Anti-Depressant Like Effect of Methyl Gallate Isolated from Acer barbinerve in Mice

Methyl gallate: Review of pharmacological activity

Methyl gallate (MG) is a polyphenolic compound widely found in natural plants. MG has been shown to have a variety of biological functions, including anti-tumor, anti-inflammatory, anti-oxidant, neuroprotective, hepatoprotective and anti-microbial activities, and has broad research and development prospects. A total of 88 articles related to MG were searched using the PubMed, Science Direct, and Google Scholar databases, systematically investigating the pharmacological activity and molecular mechanisms of MG. There were no restrictions on the publication years, and the last search was conducted on June 5, 2023. MG can exert pharmacological effects through multiple pathways and targets, such as PI3K/Akt, ERK1/2, Caspase, AMPK/NF-κB, Wnt/β-catenin, TLR4/NF-κB, MAPK, p53, NLRP3, ROS, EMT. According to the literature, MG has the potential to be a prospective adjuvant for anticancer therapy and deserves further study.

Anti-depressant and anxiolytic potential of Acacia hydaspica R. Parker aerial parts extract: Modulation of brain antioxidant enzyme status

BACKGROUND

Oxidative stress may link to psychiatric disorders, and is being regarded as a plausible mechanism that can affect the regulation of these illnesses. The present study was undertaken to investigate the antidepressant and anxiolytic potential of A. hydaspica R. parkers. Brain oxidative stress enzyme levels were analyzed to correlate depression and stress with brain antioxidant status.

METHODS

Antidepressant and anxiolytic effect of methanol extract of A. hydaspica and its derived soluble fractions [n-hexane (AHH), ethyl-acetate (AHE), chloroform (AHC), n-butanol (AHB) and remaining aqueous fraction (AHA)] was investigated by using three behavioral models; the Forced swimming test, Tail suspension test and Elevated plus-maze test (EPM). Chronic unpredictable mild stress (CMS) was employed to induce stress in rats. AHM and AHE (200 mg/kg, p.o), fluoxetine (5 mg/kg, i.p) and diazepam (DZM) (1 mg/kg, p.o) were administered during the 7 day stress exposure period, and rats were assessed for antidepressant and anxiolytic behavioral despair paradigms. Antioxidant enzymes and oxidative stress markers were measured in brain tissue of depressed rats. Phytochemical analysis was done by GCMS experimentation.

RESULTS

AHM and AHE (acute dose) significantly (p < 0.0001) reduced the immobility time and ameliorated climbing behavior as compared to the control in FST and TST, and similar to fluoxetine. AHM and AHE showed significant (p < 0.0001) anxiolytic potential in EPM, and comparable to DZM (1 mg/kg b.w., i.p). Significant decrease in antioxidant enzyme levels and increase in MDA, H2O2 and NO level were observed in stressed rats. AHM and AHE (for 7 days/CMS) significantly improved behavior in FST, TST and EPMT. Treatment also improved antioxidant enzyme level and controlled the oxidative stress markers in brain tissues. GCMS analysis indicated the presence of 10 different chemical constituents in A. hydaspica.

CONCLUSION

The present study revealed that A. hydaspica exerts an antidepressant and anxiolytic effect by improving brain antioxidant status. The observed activities might be due to the presence of diverse phytochemicals.

Traditional uses, phytochemistry, and pharmacology of the genus Acer (maple): A review

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Acer (Aceraceae), commonly known as maple, comprises approximately 129 species that primarily grow in the northern hemisphere, especially in the temperate regions of East Asia, eastern North America, and Europe. These plants have been traditionally used to treat a wide range of diseases in East Asia and North America. Moreover, clinical studies have shown that medicinal plants belonging to Acer are highly effective in the treatment of rheumatism, bruises, hepatic disorders, eye disease, and pain, and in detoxification. This review provides a systematic and constructive overview of the traditional uses, chemical constituents, and pharmacological activities of plants of the genus Acer.

