New diterpenoids with estrogen sulfotransferase inhibitory activity from Leonurus sibiricus L

The complete chloroplast genome of Leonurus sibiricus Linnaeus (Labiatae, Leonurus Miller)

Leonurus sibiricus Linnaeus 1753, an annual or biennial herb found in northern China, Mongolia, and Russia, typically grows in stony, sandy grasslands, and pine forests. This study sequenced and reported the complete chloroplast genome of L. sibiricus for the first time. The entire circular genome measures 151,689 bp in length, with a GC content of 38.4%. A total of 133 genes were annotated, including 88 protein-coding genes, 37 tRNAs, and eight rRNAs. The genome exhibits a typical quadripartite structure, comprising a large single-copy (LSC 82,820 bp) region, a small single-copy (SSC 17,619 bp) region, and a pair of inverted repeat (IR 25,625 bp each) regions. Phylogenetic analysis using the maximum-likelihood method indicates that L. sibiricus is most closely related to L. japonicus Houttuyn. This study provides valuable genomic resources for further research on the phylogenetics and biodiversity of the genus Leonurus.

Labdane and ent-halimane diterpenoids with STAT3-inhibitory activity from Leonurus sibiricus

Nine undescribed labdane diterpenoids (1-9) and one undescribed ent-halimane diterpenoid (10) were isolated from the aerial parts of Leonurus sibiricus, together with four known analogues (11-14) during our searching for naturally occurring antitumor agents. Their structures were established by detailed spectroscopic analyses and electronic circular dichroism analysis. Compound 4 possessed a rare 10-epi labdane scaffold. All compounds except 5 were evaluated for their inhibitory activities against interleukin (IL)-6-stimulated signal transducer and activator of transcription (STAT3) expression using a luciferase reporter assay. Compound 1 showed the most inhibitory effect with the IC50 value 20.31 μM. Compound 1 inhibited the activation of JAK2/STAT3 signal pathway through binding to Gln326 of STAT3 in CNE cells. The antiproliferative evaluation of compound 1 against CNE, CAL-27, A549 and PANC-1 cells demonstrated that CNE cells were the most sensitive to 1. Furthermore, compound 1 showed moderate efficacy in inhibiting cell migration, invasion, and epithelial-mesenchymal transition in CNE cells. In addition, compound 1 also promoted ferroptosis in CNE cells in a dose-dependent manner. These results suggest that compound 1 might be a potential candidate lead for treating nasopharyngeal carcinoma.

New di-spirocyclic labdane diterpenoids from the aerial parts of Leonurus japonicus

Phytochemical investigation on the ethanol extract of a well-known medicinal herb Leonurus japonicus, led to the separation of 18 labdane type diterpenoids (1-18). Through comprehensive spectroscopic analyses and quantum chemical calculations, these compounds were structurally characterized as six new interesting 5,5,5-di-spirocyclic ones (1-6), two new (7 and 8) and six known (13-18) interesting 6,5,5-di-spirocyclic ones, a new rare 14,15-dinor derivative (9), and three new ones incorporating a γ-lactone unit (10-12). An in vitro neuroprotective assay in RSC96 cells revealed that compounds 7 and 12 exhibited neuroprotective activity in a concentration-dependent way, comparable to the reference drug N-acetylcysteine.

Anti-inflammatory labdane diterpenoids from the aerial parts of Leonurus japonicus

Twenty-two labdane-type diterpenoids, including ten pairs of 15-epimers and a pair of 13,15-epimers, were obtained from the aerial parts of a well-known medicinal plant Leonurus japonicus Houtt. While these epimers were separated by chiral HPLC, their structures were established mainly via spectroscopic methods especially NMR, X-ray crystallography and ECD techniques. Among them, seventeen compounds, encompassing three pairs of solvolysis artefacts likely due to the use of ethanol as extracting solvent, were reported for the first time in the current work. Our preliminary anti-inflammatory screening demonstrated that seven diterpenoids displayed noteworthy inhibitory effect on the NO production in LPS-induced RAW264.7 cells. In addition, the release of pro-inflammatory factors TNF-α, IL-1β and IL-6, as well as the expression of iNOS and COX-2 proteins, was also suppressed by the unreported 15,16-epoxy-6β-hydroxy-15α-methoxy-7,16-dioxolabd-8,13-diene. Further investigation into the preliminary anti-inflammatory mechanism of this compound indicated that it could block the activation of NF-κB signaling pathway.

