Neuroprotective Effects and Mechanisms of Procyanidins In Vitro and In Vivo

Bioactive Compounds from Plant Origin as Natural Antimicrobial Agents for the Treatment of Wound Infections

The rising prevalence of drug-resistant bacteria underscores the need to search for innovative and nature-based solutions. One of the approaches may be the use of plants that constitute a rich source of miscellaneous compounds with a wide range of biological properties. This review explores the antimicrobial activity of seven bioactives and their possible molecular mechanisms of action. Special attention was focused on the antibacterial properties of berberine, catechin, chelerythrine, cinnamaldehyde, ellagic acid, proanthocyanidin, and sanguinarine against Staphylococcus aureus, Enterococcus spp., Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, Serratia marcescens and Pseudomonas aeruginosa. The growing interest in novel therapeutic strategies based on new plant-derived formulations was confirmed by the growing number of articles. Natural products are one of the most promising and intensively examined agents to combat the consequences of the overuse and misuse of classical antibiotics.

Ingredients, structure and reconstitution properties of instant powder foods and the potential for healthy product development: a comprehensive review

Instant foods are widely presented in powder forms across different food segments, which potentially can be formulated with functional or beneficial compounds to provide health benefits. Many reconstituted instant powder foods form colloidal suspensions with complex structures. However, designing instant powder food could be challenging due to the structural complexity and high flexibility in formulation. This review proposed a new classification method for instant powder foods according to the solubility of ingredients and the structure of the reconstituted products. Instant powder foods containing insoluble ingredients are discussed. It summarised challenges and current advances in powder treatments, reconstitution improvement, and influences on food texture and structure to facilitate product design in related industries. The characteristics and incorporation of the main ingredients and ingredients with health benefits in product development were reviewed. Different products vary significantly in the ratios of macronutrients. The macronutrients have limited solubility in water. After being reconstituted by water, the insoluble components are dispersed and swell to form colloidal dispersions with complex structures and textures. Soluble components, which dissolve in the continuous phase, may facilitate the dispersing process or influence the solution environment. The structure of reconstituted products and destabilising factors are discussed. Both particle and molecular structuring strategies have been developed to improve wettability and prevent the formation of lumps and, therefore, to improve reconstitution properties. Various types of instant food have been developed based on healthy or functional ingredients and exhibit positive effects on the prevention of non-communicable diseases and overall health. Less processed materials and by-products are often chosen to enhance the contents of dietary fibre and phenolic compounds. The enrichment of phenolic compounds, dietary fibres and/or probiotics tend to be simultaneous in plant-based products. The process of the ingredients and the formulation of products must be tailored to design the desired structure and to improve the reconstitution property.

Grape seed-derived procyanidins decreases neuropathic pain and nerve regeneration by suppression of toll-like receptor 4-myeloid differentiation factor-88 signaling

Background: Recent studies have shown that peripheral nerve regeneration process is closely related to neuropathic pain. Toll-like receptor 4 (TLR4) signaling was involved in different types of pain and nerve regeneration. TLR4 induced the recruitment of myeloid differentiation factor-88 adaptor protein (MyD88) and NF-κB-depended transcriptional process in sensory neurons and glial cells, which produced multiple cytokines and promoted the induction and persistence of pain. Our study aimed to investigate procyanidins's effect on pain and nerve regeneration via TLR4-Myd88 signaling. Methods: Spinal nerve ligation (SNL) model was established to measure the analgesic effect of procyanidins. Anatomical measurement of peripheral nerve regeneration was measured by microscopy and growth associated protein 43 (GAP43) staining. Western blotting and/or immunofluorescent staining were utilized to detect TLR4, myeloid differentiation factor-88 adaptor protein (MyD88), ionized calcium-binding adapter molecule 1 (IBA1) and nuclear factor kappa-B-p65 (NF-κB-p65) expression, as well as the activation of astrocyte and microglia. The antagonist of TLR4 (LPS-RS-Ultra, LRU) were intrathecally administrated to assess the behavioral effects of blocking TLR4 signaling on pain and nerve regeneration. Result: Procyanidins reduced mechanical allodynia, thermal hyperalgesia and significantly suppressed the number of nerve fibers regenerated and the degree of myelination in SNL model. Compared with sham group, TLR4, MyD88, IBA1 and phosphorylation of NF-κB-p65 were upregulated in SNL rats which were reversed by procyanidins administration. Additionally, procyanidins also suppressed activation of spinal astrocytes and glial cells. Conclusion: Suppression of TLR4-MyD88 signaling contributes to the alleviation of neuropathic pain and reduction of nerve regeneration by procyanidins.

