Antidepressant and anxiolytic effects of amentoflavone isolated from Cnestis ferruginea in mice

GABAergic implications in anxiety and related disorders

Evidence indicates that anxiety disorders arise from an imbalance in the functioning of brain circuits that govern the modulation of emotional responses to possibly threatening stimuli. The circuits under consideration in this context include the amygdala's bottom-up activity, which signifies the existence of stimuli that may be seen as dangerous. Moreover, these circuits encompass top-down regulatory processes that originate in the prefrontal cortex, facilitating the communication of the emotional significance associated with the inputs. Diverse databases (e.g., Pubmed, ScienceDirect, Web of Science, Google Scholar) were searched for literature using a combination of different terms e.g., "anxiety", "stress", "neuroanatomy", and "neural circuits", etc. A decrease in GABAergic activity is present in both anxiety disorders and severe depression. Research on cerebral functional imaging in depressive individuals has shown reduced levels of GABA within the cortical regions. Additionally, animal studies demonstrated that a reduction in the expression of GABAA/B receptors results in a behavioral pattern resembling anxiety. The amygdala consists of inhibitory networks composed of GABAergic interneurons, responsible for modulating anxiety responses in both normal and pathological conditions. The GABAA receptor has allosteric sites (e.g., α/γ, γ/β, and α/β) which enable regulation of neuronal inhibition in the amygdala. These sites serve as molecular targets for anxiolytic medications such as benzodiazepine and barbiturates. Alterations in the levels of naturally occurring regulators of these allosteric sites, along with alterations to the composition of the GABAA receptor subunits, could potentially act as mechanisms via which the extent of neuronal inhibition is diminished in pathological anxiety disorders.

Overexpression of RAD54L attenuates osteoarthritis by suppressing the HIF-1α/VEGF signaling pathway: Bioinformatics analysis and experimental validation

Osteoarthritis (OA) is a widespread chronic, progressive, degenerative joint disease that causes pain and disability. Current treatments for OA have limited effectiveness and new biomarkers need to be identified. Bioinformatics analysis was conducted to explore differentially expressed genes and DNA repair/recombination protein 54 L (RAD54L) was selected. We firstly overexpressed RAD54L in interleukin-1β (IL-1β)-induced human articular chondrocytes or in OA rats to investigate its effect on OA. Chondrocyte viability and apoptotic rate were measured by Cell Counting Kit-8 and flow cytometry, respectively. Then we evaluated OA severity in vivo by Hematoxylin-eosin staining and Osteoarthritis Research Society International standards. The expression of inflammatory mediators was tested by enzyme-linked immunosorbent assay. Finally, western blot was performed to determine the relative expression level of hypoxia-inducible factors 1α (HIF-1α) and vascular endothelial growth factor (VEGF). Overexpression of RAD54L promoted cell viability and attenuated apoptosis in IL-1β-induced human chondrocytes. A lower Osteoarthritis Research Society International score and a remarkable alleviation of chondrocyte disordering and infiltration of inflammatory cells were found in cartilage tissues of OA rats after overexpressing RAD54L. The inflammatory response induced by OA was decreased by RAD54L overexpression in vitro and in vivo. In addition, RAD54L overexpression decreased the relative expression level of HIF-1α and VEGF. Overexpression of RAD54L could attenuate OA by suppressing the HIF-1α/VEGF signaling pathway, indicating that RAD54L may be a potential treatment target for OA.

Advances in Flavonoid Research: Sources, Biological Activities, and Developmental Prospectives

At present, the occurrence of a large number of infectious and non-communicable diseases poses a serious threat to human health as well as to drug development for the treatment of these diseases. One of the most significant challenges is finding new drug candidates that are therapeutically effective and have few or no side effects. In this respect, the active compounds in medicinal plants, especially flavonoids, are potentially useful compounds with a wide range of pharmacological activities. They are naturally present in nature and valuable in the treatment of many infectious and non-communicable diseases. Flavonoids are divided into fourteen categories and are mainly derived from plant extraction, chemical synthesis and structural modification, and biosynthesis. The structural modification of flavonoids is an important way to discover new drugs, but biosynthesis is currently considered the most promising research direction with the potential to revolutionize the new production pipeline in the synthesis of flavonoids. However, relevant problems such as metabolic pathway analyses and cell synthesis protocols for flavonoids need to be addressed on an urgent basis. In the present review, new research techniques for assessing the biological activities of flavonoids and the mechanisms of their biological activities are elucidated and their modes of interaction with other drugs are described. Moreover, novel drug delivery systems, such as nanoparticles, bioparticles, colloidals, etc., are gradually becoming new means of addressing the issues of poor hydrophilicity, lipophilicity, poor chemical stability, and low bioavailability of flavonoids. The present review summarizes the latest research progress on flavonoids, existing problems with their therapeutic efficacy, and how these issues can be solved with the research on flavonoids.

Cajanus cajan (L) Millsp seeds extract prevents rotenone-induced motor- and non-motor features of Parkinson disease in mice: Insight into mechanisms of neuroprotection

ETHNOPHARMACOLOGICAL RELEVANCE

Cajanus cajan (L) Millsp (Fabaceae) seed decoction is used by traditional healers in Nigeria as nerve tonic, hence, could be beneficial in the treatment of Parkinson's disease (PD), a progressive and debilitating neurodegenerative disease that imposes great burden on the healthcare system globally.

AIM OF THE STUDY

This study aimed at investigating the neuroprotective effect of ethanol seed extract of Cajanus cajan (CC) in the treatment of rotenone-induced motor symptoms and non-motor symptoms associated with PD.

MATERIALS AND METHODS

To assess the protective action of CC on rotenone-induced motor- and non-motor symptoms of PD, mice were first pretreated with CC (50, 100 or 200 mg/kg, p.o.) an hour before oral administration of rotenone (1 mg/kg, p.o, 0.5% in carboxyl-methylcellulose) for 28 consecutive days and weekly behavioural tests including motor assessment (open field test (OFT), rotarod, pole and cylinder tests) and non-motor assessment (novel object recognition (NOR), Y-maze test (YM), forced swim and tail suspension, gastric emptying and intestinal fluid accumulation tests) were carried out. The animals were euthanized on day 28 followed by the collection of brain for assessment of oxidative stress, inflammatory markers and immunohistochemical analysis of the striatum (STR) and substantia nigra (SN). Phytochemicals earlier isolated from CC were docked with protein targets linked with PD pathology such as; catechol-O-methyltransferase (COMT), tyrosine hydroxylase (TH) and Leucine rich receptor kinase (LRRK).

RESULTS

this study showed that CC significantly reduced rotenone-induced spontaneous motor impairment in OFT, pole, cylinder and rotarod tests in mice as well as significant improvement in non-motor features (significant reversal of rotenone-induced deficits discrimination index and spontaneous alternation behaviour in NORT and YM test, respectively, reduction in immobility time in forced swim/tail suspension test, gastrointestinal disturbance in intestinal transit time in mice. Moreso, rotenone-induced neurodegeneration, oxidative stress and neuroinflammation were significantly attenuated by CC administration. In addition, docking analysis showed significant binding affinity of CC phytochemicals with COMT, TH and LRRK2 receptors.

CONCLUSION

Cajanus cajan seeds extract prevented both motor and non-motor features of Parkinson disease in mice through its antioxidant and anti-inflammatory effects. Hence, could be a potential phytotherapeutic adjunct in the management of Parkinson disease.

