The Untapped Potential of Ginsenosides and American Ginseng Berry in Promoting Mental Health via the Gut-Brain Axis

Ginsenoside Rg1 enriches gut microbial indole-3-acetic acid to alleviate depression-like behavior in mice via oxytocin signaling

BACKGROUND AND PURPOSE

Although a large collection of data has shown that ginsenosides, the major active ingredients from Ginseng, have neuroprotective and anti-depressant effect, the mechanism of action is incompletely understood. This study aims to elucidate the antidepressant mechanism of ginsenoside Rg1 (Rg1), a poorly absorbed ginsenoside, from the perspective of gut microbe to brain signaling.

METHODS

A mouse model of depression was induced by unpredictable mild stress (UMS). Behavioral and neurochemical tests were conducted to evaluate the effect and mechanism of Rg1 on depressive behavior. Non-target and target metabolomics were performed to identify the signaling metabolites underlying the antidepressant efficacy of Rg1. Gut microbial structure was analyzed by 16S rRNA sequencing and the potential functional strains associated with Rg1 action were investigated by in vitro bacterial culture. Chemical intervention was used to explore the mechanism of Rg1 and signaling metabolite.

RESULTS

Rg1 improved UMS-induced despair, anxiety-like and social avoidance behaviors in mice, which were accompanied by increased hypothalamic oxytocin secretion and restored neural proliferation in the hippocampus. Metabolomic analysis of the gut-brain axis revealed that Rg1 increased the concentration of serum and brain indole-3-acetic acid (IAA), a bacterial metabolite that was partially attributed to the enrichment of Lactobacillus murinus in the gut microbiome. Oral supplementation of IAA mimicked the anti-depressant action of Rg1, while oxytocin receptor antagonist abrogated the anti-depressant effects of both Rg1 and IAA.

CONCLUSION

Our work provides a new gut-to-brain signaling mechanism for the antidepressant effects of Rg1. In particular, Rg1 enriches the abundance of Lactobacillus murinus, which in turn increases the level of brain IAA and potentiates hypothalamic oxytocin signal. These findings suggest a promising pathway for producing antidepressant effects through gut-brain crosstalk.

Melanin resistance of heat-processed ginsenosides from Panax ginseng berry treated with citric acid through autophagy pathway

GFRS is the conversion product of Panax ginseng Meyer berry after citric acid heat treatment, which is rich in rare ginsenosides. However, the anti-melanin role of GFRS in the regulation of skin pigmentation and its material basis remains unclear. To compare the anti-melanin activity before and after citric acid heat treatment, we determined the effects of GFS and GFRS on tyrosinase activity and melanin lever under α-MSH stimulation and found the potential anti-melanin effect of GFRS. Further, Western blot and immunofluorescence methods were used to reveal the mechanism by which GFRS detects anti-melanin activity by promoting autophagy flux levels. In zebrafish models, GFRS inhibited endogenous melanin and tyrosinase better than arbutin and promoted the accumulation of autophagy levels in vivo. To determine the material basis of the anti-melanin effect of GFRS, HPLC was used to isolate and prepare 12 ginsenosides from GFRS, and their activity evaluation and structure-activity relationship analysis were performed. The results showed that the inhibitory effect of GFRS on melanin was Rg3 > Rg5 > Rk1 > Rd. Molecular docking showed that their docking fraction with mushroom tyrosinase was significantly better than that of arbutin, but the presence of C-20 glycosylation decreased the anti-melanin activity of Rd. To maximize the content of Rg3, Rg5, and Rk1, we optimized the process by using citric acid heat treatment of ginsenoside Rd and found that citric acid heat treatment at 100°C almost completely transformed Rd and obtained a high content of active ingredients. In summary, our data demonstrated that GFRS exerted anti-melanin effects by inducing autophagy. It was further revealed that Rg3, Rg5, and Rk1, as effective active components, could be enriched by the improved process of converting ginsenoside Rd by citric acid heat treatment.

Effects of ginseng berry saponins from panax ginseng on glucose metabolism of patients with prediabetes: A randomized, double-blinded, placebo-controlled, crossover trial

BACKGROUND

Prediabetes strongly increases the risk of type 2 diabetes and cardiovascular events. However, lifestyle intervention, the first-line treatment for prediabetes currently, was inconsistently beneficial for glucose metabolism, and the conventional medicines, such as metformin, is controversial for prediabetes due to the possible side effects.

