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

Celecoxib, a cyclooxygenase-2 inhibitor, offers chemoprevention against reproductive and neurobehavioural abnormalities induced by atrazine in male Wistar rats

The cyclooxygenase-2/prostanoid pathway (COX-2) serves as a potential therapeutic target in various pathological conditions. Thus, the modulatory effect of celecoxib (CXB), a COX-2 inhibitor, in atrazine-induced toxicity was investigated. Five groups (n = 6 rats per group) of adult male Wistar rats received corn oil (2 ml/kg), atrazine (ATZ, 300 mg/kg) and CXB (5.7 mg/kg) respectively and their combinations via the oral route. Results obtained showed reduced (p < 0.05) sperm motility (25.8%) and counts (27.6%), testosterone (29.9%), luteinizing (33%) and follicle stimulating hormones (78.7%) plus elevated total cholesterol (112.3%), triglyceride (115.7%), malondialdehyde levels respectively in ATZ-treated rats. Similarly, ATZ administration causes reduced locomotion (33.6%), spontaneous motor activity (46.6%) and catalepsy effects (157.3%) respectively. However, CXB divided doses moderately reverse reproductive abnormalities, modulate neurobehavioural deficits and slightly preserved COX-2 elevation following ATZ intoxication. Furthermore, histopathology of testis shows improvement in treated rats. Overall, our data suggest chemopreventive actions via pharmacological inhibition of COX-2 activity during ATZ toxicity.

Antidepressant Flavonoids and Their Relationship with Oxidative Stress

Depression is a serious disorder that affects hundreds of millions of people around the world and causes poor quality of life, problem behaviors, and limitations in activities of daily living. Therefore, the search for new therapeutic options is of high interest and growth. Research on the relationship between depression and oxidative stress has shown important biochemical aspects in the development of this disease. Flavonoids are a class of natural products that exhibit several pharmacological properties, including antidepressant-like activity, and affects various physiological and biochemical functions in the body. Studies show the clinical potential of antioxidant flavonoids in treating depressive disorders and strongly suggest that these natural products are interesting prototype compounds in the study of new antidepressant drugs. So, this review will summarize the chemical and pharmacological perspectives related to the discovery of flavonoids with antidepressant activity. The mechanisms of action of these compounds are also discussed, including their actions on oxidative stress relating to depression.

A Review on the Phytochemistry, Pharmacology, and Pharmacokinetics of Amentoflavone, a Naturally-Occurring Biflavonoid

Amentoflavone (C30H18O10) is a well-known biflavonoid occurring in many natural plants. This polyphenolic compound has been discovered to have some important bioactivities, including anti-inflammation, anti-oxidation, anti-diabetes, and anti-senescence effects on many important reactions in the cardiovascular and central nervous system, etc. Over 120 plants have been found to contain this bioactive component, such as Selaginellaceae, Cupressaceae, Euphorbiaceae, Podocarpaceae, and Calophyllaceae plant families. This review paper aims to profile amentoflavone on its plant sources, natural derivatives, pharmacology, and pharmacokinetics, and to highlight some existing issues and perspectives in the future.

Amlodipine, an L-type calcium channel blocker, protects against chlorpromazine-induced neurobehavioural deficits in mice

This study investigated the modulatory and chemopreventive benefit of amlodipine (AML), a dihydropyridine calcium channel antagonist, against neurobehavioural abnormalities (NAs) associated with chlorpromazine (CPZ) toxicity in mice. Adult mice were divided into five groups of six animals/group. Group 1 (control) was administered saline (10 mL/kg i.p.). Group 2 received CPZ (2 mg/kg i.p.). Groups 3 and 4 received bromocriptine (BMC, 2.5 mg/kg s.c.) and AML (1 mg/kg s.c.), respectively, while group 5 received their combination. Groups 3-5 later received CPZ 30 min after initial treatments. Animals were subjected to neurobehavioural tests and euthanized 18 h later. CPZ-induced NAs were characterized by significant increase (P < 0.001) in cataleptic behaviour and lowered (P < 0.05) spontaneous activity reaction time in mice. There were also significant (P < 0.001) increases in malondialdehyde levels and decreased locomotion plus learning and memory parameters (P < 0.05-0.001). AML pretreatment alone did not alleviate CPZ-induced motor deficits in the mice. While pretreatment with BMC alone attenuated CPZ-associated catalepsy, its combination with AML further protected mice against NAs. Furthermore, BMC pretreatment did not affect CPZ-induced increase in malondialdehyde level, but AML or BMC+AML significantly (P < 0.05) decreased malondialdehyde in the CPZ-treated rats. Reduced glutathione levels and activities of superoxide dismutase and catalase remained elevated in all treatment groups. In conclusion, data from this study suggest possible chemopreventive benefit of AML alone or in combination with BMC against CPZ-associated neurobehavioural deficits. The ameliorative effect of AML may be related to its antioxidant and/or calcium channel blocking property.