Neuropharmacological assessment and identification of possible lead compound (apomorphine) from Hygrophila spinosa through in-vivo and in-silico approaches

The aim of this research is to examine possible neurological activity of methanol, ethyl acetate, and aqueous extracts of Hygrophila spinosa and identify possible lead compounds through in silico analysis. In vivo, neuropharmacological activity was evaluated by using four distinct neuropharmacological assessment assays. Previously reported GC-MS data and earlier literature were utilized to identify the phytochemicals present in Hygrophila spinosa. Computational studies notably molecular docking and molecular dynamic simulations were conducted with responsible receptors to assess the stability of the best interacting compound. Pharmacokinetics properties like absorption, distribution, metabolism, excretion, and toxicity were considered to evaluate the drug likeliness properties of the identified compounds. All the in vivo results support the notion that different extracts (methanol, ethyl acetate, and aqueous) of Hygrophila spinosa have significant (*p = 0.05) sedative-hypnotic, anxiolytic, and anti-depressant activity. Among all the extracts, specifically methanol extracts of Hygrophila spinosa (MHS 400 mg/kg.b.w.) showed better sedative, anxiolytic and antidepressant activity than aqueous and ethyl acetate extracts. In silico molecular docking analysis revealed that among 53 compounds 7 compounds showed good binding affinities and one compound, namely apomorphine (CID: 6005), surprisingly showed promising binding affinity to all the receptors . An analysis of molecular dynamics simulations confirmed that apomorphine (CID: 6005) had a high level of stability at the protein binding site. Evidence suggests that Hygrophila spinosa has significant sedative, anxiolytic, and antidepressant activity. In silico analysis revealed that a particular compound (apomorphine) is responsible for this action. Further research is required in order to establish apomorphine as a drug for anxiety, depression, and sleep disorders.Communicated by Ramaswamy H. Sarma.

Natural Flavonoid Apigenin, an Effective Agent Against Nervous System Cancers

Cancer is a serious public health concern worldwide, and nervous system (NS) cancers are among the most life-threatening malignancies. Efforts have been devoted to introduce natural anticancer agents with minimal side effects. Apigenin is an edible flavonoid that is abundantly found in many vegetables and fruits. Various pharmaceutical activities, including anti-inflammatory, antioxidative, antimicrobial, and anticancer effects have been reported for apigenin. This review provides insights into the therapeutic effects of apigenin and flavonoids with similar structure on glioblastoma and neuroblastoma. Current evidence indicates that apigenin has the unique ability to cross the blood-brain barrier, and its antioxidative, anti-inflammatory, neurogenic, and neuroprotective effects have made this flavonoid a great option for the treatment of neurodegenerative disorders. Meanwhile, apigenin has low toxicity on normal neuronal cells, while induces cytotoxicity on NS cancer cells via triggering several signal pathways and molecular targets. Anticancer effects of apigenin have been contributed to various mechanisms such as induction of cell cycle arrest and apoptosis, and inhibition of migration, invasion, and angiogenesis. Although apigenin is a promising pharmaceutical agent, its low bioavailability is an important issue that must be solved before introducing to clinic. Recently, nano-delivery of apigenin by liposomes and poly lactic-co-glycolide nanoparticles has greatly improved functionality of this agent. Hence, investigating pharmaceutical effects of apigenin-loaded nanocarriers on NS cancer cell lines and animal models is recommended for future studies.

Short-term effects and safety of a natural oral supplement containing glucosinolates, phytosterols, and citrus flavonoids compared with hormone treatment for the management of postmenopausal symptomatic women: a pilot single-center randomized phase 2 clinical trial

OBJECTIVE

This study aimed to evaluate the short-term efficacy and safety of an oral herbal supplement containing glucosinolates, phytosterols, and citrus flavonoids for menopausal symptoms in comparison with estrogen plus progestogen therapy (EPT) among postmenopausal women.

METHODS

This was a pilot single-blinded, three-armed phase II randomized clinical trial, controlled with EPT. Sixty participants were randomly assigned to receive treatment for 3 months: (1) an oral herbal supplement of 1,500 mg/d (G1, n = 20), (2) an oral herbal supplement of 3,000 mg/d (G2, n = 20), or (3) conjugated equine estrogens 0.625 mg/d plus medroxyprogesterone acetate of 5 mg/d (EPT group, n = 20). The primary endpoint was the intensity of menopausal symptoms as measured using the Menopause-Specific Quality of Life Questionnaire (global and domain scores). The Menopause-Specific Quality of Life Questionnaire uses a 7-point scale to rate the symptom intensity, with higher scores indicating severity. The secondary endpoints were hormonal, lipid, and safety profiles.

RESULTS

Fifty-four participants (n = 54) completed the study. The mean, model-estimated, and global menopausal symptom scores at 3 months were 85.8 in the EPT group, 61.3 in G1, and 62.5 in G2. Participants treated with the herbal compound had lower global (13.7 [6.9-20.4], P < 0.001) and physical symptom scores (6.6 [1.6-11.5], P = 0.002) on the second month and lower psychosocial symptom scores (3.8 [1.3 to 6.3], P < 0.001) on the third month of follow-up, compared with EPT. Conversely, participants receiving EPT showed better outcomes on vasomotor symptoms since the first month of treatment (-6.1 [-8.3 to -4.0], P < 0.001). The EPT group exhibited higher values of estradiol and lower follicle-stimulating hormone and luteinizing hormone since the first month of follow-up. Also, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were significantly higher in this group than in G2.

CONCLUSIONS

In this small single-blind exploratory trial, the oral herbal supplement was more efficacious in reducing global, physical, and psychosocial menopausal symptoms in the short term than EPT. However, further studies are needed to adequately assess the efficacy and safety of this herbal supplement in the treatment of menopausal symptoms.

Antidepressant- and anxiolytic-like actions of Cajanus cajan seed extract mediated through monoaminergic, nitric oxide-cyclic GMP and GABAergic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Cajanus cajan (L) Millsp, are used in Traditional medicine for the treatment of anxiety and other neurological disorders. Hence, this study is designed to investigate the antidepressant- and anxiolytic-like properties of ethanol seed extract of Cajanus cajan (CC) in mice.

MATERIALS AND METHODS

CC (50, 100 or 200 mg/kg, p.o.) was administered 1h before subjecting the animals to different behavioral models: forced swim test (FST) and tail suspension test (TST) (depressive-like behaviour), open field test (OFT), elevated plus maze (EPM), light-dark test (LDT) and hole-board test (HBT) for anxiety-like behaviour. To ascertain the pharmacodynamic of CC mice were pretreated with monoaminergic, nitrergic and GABAergic receptors antagonists. As well as molecular docking analysis of about 19 flavonoids present in CC on GABA_A, α₂ adrenoceptors and 5-HT_2A receptors.

RESULTS

CC (50, 100 or 200 mg/kg, p.o.) treatment significantly reduced immobile time in both FST and TST when compared with vehicle-treated control. However, the pretreatment of mice with prazosin/yohimbine (α_1/2 adrenoceptor antagonists, respectively), WAY100635 (5-HT_1A receptor antagonist), ketanserin (5-HT_2A receptor antagonist), sulpiride (dopamine D₂ receptor antagonist), L-N^G-Nitro arginine methyl ester (L-NAME), or methylene blue reversed the antidepressant-like effect of CC. In anxiety model, CC produced significant (p < 0.05) increase in open arms exploration and head dipping behavior which was reversed by flumazenil (benzodiazepine receptor antagonist) in the EPM. Docking analysis showed significant binding affinity of orientin, vitexin, pinostrobin and quercetin with 5HT_2A, α₂-adrenoceptor and GABA_A receptors.

CONCLUSION

Findings from this study showed that C.cajan seeds extract exerts antidepressant-like effect through participation of monoaminergic systems (5-HT₂ receptor, α₁/α₂-adrenoceptors, and dopamine D₂-receptors), nitric oxide-cyclic GMP pathway and anxiolytic-like effect via GABA_A benzodiazepine receptors. Moreso, presence of flavonoids with significant binding energies with monoaminergic and GABAergic systems support the potential of the extract in the management of mixed anxiety-depressive illness.

Exploring the multifocal role of phytoconstituents as antidepressants

Depression is the most prevalent and devastating neuropsychiatric disorder. There are several conventional antidepressants used for the treatment of depression. But due to their undesired adverse effects, patient compliance is very poor. Thus, developing novel medications for the treatment of depression is a critical strategic priority for meeting therapeutic demands. Current research is looking for alternatives to traditional antidepressants to reduce undesired side effects and increase efficacy. Phytoconstituents provide a wide research range in antidepressant treatments. In the present article, we have conducted a comprehensive assessment of neurological evidence, which supports the usefulness of phytoconstituents in the treatment of the depressive disorder. Secondary plant metabolites including alkaloids, polyphenols, glycosides, saponins, and terpenoids were found to exhibit antidepressant action. Most of the phytoconstituents were found to mediate their antidepressant effect through the upregulation of brain-derived neurotrophic factor (BDNF), serotonin, noradrenaline, and dopamine. Some were also found to exert antidepressant effects by inhibiting the monoamine oxidase (MAO) activity and hypothalamic-pituitary-adrenal (HPA) axis overactivity.