Standardization of Leonurus sibiricus L. aerial part and capillary electrophoresis quantitative analysis of its leonurine content

The quality parameters of Leonurus sibiricus L. aerial part crude drugs were evaluated. Fifteen crude drugs were collected from various locations throughout Thailand. The transverse section of the stem of L. sibiricus showed quadrangular character highlighted the ribs with angular collenchyma. The epidermis was uniseriate with abundant glandular trichomes distribution. Prismatic calcium oxalate prisms were found in the stem medullary parenchyma.The histological character of crude drug powder showed bordered pitted vessel, fragment of fiber, glandular trichome, prism crystal, spiral vessel, starch granule, and stomata. The loss on drying, total ash, acid-insoluble ash, and moisture contents should be not more than 8.18, 15.28, 4.04, and 8.91 g/100 g dry weight, whereas ethanol and water-soluble extractive values should be not less than 7.67, and 17.21 g/100 g of dry weight, respectively. Leonurine in the crude drugs were analyzed by capillary electrophoresis (CE) with photodiode array detector. The ethanolic extraction performed by Soxhlet apparatus yielded 18.86 ± 4.09 g/100 g dry weight. The electropherogram detected at 277 nm showed the migration time of leonurine at 6.2 min. The developed CE was found to be valid for leonurine quantification in L. sibiricus ethanolic extract. The contents of leonurine in 15 crude drugs ranged from 0.79 to 4.23 mg/g with the average of 2.38 ± 1.10 mg/g dry weight. This study established the pharmacognostic specification of L. sibiricus crude drug in Thailand with special reference to a bioactive compound, leonurine. CE was beneficial technique for the analysis of leonurine in L. sibiricus aerial parts.

Therapeutic effects of traditional Thai herbal blood and wind tonic formulations for treatment of menopausal symptoms

INTRODUCTION

Traditional Thai herbal medicine formulations have been used as alternative therapies for menopausal symptoms due to concerns from adverse effects associated with hormone therapy. This study aimed to demonstrate the effects of traditional Thai herbal blood and wind tonic formulations used by a traditional Thai medicine doctor, Mr. Somporn Chanwanitsakul, in postmenopausal women.

MATERIALS AND METHODS

A pilot clinical study was conducted on thirty-five postmenopausal women, referring to Tambon Thung Tam Sao Health Promotion Hospital, Hat Yai, Songkhla, from October 2019 to March 2020. The participants consumed combined Thai herbal formulations including blood tonic and wind tonic thrice daily for four weeks. Outcomes were assessed at baseline, end of treatment (4 weeks), and follow-up (8 weeks). Pre- and post-treatment measures included menopause rating scale, sleep quality, and quality of life questionnaire. All data were analyzed using SPSS software at the significance level of 0.05.

RESULTS

Therapeutic effects of Thai herbal medicine formulations on menopausal symptoms intensity were assessed by modified Menopause Rating Scale (MRS). Severity of women's total menopausal symptoms decreased significantly (p < 0.05) at end of treatment and follow-up. Analysis of changes in specific symptoms indicated significantly less moderate headache, mild hot flashes, sweating, emotional instability, irritability, anxiety, sleep problem, lethargy, back pain, joint pain, muscular discomfort, dry skin, dryness of vagina, boring sex, and frequent urination (MRS score 0). In addition, subjective analysis of sleep quality using Pittsburgh Sleep Quality Index (PSQI) data revealed significant post-treatment improvements in subjective sleep quality and daytime dysfunction over the last month (PSQI score 0). Furthermore, subjective analysis of quality of life using World Health Organization Quality of Life Brief showed significant post-treatment improvement in psychological health (score 23).

CONCLUSION

The findings demonstrate that Thai herbal medicine formulations used by a traditional Thai medicine doctor, Mr. Somporn Chanwanitsakul, are effective for treating menopausal symptoms and improve sleep quality and quality of life in postmenopausal women.

seco-Labdanes: A Study of Terpenoid Structural Diversity Resulting from Biosynthetic C-C Bond Cleavage

The cleavage of a C-C bond is a complexity generating process, which complements oxidation and cyclisation events in the biosynthesis of terpenoids. This process leads to increased structural diversity in a cluster of related secondary metabolites by modification of the parent carbocyclic core. In this review, we highlight the diversifying effect of C-C bond cleavage by examining the literature related to seco-labdanes-a class of diterpenoids arising from such C-C bond cleavage events.

Isolation, reactivity, pharmacological activities and total synthesis of hispanolone and structurally related diterpenes from Labiatae plants

Hispanolone is a furolabdane diterpene isolated from Ballota hispanica, whose natural product chemistry has been summarized and updated here, including several aspects associated with the isolation, structure determination, hemisynthesis, total synthesis, and pharmacology, and related hispanolone diterpenoids that have attracted the interest of different laboratories from diverse perspective and expertise in the last forty-two years.

