Composition analysis and antioxidant activity evaluation of a high purity oligomeric procyanidin prepared from sea buckthorn by a green method

Effects of Pulsed Electric Field and High-Pressure Processing Treatments on the Juice Yield and Quality of Sea Buckthorn

Sea buckthorn juice has high nutritional value and a rich flavor that consumers enjoy. Traditional sea buckthorn thermal processing (TP) technology has problems such as low juice yield, poor quality, and poor flavor. Sea buckthorn berries are processed using a technique combining pulsed electric field (PEF) and high-pressure processing (HPP) to increase juice yield and study its impact on the quality and volatile aroma of sea buckthorn juice. Results have show that, compared with TP, under the condition of PEF-HPP, the juice yield of sea buckthorn significantly increased by 11.37% (p > 0.05); TP and PEF-HPP treatments could effectively kill microorganisms in sea buckthorn juice, but the quality of sea buckthorn juice decreased significantly after TP treatment (p > 0.05), whereas PEF-HPP coupling technology could maximally retain the nutrients of sea buckthorn juice while inhibiting enzymatic browning to improve color, viscosity, and particle size. The flavor of sea buckthorn juice is analyzed using electronic nose (E-nose) and gas chromatography-ion mobility spectrometer (GC-IMS) techniques, and it has been shown that PEF-HPP retains more characteristic volatile organic compounds (VOCs) of sea buckthorn while avoiding the acrid and pungent flavors produced by TP, such as benzaldehyde, (E)-2-heptenal, and pentanoic acid, among others, which improves the sensory quality of sea buckthorn juice. PEF-HPP technology is environmentally friendly and efficient, with significant economic benefits. Research data provide information and a theoretical basis for the sea buckthorn juice processing industry.

Anti-skin aging effect of sea buckthorn proanthocyanidins in D-galactose-induced aging mice

Oxidative stress in skin cells caused by changes in the external environment is one of the principal causes of skin aging. Sea buckthorn proanthocyanidins (SBPs) have good free radical scavenging ability. We established a senescence model by injecting 500 mg/kg D-galactose into the dorsal necks of mice, and then different doses of SBP (25, 50, and 100 mg/kg) were gavaged to explore the effects of SBP on the skin tissues of senescent mice and elucidate the related mechanism of action. The results reveal that SBP can alleviate the skin aging phenomenon caused by D-galactose-induced aging. It can also enhance the total antioxidant capacity in the body, thereby strengthening the body's antioxidant defense capability. In addition, SBP can effectively improve skin aging by regulating the TGF-β1/Smads pathway and MMPs/TIMP system, increasing the relative content of Col I and tropoelastin, further maintaining the stability of collagen fiber and elastic fiber structure. These results will provide the development and production of the antioxidant function of cosmetics and health products, providing a new train of thought.

Preparation of DES lignin-chitosan aerogel and its adsorption performance for dyes, catechin and epicatechin

Herein, DES lignin was obtained by pretreatment of grapevine with a deep eutectic solvent (ChCl-LA). A novel chitosan-DES lignin composite aerogel material (CS-LIG aerogel) was prepared to adsorb methylene blue (MB), Congo red (CR), catechin (C), and epicatechin (EC). The CS-LIG aerogel was systematically characterized by modern technological instruments. It was demonstrated that the DES lignin was successfully incorporated and had an important effect on the morphological structure and adsorption of dyes and natural products in the aerogel. The adsorption kinetic models for both adsorbed CR and MB are pseudo-second-order models. Adsorption isotherms followed Langmuir for the adsorption of CR and Freundlich for the adsorption of MB. The π-π interaction and hydrogen bonding of DES lignin aromatic groups in CS-LIG aerogels were responsible for the adsorption of C and EC with 86.42 % and 90.85 % removal rates, respectively. This study opens a new avenue for the high-value utilization of DES lignin and the preparation of chitosan-based composites for the adsorption of dyes and purification of natural products.

