Chemical Constituents of Pedicularis longiflora var. tubiformis (Orobanchaceae), a Common Hemiparasitic Medicinal Herb from the Qinghai Lake Basin, China

Pedicularis longiflora var. tubiformis (Orobanchaceae) is an abundant parasitic herb mainly found in the Xiaopohu wetland of the Qinghai Lake Basin in Northwestern China. The species has an important local medicinal value, and in this study, we evaluated the chemical profile of its stems, leaves and seeds using mass spectrometry. Dried samples of stems, leaves and seeds were grinded, weighted, and used for a series of extractions with an ultrasonic device at room temperature. The chemical profiles for each tissue were determined using Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS). Twenty-seven amino acids and organic acids were identified and quantified from stems, leaves and seeds. The content of amino acids detected in leaves and seeds was higher than the amount found in stems. Six flavonoids were also detected, including isoorientin, orientin, luteolin-7-O-glucoside, luteolin, apigenin and tricin. The concentrations of luteolin-7-O-glucoside, luteolin and tricin were the highest and more concentrated in leaves, while that of orientin was the lowest and mainly found in stems. Soluble monosaccharides and oligosaccharides below tetramer were also examined, and our analyses detected the presence of arabitol, fructose, galacturonic acid, glucose, glucuronic acid, inositol, sucrose, and trehalose. This is the first study to identify and quantify the main components of amino acids, organic acids, flavonoids and soluble sugars from stems, leaves and seeds of P. longiflora var. tubiformis. Eight of the amino acids detected are essential for humans, highlighting the medicinal importance of this species. Results shown here can be used as a reference case to develop future studies on the chemical constituents of Pedicularis herbs and other medicinal plants from the Tibetan region

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity.Peer reviewe