Involvement of Glutamate Cysteine Ligase Genes in Tolerance to Emamectin Benzoate in Spodoptera frugiperda and Their Putative Regulatory Mechanisms

As the rate-limiting enzyme in de novo Glutathione (GSH) biosynthesis, the mammalian glutamate cysteine ligase (Gcl) catalytic (Gclc) and modifier (Gclm) subunits are regulated at multiple levels, whereas the function and regulatory mechanism of insect Gcl remain to be explored. In this study, we identified and characterized SfGclc and SfGclm in Spodoptera frugiperda. SfGclc and SfGclm were highly expressed in the hindgut and relatively less expressed in other tissues. The exposure of the third instar larvae to LC30 of emamectin benzoate (EMB) significantly reduced the GSH content with a concomitant upregulation of SfGclc and SfGclm. Further in vivo pretreatment with L-BSO, the Gcl inhibitor, increased the susceptibility of S. frugiperda to EMB. Consistently, overexpression of SfGclc and SfGclm increased the Sf9 cell viability under EMB treatment. Finally, both RNAi and the dual-luciferase reporter assay in Sf9 cells revealed that SfGclc is regulated by transcription factor CncC. These data provide insights into the function and regulatory mechanism of insect Gcl, and they imply that disruption of the redox homeostasis might be a practical strategy to enhance the insecticidal activity of EMB and other insecticides.

Biological and pharmacological aspects of tannins and potential biotechnological applications

Secondary metabolites are divided into three classes: phenolic, terpenoid, and nitrogenous compounds. Phenolic compounds are also known as polyphenols and include tannins, classified as hydrolysable or condensed. Herein, we explored tannins for their ROS reduction characteristics and role in homeostasis. These activities are associated with the numbers and degree of polymerisation of reactive hydroxyl groups present in the phenolic rings of tannins. These characteristics are associated with anti-inflammatory, anti-aging, and anti-proliferative health benefits. Tannins can reduce the risk of cancer and neurodegenerative diseases, such as cardiovascular diseases and Alzheimer's, respectively. These biomolecules may be used as nutraceuticals to maintain good gut microbiota. Industrial applications include providing durability to leather, anti-corrosive properties to metals, and substrates for 3D printing and in bio-based foam manufacture. This review updates regarding tannin-based research and highlights its biological and pharmacological relevance and potential applications.

Anemonin reduces hydrogen peroxide-induced oxidative stress, inflammation and extracellular matrix degradation in nucleus pulposus cells by regulating NOX4/NF-κB signaling pathway

BACKGROUND

Excessive oxidative stress plays a critical role in the progression of various diseases, including intervertebral disk degeneration (IVDD). Recent studies have found that anemonin (ANE) possesses antioxidant and anti-inflammatory effects. However, the role of ANE in IVDD is still unclear. Therefore, this study investigated the effect and mechanism of ANE on H₂O₂ induced degeneration of nucleus pulposus cells (NPCs).

METHODS

NPCs were pretreated with ANE, and then treated with H₂O₂. NOX4 was upregulated by transfection of pcDNA-NOX4 into NPCs. Cytotoxicity was detected by MTT, oxidative stress-related indicators and inflammatory factors were measured by ELISA, mRNA expression was assessed by RT-PCR, and protein expression was tested by western blot.