Selaginella uncinata flavonoids ameliorated ovalbumin-induced airway inflammation in a rat model of asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Selaginella uncinata (Desv.) Spring, known as "Cuiyuncao", is a perennial herb widely distributed in the Southeast Asian countries. In the folk medicine, the local minority commonly use it to treat cough and asthma for centuries.

AIM OF THE STUDY

This study was carried out to investigate the protective mechanisms of total flavonoids from S. uncinata (SUF) on airway hyperresponsiveness, cytokine release and bitter taste receptors (T2Rs) signaling with emphasis on inflammatory responses in a rat model of ovalbumin (OVA)-induced asthma.

MATERIALS AND METHODS

Rats were sensitized and challenged with OVA to induce typical asthmatic reactions. Pathological changes of lung tissue were examined by HE staining. The serum levels of T cell-associated cytokines (IFN-γ, IL-4, IL-5 and IL-13), total IgE and OVA-specific IgE were determined by enzyme-linked immunosorbent assay (ELISA). Gene expressions of T2R10, IP3R1 and Orai1 in lung tissue were assayed by fluorescence quantitative real-time polymerase chain reaction (FQ-PCR) while protein expressions of NFAT1 and c-Myc were assayed by western blot analysis. The activation of SUF was investigated on tansgentic T2R10-GFP HEK293 cells.

RESULTS

SUF treatment attenuated airway hyperresponsiveness and goblet cell hyperplasia compared with OVA-challenged asthmatic rats. The serum levels of IL-4, IL-5 and IL-13 as well as total and OVA-specific IgE were decreased while serum IFN-γ was increased in SUF-treated rats. SUF treatment significantly up-regulated T2R10 gene expression, down-regulated IP3R1 and Orai1 gene expression. SUF further suppressed eotaxin, NFAT1 and c-Myc protein expression in lung tissues of OVA-challenged rats.

CONCLUSIONS

These results imply that SUF exerts anti-inflammatory function through the T2R10/IP3R1/NFAT1 dependent signaling pathway, and may warrant further evaluation as a possible agent for the treatment of asthma.

Modulatory effect of standardised amentoflavone isolated from Juniperus communis L. agianst Freund's adjuvant induced arthritis in rats (histopathological and X Ray anaysis)

ETHOPHARMACOLOGIC RELEVANCE

Juniperus communis. L. is a shrub or small evergreen tree, native to Europe, South Asia, and North America, and belongs to family Cupressaceae. It has been used traditionally in unani system and in Swedish medicine as a decoction in inflammatory diseases. The main chemical constituents, which were reported in J. communis L. was α-pinene,, apigenin, sabinene, β-sitosterol, campesterol, limonene, Amentoflavone (AF), cupressuflavone, and many others.

AIM

The aim of present study was to isolate the amentoflavone from the plant juniperus communis L. extracts and its protective effects against Freund's adjuvant induced arthritis in rats.

MATERIAL METHODS

Adjuvant arthritis was induced by an injection of 1mg heat killed Mycobacterium tuberculosis (CFA) into the left hind paw of rat by sub planter route (at day 0). The experiment was designed and modified as per method available in literature.

RESULTS

The study showed that at a dose of 40mg/kg of amentoflavone (AF) from methanolic extract of Juniperus Communis L. possessed potentially useful anti-arthritic activity as it gave a positive result in controlling inflammation in the adjuvant induced experimental model.

