flower extracts: Anti-struvite, anti-inflammatory, analgesic, and antidepressant activities

The Papaver rhoeas L. (P. rhoeas) plant, which belongs to the Papaveraceae family, is also used as food and is exploited to treat several health problems. The purpose of this research is to determine the anti-struvite, anti-inflammatory, analgesic, and antidepressant effects of the stem extract (SE) and flower extract (FE) of the plant P. rhoeas. We used polarizing microscopy and Fourier transform infrared spectrometry (FT-IR) to evaluate the anti-struvite effect of our plant. The edema approach induced by the carrageenan molecule was used to study the anti-inflammatory impact of our extracts. The analgesic test was determined by calculating the number of abdominal contractions induced by the intraperitoneal (IP) administration of acetic acid. To evaluate the antidepressant effect of our extracts, we used the forced swimming test (FST). According to the results of the secondary metabolite extraction, both extracts contained high contents of secondary metabolites, while the results of the screening test showed that flavonoids, alkaloids, phenols, tannins, coumarins, saponins, and terpenoids were present. The result of struvite crystallization inhibition observed by polarizing microscopy and FT-IR shows the inhibition of struvite crystal aggregation by SE by decreasing the amount and size of crystals in a manner similar to cystone. The results of anti-inflammatory activity show maximum inhibition of edema after six hours of carrageenan injection in rats (T₆) for all extracts, with a maximum value of 86.36% for SE at the dose of 200 mg/kg. Regarding the analgesic effect of our plant, the lowest number of abdominal contractions was observed in rats treated with SE at a dose of 400 mg/kg. The FST results show that the lowest immobilization time was observed in rats treated with FE at a dose of 400 mg/kg. The results obtained show that the flowers and stems of P. rhoeas can constitute a rich source of bioactive molecules with potential pharmaceutical applications.

Behavioral Despair Is Blocked by the Flavonoid Chrysin (5,7-Dihydroxyflavone) in a Rat Model of Surgical Menopause

Women have a high susceptibility to the negative effects of stress. Hormonal changes experienced throughout their reproductive life partially contribute to a higher incidence of anxiety and depression symptoms, particularly, during natural or surgical menopause. In preclinical research, the flavonoid chrysin (5,7-dihydroxyflavone) exerts anxiolytic- and anti-despair-like effects; however, it is unknown whether chrysin exerts a protective effect against the behavioral changes produced by acute stress on locomotor activity and behavioral despair in rats at 12-weeks post-ovariectomy. Ovariectomized female Wistar rats were assigned to eight groups: vehicle group (10% DMSO), three groups with chrysin and three groups with the same dose of allopregnanolone (0.5, 1, and 2 mg/kg), and one group with diazepam (2 mg/kg). The treatments were administered for seven consecutive days and the effects were evaluated in the locomotor activity and swimming tests. Chrysin (2 mg/kg) increased the latency to first immobility and decreased the total immobility time in the swimming test as the reference drugs allopregnanolone and diazepam (2 mg/kg); while locomotor activity prevented the behavioral changes produced by swimming. In conclusion, chrysin exerts a protective effect against the behavioral changes induced by acute stress, similarly to the neurosteroid allopregnanolone and the benzodiazepine diazepam in rats subjected to a surgical menopause model.

Ethnomedicine and neuropsychopharmacology in Mesoamerica

ETHNOPHARMACOLOGICAL RELEVANCE

The burden of disease caused by mental and neurological disorders is increasing globally, to a disproportionate degree in Latin America. In contrast to the many psychoactive plants with a use history in Mesoamerican cultures, the translation to the wider population of knowledge around numerous botanicals used contemporarily by indigenous Mesoamerican societies to treat psychological and neurological disorders did not receive the same attention.

MATERIAL AND METHODS

We used the previously published Mesoamerican Medicinal Plant Database to extract species and associated botanical drugs used as treatments for illnesses associated with the nervous system by Mesoamerican cultures in Belize, Guatemala, and Mexico. With the critical use of published pharmacological literature, the cross-culturally most salient genera are systematically reviewed.

RESULTS

From 2188 plant taxa contained in the database 1324 are used as treatments for illnesses associated with the nervous system. The ethnomedical data was critically confronted with the available biomedical literature for the 58 cross-culturally most salient genera. For a considerable proportion of the frequently used taxa, preclinical data are available, mostly validating ethnomedicinal uses.

CONCLUSION

This quantitative approach facilitates the prioritization of taxa for future pre-clinical, clinical and treatment outcome studies and gives patients, practitioners, and legislators a fundamental framework of evidence, on which to base decisions regarding phytomedicines.

