Antidepressant properties of some Hypericum canariense L. and Hypericum glandulosum Ait. extracts in the forced swimming test in mice

Deciphering Neuroprotective Effect of Rosmarinus officinalis L. (syn. Salvia rosmarinus Spenn.) through Preclinical and Clinical Studies

Rosmarinus officinalis L. (RO, rosemary) is a well-known medicinal, aromatic, and culinary herb with traditional use in European folk medicine against memory deficits and neurodegenerative disorders. This review highlights the different neuroprotective activities of RO investigated in both preclinical and clinical studies, as well as in silico molecular docking of bioactive compounds found in RO. The neuroprotective effect of RO was searched through databases including PubMed, Web of Science (WoS), Scopus, and Clinical Trials using the keywords "Rosmarinus officinalis, rosemary, neuroprotective effect, memory, cognitive dysfunction, Alzheimer's disease." RO, which is rich in secondary metabolites that have memory-enhancing potential, has displayed neuroprotection through different molecular mechanisms such as inhibition of cholinesterase, modulation of dopaminergic and oxytocinergic systems, mediation of oxidative and inflammatory proteins, involved in neuropathic pain, among others. RO extracts exhibited antidepressant and anxiolytic activities. Also, the plant has shown efficacy in scopolamine-, lipopolysaccharide-, AlCl3-, and H2O2-induced amnesia as well as amyloid-beta- and ibotenic acid-induced neurotoxicity and chronic constriction injury-related oxidative stress memory and cognitive impairments in animal models. A few clinical studies available supported the neuroprotective effects of RO and its constituents. However, more clinical studies are needed to confirm results from preclinical studies further and should include not only placebo-controlled studies but also studies including positive controls using approved drugs. Many studies underlined that constituents of RO may have the potential for developing drug candidates against Alzheimer's disease that possess high bioavailability, low toxicity, and enhanced penetration to CNS, as revealed from the experimental and molecular docking analysis.

Herbal Approaches in the Management of Mental Depression

BACKGROUND

Human's existence has become more stressful these days, most likely for the sake of improving one's lifestyle and fulfilling one's aspirations and needs. Depression is the most frequent neurological disorder, which affects millions of individuals worldwide. In clinical research, depression is the second most frequent chronic disease. A variety of herbal medications thought to have antidepressant-like effects have been reported in ancient pharmacopoeias from around the world. These provide several prospective chemicals that could be developed into modern mental medications while also causing no noticeable negative effects.

OBJECTIVE

The review is written to provide herbal treatment and comprehensive information about depression.

METHODS

Plants and plant formulations that were found effective in the treatment of depression are thoroughly reviewed. The antidepressant efficacies of medicinal plants, as well as their dosages, are investigated using experimental models. The review article contains 140 plants possessing antidepressant properties, 11 commercial formulations, and 25 active/isolated ingredients, as well as their chemical structure, which have been thoroughly reviewed with antidepressant activity after studying 283 references.

RESULTS

Literature revealed that a variety of medicinal plants are effective for the treatment of depression such as Hypericum perforatum, Catha edulis, Tinospora cordifolia, Curcuma longa, Ferula foetida, Rhodio larosea, Glycyrrhiza glabra, Crocus sativus, Ocimumba silicum and Embelica officinalis.

CONCLUSION

Potential compounds isolated from medicinal plants for the treatment of depressive disorders need to be established and herbal plant research could aid in this endeavour.