Neuroprotective potential of plant derived parenchymal stem cells extract on environmental and genetic models of Parkinson disease through attenuation of oxidative stress and neuroinflammation

Parkinson's disease (PD) is a neurodegenerative disorder characterized by both motor and non-motor features. The current treatment regimen for PD are dopamine enhancers which have been reported to worsen the disease prognosis after long term treatment, thus, the need for better treatment options. This study sought to investigate the protective action of Double Stem Cell® (DSC), a blend of stem cells extracts from Swiss apples (Malus Domestica) and Burgundy grapes (Vitis vinifera) on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism in mice and genetic model of PD in Drosophila melanogaster. Male albino mice were pretreated with MPTP (4 × 20 mg/kg, i.p., two hourly in 8 h), twelve hours before administration of DSC (8, 40, or 200 mg/kg, p.o.). Thereafter, behavioural, biochemical and immunohistochemical assays were carried out. The impact of vehicle or DSC supplementation on α-synuclein aggregation was evaluated in Drosophila melanogaster using the UAS-Gal4 system, female DDC-Gal4 flies were crossed with male UAS-α-synuclein, the progenies were examined for fecundity, locomotion, memory, and lifespan. MPTP-induced motor deficits in open field test (OFT), working memory impairment (Y-maze test (YMT)) and muscle incoordination (rotarod test) were ameliorated by DSC (8, 40 or 200 mg/kg) through dose-dependent and significant improvements in motor, cognitive and motor coordination. Moreso, MPTP exposure caused significant increase in lipid peroxidation and decrease in antioxidant enzymes activities (glutathione, catalase and superoxide dismutase) in the midbrain which were attenuated by DSC. MPTP-induced expression of microglia (iba-1), astrocytes (glia fibrillary acidic protein; GFAP) as well as degeneration of dopamine neurons (tyrosine hydroxylase positive neurons) in the substantia nigra (SN) were reversed by DSC. Supplementation of flies feed with graded concentration of DSC (0.8, 4 or 20 mg/ml) did not affect fecundity but improved climbing activity and lifespan. Findings from this study showed that Double Stem Cell improved motor and cognitive functions in both mice and Drosophila through attenuation of neurotoxin-induced oxidative stress and neuroinflammation.

Glimepiride Prevents 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Induced Dopamine Neurons Degeneration Through Attenuation of Glia Activation and Oxidative Stress in Mice

It is well established that there is a link between type 2 diabetes mellitus and Parkinson's disease (PD) evidenced in faster progression and more severe phenotype in patients living with diabetes suggestive of shared cellular pathways; hence, antidiabetic drugs could be a possible treatment options for disease modification. This study evaluated the effect of glimepiride (GMP), a third generation sulphonylurea, on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD in mice. Sixty mice were divided randomly into six individual groups of 10 mice each and dose orally as follows: group 1: vehicle (10 ml/kg, p.o.); group 2: MPTP (20 mg/kg, i.p. × 4 at 2-h interval); groups 3-5: GMP (1, 2, or 4 mg/kg, p.o.) + MPTP (20 mg/kg, i.p. × 4 at 2-h interval); and group 6: GMP (4 mg/kg, p.o.). Effect of glimepiride on motor activities were appraised with the use of open-field test and rotarod performance while non-motor activity was evaluated using force swim test (FST; depression) and Y-maze test (working memory). MPTP induced significant decrease in latency to fall on rotarod, distance covered/rearing in open field, mean speed and climbing in FST, and percentage alternation behavior in Y-maze suggestive of motor and non-motor dysfunction. However, MPTP-induced motor and non-motor dysfunction were ameliorated with glimepiride post-treatment. In addition, MPTP-induced increase in oxidative stress parameters and cholinergic neurotransmission was attenuated by glimepiride. In addition, MPTP-induced nigral dopamine neuron loss (decrease in tyrosine hydroxylase-positive neuron (TH)) and neuroinflammation (activation of glial fibrillary acid protein (GFAP) and ionized calcium binding adaptor molecule 1 (iba-1)) were ameliorated by GMP administration. This study showed that glimepiride ameliorates MPTP-induced PD motor and non-motor deficits through enhancement of antioxidant defense signaling and attenuation of neuroinflammatory markers. Thus, this could be useful as a disease-modifying therapy in the management of PD.

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.

Anxiolytic-like Effect of Quercetin Possibly through GABA Receptor Interaction Pathway: In Vivo and In Silico Studies

Scientific evidence suggests that quercetin (QUR) has anxiolytic-like effects in experimental animals. However, the mechanism of action responsible for its anxiolytic-like effects is yet to be discovered. The goal of this research is to assess QUR's anxiolytic effects in mouse models to explicate the possible mechanism of action. After acute intraperitoneal (i.p.) treatment with QUR at a dose of 50 mg/kg (i.p.), behavioral models of open-field, hole board, swing box, and light-dark tests were performed. QUR was combined with a GABAergic agonist (diazepam) and/or antagonist (flumazenil) group. Furthermore, in silico analysis was also conducted to observe the interaction of QUR and GABA (α5), GABA (β1), and GABA (β2) receptors. In the experimental animal model, QUR had an anxiolytic-like effect. QUR, when combined with diazepam (2 mg/kg, i.p.), drastically potentiated an anxiolytic effect of diazepam. QUR is a more highly competitive ligand for the benzodiazepine recognition site that can displace flumazenil (2.5 mg/kg, i.p.). In all the test models, QUR acted similar to diazepam, with enhanced effects of the standard anxiolytic drug, which were reversed by pre-treatment with flumazenil. QUR showed the best interaction with the GABA (α5) receptor compared to the GABA (β1) and GABA (β2) receptors. In conclusion, QUR may exert an anxiolytic-like effect on mice, probably through the GABA-receptor-interacting pathway.

Pharmacological effects and therapeutic potential of natural compounds in neuropsychiatric disorders: An update

Neuropsychiatric diseases are a group of disorders that cause significant morbidity and disability. The symptoms of psychiatric disorders include anxiety, depression, eating disorders, autism spectrum disorders (ASD), attention-deficit/hyperactivity disorder, and conduct disorder. Various medicinal plants are frequently used as therapeutics in traditional medicine in different parts of the world. Nowadays, using medicinal plants as an alternative medication has been considered due to their biological safety. Despite the wide range of medications, many patients are unable to tolerate the side effects and eventually lose their response. By considering the therapeutic advantages of medicinal plants in the case of side effects, patients may prefer to use them instead of chemical drugs. Today, the use of medicinal plants in traditional medicine is diverse and increasing, and these plants are a precious heritage for humanity. Investigation about traditional medicine continues, and several studies have indicated the basic pharmacology and clinical efficacy of herbal medicine. In this article, we discuss five of the most important and common psychiatric illnesses investigated in various studies along with conventional therapies and their pharmacological therapies. For this comprehensive review, data were obtained from electronic databases such as MedLine/PubMed, Science Direct, Web of Science, EMBASE, DynaMed Plus, ScienceDirect, and TRIP database. Preclinical pharmacology studies have confirmed that some bioactive compounds may have beneficial therapeutic effects in some common psychiatric disorders. The mechanisms of action of the analyzed biocompounds are presented in detail. The bioactive compounds analyzed in this review are promising phytochemicals for adjuvant and complementary drug candidates in the pharmacotherapy of neuropsychiatric diseases. Although comparative studies have been carefully reviewed in the preclinical pharmacology field, no clinical studies have been found to confirm the efficacy of herbal medicines compared to FDA-approved medicines for the treatment of mental disorders. Therefore, future clinical studies are needed to accelerate the potential use of natural compounds in the management of these diseases.