CONCLUSION

From the present experimental findings of both pharmacological and biochemical parameters observed, it had been concluded that at the doses of 20mg/kg and 40mg/kg of AF fraction from methanolic extract of Juniperus communis L. It possesses useful anti-arthritic activity since it gives a positive result in controlling inflammation in the adjuvant induced arthritic model in rats. The drug is a promising anti-arthritic agent of plant origin in the treatment of inflammatory disorders.

Potentials of Mangifera indica in the treatment of depressive-anxiety disorders: possible mechanisms of action

BACKGROUND

Mangifera indica (Anacardiaceae) is an important herb in the traditional African and Ayurvedic medicines. The stem barks are used in the treatment of hypertension, insomnia, tumour, depression, rheumatism and as a tonic. This study was carried out to investigate antidepressant- and anxiolytic-like effect of the hydroethanol stem bark extract of M. indica (HeMI) in mice.

METHODS

HeMI (12.5-100 mg/kg, p.o.) was administered 1 h before subjecting the animal to the forced swim test (FST), tail suspension test (TST) and elevated plus maze tests (EPM).

RESULTS

HeMI (12.5-100 mg/kg, p.o.) treatment produced significant reduction in immobility time [F(6.56)=8.35, p<0.001], [F(6,56)=7.55, p<0.001] in the FST and TST, respectively. Moreover, co-administration of sub-therapeutic doses of imipramine or fluoxetine with HeMI (3.125 mg/kg) elicited significant reduction in time spent immobile in the FST. However, pretreatment of mice with parachlorophenylalanine, metergoline, yohimbine or sulpiride abolished the antidepressant-like effect elicited by HeMI. In the EPM, HeMI produced significant [F(5,42)=8.91, p<0.001] increase in open arms exploration by 75.55 % and this effect was blocked by pretreatment of mice with flumazenil or metergoline.

CONCLUSIONS

Findings from this study showed antidepressant-like effect of M. indica through interaction with 5-HT2 receptor, α2-adrenoceptor and dopamine D2-receptors. Also, an anxiolytic-like effect through its affinity for 5-HT2 and benzodiazepine receptors. Hence, M. indica could be a potential phytotherapeutic agent in the treatment of mixed anxiety-depressive illness.

Amentoflavone protects hippocampal neurons: anti-inflammatory, antioxidative, and antiapoptotic effects

Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in epilepsy models. Prior to model establishment, mice were intragastrically administered 25 mg/kg amentoflavone for 3 consecutive days. Amentoflavone effectively prevented pilocarpine-induced epilepsy in a mouse kindling model, suppressed nuclear factor-κB activation and expression, inhibited excessive discharge of hippocampal neurons resulting in a reduction in epileptic seizures, shortened attack time, and diminished loss and apoptosis of hippocampal neurons. Results suggested that amentoflavone protected hippocampal neurons in epilepsy mice via anti-inflammation, antioxidation, and antiapoptosis, and then effectively prevented the occurrence of seizures.

Neuropharmacological activities of Taxus wallichiana bark in Swiss albino mice

Aims:

The bark of Taxus wallichiana is widely used for preparing a decoction and consumed as a tea by several tribal communities of the Indian subcontinent. The sedative, motor coordination, anxiolytic, and antidepressant effects of the hydroalcoholic extract of T. wallichiana bark and its ethylacetate fraction were evaluated in mice models of behavior analysis.

Materials and Methods:

The effects were evaluated on diazepam-induced sleeping time, elevated plus maze and light and dark box, and on the forced swimming test. General locomotor activity and motor coordination effects were evaluated in the actophotmeter and rota-rod tests respectively.

Statistical Analysis:

Results are expressed as mean ± standard error of the mean. Statistical analysis was performed using ANOVA, followed by post-hoc Dunnett's test. *P < 0.05, **P < 0.01, ***P < 0.001 were considered as significant.

Results:

Both the hydroalcoholic extract and ethylacetate fraction showed a marked decrease in latency of sleep onset, prolonged the diazepam-induced sleeping time, decreased spontaneous locomotor activity; whereas ethylacetate fraction produced anxiolytic and antidepressant activity.