Antioxidant activities of artesunate-procyanidin hybrid compound in erythrocyte and liver of Plasmodium berghei NK65-infected mice

Resistance of malaria parasites to conventionally used antimalarial drugs has necessitated the search for new potent antimalarials, especially those that can also ameliorate oxidative stress-mediated secondary complications. This has led to the synthesis of an antimalarial artesunate-procyanidin hybrid compound (PC14), but it has not been evaluated for its antioxidant activity. This study was carried out to evaluate the antioxidant activities of PC14 in the erythrocyte and liver of Plasmodium berghei NK65-infected mice. A hundred mice were randomly divided into 10 equal groups (A-J). Mice in Groups B-J were inoculated with P. berghei NK65 while group A mice were not inoculated. Starting from Day 3 post-inoculation, dimethyl sulfoxide (DMSO) (5%) was administered to mice in Groups A and B (normal and negative controls, respectively), while various doses of chloroquine, artesunate, procyanidin, and PC14 were administered to their respective groups for 3 days. Thereafter, antioxidant parameters were determined in the erythrocyte and liver on Days 6 and 10 post-inoculation. A significant increase (P < 0.05) was observed in malondialdehyde levels in the erythrocyte and liver of negative control on Day 10 post-inoculation compared to normal controls. Significant reduction (P < 0.05) was observed in activities of liver catalase and superoxide dismutase and erythrocyte glutathione peroxidase and glutathione-S-transferase of negative control on Days 6 and 10 compared to normal controls. However, PC14 at various doses significantly (P < 0.05) reversed these alterations. The results suggest that PC14 possesses antioxidant activity, and it enhanced antioxidant defense in the erythrocyte and liver of P. berghei-infected mice.

Flavonoid Extract from Seed Residues of Hippophae rhamnoides ssp. sinensis Protects against Alcohol-Induced Intestinal Barrier Dysfunction by Regulating the Nrf2 Pathway

Alcohol has been demonstrated to disrupt intestinal barrier integrity. Some flavonoid compounds that exert antioxidant activity have a protective effect on intestinal barrier function. As an important medicinal and edible plant, sea buckthorn (Hippophae) seeds are rich in flavonoids, but their protective effect on the intestinal barrier has not been reported. In our research, 76 kinds of flavonoids were identified in Hippophae rhamnoides ssp. sinensis seed residue flavonoids (HRSF) by ultra-performance liquid chromatography-tandem mass spectrometry. Kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, kaempferol-3-O-robinoside-7-O-rhamnoside, isorhamnetin-3-O-2G-rhamnosylrutinoside, quercetin-3-O-rutinoside, (-)-epigallocatechin, and B type of procyanidin were the most abundant substances, accounting for 15.276%, 15.128%, 18.328%, 10.904%, 4.596%, 5.082%, and 10.079% of all identified flavonoids, respectively. Meanwhile, pre-treatment with HRSF was able to prevent alcohol-induced disruption of intestinal barrier integrity through elevating the transepithelial monolayer resistance value, inhibiting the flux of fluorescein isothiocyanate-dextran, and upregulating the mRNA and protein level of TJs (occludin and ZO-1). Furthermore, it was also able to reverse alcohol-induced oxidative stress through suppressing the accumulation of reactive oxygen species and malondialdehyde, improving the glutathione level and superoxide dismutase activity. Finally, the results showed that HRSF pre-treatment effectively elevated the erythroid-related factor 2 mRNA and protein level compared with the alcohol-alone treatment group. Our research was the first to demonstrate that HRSF could prevent alcohol-induced intestinal barrier dysfunction through regulating the Nrf2-mediated pathway in order to attenuate oxidative stress and enhance TJ expression.

Anti-Aging Effect and Mechanism of Proanthocyanidins Extracted from Sea buckthorn on Hydrogen Peroxide-Induced Aging Human Skin Fibroblasts

Oxidative stress is the leading cause of skin aging damage. Excessive accumulation of reactive oxygen species (ROS) in cells induced by hydrogen peroxide (H₂O₂) triggers a decrease in collagen synthesis and an increase in collagen degradation, which are biomarkers of skin aging. We evaluated the potential protective mechanism of Sea buckthorn proanthocyanidins (SBP) against the oxidative stress-induced skin aging process from multiple aspects. We treated human skin fibroblasts (HSFs) with 300 µmoL/L of H₂O₂ for 24 h, followed by 25, 50, and 100 µg/mL of SBP for 24 h. The results showed that SBP could enhance the activities of superoxide dismutase (SOD) and glutathione (GSH), effectively remove excess ROS, and significantly improve the changes in cell morphology and viability caused by excessive ROS in skin cells. In addition, SBP could promote the synthesis of Col I in aging HSFs through the TGF-β1/Smads pathway and inhibit the degradation of Col I by regulating the MMPs/TIMPs system, thereby maintaining the stability of the ECM structure to achieve anti-aging purposes. Finally, we studied the migration ability of SBP, and the results showed that 100 µg/mL of SBP was most conducive to the cell migration of senescent cells, laying a foundation for follow-up animal experiments. These results will increase the application value of SBP in the cosmetic and antioxidative functional food industries.