Insights into the Explicit Protective Activity of Herbals in Management of Neurodegenerative and Cerebrovascular Disorders

The longstanding progressive neurodegenerative conditions of the central nervous system arise mainly due to deterioration, degradation and eventual neuronal cell loss. As an individual ages, the irreversible neurodegenerative disorders associated with aging also begin to develop, and these have become exceedingly prominent and pose a significant burden mentally, socially and economically on both the individual and their family. These disorders express several symptoms, such as tremors, dystonia, loss of cognitive functions, impairment of motor activity leading to immobility, loss of memory and many more which worsen with time. The treatment employed in management of these debilitating neurodegenerative disorders, such as Parkinson’s disease (which mainly involves the loss of dopaminergic neurons in the nigrostriatal region), Alzheimer’s disease (which arises due to accumulation of Tau proteins causing diffusive atrophy in the brain), Huntington’s disease (which involves damage of striatal and spinal neurons, etc.), have several adverse effects, leading to exploration of several lead targets and molecules existing in herbal drugs. The current review highlights the mechanistic role of natural products in the treatment of several neurodegenerative and cerebrovascular diseases such as Parkinson’s disease, Alzheimer’s disease, ischemic stroke and depression.

Monoaminergic system involvement in the antidepressant-like and anxiolytic-like properties of novel β-dihydroagarofuran sesquiterpene alkaloid and triterpenes isolated from Gymnosporia heterophylla aerial parts in mice

Gymnosporia heterophylla (synonym Maytenus) is widely used in folk medicine for the treatment of various illness including neurological diseases. This study presents the antidepressant-like and anxiolytic-like effects of novel bioactive constituents; 3,4-seco-1-hydroxy-21-oxoolean-3,11-olide (A2), 1β,2β-diacetoxy-9β-benzoyloxy-6α-nicotinoyloxy-β-dihydroagarofuran (A5) as well as known 3-acetoxy-1β-hydroxyLupe-20(29)-ene (selective COX-2; A4) from the aerial parts of G. heterophylla. The antidepressant-like effect was studied using the forced swim test (FST) while the elevated plus maze test (EPMT) and open field test (OFT) were employed for anxiolytic-like effect. Acute treatment with A4 and A5 (0.5, 5 or 10 mg/kg) significantly reduced the duration of immobility and immobile episodes with prolongation of immobility latency in the FST with peak effects observed at 10 and 0.5 mg/kg, respectively. Moreover, antidepressant-like effect of A4 and A5 were relatively better than that of fluoxetine. Conversely, the pretreatment of mice with prazosin (1 mg/kg, α₁-adrenoceptor antagonist), yohimbine (1 mg/kg; α₂-adrenoceptor antagonist), or sulpiride (50 mg/kg; dopamine D₂-receptor antagonist) reversed antidepressant-like effect of A4 and A5 but not WAY 100635 (10 mg/kg, i.p., selective 5-HT_1A receptor antagonist), GR 127935 (5 mg/kg, i.p., selective 5-HT_1B receptor antagonist), metergoline (4 mg/kg, i.p, non-selective 5-HT₂ receptor antagonist), ketanserin (5 mg/kg, i.p., a selective 5-HT_2A receptor antagonist) or p-chlorophenylalanine (pCPA) (100 mg/kg, i.p., tryptophan hydroxylase inhibitor) in the FST. Interestingly, A2, A4 and A5 significantly increased the time spent in the open arms of the EPM suggestive of anxiolytic-like action. Findings from this study showed that the novel β-dihydroagarofuran sesquiterpene alkaloid and triterpenes possesses antidepressant-like and anxiolytic-like effects through enhancement of monoaminergic signaling.

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.

Biflavonoids: Important Contributions to the Health Benefits of Ginkgo (Ginkgo biloba L.)

Ginkgo (Ginkgo biloba L.) is one of the most distinctive plants, characterized by excellent resistance to various environmental conditions. It is used as an ornamental plant and is recognized as a medicinal plant in both traditional and Western medicine. Its bioactive potential is associated with the presence of flavonoids and terpene trilactones, but many other compounds may also have synergistic effects. Flavonoid dimers-biflavonoids-are important constituents of ginkgophytopharmaceuticals. Currently, the presence of 13 biflavonoids has been reported in ginkgo, of which amentoflavone, bilobetin, sciadopitysin, ginkgetin and isoginkgetin are the most common. Their role in plants remains unknown, but their bioactivity and potential role in the management of human health are better investigated. In this review, we have provided an overview of the chemistry, diversity and biological factors that influence the presence of biflavonoids in ginkgo, as well as their bioactive and health-related properties. We have focused on their antioxidant, anticancer, antiviral, antibacterial, antifungal and anti-inflammatory activities as well as their potential role in the treatment of cardiovascular, metabolic and neurodegenerative diseases. We also highlighted their potential toxicity and pointed out further research directions.

An ethnopharmacological review on the therapeutical properties of flavonoids and their mechanisms of actions: A comprehensive review based on up to date knowledge

Flavonoids -a class of low molecular weight secondary metabolites- are ubiquitous and cornucopia throughout the plant kingdom. Structurally, the main structure consists of C6-C3-C6 rings with different substitution patterns so that many sub-classes are obtained, for example: flavonols, flavonolignans, flavonoid glycosides, flavans, anthocyanidins, aurones, anthocyanidins, flavones, neoflavonoids, chalcones, isoflavones, flavones and flavanones. Flavonoids are evaluated to have drug like nature since they possess different therapeutic activities, and can act as cardioprotective, antiviral, antidiabetic, anti-inflammatory, antibacterial, anticancer, and also work against Alzheimer's disease and others. However, information on the relationship between their structure and biological activity is scarce. Therefore, the present review tries to summarize all the therapeutic activities of flavonoids, their mechanisms of action and the structure activity relationship.

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Latest updated ethnopharmacological review of the therapeutic effects of flavonoids.

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Flavonoids are attracting attention because of their therapeutic properties.

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Flavonoids are valuable candidates for drug development against many dangerous diseases.

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This overview summarizes the most important therapeutic effect and mechanism of action of flavonoids.

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General knowledge about the structure activity relationship of flavonoids is summarized.

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Substitution of chemical groups in the structure of flavonoids can significantly change their biological and chemical properties.

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The chemical properties of the basic flavonoid structure should be considered in a drug-based structural program.

Insights Into Amentoflavone: A Natural Multifunctional Biflavonoid

Amentoflavone is an active phenolic compound isolated from Selaginella tamariscina over 40 years. Amentoflavone has been extensively recorded as a molecule which displays multifunctional biological activities. Especially, amentoflavone involves in anti-cancer activity by mediating various signaling pathways such as extracellular signal-regulated kinase (ERK), nuclear factor kappa-B (NF-κB) and phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), and emerges anti-SARS-CoV-2 effect via binding towards the main protease (Mpro/3CLpro), spike protein receptor binding domain (RBD) and RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2. Therefore, amentoflavone is considered to be a promising therapeutic agent for clinical research. Considering the multifunction of amentoflavone, the current review comprehensively discuss the chemistry, the progress in its diverse biological activities, including anti-inflammatory, anti-oxidation, anti-microorganism, metabolism regulation, neuroprotection, radioprotection, musculoskeletal protection and antidepressant, specially the fascinating role against various types of cancers. In addition, the bioavailability and drug delivery of amentoflavone, the molecular mechanisms underlying the activities of amentoflavone, the molecular docking simulation of amentoflavone through in silico approach and anti-SARS-CoV-2 effect of amentoflavone are discussed.

Cnestis ferruginea Vahl ex DC (Connaraceae) downregulates expression of immediate early genes in kainic acid-induced temporal lobe epilepsy in mice

OBJECTIVES

This study investigates the influence of Cnestis ferruginea (CF) on kainic acid (KA)-induced immediate early genes (IEGs) associated with hippocampal sclerosis in temporal lobe epilepsy (TLE) in mice.

