Ginsenosides and Biotic Stress Responses of Ginseng

Effects of a co-bacterial agent on the growth, disease control, and quality of ginseng based on rhizosphere microbial diversity

BACKGROUND

The ginseng endophyte Paenibacillus polymyxa Pp-7250 (Pp-7250) has multifaceted roles such as preventing ginseng diseases, promoting growth, increasing ginsenoside accumulation, and degrading pesticide residues, however, these effects still have room for improvements. Composite fungicides are an effective means to improve the biocontrol effect of fungicides, but the effect of Pp-7250 in combination with its symbiotic bacteria on ginseng needs to be further investigated, and its mechanism of action has not been elucidated. In this study, a series of experiments was conducted to elucidate the effect of Paenibacillus polymyxa and Bacillus cereus co-bacterial agent on the yield and quality of understory ginseng, and to investigate their mechanism of action.

RESULTS

The results indicated that P. polymyxa and B. cereus co-bacterial agent (PB) treatment improved ginseng yield, ginsenoside accumulation, disease prevention, and pesticide degradation. The mechanism is that PB treatment increased the abundance of beneficial microorganisms, including Rhodanobacter, Pseudolabrys, Gemmatimonas, Bacillus, Paenibacillus, Cortinarius, Russula, Paecilomyces, and Trechispora, and decreased the abundance of pathogenic microorganisms, including Ellin6067, Acidibacter, Fusarium, Tetracladium, Alternaria, and Ilyonectria in ginseng rhizosphere soil. PB co-bacterial agents enhanced the function of microbial metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of antibiotics, biosynthesis of amino acids, carbon fixation pathways in prokaryotes, DNA replication, and terpenoid backbone biosynthesis, and decreased the function of microbial plant pathogens and animal pathogens.

CONCLUSION

The combination of P. polymyxa and B. cereus may be a potential biocontrol agent to promote the resistance of ginseng to disease and improve the yield, quality, and pesticide degradation.

Mini-encyclopedia of mitochondria-relevant nutraceuticals protecting health in primary and secondary care-clinically relevant 3PM innovation

Despite their subordination in humans, to a great extent, mitochondria maintain their independent status but tightly cooperate with the "host" on protecting the joint life quality and minimizing health risks. Under oxidative stress conditions, healthy mitochondria promptly increase mitophagy level to remove damaged "fellows" rejuvenating the mitochondrial population and sending fragments of mtDNA as SOS signals to all systems in the human body. As long as metabolic pathways are under systemic control and well-concerted together, adaptive mechanisms become triggered increasing systemic protection, activating antioxidant defense and repair machinery. Contextually, all attributes of mitochondrial patho-/physiology are instrumental for predictive medical approach and cost-effective treatments tailored to individualized patient profiles in primary (to protect vulnerable individuals again the health-to-disease transition) and secondary (to protect affected individuals again disease progression) care. Nutraceuticals are naturally occurring bioactive compounds demonstrating health-promoting, illness-preventing, and other health-related benefits. Keeping in mind health-promoting properties of nutraceuticals along with their great therapeutic potential and safety profile, there is a permanently growing demand on the application of mitochondria-relevant nutraceuticals. Application of nutraceuticals is beneficial only if meeting needs at individual level. Therefore, health risk assessment and creation of individualized patient profiles are of pivotal importance followed by adapted nutraceutical sets meeting individual needs. Based on the scientific evidence available for mitochondria-relevant nutraceuticals, this article presents examples of frequent medical conditions, which require protective measures targeted on mitochondria as a holistic approach following advanced concepts of predictive, preventive, and personalized medicine (PPPM/3PM) in primary and secondary care.

A systematic review of ginsenoside biosynthesis, spatiotemporal distribution, and response to biotic and abiotic factors in American ginseng

American ginseng (Panax quinquefolius) has gained recognition as a medicinal and functional food homologous product with several pharmaceutical, nutritional, and industrial applications. However, the key regulators involved in ginsenoside biosynthesis, the spatiotemporal distribution characteristics of ginsenosides, and factors influencing ginsenosides are largely unknown, which make it challenging to enhance the quality and chemical extraction processes of the cultivated American ginseng. This review presents an overview of the pharmacological effects, biosynthesis and spatiotemporal distribution of ginsenosides, with emphasis on the impacts of biotic and abiotic factors on ginsenosides in American ginseng. Modern pharmacological studies have demonstrated that American ginseng has neuroprotective, cardioprotective, antitumor, antidiabetic, and anti-obesity effects. Additionally, most genes involved in the upregulation of ginsenoside biosynthesis have been identified, while downstream regulators (OSCs, CYP450, and UGTs) require further investigation. Futhermore, limited knowledge exists regarding the molecular mechanisms of the impact of biotic and abiotic factors on ginsenosides. Notably, the nonmedicinal parts of American ginseng, particularly its flowers, fibrous roots, and leaves, exhibit higher ginsenoside content than its main roots and account for a considerable amount of weight in the whole plant, representing promising resources for ginsenosides. Herein, the prospects of molecular breeding and metabolic engineering based on multi-omics to improve the unstable quality of cultivated American ginseng and the shortage of ginsenosides are proposed. This review highlights the gaps in the current research on American ginseng and proposes solutions to address these limitations, providing a guide for future investigations into American ginseng ginsenosides.

