Two new ionone glycosides from the roots ofRehmannia glutinosaLibosch

Apocarotenoids from the fresh roots of Rehmannia glutinosa and their anti-pulmonary fibrosis activity

Six undescribed compounds (1-6) and twenty-three known analogues (7-29) were isolated from the fresh roots of Rehmannia glutinosa. The structures of the compounds (1-29) were established through the application of spectroscopic analysis. Compounds 3, 4, 6, 8, 13, 18, 21, 22, 25, and 28 exhibited excellent anti-pulmonary fibrosis activity. The potential mechanistic pathway of 3 was also investigated, whose results indicate that compound 3 ameliorate TGF-β1 induced BEAS-2B cell injury via PI3K/AKT/NF-κB signaling pathway.

Compounds from Rehmannia glutinosa and the activity to suppress α-glucosidase

Rehmannia glutinosa was extensively used to control blood sugar in diabetes treatment in tradition Chinese medicine. In the present study, three new compounds, including an iridoid rehmannia A (1) and two ionone rehmannias B-C (7-8), together with fourteen known compounds (2-6 and 9-17), were isolated from the roots of R. glutinosa. The structures of these compounds were determined by physicochemical constants and spectral analysis (1D, 2D-NMR and MS). The effect of 1-17 on α-glucosidase activity was tested in vitro. Compounds 9, 10, and 11 (IC50: 5.0, 3.1, and 6.3 mM) showed moderate activity to suppress α-glucosidase relative to acarbose (IC50 = 3.0 mM). The findings provided some new insights to understand the hypoglycemic effect of R. glutinosa and the development towards the α-glucosidase inhibitor drugs.

Yunvjian decoction attenuates lipopolysaccharide-induced periodontitis by suppressing NFκB/NLRP3/IL-1β pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Yunvjian decoction (YNJ) is a traditional Chinese herbal prescription that has been used in the clinical treatment of periodontitis. However, the underlying molecular mechanism of YNJ in the periodontitis treatment is not well understood.

AIM OF THE STUDY

The purpose of this study was to evaluate the therapeutic effects of YNJ against periodontitis and its underlying molecular mechanisms.

MATERIALS AND METHODS

Orthodontic ligation and lipopolysaccharide (LPS)-induced periodontitis rat model was established. YNJ groups were gavaged with YNJ decoction (5 g/kg/d or 10 g/kg/d) for four months. The rats in positive control group were gavaged with metronidazole (MDZ, 100 mg/kg/d) for four months. The maxilla was scanned by micro-computed tomography. The chemical compositions of YNJ were identified using ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry. The molecular mechanism of YNJ were predicted using network pharmacological analysis and validated using immune-staining and Western blot.

RESULTS

YNJ treatment decreased the distance between cementoenamel junction and alveolar bone crest on the sagittal slide of the periodontitis rats. Western blot showed YNJ downregulated the protein levels of the bone resorption marker (receptor activator of nuclear factor-κB ligand), while upregulated the levels of the bone formation markers (bone morphogenetic protein 2, runt-related transcription factor 2, alkaline phosphatase, and osteoprotegerin) in alveolar bone of the periodontitis rats. Hematoxylin and eosin, immunohistochemical staining, and Western blot analysis indicated that YNJ attenuated the inflammation and decreased the levels of interleukin-6 and tumor necrosis factor-α in the alveolar bone. In addition, a total of 61 compounds were identified from YNJ. Network pharmacology indicated that the nucleotide binding oligomerization domain-like receptor signaling pathway was the main pathway for YNJ in the treatment of periodontitis. The experiments confirmed that YNJ administration inhibited LPS induced-pyroptosis in alveolar bone through suppressing the phosphorylation of nuclear factor κB, reduced expression of NOD-like receptor family pyrin domain containing 3, and Caspase-1, subsequently suppressing the interleukin-1β secretion.

CONCLUSION

YNJ is an effective therapeutic strategy for periodontitis and acts by inhibiting pyroptosis and NFκB/NLRP3/IL-1β pathway in alveolar bone.

Effects and mechanisms of frehmaglutin D and rehmaionoside C improve LPS-induced acute kidney injury through the estrogen receptor-mediated TLR4 pathway in vivo and in vitro

BACKGROUND

Sepsis-induced acute kidney injury (S-AKI) is an inflammatory disease with sex differences and there has no effective drugs to cure it. Frehmaglutin D (Fre D) and rehmaionoside C (Reh C) are two violetone compounds with estrogenic activity isolated from Rehmannia glutinosa. However, whether these two drugs exert protective effects on S-AKI through their estrogen-like activity are unclear.

