Pentacyclic Triterpenoid Saponins Research Articles

Dipsacoside B Attenuates Atherosclerosis by Promoting Autophagy to Inhibit Macrophage Lipid Accumulation.

Atherosclerosis is a chronic inflammatory disease characterized by lipid accumulation and foam cell formation in the arterial wall. Promoting macrophage autophagy has emerged as a promising therapeutic strategy against atherosclerosis. Dipsacoside B (DB) is an oleanane-type pentacyclic triterpenoid saponin extracted from Lonicerae flos with potential anti-atherosclerotic properties. In this study, we investigated the effects of DB on atherosclerosis progression in ApoE-/- mice fed a high-fat diet and explored the underlying mechanisms in oxidized low-density lipoprotein (ox-LDL)-induced foam cells. DB treatment significantly reduced atherosclerotic lesion size, improved plaque stability, and regulated lipid metabolism without impairing liver and kidney function in ApoE-/- mice. In vitro studies revealed that DB dose-dependently inhibited ox-LDL internalization and intracellular lipid accumulation in RAW264.7 macrophages. Mechanistically, DB induced autophagy, as evidenced by increased autophagosome formation and upregulated expression of autophagy markers LC3-II and p62 both in vivo and in vitro. Inhibition of autophagy by chloroquine abolished the antiatherosclerotic and pro-autophagic effects of DB. Furthermore, DB treatment increased LC3-II and p62 mRNA levels, suggesting transcriptional regulation of autophagy. Collectively, our findings demonstrate that DB exerts anti-atherosclerotic effects by inhibiting foam cell formation via autophagy induction, providing new insights into the pharmacological actions of DB and its potential as a therapeutic agent against atherosclerosis.

Synthesis, characterization and anticancer, antibacterial activities of pentacyclic triterpenoid glycoside derivatives

As a kind of glycoside, pentacyclic triterpenoid saponins have good biological activities, such as anticancer, antibacterial, antiviral and hypoglycemic effects [1]. In this paper, twenty-four pentacyclic triterpenoid derivatives, including twelve monosaccharide derivatives, were designed and synthesized. The anticancer effect and antibacterial activities of all compounds were evaluated. It is noteworthy that compound UA-2b has the strongest inhibitory effect on the growth of A549, Hela and HepG2 cancer cells (IC50 = 5.37 ± 0.22 µM, 5.82 ± 0.25 µM and 5.47 ± 0.06 µM, respectively). Compounds OA-2b, OA-6a, OA-6b, UA-2b and UA-6a have the best activity against Escherichia coli 1924 (MIC = 16 μg/ml).

Ecliptasaponin A protects heart against acute ischemia-induced myocardial injury by inhibition of the HMGB1/TLR4/NF-κB pathway

Ethnopharmacological relevanceEclipta prostrata (Linn.) is a traditional medicinal Chinese herb that displays multiple biological activities, such as encompassing immunomodulatory, anti-inflammatory, anti-tumor, liver-protective, antioxidant, and lipid-lowering effects. Ecliptasaponin A (ESA), a pentacyclic triterpenoid saponin isolated from Eclipta prostrata (Linn.), has been demonstrated to exert superior anti-inflammatory activity against many inflammatory disorders. Aim of the studyInflammation plays a critical role in acute myocardial infarction (AMI). This study aims to explore the treatment effects of ESA in AMI, as well as the underlying mechanism. MethodsAn AMI mouse model was established in mice via left anterior descending coronary artery (LAD) ligation. After surgery, ESA was injected at doses of 0.5, 1.25, and 2.5 mg/kg, respectively. Myocardial infarction size, cardiomyocyte apoptosis and cardiac echocardiography were studied. The potential mechanism of action of ESA was investigated by RNA-seq, Western blot, surface plasmon resonance (SPR), molecular docking, and immunofluorescence staining. ResultsESA treatment not only significantly reduced myocardial infarct size, decreased myocardial cell apoptosis, and inhibited inflammatory cell infiltration, but also facilitated to improve cardiac function. RNA-seq and Western blot analysis proved that ESA treatment-induced differential expression genes mainly enriched in HMGB1/TLR4/NF-κB pathway. Consistently, ESA treatment resulted into the down-regulation of IL-1β, IL-6, and TNF-α levels after AMI. Furthermore, SPR and molecular docking results showed that ESA could bind directly to HMGB1, thereby impeding the activation of the downstream TLR4/NF-κB pathway. The immunofluorescence staining and Western blot results at the cellular level also demonstrated that ESA inhibited the activation of the HMGB1/TLR4/NF-κB pathway in H9C2 cells. ConclusionOur study was the first to demonstrate a cardiac protective role of ESA in AMI. Mechanism study indicated that the treatment effects of ESA are mainly attributed to its anti-inflammatory activity that was mediated by the HMGB1/TLR4/NF-κB pathway.

