Natural Phenolic Compounds with Neuroprotective Effects.

Neurodegenerative disorders are characterized by mitochondrial dysfunction and subsequently oxidative stress, inflammation, and apoptosis that contribute to neuronal cytotoxicity and degeneration. Huntington's (HD), Alzheimer's (AD), and Parkinson's (PD) diseases are three of the major neurodegenerative diseases. To date, researchers have found various natural phytochemicals that could potentially be used to treat neurodegenerative diseases. Particularly, the application of natural phenolic compounds has gained significant traction in recent years, driven by their various biological activities and therapeutic efficacy in human health. Polyphenols, by modulating different cellular functions, play an important role in neuroprotection and can neutralize the effects of oxidative stress, inflammation, and apoptosis in animal models. This review focuses on the current state of knowledge on phenolic compounds, including phenolic acids, flavonoids, stilbenes, and coumarins, as well as their beneficial effects on human health. We further provide an overview of the therapeutic potential and mechanisms of action of natural dietary phenolics in curing neurodegenerative diseases in animal models.

Biochemical changes and enhanced accumulation of phenolic compounds in cell culture of Perilla frutescens (L.) by nano-chemical elicitation.

Perilla frutescens (L.) Britt is a renowned medicinal plant with pharmaceutically valuable phenolic acids and flavonoids. The present study was aimed to study the eliciting effect of silver and copper nanoparticles (AgNPs and CuNPs, 50 and 100 mg/L), and methyl jasmonate (MeJa, 50 and 100 µM) on the biochemical traits, the accumulation of phenolic compounds and antioxidative capacity of P. frutescens cell suspension culture. Suspension cells were obtained from friable calli derived from nodal explants in Murashige and Skoog (MS) liquid medium containing 1 mg/L 2,4-D and 1 mg/L BAP. The 21 days old cell suspension culture established from nodal explant derived callus supplemented with 100 mg/L MeJa resulted in the highest activity of catalase and guaiacol peroxidase enzymes, and CuNPs 100 mg/L treated cells indicated the maximum content of total phenol, total anthocyanin, superoxide dismutase, malondialdehyde, and H2O2. Also, the highest content of ferulic acid (1.41 ± 0.03, mg/g DW), rosmarinic acid (19.29 ± 0.12, mg/g DW), and phenylalanine ammonia-lyase (16.81 ± 0.18, U/mg protein) were observed with 100 mg/L CuNPs, exhibiting a total increase of 1.58-fold, 2.12-fold, and 1.51-fold, respectively, higher than untreated cells. On the other hand, AgNPs 100 mg/L treated cells indicated the most amounts of caffeic acid (0.57 ± 0.03, mg/g DW) and rutin (1.13 ± 0.07, mg/g DW), as well as the highest scavenging potential of free radicals. Overall, the results of the present study can be applied for the large-scale production of valuable phenolic acids and flavonoids from P. frutescens through CuNPs and AgNPs 100 mg/L elicited cell suspension cultures.

Comparative assessment of the biological activity of the green synthesized silver nanoparticles and aqueous leaf extract of Perilla frutescens (L.).

Green synthesized nanoparticles (GSNPs) display fascinating properties compared to physical and chemical synthesized ones. GSNPs are currently used in numerous applications such as food packaging, surface coating agents, environmental remediation, antimicrobial, and medicine. In the present study, the aqueous leaf extract of Perilla frutescens L. having suitable capping, reducing, and stabilizing compounds was used for green synthesis of silver nanoparticles (Pf-AgNPs). The bioreductant capacity of aqueous leaf extract of P. frutescens for Pf-AgNPs was determined by different confirmatory techniques including UV-Visible spectroscopy, XRD, FESEM, EDX, zeta potential, DLS, SERS, and FTIR analysis. The results exhibited that Pf-AgNPs had optimal size (< 61 nm), shape (spherical), and stability (- 18.1 mV). The antioxidant activity of Pf-AgNPs with both DPPH and FRAP assays was significantly higher compared to P. frutescens extract. Furthermore, Pf-AgNPs had high antimicrobial activity against Escherichia coli and Staphylococcus aureus (MIC = 0.78 mg/mL), and Candida albicans (MIC = 8 mg/mL) while the plant extract showed low antimicrobial activity against both bacterial strains and the fungus tested. Pf-AgNPs and P. frutescens extract also exhibited moderate toxicity on MCF-7 cancer cells with IC50 values of 346.2 and 467.4 µg/mL, respectively. The results provide insights into using the biosynthesized Pf-AgNPs as an eco-friendly material for a wide range of biomedical applications.

Phenolics diversity among wild populations of Salvia multicaulis: as a precious source for antimicrobial and antioxidant applications.

The genus Salvia L. belongs to the Lamiaceae family including several known species rich in natural compounds that are extensively used in pharmaceutical, food, and cosmetic industries. Salvia multicaulis populations contain a broad diversity of flavonoids and phenolic acids. The present study aimed to explore biological and pharmacological effects including antimicrobial and antioxidant activities of nineteen S. multicaulis populations (SMPs) grown in Iran for the first time. High content of rosmarinic acid (RA) in SMP12 (Gazan) (5.65 ± 0.33 mg/g DW) caused high antimicrobial activity against two bacteria (Staphylococcus aureus, Escherichia coli) and the fungus Candida albicans, while methanolic extract of SMP1 (Taleghan) showed high antioxidant activity due to high content of salvianolic acid A (SAA) and quercetin (0.53 ± 0.04 and 0.49 ± 0.12 mg/g DW, respectively). Altogether these results can be considered for further commercial exploitations to meet the demands of the food and pharmaceutical industries.[Formula: see text].

Triterpenic and phenolic acids production changed in Salvia officinalis via in vitro and in vivo polyploidization: A consequence of altered genes expression.

The induction of polyploidy is an efficient technique for creating a diversity of genetic, phenotypic, and phytochemical novelties in plant taxa. Sage (Salvia officinalis L.) is a well-known medicinal plant rich of valuable bioactive molecules such as triterpenic and phenolic acids. In the present study, the effect of in vitro and in vivo polyploidization on morphological characteristics, anatomical structures, phytochemical traits, and expression level of the genes involved in the biosynthesis of major triterpenic acids (ursolic, betulinic, and oleanolic acids) of the plant was studied. The sterile seeds treated with different concentrations (0, 0.05, 0.1, and 0.2%) of colchicine for 24 and 48 h were considered for polyploidy induction. Flow cytometry and chromosome counting were used to confirm the ploidy level of diploid (2n = 2x = 14, 2C DNA = 1.10 pg) and tetraploid (2n = 4x = 28, 2C DNA = 2.12 pg) plants after seven months. The highest polyploidy induction was obtained by applying 0.1% (w/v) colchicine for 48 h with an efficiency of 19.05% in vitro tetraploidy. Polyploids showed differences in leaf shape and color, leaf and stem thickness, trichrome density, root length, plant height, and number of leaves compared to diploid plants. There was also a significant decrease in rosmarinic acid content in polyploid (plants) as compared to diploid plants. Although a significant decrease in ursolic acid content was observed in polyploids, betulinic acid content associated with the expression levels of genes encoding enzymes being active in triterpene biosynthesis such as squalene epoxidase (SQE) and lupeol synthase (LUS). The expression of SQE and LUS was significantly increased in in vitro tertaploids (2.9-fold) and in vivo mixoploids (2.4-fold). The results confirm the idea that induced polyploidy can randomly alter breeding traits of plants as well as the content of bioactive compounds.