PURPOSE

This study aimed to explore the effects and mechanisms of Fre D and Reh C on lipopolysaccharide (LPS)-induced S-AKI through the estrogen receptor pathway in vivo and in vitro and to explore the interaction between ER and TLR4 for the first time.

METHODS

The LPS-induced female BALB/c mice S-AKI mouse model was established by adding the estrogen receptor antagonist ICI182,780. Renal function, inflammation, oxidative stress, apoptosis, immune cells, and expression of key proteins of the ER-TLR4-IL-1β pathway were tested. The affinity of Fre D and Reh C for the ER was investigated by molecular docking. Then, an in vitro S-AKI model was established, and ERα/ERβ antagonists (MPP/PHTPP) were added and combined with gene overexpression techniques. The interaction between ER and TLR4 was further explored by Co-IP, GST pull-down and SPR techniques.

RESULTS

Fre D and Reh C ameliorated LPS-induced renal damage, inflammation in mice, regulated the immune cells, decreased ROS levels, increased ERα and ERβ protein expression, and decreased TLR4, caspase 11 and IL-1β protein expression. These effects were blocked by ICI182,780. Molecular docking results showed that Fre D and Reh C bound ERα and ERβ with similar potency. The results of in vitro suggested that Fre D and Reh C reduced the levels of inflammation, ROS and apoptosis, TLR4, caspase 11, and IL-1β protein expression and increased ERα/ERβ protein expression in cells. All of these effects were reversed by the addition of MPP/PHTPP and further enhanced after ERα/ERβ gene overexpression with no significant difference in effects. Moreover, there was an indirect or direct interaction between ER and TLR4, and the binding of ERα and ERβ to TLR4 was concentration dependent.

CONCLUSION

Fre D and Reh C may improve S-AKI through the ER-TLR4-IL-1β pathway and may act on both ERα and ERβ receptors. Moreover, ERα and ERβ may interact directly or indirectly with TLR4, which was studied for the first time.

Tetraenone A: A New β-Ionone Derivative from Tetraena aegyptia

In this study, the chemical investigation of Tetraena aegyptia (Zygophyllaceae) led to the identification of a new megastigmene derivative, tetraenone A ((2S, 5R, 6R, 7E)-2-hydroxy-5,6-dihydro-β-ionone) (1), along with (3S, 5R, 6S, 7E)-3-hydroxy-5,6-epoxy-5,6-dihydro-β-ionone- (2), 3,4-dihydroxy-cinnamyl alcohol-4-glucoside (3), 3β,19α-dihydroxy-ursan-28-oic acid (4), quinovic acid (5), p-coumaric acid (6), and ferulic acid (7), for the first time. The chemical structures of 1-7 were confirmed by analysis of their 1D and 2D NMR and HRESIMS spectra and by their comparison with the relevant literature. The absolute configurations of 1 and 2 were assigned based on NOESY interactions and ECD spectra. Conformational analysis showed that 1 existed exclusively in one of the two theoretically possible chair conformers with a predominant s-trans configuration for the 3-oxobut-1-en-1-yl group with the ring, while the half-chair conformer had a pseudo-axial hydroxy group that was predominant over the other half-chair conformation. Boat conformations were not among the most stable conformations, and the s-trans isomerism was in favor of s-cis configuration. In silico investigation revealed that 1 and 2 had more favorable binding interactions with Mpro rather than with TMPRSS2. Accordingly, molecular dynamic simulations were performed on the complexes of compounds 1 and 2 with Mpro to explore the stability of their interaction with the target protein structure. Compounds 1 and 2 might offer a possible starting point for developing covalent inhibitors of Mpro of SARS-CoV-2.

Centrantheroside F, a new ionone glycoside from Centranthera grandiflora

One new ionone glycoside, named centrantheroside F (1), together with 9 known compounds (2-10), were isolated from the roots of Centranthera grandiflora. Their structures were determined by spectroscopic data analyses and comparing with the literature data. The absolute configuration of 1 was confirmed via 2 D NMR and electronic circular dichroism (ECD). All isolated compounds were evaluated for their inhibitory activity on lipopolysaccharide (LPS)-induced nitric oxide (NO) production.