METHODS

Animals were randomly divided into preventive treatment; vehicle (10 mL/kg, p.o.) or CF (400 mg/kg, p.o.) for three consecutive days before KA (5 mg/kg, i.p.) on days 4 and 5. In the reversal model, KA (5 mg/kg, i.p.) was administered on days 1 and 2 before CF (400 mg/kg) administration on days 3-5. Animals were euthanized on day 5, 6 h after KA exposure in preventive model and 1 h after CF administration in reversal model to estimate markers of IEGs.

RESULTS

KA upregulated the expression of c-Fos protein by 3.32-, 9.45-, 8.13-, and 8.66-fold in the hippocampal CA1, CA2, CA3, and DG regions, respectively. Also, KA elevated inducible nitric oxide synthase protein expression by 10.9-, 10.6-, 9.78-, and 9.51-fold. Besides, mRNA expression of brain-derived neurotrophic factors and heat shock protein was increased by 2.38- and 1.39-fold, respectively, after exposure to KA which were attenuated by CF.

CONCLUSIONS

CF attenuated KA-induced IEGs and could be used as an adjunct in TLE.

Emerging Role of Flavonoids as the Treatment of Depression

Depression is one of the most frequently observed psychological disorders, affecting thoughts, feelings, behavior and a sense of well-being in person. As per the WHO, it is projected to be the primitive cause of various other diseases by 2030. Clinically, depression is treated by various types of synthetic medicines that have several limitations such as side-effects, slow-onset action, poor remission and response rates due to complicated pathophysiology involved with depression. Further, clinically, patients cannot be given the treatment unless it affects adversely the job or family. In addition, synthetic drugs are usually single targeted drugs. Unlike synthetic medicaments, there are many plants that have flavonoids and producing action on multiple molecular targets and exhibit anti-depressant action by affecting multiple neuronal transmissions or pathways such as noradrenergic, serotonergic, GABAnergic and dopaminergic; inhibition of monoamine oxidase and tropomyosin receptor kinase B; simultaneous increase in nerve growth and brain-derived neurotrophic factors. Such herbal drugs with flavonoids are likely to be useful in patients with sub-clinical depression. This review is an attempt to analyze pre-clinical studies, structural activity relationship and characteristics of reported isolated flavonoids, which may be considered for clinical trials for the development of therapeutically useful antidepressant.

Influence of Smallanthus sonchifolius (Yacon) on the Activity of Antidepressant Drugs in Mice

Depression is one of the most common mental disorders in the world that negatively affects the daily functioning of patients. Numerous studies are currently being conducted to examine the antidepressant potential of innovative synthetic compounds and herbal substances. Yacon, Smallantchus sonchifolius, belongs to plants with numerous health-beneficial properties. Yacon-based products are regarded as a functional food. In our study, we attempted to check whether administration of Yacon tuber extract would have an antidepressant effect in the forced swim test (FST) in mice and whether its intake could influence the activity of conventional antidepressant drugs with different mechanisms of action, i.e., imipramine hydrochloride, fluoxetine hydrochloride, and reboxetine mesylate. The spontaneous locomotor activity of the tested mice was also investigated to eliminate any false-positive results. We demonstrated that an intragastric administration of the Yacon tuber extract at a dose of 100 mg/kg induced the antidepressant-like behavior in the FST in mice and that a combined administration of the sub-effective doses of the Yacon extract (50 mg/kg) with imipramine hydrochloride (7.5 mg/kg), fluoxetine hydrochloride (20 mg/kg), or reboxetine mesylate (5 mg/kg) significantly reduced the immobility time of animals in this behavioral test. The obtained results were not affected by the increased locomotor activity of the tested subjects. In conclusion, our findings suggest that Yacon tuber extract is promising as an alternative mood-improving product since it possesses an antidepressant potential and it can acts synergistically with conventional antidepressant drugs.

An overview on therapeutic and medicinal potential of poly-hydroxy flavone viz. Heptamethoxyflavone, Kaempferitrin, Vitexin and Amentoflavone for management of Alzheimer's and Parkinson's diseases: a critical analysis on mechanistic insight

Neurodegenerative disorders occur when nerve cells in the brain or peripheral nervous system partial or complete fail in their functions and sometimes even die due to some injuries or aging. Neurodegenerative disorders such as Alzheimer's Disease (AD) and Parkinson's Disease (PD), have been majorly resulted due to degeneration of neurons and neuroinflammation progressively. There are many similarities that correlates both AD and PD on a cellular and sub-cellular level. Therefore, a hope for therapeutic advancement for simultaneous upgradation in both the diseases are directly depending on the discovery of common mechanism at molecular and cellular level. Recent and past evidences from scientific literature supporting the efficacy of plants flavonoids in treatment and protection of both AD and PD. Further, dietary flavones, specially Heptamethoxyflavone, Kaempferitrin, Vitexin and Amentoflavone gains recently much more attention for producing many health beneficiary effects including neuroprotection. Despite of these evidence a detailed updated overview of neuroprotective effects against both AD and PD by Heptamethoxyflavone, Kaempferitrin, Vitexin and Amentoflavone are still missing. In this context several published studies were assessed by using various online electronic search engines/databases to meet the objective from 1981 to 2021 (Approx. 224). Therefore, present review was designed to deliver the detailed description on these flavones including therapeutic benefits in AD, PD and other CNS complications with critical analysis on underlying mechanisms.

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.

Quercetin and/or Ascorbic Acid Modulatory Effect on Phenobarbital-Induced Sleeping Mice Possibly through GABAA and GABAB Receptor Interaction Pathway

Depressive disorder is a recurrent illness that affects large numbers of the general population worldwide. In recent years, the goal of depression treatment has moved from symptomatic response to that of full remission. However, treatment-resistant depression is a major challenge in the treatment of depression or depression-related disorders. Consensus opinion, therefore, suggests that effective combined aggressive initial treatment is the most appropriate strategy. This study aimed to evaluate the effects of quercetin (QUR) and/or ascorbic acid (AA) on Phenobarbital-induced sleeping mice. QUR (50 mg/kg) and/or AA (25 mg/kg) with or without intraperitoneally pre-treated with GABA receptor agonist (diazepam: 2 mg/kg, i.p.) or antagonist (Flumazenil: 2.5 mg/kg, i.p.) to underscore the effects, as well as the possible involvement of the GABA receptor in the modulatory action of QUR and AA in sleeping mice. Additionally, an in silico study was undertaken to predict the involvement of GABA receptors in the sleep mechanism. Findings suggest that the pretreatment of QUR and AA modulated the onset and duration of action of the standard drugs in experimental animals. The acute administration of QUR and/or AA significantly (p < 0.05) reversed the DZP-mediated onset of action and slightly reversed the duration of sleep time in comparison to the vehicle (control) group. A further combination of QUR or AA with the FLU resulted in an enhancement of the onset of action while reducing the duration of action, suggesting a FLU-like effect on the test animals. In in silico studies, AA and QUR showed good to moderate binding affinities with GABA_A and GABA_B receptors. Both QUR and AA produced a stimulatory-like effect on mice, possibly through the GABA_A and GABA_B receptor interaction pathways. Further studies are necessary to verify this activity and clarify the exact mechanism of action(s) involved.

Discovery and proteomics analysis of effective compounds in Valeriana jatamansi jones for the treatment of anxiety

ETHNOPHARMACOLOGICAL RELEVANCE

Zhizhu Xiang (ZZX for short) is the root and rhizome of Valeriana jatamansi Jones, which is a Traditional Chinese Medicine (TCM) used to treat various mood disorders for more than 2000 years, especially anxiety. However, there have been few investigations to clarify the compounds in ZZX for the treatment of anxiety.

AIM OF THE STUDY

Our previous study has identified five anti-anxiety components, including hesperidin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C and chlorogenic acid, from extract of ZZX. In order to find the optimal combination and the underlying mechanism of these five components in the treatment of anxiety disorder, researches were designed based on uniform design method and proteomic technology.

MATERIALS AND METHODS

The samples with different proportion and content of the five active components were arranged by uniform design method. Then a mathematical model was formulated using partial least square method and stepwise regression analysis. Moreover, the empty bottle stress-induced anxiety rat model was established, and the anti-anxiety effect was recorded by the unconditioned reflex elevated maze test and the open field test. In addition, the isobaric tags for relative and absolute quantitation (iTRAQ) technique, along with the multidimensional liquid chromatography and high-resolution mass spectrometry were applied in proteomic study. At last, the result of proteomic analysis was further confirmed by Western blot.