Development and validation of high-performance liquid chromatography method for the simultaneous quantification of rivastigmine hydrogen tartrate and asiaticoside co-loaded in niosomes: A Box–Behnken design approach

Rivastigmine hydrogen tartrate (RHT), a reversible cholinesterase inhibitor, is considered as the first-line therapy for mild to moderate Alzheimer’s disease. Asiaticoside (AS), a pentacyclic triterpenoid saponin, is well known as cognitive enhancer due to its antioxidant effect. Based on the hypothesis of their synergistic therapeutic potential, RHT and AS were co-encapsulated in niosomal formulation. A simple, precise, and accurate high-performance liquid chromatography method was developed for simultaneous quantitative analysis. The chromatographic parameters were optimized by Box-Behnken experimental design. The separation was performed on a reversed-phase Phenomenex C18 (150 mm × 4.6 mm, 5 μm) column at 30 °C under the UV detection of 210 nm. The optimized mobile phase consisted of a mixture of 20 mM potassium dihydrogen phosphate buffer (pH 2.6) and acetonitrile (72:28 % v/v) under the isocratic mode at the flow rate of 0.9 mL/min. The developed method was fully validated under the ICH guidelines and could be successfully applied for simultaneous quantitative analysis of RHT and AS in niosomal formulation.

Pedunculoside promotes oral ulcer healing in mice by upregulating STAT3 and Smad3

BackgroundPedunculoside (PE) is a pentacyclic triterpenoid saponin found in the dried barks of the Ilex rotunda Thunb. In traditional Chinese medicine, the juice extracted from various Ilex species is commonly used for treating inflammatory diseases. ObjectiveThis study aims to investigate the potential of PE in promoting the healing of oral ulcers in mice and to explore its possible mechanism. Materials and MethodsA mouse model of oral ulcer was established to evaluate the healing promotion effects of PE, and an in-vitro inflammatory cell model was established by using primary fibroblasts isolated from mouse oral mucosal tissue. Gene transcription and protein expression related to cell proliferation, migration, and collagen synthesis were measured. ResultsPE showed the highest cure rate of 85.7% for oral ulcers in mice within 7-days treatment. It significantly promoted cell proliferation and collagen secretion in fibroblast in-vitro model. PE also upregulated the gene transcription of Smad3, Col1a1 and Col3a1. Furthermore, PE antagonized the inhibitory effect of WP1066 on STAT3activation, but did not affect cell migration. ConclusionThis study demonstrates that PE has potential therapeutic effects in promoting oral ulcer healing in mice. The improvement was achieved by the increasing collagen synthesis through the upregulation of STAT3 and Smad3 in mucosa fibroblasts. These results provide a preliminary pharmacological work for developing PE as a potential treatment agent for oral ulcers.

Effects of camellia saponins on biofilm formation and virulence factor genes of Bacillus cereus

Bacillus cereus is a common foodborne pathogen that can cause vomiting or diarrheal food poisoning and may not be suppressed using conventional cleaning procedures due to its ability to form biofilms. Biofilms have brought enormous challenges to the food safety industry. Camellia saponins are a class of oleanolanetype pentacyclic triterpenoid saponins that naturally exist in Camellia oleifera. This study demonstrated that the MBIC of camellia saponins against B. cereus was 64 mg/mL, and that the inhibitory effects on B. cereus upon adding saponins at different time periods varied as shown via scanning electron microscopy. However, the best inhibitory effect on biofilms was achieved through the addition of 1 mL of camellia saponins (1/2 MBIC) initially and adding 1 mL of camellia saponins (1/2 MBIC) again after 12 h, resulting in a decreased secretion of extracellular polymers and weakening the ability of the bacteria to form biofilms. The results showed that the swarming motility was significantly inhibited by camellia saponins. Furthermore, in the process of biofilm formation, camellia saponins could inhibit the production of extracellular proteins. qRT-PCR showed that the expression of six enterotoxin B. cereus virulence genes (hblA, hblD, cerA, cerB, nheA and hlyIII) was significantly inhibited by camellia saponins.

