Cellular stress response mechanisms as therapeutic targets of ginsenosides

Ginsenoside Rb1 stabilized and paclitaxel / protopanaxadiol co-loaded nanoparticles for synergistic treatment of breast tumor

Ginsenosides are the major and key components for ginseng to exert its wide and beneficial therapeutic efficacy in clinic. Meanwhile, many ginsenosides and their metabolites showed in vitro an in vivo anti-tumor activity, among which ginsenoside Rb1 has attracted much attention due to its good solubility and amphipathy. In this study, the self-assembly behavior of Rb1 was investigated and the Rb1 nano-assembly could further stabilize or encapsulated hydrophobic drugs such as protopanaxadiol (PPD) and paclitaxel (PTX) to form nanoparticles, based on which, a natural nanoscale drug delivery system, ginsenoside Rb1 stabilized and PTX/PPD co-loaded nanoparticles (GPP NPs) were prepared. The resultant GPP NPs exhibited a small particle size of 126.2 nm, a narrow size distribution (PDI=0.145), and a zeta potential of -27.3 mV. PTX loading content was 11.06% with an encapsulation efficiency of 93.86%. GPP NPs were spherical and stable in normal saline, 5% glucose, PBS, plasma, or on-shelf storage for 7 days. Both PTX and PPD existed in an amorphous state in GPP NPs and were released in a sustained pattern. GPP NPs showed 10-fold higher in vitro anti-tumor activity of than PTX injections. In the in vivo experiment, GPP NPs achieved a much higher tumor inhibition rate than PTX injections (64.95% vs 43.17%, P < 0.01) and certain tumor target ability. In conclusion, GPP NPs had significantly enhanced anti-tumor efficacy and improved tumor microenvironment, thus were promising to be developed into a novel anti-tumor agent for the treatment of breast tumor.

Systematic Description of the Content Variation of Natural Products (NPs): To Prompt the Yield of High-Value NPs and the Discovery of New Therapeutics

Natural products (NPs) have long been associated with human production and play a key role in the survival of species. Significant variations in NP content may severely affect the "return on investment" of NP-based industries and render ecological systems vulnerable. Thus, it is crucial to construct a platform that relates variations in NP content to their corresponding mechanisms. In this study, a publicly accessible online platform, NPcVar (http://npcvar.idrblab.net/), was developed, which systematically described the variations of NP contents and their corresponding mechanisms. The platform comprises 2201 NPs and 694 biological resources, including plants, bacteria, and fungi, curated using 126 diverse factors with 26,425 records. Each record contains information about the species, NP, and factors involved, as well as NP content data, parts of the plant that produce NPs, the location of the experiment, and reference information. All factors were manually curated and categorized into 42 classes which belong to four mechanisms (molecular regulation, species factor, environmental condition, and combined factor). Additionally, the cross-links of species and NP to well-established databases and the visualization of NP content under various experimental conditions were provided. In conclusion, NPcVar is a valuable resource for understanding the relationship between species, factors, and NP contents and is anticipated to serve as a promising tool for improving the yield of high-value NPs and facilitating the development of new therapeutics.

A systematic exploration of ginsenoside Rg5 reveals anti-inflammatory functions in airway mucosa cells

Background

Hyperactivated airway mucosa cells overproduce mucin and cause severe breathing complications. Here, we aimed to identify the effects of saponins derived from Panax ginseng on inflammation and mucin overproduction.

Methods

NCI-H292 cells were pre-incubated with 16 saponins derived from P. ginseng, and mucin overproduction was induced by treatment with phorbol 12-myristate 13-acetate (PMA). Mucin protein MUC5AC was quantified by enzyme-linked immunosorbent assay, and mRNA levels were analyzed using quantitative polymerase chain reaction (qPCR). Moreover, we performed a transcriptome analysis of PMA-treated NCI-H292 cells in the absence or presence of Rg5, and differential gene expression was confirmed using qPCR. Phosphorylation levels of signaling molecules, and the abundance of lipid droplets, were measured by western blotting, flow cytometry, and confocal microscopy.