A systematic review on botany, processing, application, phytochemistry and pharmacological action of Radix Rehmnniae

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Rehmanniae (RR) is the tuber root of Rehmannia glutionsa Libosch, which was firstly recorded in Shennong's Classic of Materia Medica (⟪⟫). RR is a non-toxic and wide used traditional Chinese medicine. RR has the effect of clearing heat, generating essence, cooling blood, stopping bleeding, nourishing yin and blood, and filling marrow. It is used in clinic in the form of processed decoction pieces, including Dry Radix Rehmnniae (DRR) and Rehmanniae Radix Praeparata (RRP). The application of RR in traditional Chinese medicine (TCM) prescriptions can treat various diseases, such as anemia, irregular menstruation, deficiency of liver yin, renal failure and so on.

AIM OF REVIEW

This paper aims to provide a comprehensive and productive review of RR, which mainly contains botanical characteristics, processing methods, traditional application, chemical composition, quality control and pharmacological action.

MATERIALS AND METHODS

Literature search was conducted through the Web of Science, Baidu Scholar, ScienceDirect, PubMed, CNKI, and WanFang DATA using the keywords "Radix Rehmnniae", "Rehmanniae Radix Praeparata", "processing", "clinical application", "chemical composition", "quality control", and "pharmacological action". In addition, information was collected from relevant textbooks, reviews, and documents.

RESULTS

RR is a traditional Chinese herbal medicine with clinical value and rich resources. More than 100 components have been isolated and identified from RR. It has multiple pharmacological actions, such as hemostasis, antioxidation, anti-osteoporosis, lowering blood sugar, improving renal function, anti-inflammation, protecting neuronal function, antidepression and anti-anxiety. DRR and RRP are two different processed products of RR. After processing, there are great changes in property, taste, efficacy, clinical application, chemical composition and pharmacological action. At present, identifying chemical constituents of RR and its medicinal value has been deeply studied. However, there is a lack of research on the reasons for the differences in pharmacological effects between DRR and RRP. The reasons for these differences need to be further verified. Catalpol, the active component of RR, has been studied extensively in the literature, but the pharmacological effects of catalpol cannot represent the pharmacological effects of the whole RR. In the future, effective components such as rehmannioside D, polysaccharide, total glycosides, and effective parts in RR need to be further studied and developed. The pharmacodynamic material basis and mechanism of RR need to be further discussed. The scientific connotation and processing methods of RRP need to be studied and standardized.

Three New 2,2'-Difurylketone Derivatives and Two New Chromones from the Rehmanniae Radix Praeparata

Rehmanniae Radix Praeparata is the processed products of the root of Rehmannia glutinosa. It has been used as a Traditional Chinese Medicine for thousands of years, and it has been found to possess widely pharmacological activities. In this study, three new 2,2'-difurylketone derivatives (rehmanniaeketone A-C) and two new chromones [3,8-dihydroxy-2-(2-hydroxyethyl)chromone and 3,8-dihydroxy-2-[(2-O-α-D-galactopyranosyloxy)ethyl]chromone] were isolated from the Rehmanniae Radix Praeparata. Furthermore all of the compounds were subjected to cytotoxic testing against the human lung carcinoma A549 cells. The cytotoxic results showed that rehmanniaeketone B and rehmanniaeketone C exhibited more stronger inhibition effects on the cell activity of A549 cells with the IC₅₀ 5.23 μM and 2.05 μM than other compounds. And 3,8-dihydroxy-2-(2-hydroxyethyl)chromone exhibited moderately inhibitory activity with the IC₅₀ 61 μM. Rehmanniaeketone A and 3,8-dihydroxy-2-[(2-O-α-D-galactopyranosyloxy]chromone showed no inhibitory effects.

Isolation of endophytic bacteria from Rehmannia glutinosa Libosch and their potential to promote plant growth

In order to study the growth promoting potential of endophytic bacteria from Rehmannia glutinosa Libosch, a total of 25 different bacteria belonging to 7 genera were identified by 16S rRNA gene sequencing, including Bacillus, Micrococcus, Lysinibacillus, Brevibacterium, Halomonas, Kocuria and Terribacillus. In this study, thirteen bacterial strains were found to solubilize inorganic phosphate, with the isolate Kocuria rosea (EH15) having the highest phosphorus dissolution activity (3.70 μg/mL). Twelve isolates were positive for nitrogen fixation abilities. Twenty-two strains produced indole-3-acetic acid (IAA) in the presence of L-tryptophan, and eleven of the twenty-two isolates synthesized IAA in the absence of L-tryptophan. The strain K. rosea (EH15) was capable of producing the highest IAA amount (15.36 and 7.98 mg/L) in Luria Bertani (LB) broth containing 0.2% L-tryptophan and lacking L-tryptophan, respectively. Ten isolates had siderophore production abilities with Bacillus amyloliquefacieus EH10 (0.26) and Brevibacterium frigoritolerans EH13 (0.32) showing high siderophore production characteristics. Five bacteria endogenous were selected to evaluate the growth parameters of Brassica napus L. and all isolates exhibited a significantly greater increase in seedling height, root length, fresh weight and dry weight, than the control plants. The greatest improvement appeared in the case of co-inoculation of EH10 and EH15, except in dry weight, and the biggest enhancement in dry weight occurred in the strain EH15. In general, these endophytic bacteria indicate a potential as microbial fertilizers to promote the growth of R. glutinosa Libosch.