Sea Buckthorn Proanthocyanidins are the Protective Agent of Mitochondrial Function in Macrophages Under Oxidative Stress

Sea buckthorn proanthocyanidins (SBP) are the most important antioxidant components of sea buckthorn, which are widely used in functional foods and cosmetics. Studies have shown that SBP have significant protective effects on macrophages against oxidative stress induced by hydrogen peroxide (H₂O₂). However, the mechanism remains uncertain. In the present study, we explored the effects of SBP on mitochondrial function and the mechanism of their protective effects against oxidative stress in cells. Our results showed that SBP could increase mitochondrial membrane potential, inhibit mPTP opening, reduce mitochondrial swelling, and enhance mitochondrial synthesis and metabolism. Thus, they alleviated oxidative damage and protected the cells against mitochondrial function. Western blot analysis showed that SBP had a protective effect on RAW264.7 cells by activating the AMPK-PGC1α-Nrf2 pathway. These results showed that SBP alleviated mitochondrial damage and dysfunction caused by oxidative stress. This study revealed the mechanism of SBP in reducing oxidative damage and provided a theoretical basis for further research on natural bioactive compounds to exert antioxidant activity and prevent arteriosclerosis and other diseases.

Regulatory Effect of Sea-Buckthorn Procyanidins on Oxidative Injury HUVECs

As society develops and aging populations increase, the incidence of arteriosclerosis, a seriously harmful cardiovascular disease (CVD) which mostly results from endothelial cellular oxidative damage, has continuously risen. Procyanidins from sea-buckthorn is a powerful antioxidant, although its protective effect on the cardiovascular system is not yet clearly understand. In this study, oxidative damaged HUVECs induced by palmitate acid (PA) were used as a model and the regulatory effect of procyanidins from sea-buckthorn (SBP) on HUVECs were investigated. The results showed SBP can be used for 12 h by HUVECs and had no detective cytotoxicity to them under 400 μg/L. Also, different concentrations of SBP can increase mitochondrial membrane potential and NO level and decrease LDH leakage in a dose-effect relationship, indicating SBP can improve oxidative damage. In addition, western blots and qPCR results showed SBP regulation on oxidative injured HUVECs is probably through p38MAPK/NF-κB signal pathway. This study revealed the molecular mechanism of procyanidins in decreasing endothelial oxidative damage, providing a theoretical foundation for further research on natural bioactive compounds to exert antioxidant activity in the body and prevent and improve cardiovascular diseases.

Effects of Ball Milling Combined With Cellulase Treatment on Physicochemical Properties and in vitro Hypoglycemic Ability of Sea Buckthorn Seed Meal Insoluble Dietary Fiber

To improve the rough texture and hypoglycemic ability of sea buckthorn insoluble dietary fiber (IDF), a novel combined modification method was developed in this study. The IDF was treated with ball milling and cellulase treatment to obtain co-modified insoluble dietary fiber (CIDF). The physicochemical and functional properties of IDF, milled insoluble dietary fiber (MIDF), and CIDF were studied. After treatments, MIDF had smaller particle sizes and a looser structure, and CIDF exhibited a wrinkled surface and sparse porous structure according to scanning electron microscopy (SEM) and X-ray diffraction. Compared to IDF, MIDF and CIDF showed improved water-holding, oil-binding, and swelling capacities, improved by 16.13, 14.29, and 15.38%, and 38.5, 22.2, and 25.0%, for MIDF and CIDF, respectively. The cation exchange ability of modified samples showed improvement as well. Treatments also changed the fluidity of MIDF and CIDF. Due to the smaller particles and increased stacking, the bulk density (BD) and angle of repose of MIDF improved by 33.3% and 4.1° compared to IDF, whereas CIDF had a looser structure and thus decreased by 7.1% and 13.3° with increased fluidity. Moreover, the modification also enhanced the effects of CIDF on glucose adsorption, glucose diffusion inhibition, starch digestion inhibition, starch pasting interference, and α-amylase activity inhibition. In summary, IDF modified by ball milling combined with cellulose treatment could be developed as a functional ingredient for regulating glucose content.