Results

Ginsenoside Rg5 effectively reduced MUC5AC secretion and decreased MUC5AC mRNA levels. A systematic functional network analysis revealed that Rg5 upregulated cholesterol and glycerolipid metabolism, resulting in the production of lipid droplets to clear reactive oxygen species (ROS), and modulated the mitogen-activated protein kinase and nuclear factor (NF)-κB signaling pathways to regulate inflammatory responses. Rg5 induced the accumulation of lipid droplets and decreased cellular ROS levels, and N-acetyl-l-cysteine, a ROS inhibitor, reduced MUC5AC secretion via Rg5. Furthermore, Rg5 hampered the phosphorylation of extracellular signal-regulated kinase and p38 proteins, affecting the NF-κB signaling pathway and pro-inflammatory responses.

Conclusion

Rg5 alleviated inflammatory responses by reducing mucin secretion and promoting lipid droplet-mediated ROS clearance. Therefore, Rg5 may have potential as a therapeutic agent to alleviate respiratory disorders caused by hyperactivation of mucosa cells.

Water-soluble saponins accumulate in drought-stressed switchgrass and may inhibit yeast growth during bioethanol production

BACKGROUND

Developing economically viable pathways to produce renewable energy has become an important research theme in recent years. Lignocellulosic biomass is a promising feedstock that can be converted into second-generation biofuels and bioproducts. Global warming has adversely affected climate change causing many environmental changes that have impacted earth surface temperature and rainfall patterns. Recent research has shown that environmental growth conditions altered the composition of drought-stressed switchgrass and directly influenced the extent of biomass conversion to fuels by completely inhibiting yeast growth during fermentation. Our goal in this project was to find a way to overcome the microbial inhibition and characterize specific compounds that led to this inhibition. Additionally, we also determined if these microbial inhibitors were plant-generated compounds, by-products of the pretreatment process, or a combination of both.

RESULTS

Switchgrass harvested in drought (2012) and non-drought (2010) years were pretreated using Ammonia Fiber Expansion (AFEX). Untreated and AFEX processed samples were then extracted using solvents (i.e., water, ethanol, and ethyl acetate) to selectively remove potential inhibitory compounds and determine whether pretreatment affects the inhibition. High solids loading enzymatic hydrolysis was performed on all samples, followed by fermentation using engineered Saccharomyces cerevisiae. Fermentation rate, cell growth, sugar consumption, and ethanol production were used to evaluate fermentation performance. We found that water extraction of drought-year switchgrass before AFEX pretreatment reduced the inhibition of yeast fermentation. The extracts were analyzed using liquid chromatography-mass spectrometry (LC-MS) to detect compounds enriched in the extracted fractions. Saponins, a class of plant-generated triterpene or steroidal glycosides, were found to be significantly more abundant in the water extracts from drought-year (inhibitory) switchgrass. The inhibitory nature of the saponins in switchgrass hydrolysate was validated by spiking commercially available saponin standard (protodioscin) in non-inhibitory switchgrass hydrolysate harvested in normal year.

CONCLUSIONS

Adding a water extraction step prior to AFEX-pretreatment of drought-stressed switchgrass effectively overcame inhibition of yeast growth during bioethanol production. Saponins appear to be generated by the plant as a response to drought as they were significantly more abundant in the drought-stressed switchgrass water extracts and may contribute toward yeast inhibition in drought-stressed switchgrass hydrolysates.

Immunostimulatory 6/6/6/6 Tetracyclic Triterpenoid Saponins with the Methyl-30 Incorporated Cyclization from the Root of Colquhounia elegans

Two novel triterpenoid saponins, colqueleganoids A (1) and B (2), with the first methyl-30 incorporated 6/6/6/6-cyclized carbon skeleton (named colquelegane), were isolated from the root of Colquhounia elegans. Their structures including absolute configuration were determined by spectroscopic methods and X-ray crystallographic analyses. Interestingly, both compounds significantly enhanced TNF-α production and 1 also increased the IL-6 production in RAW264.7 macrophages stimulated with lipopolysaccharide (LPS), suggesting their potential application as immunostimulants in immunotherapy and vaccination.

HSF-1 mediated combined ginsenosides ameliorating Alzheimer's disease like symptoms in Caernorhabditis elegans

There are few effective medications to treat Alzheimer's disease (AD). It has been suggested that several ginsenosides possess mild or moderate anti-AD activity. In our present work, a preferred combined ginsenosides was shown to have a more significant benefit effect on AD-like symptoms of worm paralysis and hypersensitivity to exogenous 5-HT in C. elegans. The combined ginsenosides can suppress Aβ deposits and Aβ oligomers, alleviating the toxicity induced by Aβ overexpression more effectively than used alone. Its anti-AD effect was partially abolished by hsf-1 RNAi knocked down or hsf-1 inactivation by point mutation, but not by daf-16 or skn-1 RNAi knocked down. Furthermore, it markedly activated hsp-16.2 gene expression downstream of HSF-1. Our results demonstrated that HSF-1 signaling pathway exerts an important role in mediating the therapeutic effect of combined ginsenosides on AD worms. These results provided powerful evidences and theoretical foundation for reshaping medicinal products of ginsenosides and ginseng on prevention of neurodegenerative diseases.