Bioactive Potential: A Pharmacognostic Definition through the Screening of Four Hypericum Species from the Canary Islands

In this work, we propose a general methodology to assess the bioactive potential (BP) of extracts in the quest of vegetable-based drugs. To exemplify the method, we studied the anticancer potential (AP) of four endemic species of genus Hypericum (Hypericum canariense L, Hypericum glandulosum Aiton, Hypericum grandifolium Choisy and Hypericum reflexum L.f) from the Canary Islands. Microextracts were obtained from the aerial parts of these species and were tested against six human tumor cell lines, A549 (non-small-cell lung), HBL-100 (breast), HeLa (cervix), SW1573 (non-small-cell lung), T-47D (breast) and WiDr (colon). The methanol–water microextracts were evaluated further for cell migration, autophagy and cell death. The most promising bioactive polar microextracts were analyzed by UHPLC–DAD–MS. The extraction yield, the bioactivity evaluation and the chemical profiling by LC–MS suggested that H. grandifolium was the species with the highest AP. Label-free live-cell imaging studies on HeLa cells exposed to the methanol–water microextract of H. grandifolium enabled observing cell death and several apoptotic hallmarks. Overall, this study allows us to select Hypericum grandifolium Choisy as a source of new chemical entities with a potential interest for cancer treatment.

Natural Products for the Treatment of Post-stroke Depression

Post-stroke depression (PSD) is the most frequent and important neuropsychiatric consequence of stroke. It is strongly associated with exacerbated deterioration of functional recovery, physical and cognitive recoveries, and quality of life. However, its mechanism is remarkably complicated, including the neurotransmitters hypothesis (which consists of a monoaminergic hypothesis and glutamate-mediated excitotoxicity hypothesis), inflammation hypothesis, dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, and neurotrophic hypothesis and neuroplasticity. So far, the underlying pathogenesis of PSD has not been clearly defined yet. At present, selective serotonin reuptake inhibitors (SSRIs) have been used as the first-line drugs to treat patients with PSD. Additionally, more than SSRIs, a majority of the current antidepressants complied with multiple side effects, which limits their clinical application. Currently, a wide variety of studies revealed the therapeutic potential of natural products in the management of several diseases, especially PSD, with minor side effects. Accordingly, in our present review, we aim to summarize the therapeutic targets of these compounds and their potential role in-clinic therapy for patients with PSD.

Medicinal Plants in the Treatment of Depression: Evidence from Preclinical Studies

Medicinal plants and their extracts are natural remedies with enormous potential for treating various diseases, including depression and anxiety. In the case of depression, hundreds of plants have traditionally been used in folk medicine for generations. Different plant extracts and natural products have been analyzed as potential antidepressant agents with validated models to test for antidepressant-like effects in animals, although other complementary studies have also been employed. Most of these studies focus on the possible mediators implicated in these potential effects, with dopamine, serotonin, and noradrenaline being the principal neurotransmitters implicated, both through interference with receptors and with their metabolism by monoamino oxidases, as well as through neuro-endocrine and neuroprotective effects. There are approximately 650 reports of antidepressant-like medicinal plants in PubMed; 155 of them have been compiled in this review, with a relevant group yielding positive results. Saffron and turmeric are the most relevant species studied in both preclinical and clinical studies; St. John's wort or kava have also been tested extensively. To the best of our knowledge, no review to date has provided a comprehensive understanding of the biomolecular mechanisms of action of these herbs or of whether their potential effects could have real benefits. The purpose of this narrative review is to provide an update regarding medicinal plants from the year 2000 to the present to examine the therapeutic potential of these antidepressant-like plants in order to contribute to the development of new therapeutic methods to alleviate the tremendous burden that depression causes worldwide.