Potential of asiaticoside encapsulated alginate chitosan nanoparticles in the management of antiproliferative activity in C6 glioma cells

BackgroundAsiaticoside is a pentacyclic triterpenoid saponin constituent of the medicinal herb Centella asiatica, known for its neuroprotective, anticancer and other biological effects. The present study aims to develop and characterise asiaticoside encapsulated alginate chitosan nanoparticles (ACNPs) and evaluate their antiproliferative potential on C6 glioma cells. MethodsACNPs were prepared by the ionic gelation polyelectrolyte complexation technique and characterised by dynamic light scattering, scanning electron microscopy and transmission electron microscopy. Cytotoxicity and antiproliferative effect of ACNPs were studied on C6 glioma cells using MTT and EdU-assays. Apoptosis/necrosis in C6 glioma cells was determined by annexin V and acridine orange/ethidium bromide (AO/EtBr) assays. Intracellular ROS generation in C6 glioma cells exposed with ACNP was determined by DCFDA assay using flow cytometry. Cell cycle analysis in C6 glioma cells treated with ACNP was performed by flow cytometry. ResultsSynthesised ACNPs showed spherical shape with 200 nm particle size, good thermal stability, and an acceptable polydispersity index. ASI from synthesized ACNPs demonstrated 90% encapsulation efficiency (EE) and 10% drug release within 24 h. Upon ACNP treatment mBA cells exhibited good cell viability and intact cell morphology. However, C6 cells displayed dose-dependent cytotoxicity when treated with ACNP. Annexin V and acridine orange/ethidium bromide (AO/EtBr) assays revealed late apoptosis and necrosis (p < 0.05) in C6 glioma cells treated with ACNP. Likewise, ACNPs significantly augmented reactive oxygen species generation (p < 0.05) in C6 glioma cells. ACNP treatment also resulted in cell cycle arrest at the G1 phase with chromatin condensation in C6 glioma cells. ConclusionsThese findings suggest that ACNPs act as an antiproliferative agent against C6 glioma cells via an increased intracellular ROS pathway that promotes apoptosis/necrosis. This study throws light on more in-depth mechanistic aspects of managing brain disorders using C. asiatica and its phytoconstituents.

Diverse terpenoid glycosides with in vitro cytotoxicity from Glechoma longituba

Terpenoids are the largest class of all known natural products, possessing structural diversity and numerous biological activities. Ten previously undescribed terpenoid glycosides, glechlongsides A-J (1–10), were isolated from the ethanol extract of the whole plant of Glechoma longituba, including diterpenoid glycoside and pentacyclic triterpenoid saponin. The structures of these compounds were characterized by extensive analysis of 1D and 2D NMR as well as HRESIMS spectra. In addition, glechlongsides F–I (6–9) exhibited weak cytotoxicity against human cancer cell lines BGC-823, Be1, HCT-8, A2780, and A549 with IC50 values ranging from 3.77 to 30.95 μM, respectively.

α-Hederin induces human colorectal cancer cells apoptosis through disturbing protein homeostasis

Protein homeostasis and quality control are crucial for normal cellular activities, and a severe imbalance in protein homeostasis can lead to cell death. α-Hederin, a pentacyclic triterpenoid saponin isolated from Fructus Akebia, has a clear role in promoting colorectal cancer (CRC) cell apoptosis and has been recently used for CRC therapy. However, whether the pro-apoptotic activity of α-hederin in CRC cells involves disturbing protein homeostasis remains unknown. Here, we aimed to uncover the underlying molecular mechanism of α-hederin-induced apoptosis in CRC cells. Cell viability and proliferation were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) and 5-ethynyl-2′-deoxyuridine (EdU) assays, respectively. Apoptosis was detected using flow cytometry and western blotting. Autophagic flux was examined by western blotting and AdPlus-mCherry-GFP-LC3B adenovirus infection assays, and western blotting and immunofluorescence staining were performed to detect the expression of proteins in related pathways. The results showed that α-hederin significantly inhibited the growth and promoted the apoptosis of human CRC cells. Furthermore, α-Hederin induced endoplasmic reticulum (ER) stress, but inhibited proteasomal degradation. Also, the autophagic flux was blocked by α-hederin although this drug promoted autophagosome formation, and the lysosomal degradation was inhibited. Expression of p-JNK and p-p38 were increased by α-hederin. So, our findings provide strong evidence that α-hederin disrupts protein homeostasis by blocking ER-associated degradation (ERAD) and autophagic flux, thereby contributing to apoptosis. PERK-eIF2α-ATF4-CHOP and IRE1-ASK1-JNK/p38 signal pathway may be involved in those regulation. Our results make it a promising alternative or adjunct therapeutic candidate for CRC.