Evolution of the adaptogenic concept from traditional use to medical systems: Pharmacology of stress- and aging-related diseases

Adaptogens comprise a category of herbal medicinal and nutritional products promoting adaptability, resilience, and survival of living organisms in stress. The aim of this review was to summarize the growing knowledge about common adaptogenic plants used in various traditional medical systems (TMS) and conventional medicine and to provide a modern rationale for their use in the treatment of stress-induced and aging-related disorders. Adaptogens have pharmacologically pleiotropic effects on the neuroendocrine-immune system, which explain their traditional use for the treatment of a wide range of conditions. They exhibit a biphasic dose-effect response: at low doses they function as mild stress-mimetics, which activate the adaptive stress-response signaling pathways to cope with severe stress. That is in line with their traditional use for preventing premature aging and to maintain good health and vitality. However, the potential of adaptogens remains poorly explored. Treatment of stress and aging-related diseases require novel approaches. Some combinations of adaptogenic plants provide unique effects due to their synergistic interactions in organisms not obtainable by any ingredient independently. Further progress in this field needs to focus on discovering new combinations of adaptogens based on traditional medical concepts. Robust and rigorous approaches including network pharmacology and systems pharmacology could help in analyzing potential synergistic effects and, more broadly, future uses of adaptogens. In conclusion, the evolution of the adaptogenic concept has led back to basics of TMS and a new level of understanding of holistic approach. It provides a rationale for their use in stress-induced and aging-related diseases.

Review of ginsenosides targeting mitochondrial function to treat multiple disorders: Current status and perspectives

Mitochondrial dysfunction contributes to the pathogenesis and prognosis of many common disorders, including neurodegeneration, stroke, myocardial infarction, tumor, and metabolic diseases. Ginsenosides, the major bioactive constituents of Panax ginseng (P. ginseng), have been reported to play beneficial roles in the molecular pathophysiology of these diseases by targeting mitochondrial dysfunction. In this review, we first introduce the types of ginsenosides and basic mitochondrial functions. Then, recent findings are summarized on different ginsenosides targeting mitochondria and their key signaling pathways for the treatment of multiple diseases, including neurological disorders, cancer, heart disease, hyperglycemia, and inflammation are summarized. This review may explain the common targets of ginsenosides against multiple diseases and provide new insights into the underlying mechanisms, facilitating research on the clinical application of P. ginseng.

Protective Roles of Cytosolic and Plastidal Proteasomes on Abiotic Stress and Pathogen Invasion

Protein malfunction is typically caused by abiotic stressors. To ensure cell survival during conditions of stress, it is important for plant cells to maintain proteins in their respective functional conformation. Self-compartmentalizing proteases, such as ATP-dependent Clp proteases and proteasomes are designed to act in the crowded cellular environment, and they are responsible for degradation of misfolded or damaged proteins within the cell. During different types of stress conditions, the levels of misfolded or orphaned proteins that are degraded by the 26S proteasome in the cytosol and nucleus and by the Clp proteases in the mitochondria and chloroplasts increase. This allows cells to uphold feedback regulations to cellular-level signals and adjust to altered environmental conditions. In this review, we summarize recent findings on plant proteolytic complexes with respect to their protective functions against abiotic and biotic stressors.

Anti-Inflammatory Potential of Cultured Ginseng Roots Extract in Lipopolysaccharide-Stimulated Mouse Macrophages and Adipocytes

