Glycosyltransformation of ginsenoside Rh2 into two novel ginsenosides using recombinant glycosyltransferase from Lactobacillus rhamnosus and its in vitro applications

Discovery and mechanistic exploration of promiscuous xylosyltransferase based on protein engineering

Glycosylation is an effective means to alter the structure and properties of plant compounds, influencing the pharmacological activity of natural products (NPs) to obtain highly active NPs. In nature, glucosides are the most widely distributed, while other glycosides such as xylosides are less common and present in lower quantities. This is due to the scarcity of xylosyltransferases with substrate promiscuity in nature, and the modification of their catalytic function is also quite challenging. In this study, we first performed a phylogenetic analysis of reported UDP-glycosyltransferases (UGTs) of plant and microbiological origin and identified a unique motif region from the UGTs of the Bacillus genus, which may be responsible for the broad sugar donor catalytic activity of the UGTs in the Bacillus genus. Then, utilizing protein engineering techniques, we have evolved a xylosyltransferase M3-2, which exhibited high substrate promiscuity, sugar donor promiscuity, and site selectivity, enabling the synthesis of a variety of O-glycosides. In addition, another mutant M3-1 has been engineered to alter the sugar donor specificity of the UGT, enabling the switch from UDP-Glc donor to UDP-Xyl. The improved enzymatic activity is likely attributed to stable hydrophobic interactions and hydrogen bonding interactions between the enzyme and the substrate. In order to synthesize xylosylated products more economically and efficiently, an in vitro synthetic pathway that utilizes NPs and inexpensive glucuronic acid as starting materials was designed. Through this pathway, we successfully synthesized a variety of unnatural xylosylated products belonging to O-glycosides, one of which 10a possesses excellent anti-inflammatory activity. We anticipate that this work will contribute to the future discovery and industrial production of unnatural glycosides.

Biosynthesis of a Novel Ginsenoside with High Anticancer Activity by Recombinant UDP-Glycosyltransferase and Characterization of Its Biological Properties

UDP-glycosyltransferases (UGTs) contribute to catalyzing the glycosylation of numerous functional natural products and novel derivatives with improved bioactivities. UDP-glucose sterol glucosyltransferase (SGT) is normally involved in the synthesis of sterol glycosides in a variety of organisms. SGT was derived from Salinispora tropica CNB-440 and heterologously expressed in Escherichia coli BL21 (DE3). Novel 12-O-glucosylginsenoside Rh2 was identified using HPLC, high-resolution MS (HR-MS), and NMR analysis. The cell viability assay was performed on 12-O-glucosylginsenoside-treated AGS stomach cancer, HeLa cervical cancer, U87MG glioma, and B16F10 melanoma cell lines. Protein structure modeling, molecular docking, and dynamics simulations were performed using AutoDock 4.2 and GROMACS 2020.1 software. The SGT gene is comprised of 1284 nucleotides and codes for 427 amino acids. The 12-O-glucosylginsenoside Rh2 may be a potential anticancer agent due to its potent viability inhibition of cancer cells. Structural analysis showed critical perspectives into the intermolecular interactions, stability, and binding energetics of the enzyme-ligand complex, with outcomes complementing the experimental data, thereby deepening our understanding of the structural basis of SGT-mediated glycosylation and its functional implications. This report presents a novel ginsenoside, 12-O-glucosylginsenoside Rh2, utilizing reshuffled SGT derived from S. tropica, and provides a promising candidate for anticancer drug research and development.

Ginsenoside Rh2 suppresses ferroptosis in ulcerative colitis by targeting specific protein 1 by upregulating microRNA-125a-5p

BACKGROUND

Worldwide, ulcerative colitis (UC) is becoming increasingly fast growing. Ginsenoside Rh2 has been reported to alleviate UC. However, the latent biological mechanism of Rh2 in the treatment of UC remains uncertain. In this study, the goal was to determine the therapeutic effect of Rh2 on dextran sulfate sodium (DSS)-induced UC.

METHODS

A DSS-induced UC mouse model was established and divided into 7 groups for Rh2 gavage and/or miR-125a-5p lentivirus injection (n = 10 per group). Colonic specimens were collected for phenotypic and pathological analysis. miR-125a-5p and specific protein 1 (SP1) expression, inflammation-related factors IL-6 and IL-10, and apoptosis were detected in mice. Human normal colon epithelial cell line NCM460 was treated with H2O2 and ferric chloride hexahydrate to construct an in vitro cell model of colitis and induce ferroptosis. Independent sample t-test was used to compare cell proliferation, cell entry, apoptosis, and oxidative stress between the two groups. One way analysis of variance combined with the least significant difference t test was used for comparison between groups. Multiple time points were compared by repeated measurement analysis of variance.