PURPOSE

This study was designed to evaluate the effects of Zhenyuan Capsule, a Chinese patented medicine consisting of ginseng berry saponins extracted from the mature berry of Panax Ginseng, on the glucose metabolism of prediabetic patients as a complementary therapy.

STUDY DESIGN AND METHODS

In this randomized, double-Blinded, placebo-controlled, crossover trial, 195 participants with prediabetes were randomized 1:1 to receive either placebo followed by Zhenyuan Capsule, or vice versa, alongside lifestyle interventions. Each treatment period lasted 4 weeks with a 4-week washout period in between. The primary outcomes were the changes in fasting plasma glucose (FPG) and 2-h postprandial plasma glucose (2-h PG) from baseline. Secondary outcomes includes the changes in fasting and 2-h postprandial insulin and C-peptide, the homeostatic model assessment-insulin resistance (HOMA-IR) index and quantitative insulin sensitivity check index (QUICKI) from baseline. Blood lipids and adverse events were also assessed.

RESULTS

Compared with placebo, Zhenyuan Capsule caused remarkable reduction in 2-h PG (-0.98 mmol/l) after adjusting treatment order. Zhenyuan Capsule also reduced the fasting and 2-h postprandial levels of insulin and C-peptide, lowered HOMA-IR index (-1.26), and raised QUICKI index (+0.012) when compared to placebo. Additionally, a significant increase in high density lipoprotein cholesterol (HDL-C; +0.25 mmol/l) was found in patients with Zhenyuan Capsule. No serious adverse event occurred during the study.

CONCLUSIONS

Among prediabetic patients, Zhenyuan Capsule further reduced 2-h PG level, alleviated insulin resistance and raised HDL-C level on the background of lifestyle interventions. The study protocol is registered with the Chinese Clinical Trial Registry (ChiCTR2000034000).

Characterization of the structure, anti-inflammatory activity and molecular docking of a neutral polysaccharide separated from American ginseng berries

AIM

American ginseng berries, grown in the aerial parts and harvested in August, are a potentially valuable material. The aim of the study was to analyze the specific polysaccharides in American ginseng berries, and to demonstrate the anti-inflammation effect through in vitro and in vivo experiments and molecular docking.

METHODS

After deproteinization and dialysis, the extracted crude polysaccharide was separated and purified. The structure of the specific isolated polysaccharide was investigated by Fourier Transform infrared spectroscopy (FT-IR), GC-MS and nuclear magnetic resonance (NMR), and anti-inflammatory activity was evaluated using in vitro and in vivo models (Raw 264.7 cells and zebrafish). Molecular docking was used to analyze the binding capacity and interaction with cyclooxygenase-2 (COX-2).

RESULTS

A novel neutral polysaccharide fraction (AGBP-A) was isolated from American ginseng berries. The structural analysis demonstrated that AGBP-A had a weight-average molecular weight (Mw) of 122,988 Da with a dispersity index (Mw/Mn) value of 1.59 and was composed of arabinose and galactose with a core structure containing →6)-Gal-(1→ residues as the backbone and a branching substitution at the C3 position. The side-chains comprised of α-L-Ara-(1→, α-L-Ara-(1→, →5)-α-L-Ara-(1→, β-D-Gal-(1→. The results showed that it significantly decreased pro-inflammatory cytokines in the cell model. In a zebrafish model, AGBP-A reduced the massive recruitment of neutrophils to the caudal lateral line neuromast, suggesting the relief of inflammation. Molecular docking was used to analyze the combined capacity and interaction with COX-2.

CONCLUSION

Our study indicated the potential efficacy of AGBP-A as a safe and valid natural anti-inflammatory component.

