Rutin hydrate and extract from Castanopsis tribuloides reduces pyrexia via inhibiting microsomal prostaglandin E synthase-1

Castanopsis tribuloides belongs to the oak species (Fagaceae) and it is commonly distributed in evergreen forests of Bangladesh, India, Myanmar, Nepal, China, and Thailand. Our present study aimed at uncovering the antipyretic potential of methanol extract of C. tribuloides bark (CTB) in the mice models. Baker's yeast pyrexia model was employed to determine the antipyretic potentials of the extract. Besides, molecular docking and dynamics simulation of CTB phenolic compounds were explored to validate the experimental results and gain insight into the possible antipyretic mechanism of action that can lead to the design and discovery of novel drugs against mPGES-1. The results revealed that CTB (400 mg/kg) significantly inhibited (P < 0.001) the elevated body temperature of mice since 0.5 h, which is more prominent than the standard. At dose 200 mg/kg, the bark extract also produced significant (P < 0.05) antipyretic activity since 2 h. HPLC-DAD analysis identified and quantified nine polyphenolic compounds from the extract, including rutin hydrate, (-) epicatechin, caffeic acid, catechin hydrate, catechol, trans-ferulic acid, p-coumaric acid, vanillic acid, and rosmarinic acid. Molecular docking study suggested probable competition of these phenolic compounds with glutathione, an essential cofactor for microsomal prostaglandin E synthase-1 (mPGES-1) activity. Additionally, RMSF, RMSD, Rg, and hydrogen bonds performed during MD simulations revealed that rutin hydrate (rich in CTB) bound to the mPGES-1 active site in a stable manner and thus inactivating mPGES-1. Therefore, it can be concluded that rutin hydrate reduces pyrexia in mice via downregulating PGE2 synthesis by inhibiting mPGES-1 activity.

Coordinated Regulation Among Progesterone, Prostaglandins, and EGF-Like Factors in Human Ovulatory Follicles

CONTEXT

In animal models, the luteinizing hormone surge increases progesterone (P4) and progesterone receptor (PGR), prostaglandins (PTGs), and epidermal growth factor (EGF)-like factors that play essential roles in ovulation. However, little is known about the expression, regulation, and function of these key ovulatory mediators in humans.

OBJECTIVE

To determine when and how these key ovulatory mediators are induced after the luteinizing hormone surge in human ovaries.

DESIGN AND PARTICIPANTS

Timed periovulatory follicles were obtained from cycling women. Granulosa/lutein cells were collected from in vitro fertilization patients.

MAIN OUTCOME MEASURES

The in vivo and in vitro expression of PGR, PTG synthases and transporters, and EGF-like factors were examined at the level of messenger RNA and protein. PGR binding to specific genes was assessed. P4 and PTGs in conditioned media were measured.

RESULTS

PGR, PTGS2, and AREG expressions dramatically increased in ovulatory follicles at 12 to 18 hours after human chorionic gonadotropin (hCG). In human granulosa/lutein cell cultures, hCG increased P4 and PTG production and the expression of PGR, specific PTG synthases and transporters, and EGF-like factors, mimicking in vivo expression patterns. Inhibitors for P4/PGR and EGF-signaling pathways reduced hCG-induced increases in PTG production and the expression of EGF-like factors. PGR bound to the PTGS2, PTGES, and SLCO2A1 genes.

CONCLUSIONS

This report demonstrated the time-dependent induction of PGR, AREG, and PTGS2 in human periovulatory follicles. In vitro studies indicated that collaborative actions of P4/PGR and EGF signaling are required for hCG-induced increases in PTG production and potentiation of EGF signaling in human periovulatory granulosa cells.