RESULTS

DSS-induced UC mice had significantly decreased body weight, increased disease activity index, decreased colon length, and decreased miR-125a-5p expression (all P < 0.05). In the DSS-induced mouse model, the expression of miR-125a-5p rebounded and ferroptosis was inhibited after Rh2 treatment (all P < 0.05). Inhibition of miR-125a-5p or upregulation of SP1 expression counteracted the protective effects of Rh2 on UC mice and ferroptosis cell models (all P < 0.05).

CONCLUSIONS

Rh2 mitigated DSS-induced colitis in mice and restrained ferroptosis by targeting miR-125a-5p. Downregulating miR-125a-5p or elevating SP1 could counteract the protective impacts of Rh2 on ferroptotic cells. The findings convey that Rh2 has a latent application value in the treatment of UC.

Hosts engineering and in vitro enzymatic synthesis for the discovery of novel natural products and their derivatives

Novel natural products (NPs) and their derivatives are important sources for drug discovery, which have been broadly applied in the fields of agriculture, livestock, and medicine, making the synthesis of NPs and their derivatives necessarily important. In recent years, biosynthesis technology has received increasing attention due to its high efficiency in the synthesis of high value-added novel products and its advantages of green, environmental protection, and controllability. In this review, the technological advances of biosynthesis strategies in the discovery of novel NPs and their derivatives are outlined, with an emphasis on two areas of host engineering and in vitro enzymatic synthesis. In terms of hosts engineering, multiple microorganisms, including Streptomyces, Aspergillus, and Penicillium, have been used as the biosynthetic gene clusters (BGCs) provider and host strain for the expression of BGCs to discover new compounds over the past years. In addition, the use of in vitro enzymatic synthesis strategy to generate novel compounds such as triterpenoid saponins and flavonoids is also hereby described.

Ginsenoside-Rh2 Promotes Functional Recovery after Spinal Cord Injury by Enhancing TFEB-Mediated Autophagy

Background: Following spinal cord injury (SCI), autophagy plays a positive role in neuronal protection, whereas pyroptosis triggers an inflammatory response. Ginsenoside-Rh2 (GRh2), known for its neuroprotective effects, is considered a promising drug. However, the exact molecular mechanisms underlying these protective effects remain unclear. Aim of the Study: Explore the therapeutic value of GRh2 in SCI and its potential mechanisms of action. Materials and Methods: An SCI mouse model was established, followed by random grouping and drug treatments under different conditions. Subsequently, the functional recovery of SCI mice after GRh2 treatment was assessed using hematoxylin and eosin, Masson's trichrome, and Nissl staining, footprint analysis, Basso Mouse Scale scoring, and inclined plane tests. The expression levels of relevant indicators in the mice were detected using Western blotting, immunofluorescence, and a quantitative polymerase chain reaction. Network pharmacology analysis was used to identify the relevant signaling pathways through which GRh2 exerts its therapeutic effects. Results: GRh2 promoted functional recovery after SCI. GRh2 significantly inhibits pyroptosis by enhancing autophagy in SCI mice. Simultaneously, the neuroprotective effect of GRh2, achieved through the inhibition of pyroptosis, is partially reversed by 3-methyladenine, an autophagy inhibitor. Additionally, the increase in autophagy induced by GRh2 is mediated by the promotion of transcription factor EB (TFEB) nuclear translocation and dephosphorylation. Partial attenuation of the protective effects of GRh2 was observed after TFEB knockdown. Additionally, GRh2 can modulate the activity of TFEB in mice post-SCI through the EGFR-MAPK signaling pathway, and NSC228155 (an EGFR activator) can partially reverse the effect of GRh2 on the EGFR-MAPK signaling pathway. Conclusions: GRh2 improves functional recovery after SCI by upregulating TFEB-mediated autophagic flux and inhibiting pyroptosis, indicating its potential clinical applicability.