Fluoxetine and Ketamine Reverse the Depressive but Not Anxiety Behavior Induced by Lesion of Cholinergic Neurons in the Horizontal Limb of the Diagonal Band of Broca in Male Rat

The basal forebrain cholinergic system is involved in cognitive processes, but the role of the basal forebrain cholinergic system in depression is unknown. We investigated whether a lesion of cholinergic neurons in the horizontal limb of the diagonal band of Broca (HDB) produces depressive-like behavior and whether fluoxetine or ketamine inhibits such depressive-like behaviors. Here, in rats, we used 192 IgG-saporin to eliminate the cholinergic neurons of the HDB and evaluated depressive-like behaviors using a preference test for sucrose solution and the forced swimming test. Fourteen days after the injection of 192 IgG-saporin into the HDB, the rats exhibited a significantly fewer number of choline acetyltransferase positive cell density in HDB, accompanied with neuronal loss in the entire hippocampus. Meanwhile, these rats significantly reduced preference for sucrose solution, increased immobility time in the forced swimming test, reduced locomotor activity, decreased context dependent memory in fear conditioning and the time spent in the open arms of the plus-maze. A single dose of ketamine (10 mg/kg) increased the sucrose solution consumption, reduced the immobility time in the forced swim test (FST), and increased locomotor activity compared to vehicle-treated rats. Moreover, in rats that were continuously treated with fluoxetine (10 mg/kg/day for 11 days), the sucrose solution consumption increased, the immobility time in the FST decreased, and locomotor activity increased compared to vehicle-treated rats. The present results demonstrate that a lesion of HDB cholinergic neurons results in depressive-like and anxiety-like behaviors and that antidepressants such as fluoxetine or ketamine, can reverse these depressive-like behaviors but not anxiety-like behaviors, and suggest that a lesion of HDB cholinergic neurons and followed hippocampus damage may be involved in the pathogenesis of depression.

Aliqahtani A, M. Noman O, A. Nasr F, Conte R, Calarco A, Bousta D. Subacute Assessment of the Toxicity and Antidepressant-Like Effects of Origanum Majorana L. Polyphenols in Swiss Albino Mice

Origanum majorana L. is a plant commonly used in folk medicine to treat depression and several neurological disorders. This study aims to evaluate the antidepressant-like effect of the Origanum majorana L. polyphenols (OMP) obtained from the aerial parts using two different depression model tests: The forced swimming test (FST) and the tail suspension test (TST) in Swiss albino mice. The experiments were performed on days 1, 7, 14, and 21 with daily administration of different treatments. Two different doses were chosen for this study (50 and 100 mg/kg), and paroxetine was used as a positive control. Immobility as a consequence of the depression state was significantly reduced following the treatment with OMP, indicating an antidepressant effect. A subacute toxicity study was also performed following the Organization for Economic Co-operation and Development (OECD) Guidelines (407), showing no sign of toxicity for the studied doses. The phytochemical screening revealed the presence of 12 components, all belonging to polyphenols: Arbutin, rosmarinic acid, ursolic acid, quercetin-3-O-glucoside, quercetin-7-O-glucuronic acid, luteolin-7-O-glucoside, kaempferol-3-0-glucuronic acid, Kaempferol-3-0-pentose, caffeic acid, catechin, quercetin, and rutin. These findings suggest that O. majorana has interesting antidepressant-like properties, which deserve further investigation.

Anxiolytic and antioxidant effects of Euterpe oleracea Mart. (açaí) seed extract in adult rat offspring submitted to periodic maternal separation

Many studies suggest a protective role of phenolic compounds in mood disorders. We aimed to assess the effect of Euterpe oleracea (açaí) seed extract (ASE) on anxiety induced by periodic maternal separation (PMS) in adult male rats. Animals were divided into 6 groups: control, ASE, fluoxetine (FLU), PMS, PMS+ASE, and PMS+FLU. For PMS, pups were separated daily from the dam for 3 h between postnatal day (PN) 2 and PN21. ASE (200 mg·kg^-1·day^-1) and FLU (10 mg·kg^-1·day^-1) were administered by gavage for 34 days after stress induction, starting at PN76. At PN106 and PN108, the rats were submitted to open field (OF) and forced swim tests, respectively. At PN110, the rats were sacrificed by decapitation. ASE increased time spent in the center area in the OF test, glucocorticoid receptors in the hypothalamus, tropomyosin receptor kinase B (TRKB) levels in the hippocampus, and nitrite levels and antioxidant activity in the brain stem (PMS+ASE group compared with PMS group). ASE also reduced plasma corticotropin-releasing hormone levels, adrenal norepinephrine levels, and oxidative damage in the brain stem in adult male offspring submitted to PMS. In conclusion, ASE treatment has an anti-anxiety effect in rats submitted to PMS by reducing hypothalamic-pituitary-adrenal axis reactivity and increasing the nitric oxide (NO)-brain-derived neurotrophic factor (BDNF)-TRKB pathway and antioxidant defense in the central nervous system. Novelty ASE has anti-anxiety and antioxidant effects in early-life stress. ASE reduces hypothalamic-pituitary-adrenal axis reactivity. The anxiolytic effect of ASE may involve activation of the NO-BDNF-TRKB pathway in the central nervous system.