Wild ginseng, Panax ginseng Meyer, is a traditional medicine widely used in Asia. Due to low reward and high costs, wild ginseng is produced by a plant cell culture technique called cultured ginseng roots (GR). The health benefits of wild ginseng have been well studied, but the potential health effects of GR are largely unknown. Thus, we investigated the role of a GR extract (GRE) on inflammatory responses. We firstly investigated the anti-inflammatory potential of GRE in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. GRE (100 μg/mL) dampened pro-inflammatory gene expression, cytokine release, reactive oxygen species (ROS) production, and mitogen-activated protein kinase (MAPK) activation. These anti-inflammatory responses by GRE were confirmed in mouse bone marrow-derived macrophages (BMDMs), which showed that GRE could inhibit inflammation with the induction of antioxidant levels. LPS was recently reported to impair mitochondrial bioenergetics in mouse macrophages. We next measured the mitochondrial oxygen consumption rate (OCR), determining mitochondrial function. LPS treatment downregulated OCR; however, GRE partially restored the LPS-mediated energy homeostasis defects. Furthermore, GRE-pretreated conditioned media (CM) obtained from mouse macrophages decreased CM-mediated adipocyte inflammation. Collectively, these data suggested that GRE attenuated LPS-induced inflammation, and it might be partially involved in the protection from mitochondrial dysfunction in macrophages and adipocytes.

Caffeine-Containing, Adaptogenic-Rich Drink Modulates the Effects of Caffeine on Mental Performance and Cognitive Parameters: A Double-Blinded, Placebo-Controlled, Randomized Trial

Using a placebo-controlled, double-blinded, within-participants, randomized, cross-over design, we examined the neurocognitive effects of a: (a) caffeine-containing, adaptogenic herbal-rich natural energy shot (e+ shot), (b) a matched caffeine-containing shot (caffeine), and, (c) a placebo. Participants (n = 30) were low consumers of caffeine without elevated feelings of energy. Before and three times after beverage consumption, a 27-min battery was used to assess motivation to perform cognitive tasks, mood, attention ((serial subtractions of 3 (SS3) and 7 (SS7), the continuous performance task (CPT), and the rapid visual input processing tasks)), heart rate (HR), blood pressure (BP), and motor coordination (nine-hole peg test) with a 10-min break between each post-consumption battery. The procedure was repeated for each beverage for each participant at least 48 h apart and within 30 min the same time of day using a random group assignment with blinding of researchers and subjects. To evaluate for changes in outcomes, a Treatment × Time analysis of covariance controlling for hours of prior night's sleep was used. Analysis of all outcomes and all treatment comparisons indicated that compared to placebo, both e+ shot ( Δ ¯   = 2.60; η2 = 0.098) and caffeine ( Δ ¯   = 5.30, η2 = 0.098) increased systolic BP 30 min post consumption (still within normal healthy ranges). The caffeine beverage also led to an improvement in most cognitive measures and moods 30-min post-consumption with improvements tapering at 69 and 108 min, while e+ shot noted more steady improvements with no significant differences between beverages on most cognitive and mood measures at 69 and 108 min. However, compared to caffeine, e+ shot noted a significant increase in reaction time at 108 min, while caffeine noted a small change in the opposite direction. No side-effects were reported by any intervention. These results suggest that the specific blend of adaptogens in e+ shot may modulate the neurocognitive effects of caffeine on mood, and cognition.

Ginsenoside metabolite compound-K regulates macrophage function through inhibition of β-arrestin2

Ginsenoside metabolite compound-K (C-K), which is an active metabolite of ginsenoside in vivo, can produce anti-inflammatory affects by activating glucocorticoid receptors (GRs) to inhibit the expression of β-arrestin2. Studies have shown that C-K can inhibit the function of immune cells including macrophage polarization and phagocytosis. However, the mechanism by which C-K regulates macrophage polarization is currently unclear. Toll-like receptors (TLRs) are the pattern recognition receptors on the membrane of immune cells, with TLR4 being especially important in polarization of macrophages. The Gαi-mediated activation of nuclear factor-κB (NF-κB) by TLR4 promotes inflammation and phagocytosis in macrophages by increasing the proportion of type I phenotypic macrophages (M1). Whether C-K inhibits the signal transduction of TLR4-Gαi-NF-κB and how that effects macrophage polarization regulation in murine models of RA is not reported. The coupling of G proteins with receptors is regulated by β-arrestin2, but it has been unclear whether C-K modulates the TLR4 interaction with G proteins by inhibiting the expression of β-arrestin2. To explore these questions, the collagen-induced arthritis (CIA) mouse model was employed, and mice were treated with C-K (112 mg/kg/day). The results depict that C-K treatment inhibits macrophage phagocytosis and reduces the proportion of M1. C-K decreases the overexpressed β-arrestin2, Gαi, TLR4 and NF-κB in macrophages of CIA mice, while increasing the expression of Gαs. Furthermore, C-K promotes TLR4-Gαs coupling and inhibits TLR4-Gαi coupling through β-arrestin2 regulation in macrophages, leading to a decrease in the proportion of M1 to M2 macrophages and improved outcomes in CIA mice.