Progress in Identification of UDP-Glycosyltransferases for Ginsenoside Biosynthesis

Ginsenosides, the primary pharmacologically active constituents of the Panax genus, have demonstrated a variety of medicinal properties, including anticardiovascular disease, cytotoxic, antiaging, and antidiabetes effects. However, the low concentration of ginsenosides in plants and the challenges associated with their extraction impede the advancement and application of ginsenosides. Heterologous biosynthesis represents a promising strategy for the targeted production of these natural active compounds. As representative triterpenoids, the biosynthetic pathway of the aglycone skeletons of ginsenosides has been successfully decoded. While the sugar moiety is vital for the structural diversity and pharmacological activity of ginsenosides, the mining of uridine diphosphate-dependent glycosyltransferases (UGTs) involved in ginsenoside biosynthesis has attracted a lot of attention and made great progress in recent years. In this paper, we summarize the identification and functional study of UGTs responsible for ginsenoside synthesis in both plants, such as Panax ginseng and Gynostemma pentaphyllum, and microorganisms including Bacillus subtilis and Saccharomyces cerevisiae. The UGT-related microbial cell factories for large-scale ginsenoside production are also mentioned. Additionally, we delve into strategies for UGT mining, particularly potential rapid screening or identification methods, providing insights and prospects. This review provides insights into the study of other unknown glycosyltransferases as candidate genetic elements for the heterologous biosynthesis of rare ginsenosides.

One-Step Purification and Immobilization of Glycosyltransferase with Zn-Ni MOF for the Synthesis of Rare Ginsenoside Rh2

Uridine diphosphate (UDP)-glucosyltransferases (UGTs) have received increasing attention in the field of ginsenoside Rh2 conversion. By harnessing the metal chelation between transition metal ions and imidazole groups present on His-tagged enzymes, a specific immobilization of the enzyme within metal-organic frameworks (MOFs) is achieved. This innovative approach not only enhances the stability and reusability of the enzyme but also enables one-step purification and immobilization. Consequently, the need for purifying crude enzyme solutions is effectively circumvented, resulting in significant cost savings during experimentation. The use of immobilized enzymes in catalytic reactions has shown great potential for achieving higher conversion rates of ginsenoside Rh2. In this study, highly stable mesoporous Zn-Ni MOF materials were synthesized at 150 °C by a solvothermal method. The UGT immobilized on the Zn-Ni MOF (referred to as UGT@Zn-Ni MOF) exhibited superior pH adaptability and thermal stability, retaining approximately 76% of its initial activity even after undergoing 7 cycles. Furthermore, the relative activity of the immobilized enzyme remained at an impressive 80.22% even after 45 days of storage. The strong specific adsorption property of Zn-Ni MOF on His-tagged UGT was confirmed through analysis using polyacrylamide gel electrophoresis. UGT@Zn-Ni MOF was used to catalyze the conversion reaction, and the concentration of rare ginsenoside Rh2 was generated at 3.15 μg/mL. The results showed that Zn-Ni MOF is a material that can efficiently purify and immobilize His-tagged enzyme in one step and has great potential for industrial applications in enzyme purification and ginsenoside synthesis.

Enzymatic upcycling of wild-simulated ginseng leaves for enhancing biological activities and compound K

Compound K (CK), a ginsenoside with high bioavailability, is present at low levels in wild-simulated ginseng leaves (WSGL). WSGL contains the CK precursors, Rd and F2, in amounts up to 26.4 ± 0.4 and 24.1 ± 1.9 mg/g extract, respectively. In this study, CK production in WGSL reached 25.9 ± 1.0 mg/g extract following treatment with Viscozyme, Celluclast 1.5 L, Pectinex Ultra SP-L, and their combination. The antioxidant activities indicated by oxygen radical absorbance capacity, ferric reducing antioxidant power, and ABTS- and DPPH radical scavenging activity of enzyme-treated WSGL were enhanced 1.69-, 2.51-, 2.88-, and 1.80-fold, respectively, compared to non-treated WSGL. Furthermore, the CK-enriched WSGL demonstrated a 1.94-fold decrease in SA-β-galactosidase expression in human dermal fibroblasts and a 3.8-fold enhancement of inhibition of nitric oxide release in lipopolysaccharide-induced RAW 264.7 cells relative to non-treated WSGL. Consequently, WSGL subjected to enzymatic upcycling has potential as a functional material in the food and pharmaceutical industries.