RESULTS

The optimal combination of the components from the extract of ZZX was 1.153 mg/kg hesperidin, 2.197 mg/kg Isochlorogenic acid A, 0.699 mg/kg Isochlorogenic acid B and 1.249 mg/kg Chlorogenic acid. Total 6818 proteins were identified using proteomic analysis and 80 differentially expressed proteins were used for further bioinformatic analysis. These proteins were involved in the neuroactive ligand-receptor interaction, protein digestion and absorption, cholesterol metabolism, Chagas disease, and AGE/RAGE signaling pathway.

CONCLUSIONS

The composition and proportion of anti-anxiety components in extract of ZZX was disclosed, and there was an anti-anxiety effect for the combined components of flavonoids and phenolic acids. Through proteomic analysis and Western blot, it was found that the effective components of extract of ZZX can exert synergistic anti-anxiety effects via the regulation of multi-signaling pathways. These findings could provide a preliminary research basis for the development of new low-toxic, efficient, stable and controllable anti-anxiety drugs.

Amentoflavone Ameliorates Memory Deficits and Abnormal Autophagy in Aβ25-35-Induced Mice by mTOR Signaling

Alzheimer's disease (AD) is a neurodegenerative disease in which autophagy plays a crucial role. Amentoflavone is a flavonoid obtained from various plants and has been shown to have AD-resistant neuroprotective effects. This study investigated the role of amentoflavone on memory impairment and abnormal autophagy in amyloid-β25-35 (Aβ_25-35)-induced mice to elucidate the mechanisms by which it exerts neuroprotective effects. In this experiment, the AD mouse model was established by intracerebroventricular (ICV) injection of Aβ_25-35 peptides, and amentoflavone was administered orally for 4 weeks. Behavioral changes in mice and pathological changes in the hippocampus were observed, and levels of inflammation, oxidative stress, and autophagy in the brain were detected and analyzed. PC-12 and APPswe-N2a cells were used in vitro to further investigate the effect of amentoflavone on the level of intracellular autophagy. Molecular docking was used to determine the action sites of amentoflavone. The results showed that amentoflavone improved memory function, eased anxiety symptoms in Aβ_25-35-induced mice, and reduced atrophic degeneration of neurons in the hippocampus. Moreover, amentoflavone lessened the oxidative stress and inflammation in the brains of mice. Through in vivo and in vitro experiments, we found that amentoflavone may enhance autophagy, by way of binding to the ATP site of the mTOR protein kinase domain. Amentoflavone not only interacted with mTOR, but also improved Aβ_25-35-induced cognitive dysfunction in mice by enhancing autophagy, attenuating levels of inflammation and oxidative stress, and reducing apoptosis in brain cells.

Involvement of GABAergic and nitrergic systems in the anxiolytic and hypnotic effects of Curcuma longa: its interaction with anxiolytic-hypnotics

OBJECTIVES

Concurrent use of herbs with drugs have become a major healthcare problem. Herb-drug interactions could lead to therapeutic failure or toxicity. Hence, this study seeks to evaluate the impact of combining Curcuma longa rhizome (CL) with selected anxiolytic and hypnotic drugs.

METHODS

CL (100, 200 or 400 mg/kg, p.o.) was administered to mice 1 h before subjecting the animals to elevated plus maze (EPM), hole board test (HBT), open field test (OFT) and rotarod test for anxiolytic-like effect as well as hexobarbitone-induced sleeping time (HIST) for hypnotic activity. The involvement of GABAergic and nitrergic systems in CL-induced anxiolytic and hypnotic actions were also evaluated. The effect of concurrent use of CL with midazolam, imipramine, nifedipine, propranolol and carbamazepine were evaluated in anxiolytic-hypnosis models.

RESULTS

The peak anxiolytic-like effect of CL was obtained at 400 mg/kg in the EPM and hole-board test without affecting muscle coordination in the rotarod test while the peak hypnosis-potentiation was observed at 100 mg/kg. CL-induced anxiolytic-hypnotic-like effects were reversed by the pretreatment of mice with flumazenil or NG-nitro-l-arginine.

CONCLUSIONS

Curcuma longa possesses anxiolytic and hypnotic effects through its interaction with GABAergic and nitrergic systems. Conversely, co-administration of C. longa with midazolam potentiate barbiturate-induced hypnosis.

Connaraceae: An updated overview of research and the pharmacological potential of 39 species

ETHNOPHARMACOLOGICAL RELEVANCE

An interdisciplinary scientific investigation of biologically active agents is fundamental to search for natural substances with therapeutic action. This review collected the most relevant information on traditional knowledge related to the use of plants of the Connaraceae family. This work is the first to compile all the published ethnobotanical, chemical, pharmacological, and toxicological information about this important plant family.

AIM OF THE STUDY

Our objective was to provide the scientific community with an up-to-date overview of the pharmacological potential of Connaraceae species.

MATERIAL AND METHODS

We searched NCBI Pubmed Central, Google Scholar, Scientific Electronic Library Online (SciELO), ScienceDirect, SciFinder, and Scopus databases to review the research on ethnobotanical, chemical, pharmacognostical, pharmacological, and toxicological studies with Connaraceaes. Books that address the theme were also included.

DISCUSSION AND CONCLUSION

The literature review indicated that 39 species of Connaraceaes have pharmacological potentiality. Ethnobotany reports listed 36 of the 39 species discussed. Pharmacognostical studies have been conducted with 23 species and isolates, and chemical compounds have been identified for only 15 species. At least one study has been published concerning the pharmacological activities for 20 of the 39 species analyzed. For Agelaea pentagyna, Cnestis ferruginea, Connars suberosus, and Rourea minor, pharmacological activity experiments were performed using isolated compounds, which have the highest current pharmacological potential. Studies employing a toxicological approach cover only 10 of the 39 Connaraceaes species. Thus, scientific community should conduct much more research for a broader understanding of this plant family.

Coronaridine congeners potentiate GABAA receptors and induce sedative activity in mice in a benzodiazepine-insensitive manner

To determine whether (+)-catharanthine induces sedative- or anxiolytic/anxiogenic-like activity in male mice, proper animal paradigms were used. The results showed that (+)-catharanthine induces sedative-like activity in the 63-72 mg/Kg dose range in a flumazenil-insensitive manner, but neither this effect nor anxiolytic/anxiogenic-like activity was observed at lower doses. To determine the underlying molecular mechanism of the sedative-like activity, electrophysiological and radioligand binding experiments were performed with (+)-catharanthine and (±)-18-methoxycoronaridine [(±)-18-MC] on GABA_A (GABA_ARs) and glycine receptors (GlyRs). Coronaridine congeners both activated and potentiated a variety of human (h) GABA_ARs, except hρ1. (+)-Catharanthine-induced potentiation followed this receptor selectivity (EC₅₀'s in μM): hα1β2 (4.6 ± 0.8) > hα2β2γ2 (12.6 ± 3.8) ~ hα1β2γ2 (14.4 ± 4.6) indicating that both α1 and α2 are equally important, whereas γ2 is not necessary. (+)-Catharanthine was >2-fold more potent and efficient than (±)-18-MC at hα1β2γ2. (+)-Catharanthine also potentiated, whereas (±)-18-MC inhibited, hα1 GlyRs with very low potency. Additional [³H]-flunitrazepam competition binding experiments using rat cerebellum membranes clearly demonstrated that these ligands do not bind to the benzodiazepine site. This is supported by the observed activity at hα1β2 (lacking the BDZ site) and similar effects between α1- and α2-containing GABA_ARs. Our study shows, for the first time, that (+)-catharanthine induced sedative-like effects in mice, and coronaridine congeners potentiated human α1β2γ2, α1β2, and hα2β2γ2, but not ρ1, GABA_ARs, both in a benzodiazepine-insensitive fashion, whereas only (+)-catharanthine slightly potentiated GlyRs.