Uncovering the pharmacological mechanism of motherwort (Leonurus japonicus Houtt.) for treating menstrual disorders: A systems pharmacology approach

Leonurus japonicus (motherwort) is a traditional Chinese medicine that is widely used to treat menstrual disorders (MDs). However, the pharmacological mechanisms that underlie its clinical application remain unclear. In this study, a network pharmacology-based approach was used that integrated drug-likeness evaluation, oral bioavailability prediction, target exploration, network construction, bioinformatic annotation and molecular docking to investigate the mechanisms that underlie motherwort treatment for MDs. In total, 29 bioactive compounds were collected from 51 compounds in motherwort, which shared 17 common MDs-related targets. Network analysis indicated that motherwort played a therapeutic role in MDs treatment through multiple components that acted on multiple targets. Pathway enrichment analysis showed that the putative targets of motherwort were primarily involved in various pathways associated with the endocrine system, cancers, vascular system, and anti-inflammation process. Notably, five targets (i.e., AKT1, PTGS2, ESR1, AR and PPARG) were screened as hub genes based on a degree algorithm. Moreover, most of the bioactive components in motherwort had good binding ability with these genes, implying that motherwort could regulate their biological function. Collectively, this study elucidated the molecular mechanisms that underlay the efficiency of motherwort against MDs and demonstrated the potential of network pharmacology as an approach to uncover the action mechanism of herbal medicines.

Anti-inflammatory labdane diterpenoids from Leonurus japonicus Houtt

Seven undescribed labdane diterpenoids, japonicones A-G, were isolated from the aerial parts of Leonurus japonicus Houtt. Japonicones C-G contained two keto carbonyl groups in their structures attached to C-3 and C-7, which are rare for labdane diterpenoids. The structures and absolute configurations of japonicones A-G were established by means of spectroscopic analyses (HRESIMS, 1D and 2D NMR, and ECD). Their anti-inflammatory activities were evaluated by measuring their inhibitory effects on PGE₂ production in LPS-stimulated RAW264.7 macrophages. Japonicones A-D and G showed inhibition of PGE₂ production with IC₅₀ values in the range of 8.62-30.71 μM (the positive control paracetamol showed an IC₅₀ = 5.79 μM).

A new labdane-type diterpenoid from Leonurus japonicus

Five fractions prepared from the crude extract of Leonurus japonicus were examined in order to determine their cytotoxic potential. Under the bioassay guidance, a new labdane-type diterpenoid (1), and nine known ones (2-10) along with a seco-labdane (11) were isolated from the aerial parts of Leonurus japonicus. The structure elucidation was primarily based on comprehensive spectroscopic analyses, including HRESIMS, IR, and 1D and 2D NMR methods. Compound 4 (6β-hydroxy-15,16-epoxylabda-8,13(16),14-trien-7-one) exhibited potential cytotoxicity against HeLa cell line (IC₅₀ = 23.75 μM).

Over-Expression of AtPAP1 Transcriptional Factor Enhances Phenolic Acid Production in Transgenic Roots of Leonurus sibiricus L. and Their Biological Activities

This study examines the production of five phenolic acids (chlorogenic acid, neochlorogenic acid, ferulic acid, caffeic acid and p-coumaric acid) following over-expression of AtPAP1 transcription factor by four transgenic root clones of Leonurus sibiricus after Agrobacterium rhizogenes transformation. The AtPAP1 expression level was estimated by quantitative real-time PCR. High levels of phenolic acids were found in the transgenic roots of L. sibiricus and were determined by high-performance liquid chromatography-mass spectrometry analysis. Additionally, transgenic roots showed antimicrobial potential and cytotoxic activity on glioma cells in IV grade. Our results suggest that L. sibiricus transformed roots with AtPAP1 gene over-expression may represent a potential source of phenolic acids.

New diterpenoids isolated from Leonurus japonicus and their acetylcholinesterase inhibitory activity

Three new labdane diterpenoids, leojaponicone A (1), isoleojaponicone A (2) and methylisoleojaponicone A (3), were isolated from the herb of Leonurus japonicus. The chemical structures of these secondary metabolites were elucidated on the basis of 1D and 2D NMR, including HMQC, and HMBC spectroscopic techniques. All the new compounds were tested in vitro for their acetylcholinesterase and α-glucosidase inhibitory activity. Compounds 1-3 exhibited low inhibitory effects on α-glucosidase with respect to acarbose and exhibited high inhibitory effects on acetylcholinesterase with respect to huperzine A.