Genome-Wide Comparative Profiles of Triterpenoid Biosynthesis Genes in Ginseng and Pseudo Ginseng Medicinal Plants

Saponin-rich medicinal plants, particularly ginseng and Pseudo ginseng, are valuable in traditional medical practice due to the presence of different saponins. These plants benefit from natural saponins/triterpenoids drugs, such as Ginsenosides, Gypenosides, Platycodins, and Lancemasides. Ginsenosides are highly required for research and functional materials preparation in industrial practices, and some compounds, like Compound-K, have been taken to human trials for various therapeutic applications. To elucidate the genes/transcripts profiles responsible for secondary metabolites and ginsenoside biosynthesis in Ginseng and Pseudo ginseng plant genomes, a comparative analysis was conducted in this study. Nine plant genomes with a 99% BUSCO completeness score were used, resulting in 49 KEGG secondary metabolite pathways, 571 cytochromes genes with 42 families, and 3529 carbohydrate genes with 103 superfamilies. The comparative analysis revealed 24 genes/transcripts belonging to the CYP716 family, which is involved in the ginsenoside biosynthesis pathway. Additionally, it found that various ginsenosides demonstrated strong binding affinity with twelve targets, with ginsenoside Rg3, Rg2, Rh1, Rh5, F3, Rh9, Panaxadione, Protopanaxatriol, Floral ginsenoside C, and Floral ginsenoside E exhibiting the highest binding affinities with the tested enzymes. Since these groups of enzymes are not yet fully characterized for Pseudo ginseng plants in the interconversion of triterpenoids, this comparative bioinformatics analysis could aid experimentalists in selecting and conducting characterization with practical knowledge.

β-Glucosidase and Its Application in Bioconversion of Ginsenosides in Panax ginseng

Ginsenosides are a group of bioactive compounds isolated from Panax ginseng. Conventional major ginsenosides have a long history of use in traditional medicine for both illness prevention and therapy. Bioconversion processes have the potential to create new and valuable products in pharmaceutical and biological activities, making them both critical for research and highly economic to implement. This has led to an increase in the number of studies that use major ginsenosides as a precursor to generate minor ones using β-glucosidase. Minor ginsenosides may also have useful properties but are difficult to isolate from raw ginseng because of their scarcity. Bioconversion processes have the potential to create novel minor ginsenosides from the more abundant major ginsenoside precursors in a cost-effective manner. While numerous bioconversion techniques have been developed, an increasing number of studies have reported that β-glucosidase can effectively and specifically generate minor ginsenosides. This paper summarizes the probable bioconversion mechanisms of two protopanaxadiol (PPD) and protopanaxatriol (PPT) types. Other high-efficiency and high-value bioconversion processes using complete proteins isolated from bacterial biomass or recombinant enzymes are also discussed in this article. This paper also discusses the various conversion and analysis methods and their potential applications. Overall, this paper offers theoretical and technical foundations for future studies that will be both scientifically and economically significant.

Application of Emerging Techniques in Reduction of the Sugar Content of Fruit Juice: Current Challenges and Future Perspectives

In light of the growing interest in products with reduced sugar content, there is a need to consider reducing the natural sugar concentration in juices while preserving the initial concentration of nutritional compounds. This paper reviewed the current state of knowledge related to mixing juices, membrane processes, and enzymatic processes in producing fruit juices with reduced concentrations of sugars. The limitations and challenges of these methods are also reviewed, including the losses of nutritional ingredients in membrane processes and the emergence of side products in enzymatic processes. As the existing methods have limitations, the review also identifies areas that require further improvements and technological innovations.

The ways for ginsenoside Rh2 to fight against cancer: the molecular evidences in vitro and in vivo

Cancer is a global public health issue that becomes the second primary cause of death globally. Considering the side effects of radio- or chemo-therapy, natural phytochemicals are promising alternatives for therapeutic interventions to alleviate the side effects and complications. Ginsenoside Rh2 (GRh2) is the main phytochemical extracted from Panax ginseng C.A. Meyer with anticancer activity. GRh2 could induce apoptosis and autophagy of cancer cells and inhibit proliferation, metastasis, invasion, and angiogenesis in vitro and in vivo. In addition, GRh2 could be used as an adjuvant to chemotherapeutics to enhance the anticancer effect and reverse the adverse effects. Here we summarized the understanding of the molecular mechanisms underlying the anticancer effects of GRh2 and proposed future directions to promote the development and application of GRh2.