Gut Microbiota: A Pivotal Hub for Polyphenols as Antidepressants

Polyphenols, present in a broad range of plants, have been thought to be responsible for many beneficial health effects, such as an antidepressant. Despite that polyphenols can be absorbed in the small intestine directly, most of them have low bioavailability and reach the large intestine without any modifications due to their complex structures. The interaction between microbial communities and polyphenols in the intestine is important for the latter to exert antidepressant effects. Gut microbiota can improve the bioavailability of polyphenols; in turn, polyphenols can maintain the intestinal barrier as well as the community of the gut microbiota in normal status. Furthermore, gut microbita catabolize polyphenols to more active, better-absorbed metabolites, further ameliorating depression through the microbial-gut-brain (MGB) axis. Based on this evidence, the review illustrates the potential role of gut microbiota in the processes of polyphenols or their metabolites acting as antidepressants and further envisions the gut microbiota as therapeutic targets for depression.

Novel potential of metformin on valproic acid-induced autism spectrum disorder in rats: involvement of antioxidant defence system

Prenatal exposure to valproic acid (VPA) has been shown to increase the risk of autism in children. This study examined the effect of metformin on VPA-induced autism spectrum disorders in rats. Pregnant albino rats administered VPA (500 mg/kg, i.p.) or normal saline (10 mL/kg, i.p.; vehicle-control) on gestational day 12.5. The pups were given metformin (5, 50 or 500 mg/kg, p.o.) or vehicle (10 mL/kg, p.o.) daily from postnatal day (PND) 21-50. Social behaviour, spatial learning/reference memory, repetitive behaviour and anxiety were assessed using the three-chamber social assay, Morris water maze (MWM), Y maze and elevated plus maze tests (EPM), respectively. On PND 51, the animals were euthanized and brains removed for biochemical assay. In utero VPA exposure caused significant reduction in sociability index, social novelty preference index in three-chambered apparatus and spatial learning and reference memory deficits in the MWM task as well as increase in repetitive/anxiety-like behaviour in Y maze and EPM tests, respectively, which were ameliorated by post-treatment with metformin in a dose-dependent manner. Moreover, prenatal VPA increased malondialdehyde (MDA) and nitrite levels as well as deficits in antioxidant enzymes activities in the hippocampus and prefrontal cortex (PFC) which were attenuated by metformin administration. Similarly, VPA-induced increase in acetylcholinesterase activity in the hippocampus and PFC were attenuated by postnatal treatment with metformin. Findings from this study showed that postnatal administration of metformin prevented valproic acid-induced autistic-like behaviour. Hence, metformin could be a potential adjunct in the management of autism spectrum disorders.

Amentoflavone, a novel cyanobacterial killing agent from Selaginella tamariscina

Harmful cyanobacterial bloom (HCB) by Microcystis aeruginosa is increasingly becoming a serious concern to the environment and human health alike. Currently, many physical, chemical, and biological controls are underway to eliminate HCB, but natural chemicals are rarely used. To find a control agent with low environmental toxicity and high potential for practical use, 60 plant extracts were screened. Only Selaginella tamariscina extract killed all four Microcystis aeruginosa strains, but not the other tested bacteria. Chloroform fraction of S. tamariscina extract (CSE) showed the highest killing activity. The effects of CSE on M. aeruginosa were monitored using differential interference contrast microscopy and flow-cytometry analysis, scanning electron microscopy, and transmission electron microscopy. The images showed that CSE-treated cells were abnormally altered, with damaged cell membranes, peptidoglycan layers, and cytoplasm. Quadrupole time-of-flight liquid chromatography-mass spectrometry was used to identify amentoflavone as a major active compound. Pure amentoflavone, even at low concentrations showed a powerful killing effect on M. aeruginosa, but not on other non-cyanobacteria. Overall, in this study, we have highlighted the potentials of S. tamariscina extracts and amentoflavone as selective HCB control agents.

Neuroprotective Polyphenols: A Modulatory Action on Neurotransmitter Pathways

BACKGROUND

Balance in neurotransmission is essential for the proper functioning of the nervous system and even a small, but prolonged disturbance, can induce the negative feedback mechanisms leading to various neuropathologies. Neurodegenerative and mood disorders such as Alzheimer's, Parkinson's or affective disorders are increasing medical and social problems. Among the wide spectrum of potentially destructive events, oxidative stress and disrupted metabolism of some neurotransmitters such as acetylcholine, GABA, glutamate, serotonin or dopamine appear to play a decisive role. Biologically active plant polyphenols have been shown to exert a positive impact on the function of the central nervous system by modulation of metabolism and the action of some neurotransmitters.

METHODS

Based on published research, the pharmacological activities of some naturally occurring polyphenols have been reviewed, with a focus on their potential therapeutic importance in the regulation of neurotransmitter systems.

RESULTS

Phytochemicals can be classified into several groups and most of them possess anticancer, antioxidative, anti-inflammatory and neuroprotective properties. They can also modulate the metabolism or action of some neurotransmitters and/or their receptors. Based on these properties, phytochemicals have been used in traditional medicine for ages, although it was focused mainly on treating symptoms. However, growing evidence indicates that polyphenols may also prevent or slow neurological diseases.

CONCLUSION

Phytochemicals seem to be less toxic than synthetic drugs and they can be a safer alternative for currently used preparations, which exert adverse side effects. The neuroprotective actions of some plant polyphenols in the regulation of neurotransmitters metabolism, functioning of neurotransmitters receptors and antioxidative defense have potential therapeutic applications in various neurodegenerative disorders.

Ameliorative influence of Cnestis ferruginea vahl ex DC (Connaraceae) root extract on kainic acid-induced temporal lobe epilepsy in mice: Role of oxidative stress and neuroinflammation

ETHNOPHARMACOLOGY RELEVANCE: the root decoction of Cnestis ferruginea Vahl ex DC (Connaraceae) is widely used in traditional African medicine for the treatment of various ailments including pain, inflammation and epilepsy. We have earlier reported anticonvulsant effect of Cnestis ferruginea root extract in mice.

AIM OF THE STUDY

to evaluate the effect of ethanolic root extract of Cnestis ferruginea (CF) on kainic acid (KA)-induced temporal lobe epilepsy (TLE) in mice as well as the involvement of inflammatory mediators and oxidative stress.

MATERIALS AND METHODS

mice were randomly divided into preventive treatment (vehicle (normal saline) or CF (400 mg/kg, p.o.) for 3 consecutive days before KA (5 mg/kg, i.p.) on days 4 and 5. In the reversal model, KA (5 mg/kg, i.p.) was administered on days 1 and 2 before vehicle or CF (400 mg/kg) administration on days 3-5. The effect of treatments on seizure severity was recorded using Racine scale. Animals were euthanized on day 5, 6 h after last KA exposure in preventive model and 1 h after CF administration in reversal model to estimate markers of oxidative stress and neuroinflammation.

RESULTS

exposure of mice to KA induced TLE evidenced in increased severity of seizures which was significantly reduced by the pre- and post-treatment of mice with CF. Moreso, KA-induced malondialdehyde/nitrite generation and GSH deficit in the brain were attenuated by CF treatments. KA-induced up-regulation of inflammatory transcription factors; cyclooxygenase-2 (COX-2) and nuclear facor-kappaB (NF-κB) in the CA1, CA2, CA3 and dentate gyrus (DG) regions of the hippocampus regions were attenuated by CF treatments.

CONCLUSION

findings from this study showed that Cnestis ferruginea root extract ameliorated KA-induced TLE through enhancement of antioxidant defense mechanism and attenuation of neuro-inflammatory transcription factors. Thus, could possibly be a potential phytotherapeutic agent in the management of temporal lobe epilepsy.