Rehmapicroside ameliorates cerebral ischemia-reperfusion injury via attenuating peroxynitrite-mediated mitophagy activation

Peroxynitrite (ONOO^-)-mediated mitophagy activation represents a vital pathogenic mechanism in ischemic stroke. Our previous study suggests that ONOO^- mediates Drp1 recruitment to the damaged mitochondria for excessive mitophagy, aggravating cerebral ischemia/reperfusion injury and the ONOO^--mediated mitophagy activation could be a crucial therapeutic target for improving outcome of ischemic stroke. In the present study, we tested the neuroprotective effects of rehmapicroside, a natural compound from a medicinal plant, on inhibiting ONOO^--mediated mitophagy activation, attenuating infarct size and improving neurological functions by using the in vitro cultured PC12 cells exposed to oxygen glucose deprivation with reoxygenation (OGD/RO) condition and the in vivo rat model of middle cerebral artery occlusion (MCAO) for 2 h of transient cerebral ischemia plus 22 h of reperfusion. The major discoveries include following aspects: (1) Rehmapicroside reacted with ONOO^- directly to scavenge ONOO^-; (2) Rehmapicroside decreased O₂^- and ONOO^-, up-regulated Bcl-2 but down-regulated Bax, Caspase-3 and cleaved Caspase-3, and down-regulated PINK1, Parkin, p62 and the ratio of LC3-II to LC3-I in the OGD/RO-treated PC12 cells; (3) Rehmapicroside suppressed 3-nitrotyrosine formation, Drp1 nitration as well as NADPH oxidases and iNOS expression in the ischemia-reperfused rat brains; (4) Rehmapicroside prevented the translocations of PINK1, Parkin and Drp1 into the mitochondria for mitophagy activation in the ischemia-reperfused rat brains; (5) Rehmapicroside ameliorated infarct sizes and improved neurological deficit scores in the rats with transient MCAO cerebral ischemia. Taken together, rehmapicroside could be a potential drug candidate against cerebral ischemia-reperfusion injury, and its neuroprotective mechanisms could be attributed to inhibiting the ONOO^--mediated mitophagy activation.

"Quantity-effect" research strategy for comparison of antioxidant activity and quality of Rehmanniae Radix and Rehmannia Radix Praeparata by on-line HPLC-UV-ABTS assay

Background

Quantitation analysis and chromatographic fingerprint of multi-components are frequently used to evaluate quality of herbal medicines but fail to reveal activity of the components. It is necessary to develop a rational approach of chromatography coupled with activity detection for quality assessment of herbal medicines.

Methods

An on-line HPLC-ultraviolet detection-2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging (HPLC-UV-ABTS) method was developed to obtain the chromatographic fingerprints and ABTS^+• inhibition profiles (active fingerprints) of Rehmanniae Radix (Dihuang) and Rehmannia Radix Praeparata (Shu Dihuang). Eighteen compounds showing ABTS^+• inhibition activity were identified by HPLC-fourier-transform mass spectrometry (HPLC-FTMS). Verbascoside was used as a positive control to evaluate the total activities of the samples and the contribution rate of each compound. The similarities of the chromatographic and active fingerprints were estimated by the vectorial angle cosine method.