Conclusions:

Both hydroalcoholic extract and its ethylacetate fraction of the bark of T. wallichiana have bioactive principles, which induce neuropharmacological changes.

Antipsychotic activity of standardized Bacopa extract against ketamine-induced experimental psychosis in mice: Evidence for the involvement of dopaminergic, serotonergic, and cholinergic systems

CONTEXT

Schizophrenia is a chronic disabling psychiatric disorder affecting 1% of the population worldwide. Due to the adverse effects of available antipsychotic medications, recent investigations have focused on the search for well-tolerated, safe molecules from natural resources to control the severity and progression of schizophrenia.

OBJECTIVE

To screen the standardized extract of Bacopa monniera Linn. (Scrophulariaceae) (BM) for its antipsychotic potential in the ketamine-induced psychosis model with mice.

MATERIALS AND METHODS

Graded dose of BM (40, 80, and 120 mg/kg, p.o.) were given to the mice 1 h prior to ketamine administration and tested for positive symptoms and cognitive deficits. A chronic ketamine treatment regimen was used to study the effect of BM on negative symptoms such as immobility enhancement. Each mouse was used once for the behavioral studies.

RESULTS

BM reduced ketamine-induced hyperactivity with an EC50 value of 76.60 mg/kg. The 80 mg/kg dose was used for all other behavior analysis. Pretreatment with BM at 80 mg/kg showed two-fold increases in transfer latency time (TLT) in passive avoidance task. Chronic BM pretreatment (80 mg/kg p.o. daily × 10 d) ameliorated the ketamine-induced enhanced immobility effect by 21% in the forced swim test. BM treatment reversed ketamine-induced increase in monoamine oxidase activity in both cortex and striatum and normalized the acetylcholinesterase activity and the glutamate levels in the hippocampus.

DISCUSSION AND CONCLUSION

Overall our findings suggest that BM possesses antipsychotic properties which might be due to its modulatory action on dopamine, serotonin, and glutamate neurotransmission.

Antidepressant-like effect of the hydroethanolic leaf extract of Alchornea cordifolia (Schumach. & Thonn.) Mull. Arg. (Euphorbiaceae) in mice: involvement of monoaminergic system

ETHNOPHARMACOLOGICAL RELEVANCE

The leaf of Alchornea cordifolia (Euphorbiaceae) is used in traditional African medicine in the treatment of various neurological and psychiatric disorders including depression. Previous studies have shown its potent antidepressant-like effect in the forced swimming test (FST). Hence, this study sought to investigate the involvement of monoaminergic systems in the antidepressant-like effect elicited by hydroethanolic leaf extract of Alchornea cordifolia (HeAC) in the FST.

MATERIALS AND METHODS

HeAC (25-400mg/kg, p.o.) was administered 1h before the FST. To investigate the contribution of monoaminergic systems to antidepressant-like effect, receptors antagonists were injected 15min before oral administration of HeAC (200mg/kg) to mice and 1h thereafter, subjected to FST.

RESULTS

HeAC (200 and 400mg/kg, p.o.) produced dose dependent and significant (P<0.001) antidepressant-like effect, in the FST, without accompanying changes in spontaneous locomotor activities in the open-field test. The anti-immobility effect of HeAC (200mg/kg) in the FST was prevented by pretreatment of mice with SCH 23390 (0.05mg/kg, s.c., a dopamine D1 receptor antagonist), sulpiride (50mg/kg, i.p., a dopamine D2 receptor antagonist), prazosin (1mg/kg, i.p., an α1-adrenoceptor antagonist), yohimbine (1mg/kg, i.p., an α2-adrenoceptor antagonist), and GR 127993 (5-HT1B receptor antagonist). Similarly, 3 days intraperitoneal injection of p-chlorophenylalanine (pCPA, 150mg/kg, i.p., an inhibitor of serotonin synthesis) prevented the antidepressant-like effect elicited by HeAC. The combination of subeffective doses of imipramine (5mg/kg, p.o.) or fluoxetine (5mg/kg, p.o.), with HeAC (25mg/kg, p.o., subeffective dose) produced a synergistic antidepressant-like effect in the FST.