RESULTS

ANE attenuated H₂O₂-induced inhibition of NPCs activity. H₂O₂ enhanced oxidative stress, namely, increased ROS and MDA levels and decreased SOD level. However, these were suppressed and pretreated by ANE. ANE treatment repressed the expression of inflammatory factors (IL-6, IL-1β and TNF-α) in H₂O₂-induced NPCs. ANE treatment also prevented the degradation of extracellular matrix induced by H₂O₂, showing the downregulation of MMP-3, 13 and ADAMTS-4, 5 and the upregulation of collagen II. NOX4 is a key factor regulating oxidative stress. Our study confirmed that ANE could restrain NOX4 and p-NF-κB. In addition, overexpression of NOX4 counteracted the antioxidant and anti-inflammatory activities of ANE in H₂O₂-induced NPCs, and the inhibition of the degradation of extracellular matrix induced by ANE was also reversed by overexpression of NOX4.

CONCLUSION

ANE repressed oxidative stress, inflammation and extracellular matrix degradation in H₂O₂-induced NPCs by inhibiting NOX4/NF-κB pathway. Our study indicated that ANE might be a candidate drug for the treatment of IVDD.

Metabolic Fate of Orally Ingested Proanthocyanidins through the Digestive Tract

Proanthocyanidins (PACs), which are oligomers or polymers of flavan-3ols with potent antioxidative activity, are well known to exert a variety of beneficial health effects. Nonetheless, their bioaccessibility and bioavailability have been poorly assessed. In this review, we focused on the metabolic fate of PACs through the digestive tract. When oligomeric and polymeric PACs are orally ingested, a large portion of the PACs reach the colon, where a small portion is subjected to microbial degradation to phenolic acids and valerolactones, despite the possibility that slight depolymerization of PACs occurs in the stomach and small intestine. Valerolactones, as microbiota-generated catabolites of PACs, may contribute to some of the health benefits of orally ingested PACs. The remaining portion interacts with gut microbiota, resulting in improved microbial diversity and, thereby, contributing to improved health. For instance, an increased amount of beneficial gut bacteria (e.g., Akkermansia muciniphila and butyrate-producing bacteria) could ameliorate host metabolic functions, and a lowered ratio of Firmicutes/Bacteroidetes at the phylum level could mitigate obesity-related metabolic disorders.

Salix subserrata Bark Extract-Loaded Chitosan Nanoparticles Attenuate Neurotoxicity Induced by Sodium Arsenate in Rats in Relation with HPLC-PDA-ESI-MS/MS Profile

Pollution is a worldwide environmental risk. Arsenic (As) is an environmental pollutant with a major health concern due to its toxic effects on multiple body organs, including the brain. Humans are exposed to As through eating contaminated food and water or via skin contact. Salix species (willow) are plants with medicinal efficacy. Salix subserrata Willd bark extract-loaded chitosan nanoparticles (SBE.CNPs) was formulated, characterized, and evaluated against As-induced neurotoxicity. The stem bark was selected for nanoparticle formulation based on HPLC-PDA-ESI-MS/MS profiling and in vitro antioxidant assessment using free radical scavenging activity. SBE.CNPs demonstrated an average un-hydrated diameter of 193.4 ± 24.5 nm and zeta potential of + 39.6 ± 0.4 mV with an encapsulation efficiency of 83.7 ± 4.3%. Compared to As-intoxicated rats, SBE.CNP-treated rats exhibited anxiolytic activity and memory-boosting as evidenced in open field test, light-dark activity box, and Y-maze. Also, it increased the antioxidant biomarkers, including superoxide dismutase and glutathione peroxidase associated with reducing the malondialdehyde levels and apoptotic activity. Besides this, SBE.CNPs maintained the brain architecture and downregulated both nuclear factor-kappa B and heme oxygenase-1 expression. These results suggest that SBE.CNP administration showed promising potent neuroprotective and antioxidative efficiencies against arsenic-induced oxidative threats.