Results

The results showed that the HPLC-UV-ABTS method could efficiently detect antioxidant activity of the herbal medicine samples. The antioxidants were different between the two herbs and several new antioxidants were identified in Shu Dihuang. A function equation was generated in terms of the negative peak area (x) and the concentrations of verbascoside (y, μg/mL), y = 2E-07 × ⁴ - 8E-05 × ³ + 0.0079 × ² + 0.5755x + 1.4754, R² = 1. Iridoid glycosides were identified as main antioxidants and showed their higher contributions to the total activity of the samples. The total contributions of the three main active components in the Dihuang and Shu Dihuang samples to the total activity, such as echinacoside, verbascoside and an unknown compound, were 39.2–58.1% and 55.9–69.4%, respectively. The potencies of the main active components in the Shu Dihuang samples were two to ten times those in the Dihuang samples. Similarity values for S12 in the chromatographic fingerprints and S03, S12 and P03 in the active fingerprints were less than 0.9. The three batches of samples might show their different quality with the other samples.

Conclusions

The results suggested that the combination of “quantity-effect” research strategy and the HPLC-UV-ABTS analysis method could comprehensively evaluate the active components and quality of Dihuang and Shu Dhuang.

Metabolite accumulation and metabolic network in developing roots of Rehmannia glutinosa reveals its root developmental mechanism and quality

Rehmannia glutinosa root contains many compounds with important medicinal properties and nutritional benefits, but only more than 140 compounds have been reported so far. Many other compounds and their accumulation and metabolic networks during its development remain unclear. In order to clarify them, its metabolic profiles at three different developmental stages were analyzed using untargeted LC-MS analysis. Multivariate analysis revealed that 434 metabolites differently accumulated in its different stages, suggesting different change trends. The metabolites having the same trend share common metabolic pathways, the metabolites showing increasing contents during its development have medical and nutritional values, and some mature root-specific metabolites may be better candidates for its quality control; 434 metabolites were mapped onto 111 KEGG pathways including 62 enzymes, whose increasing and decreasing patterns were shown during its development. Some metabolites complicatedly interacted with some enzymes and the top-10 pathways enriched from 111 KEGG pathways in network analysis. These findings extended the dataset of its identified compounds, and revealed that its development and quality were associated with the accumulation of different metabolites. Our work will lay the foundation for the better understanding of its chemical constituents, quality and developmental mechanism.

A Review on the Effect of Traditional Chinese Medicine Against Anthracycline-Induced Cardiac Toxicity

Anthracyclines are effective agents generally used to treat solid-tumor and hematologic malignancies. The use of anthracyclines for over 40 years has improved cancer survival statistics. Nevertheless, the clinical utility of anthracyclines is limited by its dose-dependent cardiotoxicity that adversely affects 10-30% of patients. Anthracycline-induced cardiotoxicity may be classified as acute/subacute or chronic/late toxicity and leads to devastating adverse effects resulting in poor quality of life, morbidity, and premature mortality. Traditional Chinese medicine has a history of over 2,000 years, involving both unique theories and substantial experience. Several studies have investigated the potential of natural products to decrease the cardiotoxic effects of chemotherapeutic agents on healthy cells, without negatively affecting their antineoplastic activity. This article discusses the mechanism of anthracycline-induced cardiotoxicity, and summarizes traditional Chinese medicine treatment for anthracycline-induced heart failure (HF), cardiac arrhythmia, cardiomyopathy, and myocardial ischemia in recent years, in order to provide a reference for the clinical prevention and treatment of cardiac toxicity.

Chemical characterization and evaluation of the antioxidants in Chaenomeles fruits by an improved HPLC-TOF/MS coupled to an on-line DPPH-HPLC method

An improved method based on HPLC-TOF/MS was developed to catalog the antioxidants in five species of Chaenomeles (Mugua). Forty-four fractions from the Mugua extracts show appreciable levels of antioxidative activity in scavenging the stable free-radical 2,2-diphenyl-1-picrylhydrazyl and the hydroxyl radicals. Twelve major antioxidant's chemical structures are identified. Antioxidant activities differ between species, but intra-species level of antioxidants, regardless of their ripeness, are similar. C. sinensis has the highest antioxidant level. A rigorous quality control procedure was implemented to ensure accuracy of antioxidant quantification. This improved procedure can be used for rapid discovery of antioxidants in other plant extracts.

A New Ionone Glycoside and Three New Rhemaneolignans from the Roots of Rehmannia glutinosa

A new ionone glycoside, frehmaglutoside I (1), and three new rhemaneolignans A-C (2-4) were isolated from the 95% EtOH extract of the roots of Rehmannia glutinosa. Their structures were determined by extensive spectroscopic (UV, IR, HR-ESI-MS, 1D and 2D NMR) analyses. In addition, these compounds were evaluated for their protective effects on cardiocytes impaired by doxorubicin in H9c2 cells. Among them, compounds 1-3 exhibited protective effects against DOX-induced cardiotoxicity.