Luteolin-7-methylether from Leonurus japonicus inhibits estrogen biosynthesis in human ovarian granulosa cells by suppression of aromatase (CYP19)

Luteolin and its analog luteolin-7-methylether from Leonurus japonicus Houtt suppress aromatase-mediated estrogen biosynthesis to alleviate polycystic ovary syndrome by the inhibition of tumor progression locus 2

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus japonicus Houtt (L. japonicus, Chinese motherwort), known as Yi Mu Cao which means "good for women", has long been widely used in China and other Asian countries to alleviate gynecological disorders, often characterized by estrogen dysregulation. It has been used for the treatment of polycystic ovary syndrome (PCOS), a common endocrine disorder in women but the underlying mechanism remains unknown.

AIM OF THE STUDY

The present study was designed to investigate the effect and mechanism of flavonoid luteolin and its analog luteolin-7-methylether contained in L. japonicus on aromatase, a rate-limiting enzyme that catalyzes the conversion of androgens to estrogens and a drug target to induce ovulation in PCOS patients.

MATERIALS AND METHODS

Estrogen biosynthesis in human ovarian granulosa cells was examined using ELISA. Western blots were used to explore the signaling pathways in the regulation of aromatase expression. Transcriptomic analysis was conducted to elucidate the potential mechanisms of action of compounds. Finally, animal models were used to assess the therapeutic potential of these compounds in PCOS.

RESULTS

Luteolin potently inhibited estrogen biosynthesis in human ovarian granulosa cells stimulated by follicle-stimulating hormone. This effect was achieved by decreasing cAMP response element-binding protein (CREB)-mediated expression of aromatase. Mechanistically, luteolin and luteolin-7-methylether targeted tumor progression locus 2 (TPL2) to suppress mitogen-activated protein kinase 3/6 (MKK3/6)-p38 MAPK-CREB pathway signaling. Transcriptional analysis showed that these compounds regulated the expression of different genes, with the MAPK signaling pathway being the most significantly affected. Furthermore, luteolin and luteolin-7-methylether effectively alleviated the symptoms of PCOS in mice.

CONCLUSIONS

This study demonstrates a previously unrecognized role of TPL2 in estrogen biosynthesis and suggests that luteolin and luteolin-7-methylether have potential as novel therapeutic agents for the treatment of PCOS. The results provide a foundation for further development of these compounds as effective and safe therapies for women with PCOS.

Preliminary Evaluation of Wound Healing Potential of Leonurus japonicus Houtt. Extracts

Leonurus japonicus Houtt. is a medicinal plant popular in Brazil as "rubim", used in local folk medicine for several applications as an anti-inflammatory, antioxidant, analgesic, and antimicrobial phytomedicine. The traditional use for wound healing is related; however, few studies have evaluated the wound healing activity. Thus, this study aimed to analyse the popular indication of the hydroalcoholic and aqueous extracts of L. japonicus aerial parts in a rat wound healing model. The initial chemical characterization was performed using flavonoid quantification and complemented with mass spectroscopy/chemometrics analysis. The wound's lesion contraction and tissue regeneration (histological study stained with hematoxylin-eosin and picrosirius) were determined. Hydroalcoholic and aqueous extracts presented high flavonoid content, and mass spectrometry analysis of the extracts demonstrated the presence of compounds with a mass between 100-650, reinforcing the presence of polyphenolic constituents. The extracts of L. japonicus improve various wound healing phases, like inflammatory modulation, wound contraction, and collagen synthesis, resulting in faster healing in rats. These effects could be related to the extracts' polyphenolic compounds.

Antichilblain Components in Eggplant Based on Network Pharmacology and Biological Evaluation

Eggplant, the fruit of Solanum melongena L. (Solanaceae), is applied externally to relieve the symptoms of chilblains in the folk in East Asia. However, the mechanisms and biological ingredients are not clear. A network pharmacology approach was used to shed light on the mechanisms of eggplant against chilblains, which illustrated that anti-inflammation and antioxidation are mainly involved in the curative effects. Bioassay-guided assays led to the isolation of 44 ingredients (1-44), including two new natural compounds (1-2) and 42 known compounds. Thirteen compounds (3-15) were first reported from the Solanum genus. The anti-inflammatory and antioxidative effects of all isolates were evaluated, and the results showed that 11 compounds have anti-inflammatory activity and 27 have antioxidant activity. Fatty acids, flavonoids, alkaloids, phenolic acids, saponins, and lignans from eggplant have certain anti-inflammatory and antioxidant effects. These results provide a scientific basis for eggplant to treat chilblains.