Recent advances in ginsenosides against respiratory diseases: Therapeutic targets and potential mechanisms

BACKGROUND

Respiratory diseases mainly include asthma, influenza, pneumonia, chronic obstructive pulmonary disease, pulmonary hypertension, lung fibrosis, and lung cancer. Given their high prevalence and poor prognosis, the prevention and treatment of respiratory diseases are increasingly essential. In particular, the development for the novel strategies of drug treatment has been a hot topic in the research field. Ginsenosides are the major component of Panax ginseng C. A. Meyer (ginseng), a food homology and well-known medicinal herb. In this review, we summarize the current therapeutic effects and molecular mechanisms of ginsenosides in respiratory diseases.

METHODS

The reviewed studies were retrieved via a thorough analysis of numerous articles using electronic search tools including Sci-Finder, ScienceDirect, PubMed, and Web of Science. The following keywords were used for the online search: ginsenosides, asthma, influenza, pneumonia, chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH), lung fibrosis, lung cancer, and clinical trials. We summarized the findings and the conclusions from 176 manuscripts on ginsenosides, including research articles and reviews.

RESULTS

Ginsenosides Rb1, Rg1, Rg3, Rh2, and CK, which are the most commonly reported ginsenosides for treating of respiratory diseases, and other ginsenosides such as Rh1, Rk1, Rg5, Rd and Re, all primarily reduce pneumonia, fibrosis, and inhibit tumor progression by targeting NF-κB, TGF-β/Smad, PI3K/AKT/mTOR, and JNK pathways, thereby ameliorating respiratory diseases.

CONCLUSION

This review provides novel ideas and important aspects for the future research of ginsenosides for treating respiratory diseases.

Limosilactobacillus fermentum-fermented ginseng improved antibiotic-induced diarrhoea and the gut microbiota profiles of rats

AIMS

This study investigated the efficacy of Limosilactobacillus fermentum-fermented ginseng for improving colitis and the gut microbiota profiles in rats and explored the benefits of the L. fermentum fermentation process to ginseng.

METHODS AND RESULTS

Ginseng polysaccharide and ginsenoside from fermented ginseng were analysed by UV and HPLC. Antibiotic-fed rats were treated with fermented ginseng and a L. fermentum-ginseng mixture. Histopathology- and immune-related factors (TNF-α, IL-1β, IL-6 and IL-10) of the colon were assayed by using pathological sections and ELISA. After treatment, fermented ginseng relieved the symptoms of antibiotic-induced diarrhoea and colon inflammation, and the expression of colon immune factors returned to normal. The gut microbial communities were identified by 16S rRNA gene sequencing. The results showed that the alterations in the gut microbiota returned to normal. In addition, the gut microbiota changes were correlated with immune factor expression after treatment. The fermented ginseng had better biological functions than a L. fermentum-ginseng mixture.

CONCLUSIONS

Fermented ginseng can relieve diarrhoea and colon inflammation and restore the gut microbiota to its original state. The process of L. fermentum fermentation can expand the therapeutic use of ginseng.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research suggested the potential function of fermented ginseng to relieve diarrhoea and recover the gut microbiota to a normal level and explored the benefits of the Limosilactobacillus fermentum fermentation process to ginseng.

Progress on the Elucidation of the Antinociceptive Effect of Ginseng and Ginsenosides in Chronic Pain

Ginseng (Panax ginseng C.A. Meyer) is a traditional Oriental herbal drug widely used in East Asia. Its main active ingredients are ginsenosides whose constituents are known to have various pharmacological activities such as anticancer, antinociception, and neuroprotection. The analgesic effects of ginsenosides, such as Rg1, Rg2, and Rb1, as well as compound K, are well known and the analgesic mechanism of action in inflammatory pain models is thought to be the down regulation of pro-inflammatory cytokine expression (TNF-α IL-1β, and IL-6). Several studies have also demonstrated that ginsenosides regulate neuropathic pain through the modulation of estrogen receptors. Recently, an increasing number of pathways have emerged in relation to the antinociceptive effect of ginseng and ginsenosides. Therefore, this review presents our current understanding of the effectiveness of ginseng in chronic pain and how its active constituents regulate nociceptive responses and their mechanisms of action.