Sargassum hystrix as a Source of Functional Food to Improve Blood Biochemistry Profiles of Rats under Stress

This study was conducted to determine the influence of Sargassum hystrix powder (SHP) as an alternative source of functional food for treating in vivo stress by measuring levels of glucose, triacylglycerol, total cholesterol, and cortisol, and liver histopathology. Wistar rats aged 3 months and weighing 150~200 g were divided into 7 groups: normal control, fasting control, negative control (stress without adaptogen), and 4 experimental conditions (stress+0.18 mg/kg diazepam, stress+450 mg/kg pellet, stress+mixture of pellet with SHP 450 mg/kg, and stress+450 mg/kg of SHP). Intake of liquids and and body weight were measured daily. Blood samples were collected on day 0 (baseline), day 5, and day 10 to analyze levels of glucose, triacylglycerol, cholesterol, and cortisol. On day 10, rats were euthanized and livers were collected to observe the severity of inflammation. The results indicated that rats receiving SHP 450 mg/kg and the mixture of pellet with SHP 450 mg/kg showed a similar ability as those receiving diazepam 0.18 mg/kg to cope with stress, indicated by an improvement in all blood biochemistry parameters. Supplementation with SHP 450 mg/kg can be used as an alternative source of functional food for overcoming oxidative stress, as indicated by its ability to improve levels of blood glucose, triacylglycerol, total cholesterol, and cortisol, and to improve liver histology by decreasing severity of liver inflammation.

Chemical Composition and Antifungal In Vitro and In Silico, Antioxidant, and Anticholinesterase Activities of Extracts and Constituents of Ouratea fieldingiana (DC.) Baill

Ouratea fieldingiana (Gardner) Engl is popularly used for wound healing. This study describes the main chemical compounds present in extracts of O. fieldingiana and evaluates their biological potential by investigating antifungal, antioxidant, and anticholinesterase activities. The action mechanism of main antifungal compound was investigated by molecular docking using the enzyme sterol 14-α demethylase, CYP51, required for ergosterol biosynthesis. The seeds and leaves were extracted with ethanol in a Soxhlet apparatus and by maceration, respectively. Both extracts were subjected to silica gel column chromatography for isolation of main constituents, followed by purification in sephadex. The structures of compounds were established by ¹H and ¹³C-NMR spectroscopy and identified by comparison with literature data as amentoflavone and kaempferol 3-O-rutinoside, respectively. The antioxidant activities of the extracts were determined by the DPPH and ABTS free radical inhibition methods. In general, the extracts with the highest antioxidant activity corresponded to those with higher content of phenolic compounds and flavonoids. The ethanol extracts and two isolated compounds presented relevant antifungal activity against several Candida strains. The in silico findings revealed that the compound amentoflavone coupled with the CYP450 protein due to the low energy stabilization (-9.39 kcal/mol), indicating a possible mechanism of action by inhibition of the ergosterol biosynthesis of Candida fungi.

Glimepiride prevents paraquat-induced Parkinsonism in mice: involvement of oxidative stress and neuroinflammation

There is a growing number of epidemiological and molecular studies which suggest that diabetes is associated with an increased risk of Parkinson's disease (PD). Hence, in this study, the effect of glimepiride (GPD), a sulphonylurea (antidiabetic) on paraquat (PQT)-induced Parkinsonism was evaluated in mice. Thirty-six mice were randomly divided into six groups (n = 6) and treated orally for 21 consecutive days as follows: Group 1: vehicle (10 mL/kg), Group 2: PQT (10 mg/kg, i.p., twice per week for 3 weeks), Group 3-5: GPD (1, 2 or 4 mg/kg) + PQT (10 mg/kg, i.p., twice per week for 3 weeks), Group 6: GPD (4 mg/kg, p.o.). The effects of the treatment on motor coordination were evaluated using the rotarod performance, bar and open field tests while working memory was assayed using Y-maze test. Paraquat injection induced significant decrease in falling time, number of crosses and percentage alternation behaviour with a concomitant increase in the duration of cataleptic behaviour in the rotarod, open field, Y-maze and bar tests, respectively, which was ameliorated by GPD treatment. PQT also increased lipid peroxidation, peroxynitrite and TNF-α generations as well as deficit in superoxide dismutase and GSH activities in the midbrain. PQT-induced oxidative stress and neuroinflammation was attenuated by GPD treatment. Findings from this study showed that GPD prevents PQT-induced motor dysfunction, memory impairment, oxidative stress and neuroinflammation through enhancement of antioxidant defense system and inhibition of pro-inflammatory cytokine release. Thus, GPD could be a potential adjunct in the management of Parkinsonism.

Identification of Bioactive Chemical Markers in Zhi zhu xiang Improving Anxiety in Rat by Fingerprint-Efficacy Study

Zhi zhu xiang (ZZX for short) is the root and rhizome of Valeriana jatamansi Jones, which is a Traditional Chinese Medicine (TCM) used to treat various mood disorders for more than 2000 years, especially anxiety. The aim of the present work was to identify the bioactive chemical markers in Zhi zhu xiang improving anxiety in rats by a fingerprint-efficacy study. More specifically, the chemical fingerprint of ZZX samples collected from 10 different regions was determined by High Performance Liquid Chromatography (HPLC) and the similarity analyses were calculated based on 10 common characteristic peaks. The anti-anxiety effect of ZZX on empty bottle stimulated rats was examined through the Open Field Test (OFT) and the Elevated Plus Maze Test (EPM). Then we measured the concentration of CRF, ACTH, and CORT in rat’s plasma by the enzyme-linked immune sorbent assay (ELISA) kit, while the concentration of monoamine and metabolites (NE, DA, DOPAC, HVA, 5-HT, 5-HIAA) in the rat’s cerebral cortex and hippocampus was analysed by HPLC coupled with an Electrochemical Detector. At last, the fingerprint-efficacy study between chemical fingerprint and anti-anxiety effect of ZZX was accomplished by partial least squares regression (PLSR). As a result, we screened out four compounds (hesperidin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C) as the bioactive chemical markers for the anti-anxiety effect of ZZX. The fingerprint-efficacy study we established might provide a feasible way and some elicitation for the identification of the bioactive chemical markers for TCM.

Simultaneous Determination of Quercitrin, Afzelin, Amentoflavone, Hinokiflavone in Rat Plasma by UFLC–MS-MS and Its Application to the Pharmacokinetics of Platycladus orientalis Leaves Extract

Leaves of Platycladus orientalis have been used as blood cooling and homeostatic therapy for thousands of years in traditional Chinese medicine. Emerging evidences of modern pharmacology have proved flavonoids as the key elements responsible for the efficacies. However, there has been no report on pharmacokinetic study of the flavonoids from Platycladus orientalis leaves extract. In this study, a sensitive and rapid ultra-flow liquid chromatography-tandem mass spectrometry method was established and validated for the simultaneous determination of amentoflavone, afzelin, hinokiflavone and quercitrin in rat plasma. The four flavonoids and luteolin (internal standard, IS) were recovered from rat plasma by methanol–ethyl acetate (v:v, 50:50). Chromatographic separation was performed on a C18 column with gradient elution. Our results showed that the recoveries from spiked control samples were more than 85% for all analytes and IS. The relative standard deviations of intra-day and inter-day precision were within 15% while the REs ranged from −6.6% to 8.0%. The validated method in this study was successfully applied to pharmacokinetic study in healthy rats after oral administration of P. orientalis leaves extract.

Distinct Hypericum perforatum L. total extracts exert different antitumour activity on erythroleukemic K562 cells

Total flower extracts of Hypericum perforatum L. obtained with 3 different solvent systems were tested on tumour cell line cultures by comparing two groups of plants harvested in different times and places. The extracts, characterized according to the spectroscopic profile and the hypericin content, were tested on the growth and apoptotic death of K562 cells, a human erythroleukemic cell line. Growth and apoptosis were analysed by viable cell count, flow cytometry, and fluorescence microscopy at 6, 24, and 48 hr of culture following 1 hr exposure to the extracts under investigation. Here, we show that Hypericum extracts are able to reduce the growth of K562 cells and induce different degrees and kinetics of apoptosis according to the group of plants of origin. Also, we highlighted interesting differences in terms of efficacy among the extracts, with some samples losing their effectiveness along the culture time and others able to maintain or even increase their efficacy. Furthermore, the data herein obtained confirm the role of non hypericin compounds that are present in different proportions in the two plant groups and in the extracts analysed.