CONCLUSION

The hydroethanolic extract of Alchornea cordifolia possesses antidepressant-like effect mediated through interaction with dopamine (D1 and D2), noradrenergic (α1 and α2 adrenoceptors), and serotonergic (5HT1B receptors) systems. Also, the potentiation of the anti-immobility effect of conventional antidepressants (fluoxetine and imipramine) by Alchornea cordifolia suggest potential therapeutic effect in depression.

Design and synthesis of new series of coumarin-aminopyran derivatives possessing potential anti-depressant-like activity

A new series of coumarin based aminopyran derivatives were designed, synthesized and evaluated for their preclinical antidepressant effect on Swiss albino mice. Among the series, compounds 21, 25, 26, 27, 32 and 33 exhibited significant activity profile in forced swimming test (FST). Compound 27 was most efficacious, which at a very low dose of 0.5mg/kg reduced the time of immobility by 86.5% as compared to the standard drug fluoxetine (FXT) which reduced the immobility time by 69.8% at the dose of 20mg/kg, ip. In addition, all active compounds were screened in dose dependent manner (at doses of 0.25, 0.5, 1mg/kg ip) in FST and tail suspension test (TST). Interestingly, all active compounds did not caused any significant alteration of locomotor activity in mice as compared to control, indicating that the hybrids did not produce any motor impairment effects. The results indicate that coumarin-aminopyran derivatives may have potential therapeutic value for the management of mental depression.

Anxiolytic-like effect of danshensu [(3-(3,4-dihydroxyphenyl)-lactic acid)] in mice

AIMS

Danshensu [3-(3,4-dihydroxyphenyl)-lactic acid], a phenylpropanoid compound isolated from Prunella vulgaris var. lilacina, is a well-known antioxidant. Although its antioxidant activity and cardioprotective effect have been reported, the pharmacological properties of danshensu in the central nervous system remain unclear. We investigated whether danshensu exerts anxiolytic-like activity in mice.

MAIN METHODS

We conducted monoamine oxidase A (MAO-A) inhibition assay on danshensu in vitro, and behavioral tests including the elevated plus-maze test (EPM), the hole-board test, the rotarod test and the open field test were employed.

KEY FINDINGS

We found that danshensu significantly inhibited the activity of MAO-A in vitro. The administration of danshensu (3 or 10mg/kg) produced a significant anxiolytic-like effect in the EPM and hole-board test. In addition, no changes in the spontaneous locomotor activity and no myorelaxant effects were observed compared to the control group; these effects were confirmed with the open field test and the rotarod test. Moreover, the anxiolytic-like properties of danshensu were antagonized by a dopamine D1 receptor antagonist (SCH 23390) but not by a 5-HT1A receptor antagonist (WAY 100635) or an α1-adrenergic receptor antagonist (prazosin).

SIGNIFICANCE

These results indicate that danshensu exerts its anxiolytic-like properties, in part, through dopaminergic neurotransmitter signaling.

Anticonvulsant, anxiolytic and hypnotic effects of aqueous bulb extract of Crinum glaucum A. chev (Amaryllidaceae): role of GABAergic and nitrergic systems

