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

Leonurus japonicus (motherwort) has been widely used to treat gynecological disorders, in which estrogen is often dysregulated, for a long time in China and other Asian countries. However, the chemical constituents and mechanisms underlying the activity of this medicinal plant are not fully understood. Seventeen of forty-six tested natural products from L. japonicus showed stimulatory or inhibitory effects on estrogen biosynthesis with different potency in human ovarian granulosa-like KGN cells. Luteolin-7-methylether (XLY29) potently inhibited 17ß-estradiol production (IC50: 5.213 µM) by decreasing the expression of aromatase, the only enzyme in vertebrates that catalyzes the biosynthesis of estrogens, but had no effect on the catalytic activity of aromatase. XLY29 decreased the expression of aromatase promoter I.3/II, and suppressed the phosphorylation of cAMP response element-binding protein. XLY29 potently inhibited phosphorylation of p38 mitogen-activated protein kinase and AKT but had no effect on phosphorylation of extracellular signal-regulated kinase and c-Jun N-terminal kinase. XLY29 also decreased the serum 17ß-estradiol level and disturbed estrous cycle in mice. These results suggest that modulation of estrogen biosynthesis is a novel effect of L. japonicus, and XLY29 warrants further investigation as a new therapeutic means for the treatment of estrogen-related diseases.

Premnafulvol A: A Diterpenoid with a 6/5/7/3-Fused Tetracyclic Core and Its Biosynthetically Related Analogues from Premna fulva.

Premnafulvol A (1), a unique diterpenoid featuring a 6/5/7/3-fused tetracyclic carbon skeleton, with three biosynthetically related analogues, premnafulvols B-D (2-4), were isolated from the aerial parts of Premna fulva. Structures of 1-4 were established by a combination of extensive spectroscopic analyses, quantum chemical calculations, and X-ray crystallography. Plausible biosynthetic pathways of 1-4 were proposed. Interestingly, 2 and 3 exhibited opposite effects on estrogen biosynthesis in human ovarian granulosa-like KGN cells by modulating the expression of aromatase.

Flavonoid glycosides isolated from Epimedium brevicornum and their estrogen biosynthesis-promoting effects.

Epimedium brevicornum Maxim has a long history of use in the treatment of estrogen deficiency-related diseases. However, the chemical constituents and mechanism of action of this medicinal plant are not fully understood. In the present study, we isolated four new isoprenylated flavonoid glycosides, as well as 16 known flavonoids (13 isoprenylated flavonoids), from this plant. The chemical structures of the new flavonoid glycosides were elucidated by extensive spectroscopic analysis. The new compounds 1-4 were potent promoters of estrogen biosynthesis in human ovarian granulosa-like KGN cells. ZW1, an isoprenylated flavonoid analogue and a specific inhibitor of phosphodiesterase 5 (PDE5), was synthesized and used to explore the mechanism of the isoprenylated analogues on estrogen biosynthesis. ZW1 treatment increased estrogen production by upregulation of aromatase mRNA and protein expression. ZW1 increased the phosphorylation of cAMP response element-binding protein (CREB). Further study showed that the inhibition of PDE5 by ZW1 increased estrogen biosynthesis partly through suppression of phosphodiesterase 3 (PDE3). Our results suggested that the isoprenylated flavonoids from E. brevicornum may produce beneficial health effects through the promotion of estrogen biosynthesis. PDE5 warrants further investigation as a new therapeutic target for estrogen biosynthesis in the prevention and treatment of estrogen-deficiency related diseases.

Plasiatine, an Unprecedented Indole-Phenylpropanoid Hybrid from Plantago asiatica as a Potent Activator of the Nonreceptor Protein Tyrosine Phosphatase Shp2.

Plasiatine (1), isolated from the seeds of Plantago asiatica, is an unprecedented indole analogue linked to a phenylpropanoid moiety via a carbon bond that builds up a novel heteromeric construction with a C19N2 scaffold. Its structure was determined by spectroscopic data and computational evidence. Notably, experimental assay demonstrated that 1 significantly enhanced the activity of the nonreceptor protein tyrosine phosphatase Shp2 in vitro in a concentration-dependent manner with an EC50 value of 0.97 µM, and activated phosphorylation of ERK, a known target of Shp2. Moreover, plasiatine (1) promoted hepatocellular HepG2 cells migration. Molecular docking suggested that plasiatine (1) binds to the catalytic cleft of Shp2. These results identified plasiatine (1) as the first small molecule Shp2 activator, and it warrants further investigation as a novel pharmaceutical tool to study the function of Shp2 in tumorigenesis.

[Cloning and sequence analysis of SOCS-2 gene in pig].

Total RNA was isolated from kidney of BaMei pig, a local strain of Chinese pig, and then the cDNA sequence of SOCS-2 gene was cloned by RT-PCR (GenBank accepted number is EF121242). Then the cloned SOCS-2 gene was inserted into PMD19-T vector by T/A cloning, transformed into DH-5alpha, tested by PCR and sequenced. The data show that the homology of the cloned porcine SOCS-2, including 822 bp, is more than 93% and that of the deduced amino acid sequence is 89% when compared with human, rat and mice. And the molecular weight of SOCS-2 protein is about 22.25 kD and PI is 8.03. The cloning of SOCS-2 gene is useful for the further research on the molecular mechanism by which regulating growth and development of organism.