The Relationship between Procyanidin Structure and Their Protective Effect in a Parkinson's Disease Model

This study evaluated the effect of grape seed-derived monomer, dimeric, and trimeric procyanidins on rat pheochromocytoma cell line (PC12) cells and in a zebrafish Parkinson’s disease (PD) model. PC12 cells were cultured with grape seed-derived procyanidins or deprenyl for 24 h and then exposed to 1.5 mm 1-methyl-4-phenylpyridinium (MPP⁺) for 24 h. Zebrafish larvae (AB strain) 3 days post-fertilization were incubated with deprenyl or grape seed-derived procyanidins in 400 µM 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 4 days. The results showed that the procyanidin dimers procyanidin B1 (B1), procyanidin B2 (B2), procyanidin B3 (B3), procyanidin B4 (B4), procyanidin B1-3-O-gallate (B1-G), procyanidin B2-3-O-gallate (B2-G), and the procyanidin trimer procyanidin C1 (C1) had a protective effect on PC12 cells, decreasing the damaged dopaminergic neurons and motor impairment in zebrafish. In PC12 cells and the zebrafish PD model, procyanidin (B1, B2, B3, B4, B1-G, B2-G, C1) treatment decreased the content of reactive oxygen species (ROS) and malondialdehyde (MDA), increased the activity of antioxidant enzymes glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD), and upregulated the expression of nuclear factor-erythroid 2-related factor (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO1), and heme oxygenase-1 (HO-1). These results suggest that in PC12 cells and the zebrafish PD model, the neuroprotective effects of the procyanidins were positively correlated with their degree of polymerization.

Foliar application of procyanidins enhanced the biosynthesis of 2-acetyl-1-pyrroline in aromatic rice (Oryza sativa L.)

BACKGROUND

Procyanidins is a polyphenolic compound with multiple properties. However, the application of exogenous procyanidins in crops has not been reported. Aromatic rice is a high-quality rice with a special aroma and popular with consumers. The 2-acetyl-1-pyrroline (2-AP) is a key compound of aromatic rice aroma. In the current study, aromatic rice plants were sprayed with procyanidins solutions at 0.25 (Pr0.25), 0.50 (Pr0.50), 1.00 (Pr1.00), 2.00 (Pr2.00) g L^-1, respectively and treatment sprayed with distilled water was taken as control (CK). The effects of exogenous procyanidins on growth and 2-AP biosynthesis of aromatic rice plants were explored.

RESULTS

Compared with CK, Pr1.00 and Pr2.00 treatments significantly increased 2-AP content by 16.67% and 37.68%, respectively. Higher proline, 1-pyrroline-5-carboxylic acid (P5C), 1-pyrroline, methylglyoxal contents, and lower γ- aminobutyric acid (GABA) content were recorded in Pr1.00 and Pr2.00 treatments than CK. Compared with CK, Pr1.00 and Pr2.00 treatments significantly improved the activities of P5CS and OAT and diminished the activity of BADH. Furthermore, compared with CK, Pr1.00 and Pr2.00 treatments significantly up-regulated the transcript levels of P5CS2, P5CR, OAT, DAO4 and down-regulated the transcript levels of BADH2. Exogenous procyanidins had no substantial effects on plant height, stem diameter, fresh weight, and dry weight of aromatic rice plants.

CONCLUSIONS

In conclusion, our findings reported the increment of 2-AP content in aromatic rice under exogenous procyanidins. Our results indicated that the application of exogenous procyanidins enhanced 2-AP biosynthesis by improving proline biosynthesis and inhibiting GABA formation.