Phytochemistry and pharmacology of anti-depressant medicinal plants: A review

Stress renders an individual to experience mental pressure and exhaustion which brings about feelings of anxiety, depression, anger and/or other negative emotions. Depression affects a person's state of mind, behaviour, health and is often associated with suicide. The use of anti-depressant drugs as therapeutic agents is associated with symptoms such as, delayed onset of action, side-effects, drug-drug and dietary interactions, sexual dysfunction, cardiac toxicity, etc. Thus, there is need to target these issues and improve current treatment options. Medicinal plants have long been used in discovering novel treatment strategies and compounds with promising roles in treating various disease conditions. There has been an increase, worldwide, in the use of medicinal plants and herbs for developing nutraceuticals for treatment of depression and other psychiatric disorders. Medicinal plants in their natural forms are valuable as they are rich in various phytochemical compounds. These phytochemical compounds have pharmacological roles in treating various diseases conditions; apart from being widely available in nature and commercially beneficial. The phytochemical compounds in plants are constantly being explored through various experimental studies to determine the molecular basis of how medicinal plants work in relation to drugs and diseases and to develop neutraceuticals for improving conditions. This review summarizes 110 medicinal plants and their phytochemical constituents that have been shown to possess anti-depressant activity. This review also highlights the various mechanisms of anti-depressant action of some of these plants and their plant parts like roots, stem, leaves, flowers, fruit or whole plant; phytochemical compounds showing anti-depressant activity such flavanoids, steroids, saponins, sugars, lectins, alkaloids, etc.; and various anti-depressant screening models used such as tail suspension test, forced swim test, chronic unpredictable stress test, sucrose preference test, monoamine oxidase inhibition assay, learned helplessness test, open field test, hole board test, etc. However, mechanistic evaluation of many of these plants still needs to be investigated and explored.

Phytochemical analysis and in vitro biological activity of three Hypericum species from the Canary Islands (Hypericum reflexum, Hypericum canariense and Hypericum grandifolium)

In the present work we carried out a phytochemical and biological investigation on three Hypericum species, i.e. Hypericum reflexum, Hypericum canariense and Hypericum grandifolium, from the Canary Islands where they are traditionally used as diuretic, wound healing, vermifuge, sedative and antidepressive agents. The polar extracts of the top flowering aerial parts, prepared by Soxhlet apparatus using a methanol-acetone (1:1) extracting mixture, were analyzed by HPLC-DAD and HPLC-MS for the content of eight biomarkers such as hypericin, hyperforin, chlorogenic acid, rutin, hyperoside, isoquercitrin, quercitrin and quercetin, whereas the hydrodistilled essential oils were analyzed by GC-FID and GC-MS. The three Hypericum species had different results in both polar and volatile constituents, H. reflexum being the only one endowed with a small amount of naphtodianthrones (hypericin and pseudohypericin), and containing high levels of chlorogenic acid, rutin and volatile mono- and sesquiterpenes. After chemical characterization, all products were in vitro biologically assayed for antiproliferative activity on human tumor cell lines by MTT assay, for antioxidant potential by DPPH, ABTS and FRAP assays, and for antimicrobial activity by the agar disc diffusion and microdilution methods. Results revealed interesting bioactivities and differences between polar extracts and essential oils, with the former being endowed with significant antioxidant activity and the latter with comparable inhibition effects on the tumor cells (A375, MDA-MB 231 and HCT 116) to that of cisplatin.

Heteropterys cotinifolia: a neuropharmacological and phytochemical approach with possible taxonomic implications

Heteropterys cotinifolia (Malpighiaceae) has been used in traditional Mexican medicine mainly for the treatment of nervous disorders. However, the specific neuropharmacological activities responsible for this use remain to be defined. The present study evaluates the antidepressant and anxiolytic effects produced by the methanolic extract of Heteropterys cotinifolia and the influence of such effects on motor activity in ICR mice. Our results show that the methanolic extract of Heteropterys cotinifolia produces a dose-dependent antidepressant effect in the forced swimming test in mice at doses from 31 to 310 mg/kg, with no reduction of mice locomotion. However, no anxiolytic properties were observed. Our findings suggest that the main extract compounds identified as chlorogenic acid and rutin may be involved in the antidepressant effects. To our knowledge, the present study constitutes the first report of pharmacological and phytochemical data of Heteropterys cotinifolia. The presence of flavonoids in the methanolic extract of Heteropterys cotinifolia may also provide further data to characterize taxonomically this species in order to be distinguished from others species closely related and belonging to the same genus.