The Effect of Leonurus sibiricus Plant Extracts on Stimulating Repair and Protective Activity against Oxidative DNA Damage in CHO Cells and Content of Phenolic Compounds

Leonurus sibiricus L. has been used as a traditional and medicinal herb for many years in Asia and Europe. This species is known to have antibacterial, anti-inflammatory, and antioxidant activity and has demonstrated a reduction of intracellular reactive oxygen species. All tested extracts of L. sibiricus showed protective and DNA repair stimulating effects in Chinese hamster ovary (CHO) cells exposed to H2O2. Preincubation of the CHO cells with 0.5 mg/mL of plant extracts showed increased expression level of antioxidant genes (SOD2, CAT, and GPx). LC-MS/MS and HPLC analyses revealed the presence of nine phenolic compounds in L. sibiricus plant extracts: catechin, verbascoside, two flavonoids (quercetin and rutin), and five phenolic acids (4-hydroxybenzoic acid, chlorogenic acid, caffeic acid, p-coumaric acid, and ferulic acid). The roots and aerial parts of in vitro L. sibiricus plant extracts, which had the strongest antioxidant properties, may be responsible for stimulating CHO cells to repair oxidatively induced DNA damage, as well as protecting DNA via enhanced activation of the antioxidant genes (SOD2, CAT, and GPx) regulating intracellular antioxidant capacity. The content of phenolic compounds in in vitro raised plants was greater than the levels found in plants propagated from seeds.

Two new diterpenoids from Leonotis leonurus R. Br

Two new diterpenoids, 14α-hydroxy-9α,13α-epoxylabd-5(6)-en-7-on-16,15-olide (1) and 13ξ-hydroxylabd-5(6),8(9)-dien-7-on-16,15-olide (2) along with six known diterpenoids were isolated from the aerial parts of Leonotis leonurus R. Br. These structures were determined on the basis of spectroscopic analyses. Some of the isolated compounds showed weak to moderate estrogen sulfotransferase inhibitory activity.

Inhibition of estrogen signaling through depletion of estrogen receptor alpha by ursolic acid and betulinic acid from Prunella vulgaris var. lilacina

Extracts of Prunella vulgaris have been shown to exert antiestrogenic effects. To identify the compounds responsible for these actions, we isolated the constituents of P. vulgaris and tested their individual antiestrogenic effects. Rosmarinic acid, caffeic acid, ursolic acid (UA), oleanolic acid, hyperoside, rutin and betulinic acid (BA) were isolated from the flower stalks of P. vulgaris var. lilacina Nakai (Labiatae). Among these constituents, UA and BA showed significant antiestrogenic effects, measured as a decrease in the mRNA level of GREB1, an estrogen-responsive protein; the effects of BA were stronger than those of UA. UA and BA were capable of suppressing estrogen response element (ERE)-dependent luciferase activity and expression of estrogen-responsive genes in response to exposure to estradiol, further supporting the suppressive role of these compounds in estrogen-induced signaling. However, neither UA nor BA was capable of suppressing estrogen signaling in cells ectopically overexpressing estrogen receptor α (ERα). Furthermore, both mRNA and protein levels of ERα were reduced by treatment with UA or BA, suggesting that UA and BA inhibit estrogen signaling by suppressing the expression of ERα. Interestingly, both compounds enhanced prostate-specific antigen promoter activity. Collectively, these findings demonstrate that UA and BA are responsible for the antiestrogenic effects of P. vulgaris and suggest their potential use as therapeutic agents against estrogen-dependent tumors.

Leonurus japonicus Houtt.: ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus japonicus Houtt. (Labiatae), commonly called Chinese motherwort ([Symbol: see text]), is an herbaceous flowering plant native to Asia. For thousands of years in China, the aerial part of Leonurus japonicus has been used to treat menoxenia, dysmenorrhea, amenorrhea, lochia, edema of the body, oliguresis, sores, ulcerations and other diseases in women. Now, Leonurus japonicus is listed in the Pharmacopoeia of the People's Republic of China. The present paper reviewed the ethnopharmacology, phytochemistry, biological actions and toxicology of Leonurus japonicus.

MATERIALS AND METHODS

Information on Leonurus japonicus was gathered via the Internet (using Elsevier, ACS, Medline Plus, CNKI, VIP, Web of Science, Google Scholar and Baidu Scholar) and libraries.

RESULTS

Approximately 140 chemical compounds have been isolated from Leonurus japonicus, and the major components have been determined to be alkaloids, diterpenes and flavones. Among these active compounds, the effects of leonurine and stachydrine have been widely investigated. The primary active components in Leonurus japonicus possess wide pharmacological actions, such as effects on the uterus as well as cardioprotective, anti-oxidative, neuroprotective and anti-cancer activities.

CONCLUSIONS

Modern pharmacological studies have demonstrated that Leonurus japonicus has marked bioactivities, especially on the uterus and as a cardioprotective agent. These activities are related to its traditional use and provide prospects for the development of novel drugs, therapeutics and health care products for women. However, the toxicity of Leonurus japonicus will require further study, and the nomenclature for Leonurus japonicus will require additional clarification.