UPLC-Q-TOF-MS/MS Analysis of Phenolic Compounds from the Fruit of Cephalostachyum fuchsianum Gamble and Their Antioxidant and Cytoprotective Activities

Bamboo is a widely distributed graminaceous plant in China and is a potential source of bioactive substances. Incidentally, bamboo’s fruit is rich in phytochemicals such as polyphenols and flavonoids, which are significant to human health. In this study, we identified the phenolic compounds of the fruit and investigated the antioxidant activities of Cephalostachyum fuchsianum Gamble (CFG) fruit polyphenols with in vitro and in vivo tests for the first time. UPLC–Q–TOF–MS/MS analysis results showed that the fruit contained 43 phenolic compounds, including 7 hydroxybenzoic acids, 12 flavonoids, 7 coumarins, 10 hydroxycinnamic acids, 1 terpenoid, and 5 lignans. The TPC of SP extracts was higher than that of IBPs extracts in FP and FF. The SP extracts in FP showed better antioxidant activities in vitro compared to those in FF. In addition, polyphenols from CFG fruits protected against H₂O₂-induced oxidative damage in HepG2 cells, and the protective effect of polyphenols in FP was superior to that in FF. The analysis results showed that CFG fruit has great potential in exploiting natural chemical substances, which can provide valuable pieces of information for the further development and utilization of CFG.

Relationship between Neuroprotective Effects and Structure of Procyanidins

This study evaluated the relationship between the neuroprotective effects of procyanidins and their structural characteristics. In vitro, a rat pheochromocytoma cell line (PC12) was exposed to the grape seed-derived procyanidin monomers: catechin (C), epicatechin (EC), and epicatechin gallate (ECG); the procyanidin dimers: procyanidin B1 (B1), procyanidin B2 (B2), procyanidin B3 (B3), procyanidin B4 (B4), procyanidin B1-3-O-gallate (B1-G), and procyanidin B2-3-O-gallate (B2-G); and the procyanidin trimers: procyanidin C1 (C1) and N-acetyl-l-cysteine (NAC) for 24 h. Cells were then incubated with 200 μM H₂O₂ for 24 h. In vivo, zebrafish larvae (AB strain) 3 days post-fertilization were incubated with NAC or procyanidins (C, EC, ECG, B1, B2, B3, B4, B1-G, B2-G, C1) in 300 µM H₂O₂ for 4 days. Different grape seed procyanidins increased the survival of PC12 cells challenged with H₂O₂, improved the movement behavior disorder of zebrafish caused by H₂O₂, inhibited the increase of ROS and MDA and the decrease of GSH-Px, CAT, and SOD activities, and up-regulated the Nrf2/ARE pathway. The neuroprotective effects of the procyanidin trimer C1 treatment group were greater than the other treatment groups. These results suggest that the neuroprotective effect of procyanidins is positively correlated with their degree of polymerization.

Protective Effects and Mechanisms of Procyanidins on Parkinson's Disease In Vivo and In Vitro

This research assessed the molecular mechanism of procyanidins (PCs) against neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its metabolite 1-methyl-4-phenylpyridinium (MPP⁺) induced Parkinson’s disease (PD) models. In vitro, PC12 cells were incubated with PCs or deprenyl for 24 h, and then exposed to 1.5 mM MPP⁺ for 24 h. In vivo, zebrafish larvae (AB strain) 3 days post-fertilization (dpf) were incubated with deprenyl or PCs in 400 μM MPTP for 4 days. Compared with MPP⁺/MPTP alone, PCs significantly improved antioxidant activities (e.g., glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT)), and decreased levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Furthermore, PCs significantly increased nuclear Nrf2 accumulation in PC12 cells and raised the expression of NQO1, HO-1, GCLM, and GCLC in both PC12 cells and zebrafish compared to MPP⁺/MPTP alone. The current study shows that PCs have neuroprotective effects, activate the nuclear factor-erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and alleviate oxidative damage in MPP⁺/MPTP-induced PD models.