Calenduloside E ameliorates non-alcoholic fatty liver disease via modulating a pyroptosis-dependent pathway.

Ethnopharmacological relevanceNon-alcoholic fatty liver disease (NAFLD) is a prevalent chronic liver condition that can have multiple underlying causes. There are no satisfactory chemical or biological drugs for the treatment of NAFLD. Longyasongmu, the bark and root of Aralia elata (Miq.) Seem, is used extensively in traditional Chinese medicine (TCM) and has been used in treating diverse liver diseases including NAFLD. Based on Aralia elata (Miq.) Seem as the main ingredient, Longya Gantai Capsules have been approved for use in China for the treatment of acute hepatitis and chronic hepatitis. Calenduloside E (CE), a natural pentacyclic triterpenoid saponin, is a significant component of saponin isolated from the bark and root of Aralia elata (Miq.) Seem. However, the role and mechanism of anti-NAFLD effects of CE is still unclear. Aim of the studyThe objective of this study was to examine the potential mechanisms underlying the protective effect of CE on NAFLD. Materials and methodsIn this study, an NAFLD model was established by Western diet in apoE−/− mice, followed by treatment with various doses of CE (5 mg/kg, 10 mg/kg). The anti-NAFLD effect of CE was assessed by the liver injury, lipid accumulation, inflammation, and pro-fibrotic phenotype. The mechanism of CE in ameliorating NAFLD was studied through transcriptome sequencing (RNA-seq). In vitro, the mouse hepatocytes (AML-12) were stimulated in lipid mixtures with CE and performed the exploration and validation of the relevant pathways using Western blot, immunofluorescence, etc. ResultsThe findings revealed a significant improvement in liver injury, lipid accumulation, inflammation, and pro-fibrotic phenotype upon CE administration. Furthermore, RNAseq analysis indicated that the primary pathway through which CE alleviates NAFLD involves pyroptosis-related inflammatory cascade pathways. Furthermore, it was observed that CE effectively suppressed inflammasome-mediated pyroptosis both in vivo and in vitro. Remarkably, the functional enrichment analysis of RNA-seq data revealed that the PI3K-Akt signaling pathway is the primarily Signaling transduction pathway modulated by CE treatment. Subsequent experimental outcomes provided further validation of CE's ability to hinder inflammasome-mediated pyroptosis through the inhibition of PI3K/AKT/NF-κB signaling pathway. ConclusionsThese findings present a novel pharmacological role of CE in exerting anti-NAFLD effects by inhibiting pyroptosis signaling pathways.

Pharmacokinetic and metabolite profile of orally administered anemoside B4 in rats with an improved exposure in formulations of rectal suppository

Ethnopharmacological relevancePulsatilla chinensis (Bunge) Regel is a traditional Chinese herbal medicine used to treat intestinal amebiasis, malaria, vaginal trichomoniasis, and bacterial infections. Anemoside B4 (AB4), a pentacyclic triterpenoid saponin, is one of the primary bioactive substances in Pulsatilla chinensis (Bunge) Regel, and gavage administration of AB4 to animals has been demonstrated to exhibit anticancer, anti-inflammatory, and antiviral actions. However, AB4 exposure in plasma is very low after oral administration, and the biotransformation of AB4 in vivo after oral administration remains unknown. Aim of the studyThe reason for conducting this research was to explore at the metabolite profile of AB4 in rats following oral administration. Additionally, we aimed to develop an appropriate extravascular formulation to increase the exposure and duration of AB4 in vivo. Materials and methodsA well-validated HPLC-QQQ-MS/MS method was used for the quantification of AB4 in plasma and was further applied to evaluate and compare the pharmacokinetic properties of AB4 dissolved in a saline solution and AB4 formulations in a rectal suppository or enteric capsule. Reliable UHPLC coupled to Q-Exactive Plus high-resolution MS was used to identify the metabolites in rat plasma, bile, urine, and faeces. ResultsAB4 was extensively metabolized, and a total of 29 metabolites were identified. The primary metabolic routes included deglycosylation, oxidation, dehydrogenation, reduction, sulfation, hydration, acetylation, and glucuronidation. The pharmacokinetic comparison showed that both the rectal suppository and enteric capsule increased the exposures of AB4 and one of its active metabolites, 23-hydroxybetulinic acid (23-HA). Notably, rectal suppositories increased systemic AB4 exposure (AUC0-∞) by approximately 49 and 28 times higher than that of the AB4 saline solution and enteric capsules, respectively. The t1/2 of AB4 was extended to approximately 7 h after rectal administration compared to 2 h after oral administration. ConclusionOverall, our study demonstrated that the mismatched exposure-response relationship of AB4 could result from extensive metabolism in the gastrointestinal and circulatory systems. Thus, a rectal suppository could be an alternative formulation of AB4 to obtain both higher and longer exposure.

