The origin of in-vitro estrogen-like activity in oregano herb extracts

Abstract

Global market of herbs has been struggling with food adulteration issues. A number of assays have been developed to aid the detection of the tampered samples and ensure high quality of the marketed products. However, herbs are marketed not only for their culinary applications but also as remedies due to high levels of biologically active constituents. Nevertheless, there is no information in the literature about the influence of herbs adulteration on the biological activity of the final product. Current study aims at assessing the influence of oregano adulteration on its in-vitro estrogen-like activity. High responses in a mammalian reporter gene assay have been detected in pure and adulterated samples, translating to 21-7,409 ng of 17β-estradiol equivalents per gram of oregano. The origin of those responses was assessed by combining fractionation and UHPLC-HRMS. Three flavones were proposed as the most active extract constituents i.e. luteolin-glucoside, luteolin-and apigenin-glucuronides all of which have been previously identified in other herbal extracts with estrogenic activity. This study underlines challenges of biological activity assessment in complex herbal extracts as well as the need for further assessment of such supplement administrations in the case of postmenopausal women and breast cancer patients undergoing hormone therapy. Highlights:  Oregano extracts exhibit estrogen-like activity in-vitro  Conjugated flavonoids are the origin of the detected biological activity  Combining bio-and chemical assays is a fast tool for detecting bioactive compounds

The Effects of Continual Consumption of Origanum vulgare on Liver Transcriptomics

“…We have previously reported functional analysis of the microbiota genetic potential [28] showing that 2% oregano in feed significantly reduced the abundance of intestinal bacterial genes involved in steroid hormone biosynthesis via Picrust functional prediction [28], we confirmed this with ileum transcriptomics, and now also in the liver. Others have shown that oregano can induce estrogenic responses in vitro and can also show estrogen-like activity [29], thus influencing steroid hormone balance. This may be beneficial as the means to help regulate steroid hormone-based imbalances, especially if the effects could be pinned to individual components of oregano which is necessary for reproducibility of the outcome.…”

Agrimonia pilosa Ledeb. Ameliorates Hyperglycemia and Hepatic Steatosis in Ovariectomized Rats Fed a High-Fat Diet

“…In our previous study, we reported estrogen-like activity in aqueous A. pilosa extract containing apigenin-glucuronide and luteolin-glucuronide as major flavonoids [ 17 ]. These conjugated flavonoids were suggested to be the most active constituents in herbal extracts with estrogenic activity [ 36 ]. A recent study reported that long-term supplementation of low doses of apigenin could improve HFD-induced comorbidity through metabolic and transcriptional regulation in the liver [ 37 ].…”

Divergent synthesis of flavones and flavanones from 2′-hydroxydihydrochalcones via palladium(ii)-catalyzed oxidative cyclization

“…Flavones and flavanones are widely occurring natural flavonoids produced by various medicinal plants and their synthetic derivatives, featuring a main 15-carbon skeleton possessing 2 phenyl rings and 1 oxacycle. 1 In recent decades, they have been considered privileged structures exhibiting various biological activities, 2 such as anti-inflammatory, 3 anti-cancer, 4 neuroprotective, 5 and estrogen-related functions 6 ( Fig. 1 ).…”