Diversity of Ginsenoside Profiles Produced by Various Processing Technologies

Ginseng is a traditional medicinal herb commonly consumed world-wide owing to its unique family of saponins called ginsenosides. The absorption and bioavailability of ginsenosides mainly depend on an individual's gastrointestinal bioconversion abilities. There is a need to improve ginseng processing to predictably increase the pharmacologically active of ginsenosides. Various types of ginseng, such as fresh, white, steamed, acid-processed, and fermented ginsengs, are available. The various ginseng processing methods produce a range ginsenoside compositions with diverse pharmacological properties. This review is intended to summarize the properties of the ginsenosides found in different Panax species as well as the different processing methods. The sugar moiety attached to the C-3, C-6, or C-20 deglycosylated to produce minor ginsenosides, such as Rb1, Rb2, Rc, Rd→Rg3, F2, Rh2; Re, Rf→Rg1, Rg2, F1, Rh1. The malonyl-Rb1, Rb2, Rc, and Rd were demalonylated into ginsenoside Rb1, Rb2, Rc, and Rd by dehydration. Dehydration also produces minor ginsenosides such as Rg3→Rk1, Rg5, Rz1; Rh2→Rk2, Rh3; Rh1→Rh4, Rk3; Rg2→Rg6, F4; Rs3→Rs4, Rs5; Rf→Rg9, Rg10. Acetylation of several ginsenosides may generate acetylated ginsenosides Rg5, Rk1, Rh4, Rk3, Rs4, Rs5, Rs6, and Rs7. Acid processing methods produces Rh1→Rk3, Rh4; Rh2→Rk1, Rg5; Rg3→Rk2, Rh3; Re, Rf, Rg2→F1, Rh1, Rf2, Rf3, Rg6, F4, Rg9. Alkaline produces Rh16, Rh3, Rh1, F4, Rk1, ginsenoslaloside-I, 20(S)-ginsenoside-Rh1-60-acetate, 20(R)-ginsenoside Rh19, zingibroside-R1 through hydrolysis, hydration addition reactions, and dehydration. Moreover, biological processing of ginseng generates the minor ginsenosides of Rg3, F2, Rh2, CK, Rh1, Mc, compound O, compound Y through hydrolysis reactions, and synthetic ginsenosides Rd12 and Ia are produced through glycosylation. This review with respect to the properties of particular ginsenosides could serve to increase the utilization of ginseng in agricultural products, food, dietary supplements, health supplements, and medicines, and may also spur future development of novel highly functional ginseng products through a combination of various processing methods.

Preparation of Polyethylene Glycol-Ginsenoside Rh1 and Rh2 Conjugates and Their Efficacy against Lung Cancer and Inflammation

Low solubility and tumor-targeted delivery of ginsenosides to avoid off-target cytotoxicity are challenges for clinical trials. In the present study, we report on a methodology for the synthesis of polyethylene glycol (PEG)-ginsenoside conjugates through a hydrolysable ester bond using the hydrophilic polymer polyethylene glycol with the hydrophobic ginsenosides Rh1 and Rh2 to enhance water solubility and passive targeted delivery. The resulting conjugates were characterized by 1H nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FT-IR). 1H NMR revealed that the C-6 and C-3 sugar hydroxyl groups of Rh1 and Rh2 were esterified. The conjugates showed spherical shapes that were monitored by field-emission transmission electron microscopy (FE-TEM), and the average sizes of the particles were 62 ± 5.72 nm and 134 ± 8.75 nm for PEG-Rh1and PEG-Rh2, respectively (measured using a particle size analyzer). Owing to the hydrophilic enhancing properties of PEG, PEG-Rh1 and PEG-Rh2 solubility was greatly enhanced compared to Rh1 and Rh2 alone. The release rates of Rh1 and Rh2 were increased in lower pH conditions (pH 5.0), that for pathophysiological sites as well as for intracellular endosomes and lysosomes, compared to normal-cell pH conditions (pH 7.4). In vitro cytotoxicity assays showed that the PEG-Rh1conjugates had greater anticancer activity in a human non-small cell lung cancer cell line (A549) compared to Rh1 alone, whereas PEG-Rh2 showed lower cytotoxicity in lung cancer cells. On the other hand, both PEG-Rh1 and PEG-Rh2 showed non-cytotoxicity in a nondiseased murine macrophage cell line (RAW 264.7) compared to free Rh1 and Rh2, but PEG-Rh2 exhibited increased efficacy against inflammation by greatly inhibiting nitric oxide production. Thus, the overall conclusion of our study is that PEG conjugation promotes the properties of Rh1 for anticancer and Rh2 for inflammation treatments. Depends on the disease models, they could be potential drug candidates for further studies.