Interactions Between Ephedra sinica and Prunus armeniaca: From Stereoselectivity to Deamination as a Metabolic Detoxification Mechanism of Amygdalin

Mahuang–Xingren (MX, Ephedra sinica Stapf-Prunus armeniaca L.) is a classic herb pair used in traditional Chinese medicine. This combined preparation reduces the toxicity of Xingren through the stereoselective metabolism of its main active ingredient amygdalin. However, whether stereoselectivity is important in the pharmacokinetic properties of amygdalin either in the traditional decoction or in the dispensing granules is unclear. Amygdalin is hydrolyzed to its metabolite, prunasin, which produces hydrogen cyanide by degradation of the cyano group. A comprehensive study of the metabolic pathway of amygdalin is essential to better understand the detoxification process. In this article, the potential detoxification pathway of MX is further discussed with regard to herb interactions. In this study, the pharmacokinetic parameters and metabolism of amygdalin and prunasin were investigated by comparing the traditional decoction and the dispensing granule preparations. In addition, several potential metabolites were characterized in an incubation system with rat liver microsomes or gut microbial enzymes. The combination of Xingren with Mahuang reduces exposure to D-amygdalin in vivo and contributes to its detoxification, a process that can be further facilitated in the traditional decoction. From the in vitro co-incubation model, 15 metabolites were identified and classified into cyanogenesis and non-cyanogenesis metabolic pathways, and of these, 10 metabolites were described for the first time. The level of detoxified metabolites in the MX traditional decoction was higher than that in the dispensing granules. The metabolism of amygdalin by the gut microbial enzymes occurred more rapidly than that by the rat liver microsomes. These results indicated that combined boiling both herbs during the preparation of the traditional decoction may induce several chemical changes that will influence drug metabolism in vivo. The gut microbiota may play a critical role in amygdalin metabolism. In conclusion, detoxification of MX may result 1) during the preparation of the decoction, in the boiling phase, and 2) from the metabolic pathways activated in vivo. Stereoselective pharmacokinetics and deamination metabolism have been proposed as the detoxification pathway underlying the compatibility of MX. Metabolic detoxification of amygdalin was quite different between the two combinations, which indicates that the MX decoctions should not be completely replaced by their dispensing granules.

Partial genome assembly of the medicinal plant Ephedra sinica.

Ephedra sinica is a high-value medicinal plant that produces important phenylpropylamino alkaloids pseudoephedrine and ephedrine. Few genomics resources exist for E. sinica, which has been characterized as a tetraploid with a monoploid genome size of 8.56 Gb. Here we reported a partial genome assembly of E. sinica (12.8 Gb) based on Illumina short-read sequencing technology at low coverage.

In search of an ideal drug for safer treatment of obesity: The false promise of pseudoephedrine

Obesity is a major public health problem worldwide. Only relatively few treatment options are, at present, available for the management of obese patients. Furthermore, treatment of obesity is affected by the widespread misuse of drugs and food supplements. Ephedra sinica is an old medicinal herb, commonly used in the treatment of respiratory tract diseases. Ephedra species contain several alkaloids, including pseudoephedrine, notably endowed with indirect sympathomimetic pharmacodynamic properties. The anorexigenic effect of pseudoephedrine is attributable primarily to the inhibition of neurons located in the hypothalamic paraventricular nucleus (PVN), mediating satiety stimuli. Pseudoephedrine influences lipolysis and thermogenesis through interaction with β3 adrenergic receptors and reduces fat accumulation through down-regulation of transcription factors related to lipogenesis. However, its use is associated with adverse events that involve to a large extent the cardiovascular and the central nervous system. Adverse events of pseudoephedrine also affect the eye, the intestine, and the skin, and, of relevance, sudden cardiovascular death related to dietary supplements containing Ephedra alkaloids has also been reported. In light of the limited availability of clinical data on pseudoephedrine in obesity, along with its significantly unbalanced risk/benefit profile, as well as of the psychophysical susceptibility of obese patients, it appears reasonable to preclude the prescription of pseudoephedrine in obese patients of any order and degree.

Potential Role of Gut Microbiota in Traditional Chinese Medicine against COVID-19

The coronavirus disease 2019 (COVID-19) spreads and rages around the world and threatens human life. It is disappointing that there are no specific drugs until now. The combination of traditional Chinese medicine (TCM) and western medication seems to be the current more effective treatment strategy for COVID-19 patients in China. In this review, we mainly discussed the relationship between COVID-19 and gut microbiota (GM), as well as the possible impact of TCM combined with western medication on GM in the treatment of COVID-19 patients, aiming to provide references for the possible role of GM in TCM against COVID-19. The available data suggest that GM dysbiosis did occur in COVID-19 patients, and the intervention of GM could ameliorate the clinical condition of COVID-19 patients. In addition, TCMs (e.g., Jinhua Qinggan granule, Lianhua Qingwen capsule, Qingfei Paidu decoction, Shufeng Jiedu capsule, Qingjin Jianghuo decoction, Toujie Quwen granules, and MaxingShigan) have been proven to be safe and effective for the treatment of COVID-19 in Chinese clinic. Among them, Ephedra sinica, Glycyrrhiza uralensis, Bupleurum chinense, Lonicera japonica,Scutellaria baicalensi, and Astragalus membranaceus are common herbs and have a certain regulation on GM, immunity, and angiotensin converting enzyme 2 (ACE2). Notably, Qingfei Paidu decoction and MaxingShigan have been demonstrated to modulate GM. Finally, the hypothesis of GM-mediated TCM treatment of COVID-19 is proposed, and more clinical trials and basic experiments need to be initiated to confirm this hypothesis.