Neuropharmacological in vivo effects and phytochemical profile of the extract from the aerial parts of Heteropterys brachiata (L.) DC. (Malpighiaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Heteropterys brachiata is a plant species that has been used in traditional Mexican medicine for the treatment of nervous disorders.

AIM OF THE STUDY

To evaluate the anxiolytic, anticonvulsant, antidepressant and sedative effects produced by the methanolic extract of Heteropterys brachiata (HbMeOH) in ICR mice. Additionally, we determine the acute toxicity profiles of the extract and the presence of its main constituents.

MATERIAL AND METHODS

The neuropharmacological effects of the extract were evaluated using a variety of models, such as the elevated plus maze (EPM), the forced swimming test (FST), the pentobarbital potentiation test (PTBt), pentylenetetrazole-induced seizures test (PTZt), and the open field test (OFT). HPLC was employed for obtention of phytochemical profile.

RESULTS

HbMeOH produced a significant antidepressant effect in FST at 500 and 750 mg/kg doses, while doses from 500 to 1500 mg/kg exhibited a clear dose-dependent anxiolytic activity in EPM. A dose of 500 mg/kg showed a significant anticonvulsant activity in PTZt and an absence of sedation effects in PTBt. The main compounds of HbMeOH were chlorogenic acid and chlorogenic acid methyl ester, as well as less abundant terpene-type compounds. Furthermore, the extract was either safe with no deaths in mice treated orally with 2000 mg/kg.

CONCLUSIONS

HbMeOH extract which contains mainly hydroxycinnamic acids and triterpene-type compounds, possesses antidepressant, anxiolytic and anticonvulsive properties and can be considered safe or of low toxicity when orally administrated. These findings lend pharmacological justification to the traditional use of Heteropterys brachiata in the treatment of nervous disorders.

PAL inhibitor evokes different responses in two Hypericum species

Accumulation of secondary metabolites (general phenols, naphthodianthrones and phloroglucinol hyperforin) in Hypericum perforatum and Hypericum canariense after application of the inhibitor (2-aminoindane-2-phosphonic acid, AIP) of the pivotal enzyme of general phenylpropanoid pathway (phenylalanine ammonia-lyase, PAL) was studied. Shoots of H. perforatum revealed more expressive growth depression, concomitantly with the inhibition of PAL activity (-60%) and decrease in soluble phenols and individual phenolic acids in response to AIP. Hypericins (hypericin, pseudohypericin and protohypericin) decreased while hyperforin increased in AIP-cultured H. perforatum. On the contrary, growth changes, decreases in soluble phenols and individual phenolic acids were less-visible in H. canariense. This was also reflected in restoration of PAL activity (+330%) and selected flavonoids even increased. Hypericins and hyperforin were present in several orders of magnitude lower amounts in comparison with H. perforatum. Increase in proline indicates potential compensatory antioxidative mechanism if phenols are depleted. Microscopy revealed also differences in secondary xylem formation and lignification between species after exposure to AIP.

Hypericum silenoides Juss. and Hypericum philonotis Cham. & Schlecht. extracts: in-vivo hypolipidaemic and weight-reducing effects in obese rats*

Objectives

This study was carried out to assess the anti-obesity effect of Hypericum silenoides Juss. and Hypericum philonotis Cham. & Schlecht. in male Wistar rats fed with a cafeteria diet.

Methods

Adult male Wistar rats with an initial body weight of 290–320 g were used in this trial. The rats were fed with a cafeteria diet for 77 days. Hypericum species were administered orally at a dose of 10, 30 or 100 mg/kg of body weight daily for 35 days. Body weight, food intake, anorexic effect and various biochemical parameters, such as serum glucose, lipid profile, alanine transaminase (ALT), aspartate transaminase (AST) and atherogenic index (AI), were assessed. Additionally, inhibitory lipase activity assay and forced swimming test were also carried out.