Vanillic acid in Panax ginseng root extract inhibits melanogenesis in B16F10 cells via inhibition of the NO/PKG signaling pathway

Panax ginseng C. A. Meyer has been widely used in skin care. Our previous study showed that the phenolic acids in ginseng root extract (GRE) impart inhibitory effects on melanogenesis. In this study, we found that as the most abundant component of phenolic acids in GRE, vanillic acid decreased tyrosinase activity and melanin levels with or without α-MSH stimulation and suppressed the expression of microphthalmia-associated transcription factor (MITF) and melanogenic enzymes in B16F10 cells. Furthermore, vanillic acid downregulated NOS activity, nitric oxide (NO) content, cGMP level, guanylate cyclase (GC) and protein kinase G (PKG) activity, and the phosphorylation of cAMP-response element-binding protein (CREB), whereas arbutin had no effect on the NO/PKG pathway. These findings indicate that vanillic acid in GRE suppressed melanogenesis by inhibiting the NO/PKG signaling pathways. This study provides a potential mechanism underlying the inhibitory effect of ginseng on melanogenesis.

Transcriptome analysis provides insights into the molecular mechanisms responsible for evisceration behavior in the sea cucumber Apostichopus japonicus

The sea cucumber Apostichopus japonicus (Selenka) is a valuable economic species in Southeast Asia. It has many fascinating behavioral characteristics, such as autolysis, aestivation, regeneration, and evisceration, thus it is a notable species for studies of special behaviors. Evisceration and autotomy are controlled by the neural network and involve a complicated physiological process. The occurrence of evisceration behavior in sea cucumbers is strongly related to their environment, and it negatively impacts their economic value. Evisceration behavior plays a pivotal role in the survival of A. japonicus, and when it is induced by dramatic changes in the coastal ecological environment and the aquaculture setting it can strongly affect the economic performance of this species. Although numerous studies have focused on intestinal regeneration of A. japonicus, less is known about evisceration behavior, especially its underlying molecular mechanisms. Thus, identification of genes that regulate evisceration in the sea cucumber likely will provide a scientific explanation for this significant specific behavior. In this study, Illumina sequencing (RNA-Seq) was performed on A. japonicus specimens in three states: normal (TCQ), eviscerating (TCZ), and 3 h after evisceration (TCH). In total, 129,905 unigenes were generated with an N50 length of 2651 base pairs, and 54,787 unigenes were annotated from seven functional databases (KEGG, KOG, GO, NR, NT, Interpro, and Swiss-Prot). Additionally, 190, 191, and 320 genes were identified as differentially expressed genes (DEGs) in the comparisons of TCQ vs. TCZ, TCZ vs. TCH, and TCQ vs. TCH, respectively. These DEGs mapped to 157, 113, and 190 signaling pathways in the KEGG database, respectively. KEGG analyses also revealed that potential DEGs enriched in the categories of "environmental information processing," "organismal system," "metabolism," and "cellular processes," and they were involved in evisceration behavior in A. japonicus. These DEGs are related to muscle contraction, hormone and neurotransmitter secretion, nerve and muscle damage, energy support, cellular stress, and apoptosis. In conclusion, through our comparative analysis of A. japonicus in different stages, we identified many candidate evisceration-related genes and signaling pathways that likely are involved in evisceration behavior. These results should help further elucidate the mechanisms underlying evisceration behavior in sea cucumbers.

Z-Ligustilide Exerted Hormetic Effect on Growth and Detoxification Enzymes of Spodoptera litura Larvae