MATERIAL AND METHODS

This review is based on a literature study of scientific journals and books from libraries and electronic sources such as SciFinder, ScienceDirect, Springer, PubMed, CNKI, Google Scholar, Baidu Scholar, and Web of Science. The literature in this review related to chemical constituents and pharmacological activities dates from 1922 to the end of October 2015. Furthermore, ethnopharmacological information on this genus was obtained from libraries and herbaria in China and USA.

RESULTS

In traditional medicine, 40 species, 11 subspecies, and one varieta of the genus Acer are known to exhibit a broad spectrum of biological activities. To date, 331 compounds have been identified from 34 species of the genus Acer, including flavonoids, tannins, phenylpropanoids, diarylheptanoids, terpenoids, benzoic acid derivatives, and several other types of compounds, such as phenylethanoid glycosides and alkaloids. Preliminary pharmacological studies have shown that the extracts and compounds isolated from this genus exhibit a broad spectrum of biological activities such as antioxidant, antitumor, anti-inflammatory, antidiabetic, hepatoprotective, and antiobesity activities, as well as promoting osteoblast differentiation. To date, reports on the toxicity of Acer species to humans are very limited, and the major safety concern of these plants is in the veterinary field.

CONCLUSIONS

Based on our systematic review, Acer species can be used to treat rheumatism, hepatic disorders, eye disease, pain, etc. effectively. Some indications from ethnomedicine have been validated by pharmacological activities, such as the anti-inflammatory and hepatoprotective activities of the species. The available literature showed that most of the activities of these species can be attributed to flavonoids and tannins. To ensure the safety and efficacy in clinical practice in the future, studies identifying active molecules and clarifying their pharmacological mechanisms as well as toxicity are needed.

Atypical Antidepressant Activity of 3,4-Bis(3,4-Dimethoxyphenyl) Furan-2,5-Dione Isolated from Heart Wood of Cedrus deodara, in Rodents

Cedrus deodara (Pinaceae) has been used traditionally in Ayurveda for the treatment of central nervous system disorders. 3,4-bis(3,4-dimethoxyphenyl)furan-2,5-dione (BDFD) was isolated from heart wood of Cedrus deodara and was shown to have antiepileptic and anxiolytic activity. Thus, the present study was aimed to explore its anti-depressant effect and to correlate the effect with serotonin and nor adrenaline levels of brain. Albino mice were used as experimental animal. Animals were divided in to three groups; vehicle control, imipramine (30 mg/kg i.p.), BDFD (100 mg/kg i.p.). Tail suspension test (TST) and forced swim test (FST) was performed to evaluate antidepressant effect of BDFD. BDFD (100 mg/kg, i.p.) showed a significant decrease in immobility time when subjected to FST whereas immobility time was not significantly altered in TST. BDFD treatment increased serotonin and noradrenaline levels in the brain which is indicative of BDFD having possible atypical antidepressant action.

Chronic non-social stress affects depressive behaviors but not anxiety in mice

The etiology of most psychiatric disorders is still incompletely understood. However, growing evidence suggests that stress is a potent environmental risk factor for depression and anxiety. In rodents, various stress paradigms have been developed, but psychosocial stress paradigms have received more attention than non-social stress paradigms because psychosocial stress is more prevalent in humans. Interestingly, some recent studies suggest that chronic psychosocial stress and social isolation affects mainly anxiety-related behaviors in mice. However, it is unclear whether chronic non-social stress induces both depression- and anxiety-related phenotypes or induces one specific phenotype in mice. In the present study, we examined the behavioral consequences of three chronic non-social stress paradigms: chronic predictable (restraint) stress (CPS), chronic unpredictable stress (CUS), and repeated corticosterone-HBC complex injection (RCI). Each of the three paradigms induced mild to severe depression/despair-like behaviors in mice and resulted in increased immobility in a tail suspension test. However, anxiety-related phenotypes, thigmotaxis and explorative behaviors, were not changed by the three paradigms. These results suggest that depression- and anxiety-related phenotypes can be dissociated in mouse stress models and that social and non-social stressors might affect brain circuits and behaviors differently.