Key findings

Oral administration of H. silenoides and H. philonotis extracts resulted in a significant decrease in body weight and serum glucose levels in obese male Wistar rats. Treatment with aqueous extract of H. silenoides showed anorexic and antidepressant effects and also significantly (P < 0.05) decreased total cholesterol, triglycerides and high-density lipoprotein-cholesterol, while low-density lipoprotein-cholesterol, AI, AST and ALT were not changed. The dichloromethane extract of H. silenoides (half maximal inhibitory concentration (IC50) = 262.79 ± 0.09 μg/ml) and hexane extract of H. philonotis (IC50 = 162.60 ± 0.02 μg/ml) showed the most potent lipase inhibitory activity.

Conclusion

Some H. silenoides and H. philonotis extracts showed a significant anti-obesity activity in cafeteria-diet-fed rats. This research provides the first scientific support for the use of the Hypericum genus for weight reduction in Mexican folk medicine.

Effects of Hypericum montbretti extract on the central nervous system and involvement of GABA (A)/Benzodiazepine receptors in its pharmacological activity

The present study was undertaken to investigate the putative activity of a methanol extract of Hypericum montbretti (Guttiferae) on the central nervous system. Rutin (1519 ppm) and quercitrin (784 ppm) were identified as the major phenolic compounds in the extract. When administered at 25, 50 and 100 mg/kg doses, the extract decreased the total number of head-dipping behaviours performed by mice during a hole-board test. Administration of both the extract and diazepam (2 mg/kg) reduced spontaneous locomotory activity, potentiated hexobarbital (60 mg/kg)-induced sleeping parameters and prevented pentylenetetrazole (80 mg/kg)-induced seizures relative to the controls. These findings are the first to indicate the sedative and anticonvulsant activities of H. montbretti extract. Atropine (2 mg/kg) and naloxone (5 mg/kg) pre-treatment did not reverse the sedative effect, indicating that muscarinic and opioidergic mechanisms did not contribute to the pharmacological action. However, pre-treatment with flumazenil (a benzodiazepine receptor antagonist) reversed both the sedative and anticonvulsant effects induced by a 100 mg/kg dose of the extract, indicating the involvement of the GABA(A)-benzodiazepine receptor complex. In conclusion, H. montbretti extract is a novel candidate as a sedative and anticonvulsant drug for the treatment of sleep disorders and for the prevention of epileptic seizures.

Antidepressant-like effect of the extracted of Kai Xin San, a traditional Chinese herbal prescription, is explained by modulation of the central monoaminergic neurotransmitter system in mouse

ETHNOPHARMACOLOGICAL RELEVANCE

Kai Xin San (KXS) is a traditional Chinese herbal prescription for the treatment of depression-like disorders, anxiety, and impairment in learning and memory, however, there is very little scientific data concerning the efficacy of this.

AIM OF THE STUDY

The present study aimed to investigate the antidepressant potential of Kai Xin San and its possible mechanisms.

MATERIALS AND METHODS

Mouse models of depression including the tail suspension test (TST) and the forced swim test (FST) were used to evaluate the effects of KXS. A possible mechanism was explored in the tests of antagonism of reserpine-induced ptosis, akinesia and hypothermia and 5-HTP induced head-twitch response in mice. The contents of monoamine neurotransmitters including epinephrine (NE), 5-hydroxytryptamine (5-HT) and dopamine (DA) in mice brain were determined by Elisa. Spontaneous motor activities of mice and rotarod test were performed to find whether KXS has excitatory or inhibitory actions on the central nervous system.