Expression of PnSS Promotes Squalene and Oleanolic Acid (OA) Accumulation in Aralia elata via Methyl Jasmonate (MeJA) Induction.

Aralia elata is an important herb due to the abundance of pentacyclic triterpenoid saponins whose important precursors are squalene and OA. Here, we found that MeJA treatment promoted both precursors accumulation, especially the latter, in transgenic A. elata, overexpressing a squalene synthase gene from Panax notoginseng(PnSS). In this study, Rhizobium-mediated transformation was used to express the PnSS gene. Gene expression analysis and high-performance liquid chromatography (HPLC) were used to identify the effect of MeJA on squalene and OA accumulation. The PnSS gene was isolated and expressed in A. elata. Transgenic lines showed a very high expression of the PnSS gene and farnesyl diphosphate synthase gene (AeFPS) and a slightly higher squalene content than the wild-type, but endogenous squalene synthase (AeSS), squalene epoxidase (AeSE), and β-amyrin synthase (Aeβ-AS) gene were decreased as well as OA content. Following one day of MeJA treatment, the expression levels of PeSS, AeSS, and AeSE genes increased significantly. On day 3, the maximum content of both products reached 17.34 and 0.70 mg·g-1, which increased 1.39- and 4.90-fold than in the same lines without treatment. Transgenic lines expressing PnSS gene had a limited capability to promote squalene and OA accumulation. MeJA strongly activated their biosynthesis pathways, leading to enhance yield.

α-Hederin Saponin Augments the Chemopreventive Effect of Cisplatin against Ehrlich Tumors and Bioinformatic Approach Identifying the Role of SDF1/CXCR4/p-AKT-1/NFκB Signaling.

Stromal cell-derived factor-1 (SDF1) and its C-X-C chemokine receptor type 4 receptor (CXCR4) are significant mediators for cancer cells' proliferation, and we studied their expression in Ehrlich solid tumors (ESTs) grown in mice. α-Hederin is a pentacyclic triterpenoid saponin found in Hedera or Nigella species with biological activity that involves suppression of growth of breast cancer cell lines. The aim of this study was to explore the chemopreventive activity of α-hederin with/without cisplatin; this was achieved by measuring the reduction in tumor masses and the downregulation in SDF1/CXCR4/pAKT signaling proteins and nuclear factor kappa B (NFκB). Ehrlich carcinoma cells were injected in four groups of Swiss albino female mice (Group1: EST control group, Group2: EST + α-hederin group, Group3: EST + cisplatin group, and Group4: EST+α-hederin/cisplatin treated group). Tumors were dissected and weighed, one EST was processed for histopathological staining with hematoxylin and eosin (HE), and the second MC was frozen and processed for estimation of signaling proteins. Computational analysis for these target proteins interactions showed direct-ordered interactions. The dissected solid tumors revealed decreases in tumor masses (~21%) and diminished viable tumor regions with significant necrotic surrounds, particularly with the combination regimens. Immunohistochemistry showed reductions (~50%) in intratumoral NFκβ in the mouse group that received the combination therapy. The combination treatment lowered the SDF1/CXCR4/p-AKT proteins in ESTs compared to the control. In conclusion, α-hederin augmented the chemotherapeutic potential of cisplatin against ESTs; this effect was at least partly mediated through suppressing the chemokine SDF1/CXCR4/p-AKT/NFκB signaling. Further studies are recommended to verify the chemotherapeutic potential of α-hederin in other breast cancer models.

