Pterostilbene production of tomato transformed with resveratrol synthase and resveratrol O-methyltransferase genes

Pterostilbene: A natural neuroprotective stilbene with anti-Alzheimer's disease properties

Alzheimer's disease (AD) is the leading cause of dementia, and no effective treatment has been developed for it thus far. Recently, the use of natural compounds in the treatment of neurodegenerative diseases has garnered significant attention owing to their minimal adverse reactions. Accordingly, the potential therapeutic effect of pterostilbene (PTS) on AD has been demonstrated in multiple in vivo and in vitro experiments. In this study, we systematically reviewed and summarized the results of these studies investigating the use of PTS for treating AD. Analysis of the literature revealed that PTS may play a role in AD treatment through various mechanisms, including anti-oxidative damage, anti-neuroinflammation, anti-apoptosis, cholinesterase activity inhibition, attenuation of β-amyloid deposition, and tau protein hyperphosphorylation. Moreover, PTS interferes with the progression of AD by regulating the activities of peroxisome proliferator-activated receptor alpha (PPAR-α), monoamine oxidase B (MAO-B), silent information regulator sirtuin 1 (SIRT1), and phosphodiesterase 4A (PDE4A). Furthermore, to further elucidate the potential therapeutic mechanisms of PTS in AD, we employed network pharmacology and molecular docking technology to perform molecular docking of related proteins, and the obtained binding energies ranged from -2.83 to -5.14 kJ/mol, indicating that these proteins exhibit good binding ability with PTS. Network pharmacology analysis revealed multiple potential mechanisms of action for PTS in AD. In summary, by systematically collating and summarizing the relevant studies on the role of PTS in treatment of AD, it is anticipated that this will serve as a reference for the precise targeted prevention and treatment of AD, either using PTS or other developed drug interventions.

Biosynthesis of pterostilbene in Escherichia coli from resveratrol on macroporous adsorption resin using a two-step substrate addition strategy

Pterostilbene (PST), a 3',5'-O-methylated derivative of resveratrol (RSV), is a potent natural antioxidant produced by some plants in trace amounts as defense compound. It exhibits various health-promoting activities, such as anticancer, antiviral, and antimicrobial effects. Large-scale biosynthesis of PST is crucial due to the challenges associated with extracting it from plants. This study aims to develop an efficient method for PST production using an engineered Escherichia coli strain by feeding RSV as a precursor. We introduced a two-step substrate addition strategy combined with immobilized RSV (IMRSV) on macroporous adsorption resin (MAR) to enhance PST production. Five MARs were selected for RSV immobilization, and the substrate addition strategy and fermentation parameters for PST synthesis were optimized. A maximum PST concentration of 403 ± 9 mg/L was achieved, representing a 239% increase over the control, which in a one-step addition of free RSV. The PST titer reached 395 ± 24 mg/L in a 3-L bioreactor. In conclusion, the combination of a two-step substrate addition system and IMRSV is a promising approach for the economical and industrial-scale production of PST.

Nutrient Solution Flowing Environment Affects Metabolite Synthesis Inducing Root Thigmomorphogenesis of Lettuce (Lactuca sativa L.) in Hydroponics

The principal difference between hydroponics and other substrate cultivation methods is the flowing liquid hydroponic cultivation substrate. Our previous studies have revealed that a suitable flowing environment of nutrient solution promoted root development and plant growth, while an excess flow environment was unfavorable for plants. To explain the thigmomorphogenetic response of excess flow-induced metabolic changes, six groups of lettuce (Lactuca sativa L.), including two flow conditions and three time periods, were grown. Compared with the plants without flow, the plants with flow showed decreased root fresh weight, total root length, root surface area, and root volume but increased average root diameter and root density. The roots with flow had more upregulated metabolites than those without flow, suggesting that the flow may trigger metabolic synthesis and activity. Seventy-nine common differential metabolites among six groups were screened, and enrichment analysis showed the most significant enrichment in the arginine biosynthesis pathway. Arginine was present in all the groups and exhibited greater concentrations in roots with flow than without flow. It can be speculated from the results that a high-flowing environment of nutrient solution promotes arginine synthesis, resulting in changes in root morphology. The findings provide insights on root thigmomorphogenesis affected by its growing conditions and help understand how plants respond to environmental mechanical forces.