RESULTS

The results showed that intragastric administration of KXS at 175, 350, 700, 1400 mg/kg/day or fluoxetine at 28 mg/kg/day for 3 days significantly reduced the duration of immobility in TST and FST, while it showed no effect on the spontaneous motor activity and rotarod performance in mice. However, the effect was not dose-dependent. The pre-treatment with KXS or fluoxetine for 3 days could elevate the contents of NE, 5-HT and DA in mice brain significantly. When the mice were treated with KXS (350 mg/kg, p.o) or desipramine (30 mg/kg, p.o) for 7 days, both of them could antagonize reserpine-induced ptosis, akinesia and hypothermia. The KXS (350 mg/kg) also increased the accumulative number of the 5-HTP-induced head twitch response in mice in 20 min when KXS at dosages of 175, 350, 700 and 1400 mg/kg/day were performed per os (p.o.) during a 1-day, 3-day or 7-day period.

CONCLUSIONS

Our results suggested that KXS exerts antidepressant-like effect. A possible mechanism, at least in part, is via the central monoaminergic neurotransmitter system and 5-HT plays a major role.

Antidepressant effect and pharmacological evaluation of standardized extract of flavonoids from Byrsonima crassifolia

Byrsonima crassifolia (Malpighiaceae) has been used in traditional medicine for the treatment of some mental-related diseases; however, its specific neuropharmacological activities remain to be defined. The present study evaluates the anxiolytic, anticonvulsant, antidepressant, sedative effects produced by the extracts of Byrsonima crassifolia, and their influence on motor activity in ICR mice. Additionally, we determine the acute toxicity profiles of the Byrsonima crassifolia extracts and the presence of neuroactive constituents. Our results show that the methanolic extract of Byrsonima crassifolia produces a significant (P<0.05) antidepressant effect in the forced swimming test in mice at 500 mg/kg dose. However, it does not possess anxiolytic, sedative, or anticonvulsant properties, and does not cause a reduction of mice locomotion (P>0.05). Although the main compound of the methanolic extract was identified as quercetin 3-O-xyloside (12 mg/kg), our findings suggest that flavonoids, such as rutin (4.4 mg/kg), quercetin (1.4 mg/kg) and hesperidin (0.7 mg/kg), may be involved in the antidepressant effects. To the best of our knowledge, the present study constitutes the first report on the presence of the flavonoids with neuropharmacological activity rutin and hesperidin in Byrsonima crassifolia. In conclusion, the present results showed that the methanolic extract standardized on flavonoids content of Byrsonima crassifolia possesses potential antidepressant-like effects in the FST in mice, and could be considered as relatively safe toxicologically with no deaths of mice when orally administered at 2000 mg/kg.

A new automated and high-throughput system for analysis of the forced swim test in mice based on magnetic field changes

INTRODUCTION

MicroAct (Neuroscience, Tokyo, Japan) was originally developed as a new system for an automated analysis of scratching behaviors in mice. This system is based on the detection of electric current in the coils according to the movement of the magnets implanted in the hind paws. We applied and improved this system to establish an automated analysis system of forced swimming behaviors in mice, which is used as an animal model of depression.

METHODS

One day before the test, male CD-1 mice were attached with a wire ring to their hind paws under inhalation anesthesia. After attaching a small magnet to both of the wire rings, each animal was placed for 6 min in a glass cylinder filled with water, which is surrounded by a coil. The swimming behaviors of the mouse were analyzed for the measurement of duration of immobility, a major marker of depression in rodents, by the detection system (MicroAct). The duration of immobility was also determined by manual measurement using the swimming behavior-recorded videotapes produced at the same time as the automated analysis.

RESULTS

The difference of the duration of immobility between naïve mice and mice with the rings was not significant. The dose-response effect of imipramine (tricyclic antidepressant, 0, 7.5, 15, 30 and 60 mg/kg, p.o.) on the duration of immobility in the last 4-min of the 6-min testing period determined by MicroAct was similar to that assessed by the manual measurement. These data from the two different methods were significantly correlated (r=0.8805). Moreover, throughput of the automated analysis was 15 times more efficient than that of the manual analysis.

DISCUSSION

These results suggest that the automated analysis system of forced swimming of mice using MicroAct can be used as a high-throughput method to examine antidepressive activity of a compound with objectivity and reliability.