Discovery of plant chemical defence mediated by a two-component system involving β-glucosidase in Panax species

Plants usually produce defence metabolites in non-active forms to minimize the risk of harm to themselves and spatiotemporally activate these defence metabolites upon pathogen attack. This so-called two-component system plays a decisive role in the chemical defence of various plants. Here, we discovered that Panax notoginseng, a valuable medicinal plant, has evolved a two-component chemical defence system composed of a chloroplast-localized β-glucosidase, denominated PnGH1, and its substrates 20(S)-protopanaxadiol ginsenosides. The β-glucosidase and its substrates are spatially separated in cells under physiological conditions, and ginsenoside hydrolysis is therefore activated only upon chloroplast disruption, which is caused by the induced exoenzymes of pathogenic fungi upon exposure to plant leaves. This activation of PnGH1-mediated hydrolysis results in the production of a series of less-polar ginsenosides by selective hydrolysis of an outer glucose at the C-3 site, with a broader spectrum and more potent antifungal activity in vitro and in vivo than the precursor molecules. Furthermore, such β-glucosidase-mediated hydrolysis upon fungal infection was also found in the congeneric species P. quinquefolium and P. ginseng. Our findings reveal a two-component chemical defence system in Panax species and offer insights for developing botanical pesticides for disease management in Panax species.

Ginsenoside Rg5 induces NSCLC cell apoptosis and autophagy through PI3K/Akt/mTOR signaling pathway

OBJECTIVE

Ginsenoside Rg5 (Rg5) is a minor ginsenoside of ginseng and has a strong anti-tumor potential. This study focused on deciphering the function of Rg5 in non-small cell lung cancer (NSCLC) and investigating its related mechanism.

METHODS

After treating human NSCLC cell lines (H1650 and A549) and bronchial epithelial cells (BEAS-2B) with increasing concentration of Rg5, cell viability was examined using methyl thiazolyl tetrazolium (MTT) assay. NSCLC cell proliferation and apoptosis were evaluated by colony formation assay and flow cytometry, respectively. The levels of proteins associated with cell cycle progression, cell apoptosis, and autophagy as well as the key markers in the PI3K/Akt/mTOR pathway were measured using western blot. A xenograft nude mouse model was established to explore the function of Rg5 in vivo.

RESULTS

NSCLC cell viability was dose- and time-dependently suppressed after Rg5 treatment. Rg5 restrained NSCLC cell proliferation by inducing G2/M phase arrest via regulation of cell cycle-related genes including p21, cyclin B1, and Cdc2. Additionally, Rg5 promoted caspase-dependent apoptosis in NSCLC cells by regulating the intrinsic mitochondrial signaling pathway. Rg5 induced autophagy via the regulation of autophagy-related proteins. The in vivo experiments revealed the inhibitory impact of Rg5 on xenograft growth. Rg5 also inactivated the PI3K/Akt/mTOR signaling pathway in NSCLC cells and mouse tumors.

CONCLUSION

Rg5 induced autophagy and caspase-dependent apoptosis in NSCLC cells by inhibiting the PI3K/Akt/mTOR signaling pathway, suggesting that Rg5 might become a promising and novel anti-tumor agent for the clinical treatment of NSCLC patients.

Effect of Soil and Root Extracts on the Innate Immune Response of American Ginseng (Panax quinquefolius) to Root Rot Caused by Ilyonectria mors-panacis

Panax quinquefolius shows much higher mortality to Ilyonectria mors-panacis root rot when grown in soil previously planted with ginseng than in soil not previously planted with ginseng, which is known as ginseng replant disease. Treatment of ginseng roots with methanol extracts of previous ginseng soils significantly increased root lesion sizes due to I. mors-panacis compared to roots treated with water or methanol extracts of ginseng roots or non-ginseng soils. Inoculation of water-treated roots with I. mors-panacis increased expression of a basic chitinase 1 gene (PqChi-1), neutral pathogenesis-related protein 5 gene (PqPR5) and pathogenesis-related protein 10-2 gene (PqPR10-2), which are related to jasmonic acid (JA), ethylene (ET) or necrotrophic infection, and also increased expression of an acidic β-1-3-glucanase gene (PqGlu), which is related to salicylic acid (SA). Infection did not affect expression of a cysteine protease inhibitor gene (PqCPI). Following infection, roots treated with ginseng root extract mostly showed similar expression patterns as roots treated with water, but roots treated with previous ginseng soil extract showed reduced expression of PqChi-1, PqPR5, PqPR10-2 and PqCPI, but increased expression of PqGlu. Methanol-soluble compound(s) in soil previously planted with ginseng are able to increase root lesion size, suppress JA/ET-related gene expression and trigger SA-related gene expression in ginseng roots during I. mors-panacis infection, and may be a factor contributing to ginseng replant disease.