Plants have evolved a variety of phytochemicals to defense insect feeding, whereas insects have also evolved diverse detoxification enzymes, which are adaptively induced as a prosurvival mechanism. Herein, Z-ligustilide in Ligusticum chuanxiong Hort. was found to exhibit a similar trend in the accumulation from December to May as the occurrence of Spodoptera litura (Fabricius) larvae. Importantly, S. litura larvae feeding enhanced Z-ligustilide level in the stem and leaf (p < 0.01). Moreover, Z-ligustilide ranging from 1 to 5 mg·g⁻¹ exhibited remarkable larvicidal activity, antifeedant activity, and growth inhibition against S. litura larvae. The LC₅₀ values of larvicidal activity for phthalides in L. chuanxiong were compared as follows: Z-ligustilide > levistilide A > senkyunolide A > 3-butylidenephthalide > senkyunolide I, implicating the critical role of conjugated structure. Notably, there was a biphasic dose response for glutathione S-transferase (GST), cytochrome P450 (CYP) 450, Acetylcholinesterase (AChE), and Carboxylesterase (CarE) activities and GSTs1, cytochrome P450 (CYP) 4S9, and CYP4M14 mRNA expression. Particularly, low dose (0.1 mg·g⁻¹) of Z-ligustilide conferred the resistance of S. litura larvae against chlorpyrifos (p < 0.05). Together, our data suggest that Z-ligustilide may function in a hormetic way in the chemical defense of L. chuanxiong against S. litura larvae.

Biogerontology: research status, challenges and opportunities

Biogerontology is the study of the biological basis of ageing and age-related diseases. The phenomenon and the process of ageing are well understood in evolutionary and biological terms; and a conceptual framework has been established within which general principles of ageing and longevity can be formulated. The phenotype of ageing in terms of progressive loss of physical function and fitness is best seen during the period of survival after the evolution-determined essential lifespan (ELS) of a species. However, the ageing phenotype is highly heterogenous and individualistic at all levels from the whole body to the molecular one. Most significantly, the process and the progression of ageing are not determined by any specific gerontogenes. Ageing is the result of imperfect maintenance and repair systems that allow a progressive shrinkage of the homeodynamic space of an individual. The challenge is to develop and apply wholistic approaches to the complex trait of ageing for maintaining and/or improving health. One such approach is that of mild stress-induced physiological hormesis by physical, mental and nutritional hormetins. Biogerontological research offers numerous opportunities for developing evidence-based novel biomedical technologies for maintaining and improving health, for preventing the onset of age-related diseases, and for extending the health-span.

Cellular stress response mechanisms of Rhizoma coptidis: a systematic review

Rhizoma coptidis has been used in China for thousands of years with the functions of heating dampness and purging fire detoxification. But the underlying molecular mechanisms of Rhizoma coptidis are still far from being fully elucidated. Alkaloids, especially berberine, coptisine and palmatine, are responsible for multiple pharmacological effects of Rhizoma coptidis. In this review, we studied on the effects and molecular mechanisms of Rhizoma coptidis on NF-κB/MAPK/PI3K–Akt/AMPK/ERS and oxidative stress pathways. Then we summarized the mechanisms of these alkaloid components of Rhizoma coptidis on cardiovascular and cerebrovascular diseases, diabetes and diabetic complications. Evidence presented in this review implicated that Rhizoma coptidis exerted beneficial effects on various diseases by regulation of NF-κB/MAPK/PI3K–Akt/AMPK/ERS and oxidative stress pathways, which support the clinical application of Rhizoma coptidis and offer references for future researches.

Ginsenoside 20(S)-Rh2 Induces Apoptosis and Differentiation of Acute Myeloid Leukemia Cells: Role of Orphan Nuclear Receptor Nur77

Ginsenoside 20(S)-Rh2 has been shown to induce apoptosis and differentiation of acute myeloid leukemia (AML) cells. However, the underlying molecular mechanisms are not fully understood. In our study, 20(S)-Rh2 induced the expression of orphan nuclear receptor Nur77 and death receptor proteins Fas, FasL, DR5, and TRAIL, as well as the cleavage of caspase 8 and caspase 3 in HL-60 cells. Importantly, shNur77 attenuated 20(S)-Rh2-induced apoptosis and Fas and DR5 expression. Meanwhile, 20(S)-Rh2 promoted Nur77 translocation from the nucleus to mitochondria and enhanced the interaction between Nur77 and Bcl-2, resulting in the exposure of the BH3 domain of Bcl-2 and activation of Bax. Furthermore, 20(S)-Rh2 promoted the differentiation of HL-60 cells as evidenced by Wright-Giemsa staining, NBT reduction assay, and detection of the myeloid differentiation marker CD11b by flow cytometry. Notably, shNur77 reversed 20(S)-Rh2-mediated HL-60 differentiation. Additionally, 20(S)-Rh2 also exhibited an antileukemic effect and induced Nur77 expression in NOD/SCID mice with the injection of HL-60 cells into the tail vein. Together, our studies suggest that the Nur77-mediated signaling pathway is highly involved in 20(S)-Rh2-induced apoptosis and differentiation of AML cells.