Phytosterol profiles and iridoids of the edible Eucommia ulmoides Oliver seeds and their anti-inflammatory potential

Physicochemical and functional characteristics of Eucommia ulmoides seed meal protein hydrolysates and their isolates

BACKGROUND

Eucommia ulmoides Oliv. seed meal (ESM) as a potential edible protein source as this by-product is usually underutilized or discarded. This study aimed to isolate antioxidant ESM protein hydrolysates (ESMHs) fractions and investigate their physicochemical properties to explore their potential applications.

RESULTS

Three fractions (F1, F2, F3) were isolated via gel chromatography, showing a positive correlation between the antioxidant capabilities and their antioxidant amino acids composition. Fluorescence spectra revealed a red shift of 3-6 nm in the maximum emission wavelength (λmax) for the fractions compared to ESMHs, indicating increased exposure of aromatic amino acids on the side chains of F1, F2, and F3 isolates. The surface hydrophobicity (H0) index for these isolates followed the order: F2 > F3 > F1, aligning with their endogenous fluorescence spectra data. These findings further verified that more hydrophobic amino acid residues were exposed as a result of the structural unfolding of proteins. Thermal stability analysis demonstrated that the isolated fractions with higher H0 required less energy for denaturation. A distinct taste difference was observed between isolated fractions and ESMHs, tyrosine, phenylalanine, histidine and arginine were closely associated with the taste generation. Additionally, the low molecular weight and high glutamic acid content of the isolated fractions would contribute to their umami taste.

CONCLUSION

The present study demonstrated that ESMHs and their isolated fractions possessed desirable functional properties, including antioxidant capacity and favorable taste profiles, thereby presenting significant potential as functional ingredients for food, cosmetics or pharmaceuticals industries. © 2025 Society of Chemical Industry.

Plant iridoids: Chemistry, dietary sources and potential health benefits

Iridoids, a diverse class of plant food monoterpenoids, are characterized by a cyclopentane-fused pyran ring structure and exhibit extensive structural diversity and functional versatility. This review highlights recent advances in iridoid chemistry, biosynthesis via the methylerythritol phosphate pathway, and advanced extraction techniques such as ultrasound-assisted, microwave-assisted, and supercritical fluid extraction. Analytical methods such as liquid chromatography-mass spectrometry enable precise identification and quantification, advancing the study of their health-promoting properties. Iridoids demonstrate potent antioxidant, anti-inflammatory, neuroprotective, antitumor, antiviral, and hepatoprotective effects suggesting their potential use in functional foods, nutraceuticals, pharmaceuticals, and cosmetics. However, for the successful commercialization of iridoid-based products, future research should aim at the cost-effective production of iridoids using sustainable production systems, biotechnological synthesis, and clinical validation. This review reveals the significant promise of iridoids in enhancing human health through potential product innovation and assessment.

Insights on therapeutic approaches of natural anti-Alzheimer's agents in the management of Alzheimer's disease: A future perspective

In the current scenario, Alzheimer's disease is a complex, challenging, and arduous health issue, and its prevalence, together with comorbidities, is accelerating around the universe. Alzheimer's disease is becoming a primary concern that significantly impacts an individual's status in life. The traditional treatment of Alzheimer's disease includes some synthetic drugs, which have numerous dangerous side effects, a high risk of recurrence, lower bioavailability, and limited treatment. Hence, the current article is a detailed study and review of all known information on plant-derived compounds as natural anti-Alzheimer's agents, including their biological sources, active phytochemical ingredients, and a possible mode of action. With the help of a scientific data search engine, including the National Center for Biotechnology Information (NCBI/PubMed), Science Direct, and Google Scholar, analysis from 2001 to 2024 has been completed. This article also described clinical studies on phytoconstituents used to treat Alzheimer's disease. Plant-derived compounds offer promising alternatives to synthetic drugs in treating Alzheimer's disease, with the potential for improving cognitive function and slowing down the progression of the disease. Further research and clinical trials are needed to fully explore their therapeutic potential and develop effective strategies for managing this complex condition.

Supercritical CO2 Extraction of Terpenoids from Indocalamus latifolius Leaves: Optimization, Purification, and Antioxidant Activity

This study aimed to investigate the efficacy of supercritical CO2 (SC-CO2) extraction in enhancing the extraction rate, purity, and antioxidant activity of Indocalamus latifolius (Keng) McClure (Poaceae) leaf terpenoids (ILLTs). Crude extracts obtained from leaves were subjected to qualitative and quantitative analyses, revealing neophytadiene, phytol, β-sitosterol, β-amyrone, squalene, and friedelin as the primary terpenoid constituents, identified through gas chromatography-mass spectrometry (GC-MS). Compared with steam distillation extraction (SD), simultaneous distillation extraction (SDE), ultra-high pressure-assisted n-hexane extraction (UHPE-Hex), ultra-high pressure-assisted ethanol extraction (UHPE-EtOH), ultrasound-assisted n-hexane extraction (UE-Hex), and ultrasound-assisted ethanol extraction (UE-EtOH), SC-CO2 exhibited a superior ILLT extraction rate, purity, and antioxidant activity. Scanning electron microscopy (SEM) observations of the residues further revealed more severe damage to both the residues and their cell walls after SC-CO2 extraction. Under optimal parameters (4.5 h, 26 MPa, 39 °C, and 20% ethyl alcohol), the ILLT extraction rate with SC-CO2 reached 1.44 ± 0.12 mg/g, which was significantly higher than the rates obtained by the other six methods. The subsequent separation and purification using WelFlash C18-l, BUCHI-C18, and Sephadex LH-20 led to an increase in the purity of the six terpenoid components from 12.91% to 93.34%. Furthermore, the ILLTs demonstrated cytotoxicity against HepG2 cells with an IC50 value of 148.93 ± 9.93 μg/mL. Additionally, with increasing concentrations, the ILLTs exhibited an enhanced cellular antioxidant status, as evidenced by reductions in both reactive oxygen species (ROS) and malondialdehyde (MDA) levels.