Pentacyclic triterpenoids saponins pannosides A-E from Tripolium pannonicum

Five previously undescribed pentacyclic triterpenoid saponins, pannoside A–E (1–5), were discovered from the whole plant of seashore aster, Tripolium pannonicum, collected from the Songdo tidal flat, Incheon, Korea. The planar structures of pannosides were elucidated as pentacyclic triterpenoids bearing sugar moieties and 3-hydroxybutyrate (3-HB) based on the interpretation of the NMR, IR spectroscopic and MS data. The relative configurations of the aglycone and sugar moieties of 1–5 were determined based on careful analysis of ROESY correlations. To determine the absolute configuration of 3-hydroxybutyrate, we utilized the phenylglycine methyl ester (PGME) derivatization with LC-MS chromatographic analysis. Pannoside E (5) exhibited inhibitory activities against diverse cancer cell lines including prostate carcinoma and non-small cell lung carcinoma, with IC50 values of 0.34 and 0.89 μM, respectively. Pannosides are the first triterpenoid saponin isolated from T. pannonicum, implying that undiscovered secondary metabolites from a halophyte could be a good source of bioactive compounds.

α-hederin regulates glucose metabolism in intestinal epithelial cells by increasing SNX10 expression

BackgroundSorting nexin 10 (SNX10) has recently been identified as a critical regulator of colorectal carcinogenesis, whose deletion promoted cell proliferation and survival in human CRC cells, and promoted colorectal tumor growth and upregulated amino-acid metabolism in mice. However, what happens when silencing SNX10 in normal human intestinal epithelial cells (IECs) remains unknown, and no drugs targeting SNX10 have been reported. Here, we first investigated the biological function and underlying mechanisms of SNX10 in normal human IECs, and found that α-hederin, a pentacyclic triterpenoid saponin, has a regulatory effect on SNX10 expression. PurposeThis study aimed to explore the function of SNX10 in IECs to provide a new target for the prevention and treatment of malignant transformation and the intervention mechanism of α-hederin for further development of potential novel agents targeting SNX10. MethodsThe transfection approach was used to construct SNX10 stable knockdown cells. Cell proliferation was detected by CCK8, clone formation, EdU, flow cytometry, and wound healing assays. Enzyme activity assays for glucose metabolism, qRT-PCR, western blotting, and immunofluorescence staining were performed to investigate the protein expression of signaling pathways. ResultsSilencing SNX10 promoted cell proliferation and cycle transition in IECs and increased the activity of key enzymes involved in glucose metabolism. Moreover, DEPDC5 expression was significantly decreased following SNX10 knockdown, followed by activation of the mTORC1 pathway. α-hederin reversed the accelerated cell proliferation, cycle progression, and glucose metabolic activity, as well as the activated mTORC1 pathway caused by SNX10 knockdown, by notably increasing SNX10 expression in a dose-dependent manner. ConclusionWe first reported that knockdown of SNX10 in normal human IECs promoted cell proliferation and activated glucose metabolism by activating the mTORC1 pathway. Meanwhile, we first found that α-hederin down-regulated glucose metabolism activity and slowed cell proliferation by increasing SNX10 expression in IECs.

Natural products of pentacyclic triterpenoids: from discovery to heterologous biosynthesis.

Covering: up to 2022Pentacyclic triterpenoids are important natural bioactive substances that are widely present in plants and fungi. They have significant medicinal efficacy, play an important role in reducing blood glucose and protecting the liver, and have anti-inflammatory, anti-oxidation, anti-fatigue, anti-viral, and anti-cancer activities. Pentacyclic triterpenoids are derived from the isoprenoid biosynthetic pathway, which generates common precursors of triterpenes and steroids, followed by cyclization with oxidosqualene cyclases (OSCs) and decoration via cytochrome P450 monooxygenases (CYP450s) and glycosyltransferases (GTs). Many biosynthetic pathways of triterpenoid saponins have been elucidated by studying their metabolic regulation network through the use of multiomics and identifying their functional genes. Unfortunately, natural resources of pentacyclic triterpenoids are limited due to their low content in plant tissues and the long growth cycle of plants. Based on the understanding of their biosynthetic pathway and transcriptional regulation, plant bioreactors and microbial cell factories are emerging as alternative means for the synthesis of desired triterpenoid saponins. The rapid development of synthetic biology, metabolic engineering, and fermentation technology has broadened channels for the accumulation of pentacyclic triterpenoid saponins. In this review, we summarize the classification, distribution, structural characteristics, and bioactivity of pentacyclic triterpenoids. We further discuss the biosynthetic pathways of pentacyclic triterpenoids and involved transcriptional regulation. Moreover, the recent progress and characteristics of heterologous biosynthesis in plants and microbial cell factories are discussed comparatively. Finally, we propose potential strategies to improve the accumulation of triterpenoid saponins, thereby providing a guide for their future biomanufacturing.