Mechanisms with network pharmacology approach of Ginsenosides in Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss, cognitive disorder, language dysfunction, and mental disability. The main neuropathological changes in AD mainly include amyloid plaque deposition, neurofibrillary tangles, synapse loss, and neuron reduction. However, the current anti-AD drugs do not demonstrate a favorable effect in altering the pathological course of AD. Moreover, long-term use of these drugs is usually accompanied with various side effects. Ginsenosides are the major active constituents of ginseng and have protective effects on AD through various mechanisms in both in vivo and in vitro studies. In this review, we focused on discussing the therapeutic potential effects and the mechanisms of pharmacological activities of ginsenosides in AD, to provide new insight for further research and clinical application of ginsenosides in the future. Recent studies on the pharmacological effects and mechanisms of ginsenosides were retrieved from Chinese National Knowledge Infrastructure, National Science and Technology Library, Wanfang Data, Elsevier, ScienceDirect, PubMed, SpringerLink, and the Web of Science database up to April 2023 using relevant keywords. Network pharmacology and bioinformatics analysis were used to predict the therapeutic effects and mechanisms of ginsenosides against AD. Ginsenosides presented a wide range of therapeutic and biological activities, including alleviating Aβ deposition, decreasing tau hyperphosphorylation, regulating the cholinergic system, resisting oxidative stress, modulating Ca2+ homeostasis, as well as anti-inflammation and anti-apoptosis in neurons, respectively. For further developing the therapeutic potential as well as clinical applications, the network pharmacology approach was combined with a summary of published studies.

Neuroprotection with Bioactive Compounds

Bioactive compounds are found in foods in small quantities and represent extra nutritional constituents known to exert beneficial effects on health beyond their nutritional value [...].

New perspective on the immunomodulatory activity of ginsenosides: Focus on effective therapies for post-COVID-19

More than 700 million confirmed cases of Coronavirus Disease-2019 (COVID-19) have been reported globally, and 10-60% of patients are expected to exhibit "post-COVID-19 symptoms," which will continue to affect human life and health. In the absence of safer, more specific drugs, current multiple immunotherapies have failed to achieve satisfactory efficacy. Ginseng, a traditional Chinese medicine, is often used as an immunomodulator and has been used in COVID-19 treatment as a tonic to increase blood oxygen saturation. Ginsenosides are the main active components of ginseng. In this review, we summarize the multiple ways in which ginsenosides affect post-COVID-19 symptoms, including inhibition of lipopolysaccharide, tumor necrosis factor signaling, modulation of chemokine receptors and inflammasome activation, induction of macrophage polarization, effects on Toll-like receptors, nuclear factor kappa-B, the mitogen-activated protein kinase pathway, lymphocytes, intestinal flora, and epigenetic regulation. Ginsenosides affect virus-mediated tissue damage, local or systemic inflammation, immune modulation, and other links, thus alleviating respiratory and pulmonary symptoms, reducing the cardiac burden, protecting the nervous system, and providing new ideas for the rehabilitation of patients with post-COVID-19 symptoms. Furthermore, we analyzed its role in strengthening body resistance to eliminate pathogenic factors from the perspective of ginseng-epidemic disease and highlighted the challenges in clinical applications. However, the benefit of ginsenosides in modulating organismal imbalance post-COVID-19 needs to be further evaluated to better validate the pharmacological mechanisms associated with their traditional efficacy and to determine their role in individualized therapy.

Synergistic Antioxidant Effect of Prebiotic Ginseng Berries Extract and Probiotic Strains on Healthy and Tumoral Colorectal Cell Lines

Oxidative stress caused by reactive oxygen species (ROS, O2•−, HO•, and H2O2) affects the aging process and the development of several diseases. A new frontier on its prevention includes functional foods with both specific probiotics and natural extracts as antioxidants. In this work, Panax ginseng C.A. Meyer berries extract was characterized for the presence of beneficial molecules (54.3% pectin-based polysaccharides and 12% ginsenosides), able to specifically support probiotics growth (OD600nm > 5) with a prebiotic index of 0.49. The administration of the extract to a probiotic consortium induced the production of short-chain fatty acids (lactic, butyric, and propionic acids) and other secondary metabolites derived from the biotransformation of Ginseng components. Healthy and tumoral colorectal cell lines (CCD841 and HT-29) were then challenged with these metabolites at concentrations of 0.1, 0.5, and 1 mg/mL. The cell viability of HT-29 decreased in a dose-dependent manner after the exposition to the metabolites, while CCD841 vitality was not affected. Regarding ROS production, the metabolites protected CCD841 cells, while ROS levels were increased in HT-29 cells, potentially correlating with the less functionality of glutathione S-transferase, catalase, and total superoxide dismutase enzymes, and a significant increase in oxidized glutathione.