Crinum glaucum A. Chev (Amaryllidaceae) (CG) is a bulbous plant widely used in folk medicine in the treatment of cough, asthma and convulsions. This study was carried out to investigate the anticonvulsant, anxiolytic and hypnotic effects of the aqueous bulb extract of C. glaucum and its possible mechanism (s) of action. The anticonvulsant activity of C. glaucum extract (400-1200 mg kg(-1) p.o.) was investigated using picrotoxin, strychnine, isoniazid, pentylenetetrazol and N-methyl-D-aspartate (NMDA)-induced seizures in mice while the elevated plus maze test (EPM) and hexobarbitone-induced sleeping time (HIST) were used to evaluate the anxiolytic and hypnotic effects, respectively. Animals were pretreated with flumazenil (3 mg kg(-1); i.p. GABA(A) receptor antagonist), cyproheptadine (4 mg kg(-1); i.p. 5-HT2 receptor antagonist), L-arginine (500 mg kg(-1); p.o. Nitric Oxide (NO) precursor) and L-Nitroarginine (L-NNA) (10 mg kg(-1) i.p. Nitric Oxide Synthase (NOS) inhibitor) were used to investigate the probable mechanism (s) of anticonvulsant activity. Oral administration of CG significantly (p < 0.001) delayed the onset of seizures induced by picrotoxin, strychnine, isoniazid and pentylenetetrazol with peak effect at 1200 mg kg(-1) in comparison to control groups. CG (800 and 1200 mg kg(-1)) strongly antagonized NMDA-induced turning behavior. Pretreatment of mice with cyproheptadine could not reverse the anticonvulsant effect of CG. However, pretreatment with flumazenil and L-NNA significantly (p < 0.05) reversed the anticonvulsant effect of CG while L-arginine pretreatment significantly (p < 0.001) delayed the onset of seizures when compared with control and extract (1200 mg kg(-1) only). CG potentiated hexobarbitone-induced sleeping time with peak effect at 400 mg kg(-1) and also significantly (p < 0.05) increased open arm exploration in EPM and had its peak anxiolytic effect at 100 mg kg(-1). The data obtained suggests that aqueous bulb extract of Crinum glaucum possess anticonvulsant, anxiolytic and hypnotic activities which involve an interaction with GABAergic, nitrergic and glutaminergic systems to exert its effects.

Natural polyphenols in the management of major depression

INTRODUCTION

Natural polyphenols, the non-essential micronutrients, found in array of plant products, are known to affect various physiological and biochemical functions in the body. Studies have shown the protective effect of these polyphenols in different neurological and mental disorders. These polyphenols modulate monoaminergic neurotransmission in the brain and thus possess antidepressant-like activity at least in animal models of depression.

AREAS COVERED

The present review discusses the use of these natural polyphenols in the treatment of major depression. The review article discusses the antidepressant potential of some important polyphenols such as amentoflavone, apigenin, chlorogenic acid, curcumin, ferulic acid, hesperidin, rutin, quercetin, naringenin, resveratrol, ellagic acid, nobiletin and proanthocyanidins. The mechanism of action of these polyphenols in the treatment of major depression is also discussed in detail.

EXPERT OPINION

There is an exciting prospect in the discovery of natural polyphenols as therapeutic agents in the treatment of major depression.

Essential Oils from the Leaves of Six Medicinal Plants of Nigeria

The chemistry of Cassia siamea L., C. occidentalis L. (Fabaceae), Cnestis ferruginea Vahl ex DC (Connaraceae), Anthocleista djalonensis A. Chev (Loganiaceae), Solanum torvum Swartz and S. erianthum G. Don (Solanaceae) volatiles grown in Nigeria have been studied. The essential oils were obtained by hydrodistillation and analyzed by GC and GC-MS. The main compounds of C. siamea were (E)-geranyl acetone (5.8%), 1-octen-3-ol (5.8%), linalool (7.8%), iso-italicene (15.4%) and (E)-β-damascenone (11.0%). On the other hand, C. occidentalis consisted mainly of (E)-geranyl acetone (8.0%), hexahydrofarnesylacetone (24.0%) and (E)-phytol acetate (40.7%). The oil of C. ferruginea was comprised mainly of (E)-geranyl acetone (13.7%), (E)-α-ionone (9.5%), phytol (5.8%), pentadecanal (6.1%) and 1-octen-3-ol (5.5%). The main compounds of A. djalonensis were α-humulene (31.9%), β-caryophyllene (17.8%), humulene epoxide II (12.7%) and caryophyllene oxide (5.9%). The main volatiles of S. torvum were (E)-phytol acetate (38.7%), pentadecanal (25.3%) and (E)-geranyl acetone (5.0%). Apart from methyl salicylate (4.5%), tetradecanal (2.2%), 2-pentyl furan (1.8%), hexahydrofarnesylacetone (1.6%) and hexadecanal (1.1%), all other compounds were either present in trace quantity or in amounts less than 1%. On the other hand, α-humulene (46.6%) and β-caryophyllene (20.6%) were the compounds occurring in higher quantities in S. erianthum. The volatile oil contents of Cassia siamea, Cnestis ferruginea, Anthocleista djalonensis and Solanum torvum are being reported for the first time.