Hederagenin Suppresses Inflammation and Cartilage Degradation to Ameliorate the Progression of Osteoarthritis: An In vivo and In vitro Study.

Osteoarthritis (OA), a common degenerative joint disease, is characterized by the progressive degradation of articular cartilage and inflammation. Hederagenin (HE) is a pentacyclic triterpenoid saponin extracted from many herb plants. It has anti-inflammatory, anti-lipid peroxidative, anti-cancer, and neuroprotective activities. However, its effect on OA has not been investigated. Our study found that HE may be a potential anti-OA drug. In vitro, HE could suppress extracellular matrix (ECM) degradation via up-regulating aggrecan and Collagen II levels as well as downregulating MMPs and ADAMTS5 levels. It could also reduce proinflammatory and inflammatory cytokines or enzymes production, including TNF-α, IL-6, iNOS, COX-2, NO, and PGE2. Besides, HE markedly reduced IL-1β-induced C28/I2 cell apoptosis and ROS accumulation. Mechanistically, HE exerted chondroprotective and anti-inflammatory effects by partly inhibiting JAK2/STAT3/MAPK signalling pathway and the crosstalk of the two pathways. Also, HE exhibited anti-apoptotic and anti-oxidative effect via targeting Keap1-Nrf2/HO-1/ROS/Bax/Bcl-2 axis. In vivo, HE significantly reduced monosodium iodoacetate (MIA) induced cartilage destruction of rats with a lower OARSI score and inflammatory cytokine levels, further demonstrating its protective effects in OA progression. These results suggest that HE is a potential compound for the development of drugs to treat OA.

Dietary tea seed saponin combined with aerobic exercise attenuated lipid metabolism and oxidative stress in mice fed a high-fat diet (HFD).

Tea seed saponins (TSS) are oleanolane-type pentacyclic triterpenoid saponin mixtures with various pharmacological effects. We aimed to explore the effects of a total of 4 weeks intragastric administration of TSS (140 mg/kg·day) combined with aerobic exercise (AE) on lipid metabolism and its associated oxidative stress in HFD-induced obese mice and to investigate the possible molecular mechanisms. TSS + AE intervention significantly reduced body weight and the adiposity index (including subcutaneous, epididymal, perirenal, and abdominal adipose) in obese mice; improved dyslipidemia by lowering serum TC, TG, and LDL-c levels; and increased HDL-c levels. TSS + AE intervention significantly improved hepatic steatosis by inhibiting lipogenetic Acc, Srebp1c, and Scd1 and upregulating lipolysis genes (Pgc1α, Pgc1β, Pparα, and Cpt1). TSS + AE intervention increased the hepatic protein expression of p-AMPK, SIRT1, and PGC-1α, as well as PPAR-γ and GLUT-4 in skeletal muscle compared with expression in the HFD group. In addition, TSS + AE also modulated oxidative stress in obese mice, which was indicated by the increased serum and liver levels of SOD, GSH, and T-AOC and decreased ROS and MDA levels. These results suggest that TSS + AE intervention can reduce fat accumulation and improve HFD-induced lipid metabolism disorders and oxidative stress. PRACTICAL APPLICATIONS: Obesity is a metabolic disease induced by excess nutritional intake and insufficient energy expenditure. Dietary modifications combined with aerobic exercise are currently an effective method for weight loss. Tea seed saponins (TSS) are a variety of biologically active oleanolane-type pentacyclic triterpenoid saponins that naturally exist in tea seeds. Few articles have focused on the effects and mechanisms of TSS combined with aerobic exercise (AE) in regulating lipid metabolism and improving oxidative damage in vivo. Using an HFD-induced obese mice model to explore the mechanism of TSS + AE in regulating lipid metabolism and its associated oxidative stress damage will help provide reliable data for the application of dietary nutrition combined with AE in anti-obesity.