Chemical Analysis and Investigation of Antimicrobial and Antibiofilm Activities of Prangos trifida (Apiaceae)

Plants of the genus Prangos are intensively investigated as potential new sources of bioactive isolated products. In this work, the chemical composition of volatile constituents (essential oils and headspace volatiles) and dichloromethane extracts, as well as antimicrobial and antibiofilm activities of essential oils and MFDEs (methanol fractions of dichloromethane extracts) of Prangos trifida from Serbia, were investigated. Volatiles of roots, leaves, stems and fruits, and fatty acids and phytosterols in dichloromethane extracts of roots and fruits were analyzed by GC-FID-MS, whereas coumarins in MFDEs by LC-MS and some isolated coumarins by 1H-NMR. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations/minimum fungicidal concentrations (MBCs/MFCs) of essential oils and MFDEs were determined against 13 microorganisms. Antibiofilm activity was assessed against four microorganisms. Additionally, congo red and ergosterol binding assays were conducted to elucidate selected mechanisms of antibiofilm action in the case of Candida albicans. Total of 52 volatile constituents, 16 fatty acids, eight phytosterols and 10 coumarins were identified. Essential oils demonstrated significant activity, surpassing that of commercial food preservatives, against six tested molds from the Aspergillus, Penicillium and Trichoderma genera, as well as against bacteria Staphylococcus aureus and Bacillus cereus. Most of the oils strongly inhibited the formation of biofilms by S. aureus, Listeria monocytogenes and Escherichia coli. MFDEs exhibited noteworthy effects against B. cereus and the tested Aspergillus species, particularly A. niger, and significantly inhibited C. albicans biofilm formation. This inhibition was linked to a marked reduction in exopolysaccharide production, while antifungal mechanisms associated with ergosterol remained unaffected.

Quantitative Analysis and Stability Study on Iridoid Glycosides from Seed Meal of Eucommia ulmoides Oliver

As a traditional Chinese medicine, Eucommia ulmoides Oliver (E. ulmoides Oliv.) is an important medicinal plant, and its barks, male flowers, leaves, and fruits have high value of utilization. The seed meal of E. ulmoides Oliv. is the waste residue produced after oil extraction from seeds of E. ulmoides Oliv. Though the seed meal of E. ulmoides Oliv. is an ideal feed additive, its medicinal value is far from being developed and utilized. We identified six natural iridoid compounds from the seed meal of E. ulmoides Oliv., namely geniposidic acid (GPA), scyphiphin D (SD), ulmoidoside A (UA), ulmoidoside B (UB), ulmoidoside C (UC), and ulmoidoside D (UD). Six natural iridoid compounds were validated to have anti-inflammatory activities. Hence, six compounds were quantified at the optimum extracting conditions in the seed meal of E. ulmoides Oliv. by an established ultra-performance liquid chromatography (UPLC) method. Some interesting conversion phenomena of six tested compounds were uncovered by a systematic study of stability performed under different temperatures and pH levels. GPA was certified to be stable. SD, UA, and UC were only hydrolyzed under strong alkaline solution. UB and UD were affected by high temperature, alkaline, and strong acid conditions. Our findings reveal the active compounds and explore the quantitative analysis of the tested compounds, contributing to rational utilization for the seeds residues of E. ulmoides Oliv.

Influences of dietary Eucommia ulmoides leaf extract on the hepatic lipid metabolism, inflammation response, intestinal antioxidant capacity, intestinal microbiota, and disease resistance of the channel catfish (Ictalurus punctatus)

The purpose of the study was to investigate the effects of Eucommia ulmoides leaf extract (ELE) on the common occurrence of liver steatosis, chronic inflammation, oxidative stress, disturbance of gut microbiota, and disease susceptibility in high-fat diet-fed channel catfish. Channel catfish fed three diets, including a high-fat diet (11% crude fat) and ELE-supplemented diets containing 1‰ or 2‰ ELE for 4 weeks. The results showed the contents of liver triacylglycerol of 1‰ and 2‰ ELE groups were reduced, and ELE treatments decreased the expression of lipogenesis related genes (srebp-1c, pparγ, and acc-1), and increased the expression of lipolysis related genes (pparα). In addition, the supplementation of ELE improved the inflammatory response of the liver and intestine. ELE could improve the destruction of intestinal morphology structure and increase the expression level of hif-1a and tight junction proteins (Occludin, Claudin2, Claudin15). 2‰ ELE significantly enhanced the antioxidant capacity of intestine by increasing the activity of SOD enzyme. Moreover, the supplement of ELE significantly increased the abundance of Cetobacterium and Romboutsia (p < 0.05). Compared with the control group, the expression of immune factor nf-κb had a significant decrease, and il-1β showed a tendency to decrease in the ELE supplement groups after pathogenic bacteria challenge. In conclusion, the ELE alleviated fatty liver disease and inflammation response, improved the oxidative capacity and physiological structure of intestine, and improved the structure of intestinal microbiota and disease resistance in HFD-fed channel catfish.