Phytochemical Combination PB125 Activates the Nrf2 Pathway and Induces Cellular Protection against Oxidative Injury

Abstract

Bioactive phytochemicals in Rosmarinus officinalis, Withania somnifera, and Sophora japonica have a long history of human use to promote health. In this study we examined the cellular effects of a combination of extracts from these plant sources based on specified levels of their carnosol/carnosic acid, withaferin A, and luteolin levels, respectively. Individually, these bioactive compounds have previously been shown to activate the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor, which binds to the antioxidant response element (ARE) and regulates the expression of a wide variety of cytoprotective genes. We found that combinations of these three plant extracts act synergistically to activate the Nrf2 pathway, and we identified an optimized combination of the three agents which we named PB125 for use as a dietary supplement. Using microarray, quantitative reverse transcription-PCR, and RNA-seq technologies, we examined the gene expression induced by PB125 in HepG2 (hepatocellular carcinoma) cells, including canonical Nrf2-regulated genes, noncanonical Nrf2-regulated genes, and genes which appear to be regulated by non-Nrf2 mechanisms. Ingenuity Pathway Analysis identified Nrf2 as the primary pathway for gene expression changes by PB125. Pretreatment with PB125 protected cultured HepG2 cells against an oxidative stress challenge caused by cumene hydroperoxide exposure, by both cell viability and cell injury measurements. In summary, PB125 is a phytochemical dietary supplement comprised of extracts of three ingredients, Rosmarinus officinalis, Withania somnifera, and Sophora japonica, with specified levels of carnosol/carnosic acid, withaferin A, and luteolin, respectively. Each ingredient contributes to the activation of the Nrf2 pathway in unique ways, which leads to upregulation of cytoprotective genes and protection of cells against oxidative stress and supports the use of PB125 as a dietary supplement to promote healthy aging.

Nrf2 Activator PB125® as a Potential Therapeutic Agent against COVID-19

“…The phenomenon is also seen in non-respiratory viruses including dengue virus (DENV) [ 19 ], rotavirus [ 20 ], herpes simplex virus [ 21 ], Zika virus [ 22 ], and HIV [ 23 ], suggesting that regulation of oxidative stress may be a need common to most, if not all, viruses and that Nrf2 activators may offer multiple ways to regain control of important pathways to increase resistance and slow viral replication. We recently described a phytochemical composition, PB125, that potently activates Nrf2 by controlling multiple steps involved in the process, especially via the Akt1/PI3K/GSK3β/Fyn pathway [ 24 ].…”

Nrf2 Activator PB125®as a Potential Therapeutic Agent Against COVID-19

“…Importantly, the point-of-entry host protein TMPRSS2, a membrane-bound serine protease, appears to be an essential requirement for SARS-Cov-2 (COVID- 19) virus. TMPRSS2 appears amenable to inhibition by PAI-1, encoded by the SERPINE1 gene which is upregulated by PB125.…”

“…Plant extracts: rosemary extract from Rosmarinus officinalis (standardized to 6% carnosol; 15% carnosic acid) was obtained from Flavex (Rehlingen, Germany), ashwagandha extract from Withania somnifera (standardized to 2% withaferin A) was obtained from Verdure Sciences (Noblesville, IN, USA), and luteolin (standardized to 98% luteolin, from Sophora japonica) was obtained from Jiaherb (Pine Brook, NJ, USA). For making PB125 solutions, the rosemary, ashwagandha, and luteolin powders were mixed at a 15:5:2 ratio by mass, then extracted at 50 mg of mixed powder per mL in ethanol overnight and the supernatant isolated [19]. Cell culture: media and antibiotics were purchased from Thermo Fisher Scientific (Waltham, MA, USA).…”

“…The phenomenon is also seen in non-respiratory viruses including Dengue virus (DENV) [14], rotavirus [15], herpes simplex virus [16], Zika virus [17], and HIV [18], suggesting that regulation of oxidative stress may be a need common to most, if not all viruses, and that Nrf2 activators may offer multiple ways to regain control of important pathways to increase resistance and slow viral replication. We recently described a phytochemical composition, PB125, that potently activates Nrf2 by controlling multiple steps involved in the process, especially via the Akt1/PI3K/GSK3/Fyn pathway [19].…”

Phytochemical and Biological Investigation of Helianthemum nummularium, a High-Altitude Growing Alpine Plant Overrepresented in Ungulates Diets

“…We used the human HepG2 cell line (hepatocellular carcinoma) that had been stably transfected with a Nrf2-responsive, ARE-regulated firefly luciferase gene construct to evaluate Nrf2/ARE activation (HepG2-ARE) as previously described [37]. The stably transfected HepG2-ARE Nrf2 reporter gene cell line was kindly provided by Steven Simmons [18,28].…”