Hederagenin ameliorates cisplatin-induced acute kidney injury via inhibiting long non-coding RNA A330074k22Rik/Axin2/β-catenin signalling pathway

BackgroundAcute kidney injury (AKI), a kidney disease with high morbidity and mortality, is characterized by a dramatic decline in renal function. Hederagenin (HDG), a pentacyclic triterpenoid saponin isolated from astragalus membranaceus, has been shown to have significant anti-inflammatory effects on various diseases. However, the effects of HDG on renal injury and inflammation in AKI has not been elucidated. MethodsIn this research, mice model of AKI was established by intraperitoneal injection of cisplatin in vivo, the inflammatory model of renal tubular epithelial cells was established by LPS stimulation in vitro, and HDG was used to intervene in vitro and in vivo models. Transcriptome sequencing was used to analyze the alterations of LncRNA and mRNA expression in AKI model and LncRNA-A330074k22Rik (A33) knockdown cells, respectively. Renal in situ electrotransfer knockdown plasmid was used to establish mice model of AKI with low expression of A33 in kidney. ResultsThe results showed that HDG effectively alleviate cisplatin-induced kidney injury and inflammation in mice. Transcriptome sequencing results showed that multiple LncRNAs in kidney of AKI model exhibited significant changes, among which LncRNA-A33 had the most obvious change trend. Subsequent results showed that A33 was highly expressed in kidney of AKI mice and LPS-induced renal tubular cells. After in situ renal electroporation knockdown plasmid down-regulated A33 in kidney of AKI mice, it was found that inhibition of A33 could significantly relieve cisplatin-induced kidney injury and inflammation of AKI, while HDG could effectively suppress the expression of A33 in vitro and in vivo, respectively. Subsequently, transcriptome sequencing was again used to analyze the changes in mRNA expression of renal tubular cells after A33 knockdown by siRNA. The results showed that a large number of inflammation-related signaling pathways were down-regulated, Axin2 and its downstream β-catenin signal were significantly inhibited. Cell recovery test showed that HDG inhibited Axin2/β-catenin signal by down-regulating A33, and improved kidney injury and inflammation of AKI. ConclusionTaken together, HDG significantly ameliorated cisplatin-induced kidney injury through LncRNA-A330074k22Rik/Axin2/β-catenin signal axis, which providing a potential therapeutic approach for the treatment of AKI.

The chromosome-level holly (Ilex latifolia) genome reveals key enzymes in triterpenoid saponin biosynthesis and fruit color change.

The Ilex L. (hollies) genus of Aquifoliaceae shows high species diversity in tropical and subtropical regions of Asia and South America. Throughout the range of the genus, Ilex species have been widely used in beverage and medicine production and as ornamentals. Here, we assembled a high-quality, chromosome-level genome of Ilex latifolia, which has extremely high economic value because of its useful secondary metabolite production and the high ornamental value of its decorative red berries. The 99.8% genome sequence was anchored to 20 pseudochromosomes, with a total length of 766.02 Mb and a scaffold N50 of 33.45 Mb. Based on the comparative genomic analysis of 14 angiosperm species, we recovered I. latifolia as the sister group to all other campanulids. Two whole-genome duplication (WGD) events were identified in hollies: one shared ancient WGD in the ancestor of all eudicots and a recent and independent WGD in hollies. We performed a genome-wide search to screen candidate genes involved in the biosynthesis of pentacyclic triterpenoid saponins in I. latifolia. Three subfamilies of CYP450 (CYP71A, CYP72A, and CYP716A) appear to have expanded. The transcriptomic analysis of I. latifolia leaves at five developmental stages revealed that two CYP716A genes and one CYP72A gene probably play important roles in this biosynthetic pathway. In addition, we totally identified 12 genes in the biosynthesis pathways of pelargonidin and cyanidin and observed their differential expression in green and red fruit pericarps, suggesting an association between pelargonidin and cyanidin biosynthesis and fruit pericarp color change. The accumulation of pelargonidin and cyanidin is expected to play an important role in the ornamental value of I. latifolia. Altogether, this study elucidated the molecular basis of the medicinal and ornamental value of I. latifolia, providing a data basis and promising clues for further applications.