Integrated Network Pharmacology and Clinical Study to Reveal the Effects and Mechanisms of Bushen Huoxue Huatan Decoction on Polycystic Ovary Syndrome

Objective

Bushen Huoxue Huatan Decoction (BHHD) is a classic prescription for treating polycystic ovary syndrome (PCOS). This study aims to explore the effects and possible mechanisms of BHHD on PCOS by integrating network pharmacology and clinical study.

Methods

The components and potential drug targets of BHHD were analysed using the TCMSP platform, and the potential pathogenesis targets for PCOS were analysed using the GeneCards and OMIM databases. Subsequently, a disease-compound-target network diagram was established to identify the targets of BHHD treatment on PCOS. In addition, protein-protein interaction analysis, KEGG pathway analysis, and Gene Ontology biological analysis were carried out to reveal the mechanisms of BHHD. To further validate the analysis, a clinical trial involving 62 PCOS patients was conducted. All patients were treated with BHHD for 3 months and the ovulation rate, anthropometric indicators, clinical symptoms, and serological indicators were measured and compared before and after treatment.

Results

The network pharmacology analysis showed that quercetin, luteolin, and kaempferol are the most significant active components in BHHD; STAT3, Jun, AKT1, MAPK3, MAPK1, and TP53 are the most critical drug targets; regulating hormones, reversing insulin (INS) resistance, exerting anti-inflammatory effects, and improving fertility might be the most important mechanisms of BHHD in the treatment of PCOS. After BHHD administration, the cyclic ovulation rate and the clinical symptoms including acanthosis nigricans and acne of patients were obviously improved. The serum endocrine levels of luteinising hormone (LH), LH/follicle-stimulating hormone, testosterone, dehydroepiandrosterone sulphate, insulin (INS), and area under the INS curve were evidently reversed, and the serum inflammatory factors levels including human interleukin (IL)-18, IL-16, IL-1β, IL-8, macrophage migration inhibitory factor, and human leukocyte differentiation antigen CD40 ligand were greatly reduced.

Conclusion

BHHD has a good therapeutic effect on PCOS, and its mechanisms may be related to regulating hormone levels, improving insulin resistance, alleviating inflammation, and promoting pregnancy.

The Role of Aromatase Enzyme in Hormone Related Diseases and Plant-Based Aromatase Inhibitors as Therapeutic Regimens

Medicinal plants have a long history of use as food and remedy in traditional and modern societies, as well as have been used as herbal drugs and sources of novel bioactive compounds. They provide a wide array of chemical compounds, many of which can not be synthesized via current synthesis methods. Natural products may provide aromatase inhibitory activity through various pathways and may act clinically effective for treating pathologies associated with excessive aromatase secretion including breast, ovarian and endometrial cancers, endometriosis, uterine fibroid, benign prostatic hyperplasia (BPH), prostate cancer, infertility, and gynecomastia. Recent studies have shown that natural products with aromatase inhibitory activity, could also be good options against secondary recurrence of breast cancer by exhibiting chemopreventive effects. Therefore, screening for new plant-based aromatase inhibitors may provide novel leads for drug discovery and development, particularly with increased clinical efficacy and decreased side effects.

Estrogen disorders: Interpreting the abnormal regulation of aromatase in granulosa cells (Review)

Ovarian granulosa cells (GCs) are the most important source of estrogen. Therefore, aromatase (estrogen synthase), which is the key enzyme in estrogen synthesis, is not only an important factor of ovarian development, but also the key to estrogen secretion by GCs. Disorders of the ovarian estrogen secretion are more likely to induce female estrogen-dependent diseases and fertility issues, such as ovarian cancer and polycystic ovary syndrome. Hence, aromatase is an important drug target; treatment with its inhibitors in estrogen-dependent diseases has attracted increasing attention. The present review article focuses on the regulation and mechanism of the aromatase activity in the GCs, as well as the specific regulation of aromatase promoters. In GCs, follicle-stimulating hormone (FSH) is dependent on the cyclic adenosine monophosphate (cAMP) pathway to regulate the aromatase activity, and the regulation of this enzyme is related to the activation of signaling pathways, such as phosphatidylinositol 3-kinase (PI3K) and extracellular signal-regulated kinase (ERK). In addition, endocrine-disrupting substance and other related factors affect the expression of aromatase, which eventually create an imbalance in the estrogen secretion by the target tissues. The present review highlights these useful factors as potential inhibitors for target therapy.