Fucoidan has many biological functions, including anti-tumor activity. Additionally, it has been suggested that low-molecular-weight fucoidans have greater bioactivities. This study aimed to examine the degradation, purification, physicochemical characterization and in vitro antitumor activity of fucoidan from Sargassum hemiphyllum (Turner) C. Agardh. Fucoidan was isolated using DEAE-cellulose-52 (F1, F2), Vc-H₂O₂ degration, and Sepharose CL-6B gel (DF1, DF2) from crude Sargassum fucoidans. Physicochemical characteristics of four isolated fucoidans were examined using chemical and monosaccharide composition, average molecular weight (Mw), and FTIR. Furthermore, the anti-proliferative effects of purified fucoidans on human hepatocellular carcinoma cells (HepG2), human Burkitt Lymphoma cells (MCF-7), human uterine carcinoma cells (Hela) and human lung cancer cells (A549) were analyzed by MTT method. The apoptosis of HepG2 cells was detected by flow cytometry. Our data suggest that the contents of polysaccharide, L-fucose and sulfate of DF2 were the highest, which were 73.93%, 23.02% and 29.88%, respectively. DF1 has the smallest molecular weight (14,893 Da) followed by DF2 (21,292 Da). The four fractions are mainly composed of fucose, mannose and rhamnose, and the infrared spectra are similar, all of which contain polysaccharide and sulfate characteristic absorption peaks. The results of MTT assay showed that the four fractions had inhibitory effects on HepG2 and A549 in the range of 0.5–8 mg/mL, and the four fractions had strong cytotoxic effects on HepG2 cells. DF2 had the best inhibitory effect on HepG2 (IC₅₀ = 2.2 mg/mL). In general, the antitumor activity of Sargassum fucoidans is related to the content of L-fucose, sulfate and molecular weight, and Sargassum fucoidan has the best inhibitory effect on HepG2 hepatocellular carcinoma cells. Furthermore, when compared to MCF-7, Hela, and A549 cells, Sargassum fucoidans had the best capacity to reduce the viability of human hepatocellular carcinoma cells (HepG2) and to induce cell apoptosis, proving itself to have a good potential in anti-liver cancer therapy.

As an acidic polysaccharide, the formation of Hyaluronic acid (HA) is typically Sodium Hyaluronate (SH) for knee repair, oral treatment, skincare and as a food additive. Nevertheless, little information is available on the anti-ageing activity of SH as a food additive. Therefore, we treated C. elegans with SH, then inferred the anti-aging activity of SH by examining the lifespan physiological indicators and senescence-associated gene expression. Compared with the control group, SH (800 μg/mL) prolonged the C. elegans’ lifespans in regular, 35 °C and H₂O₂ environment by 0.27-fold, 0.25-fold and 1.17-fold. Simultaneously, glutathione peroxidase (GSH-Px), antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT) were increased by 8.6%, 0.36% and 167%. However, lipofuscin accumulation, reactive oxygen species (ROS) and malondialdehyde (MDA) were decreased by 36%, 47.8–65.7% and 9.5–13.1%. After SH treatment, athletic ability was improved and no impairment of reproductive capacity was seen. In addition, SH inhibited the blocking effect of age-1 and up-regulated gene levels involving daf-16, sod-3, gst-4 and skn-1. In conclusion, SH provides potential applications in anti-ageing and anti-oxidation and regulates physiological function.

Anthocyanin-based smart packaging has been widely used for food freshness monitoring, but it cannot meet the requirements of smart films with antibacterial properties. This study aimed to enhance the antibacterial properties of intelligent films by incorporating Amomum tsao-ko essential oil (AEO) for mantis shrimp spoilage tracking and keeping the product fresh. A smart film was designed by introducing AEO and purple potato anthocyanin (PPA) to a polyvinyl alcohol/cellulose nanocrystal (PVA/CNC) polymer matrix. Our findings revealed that APP and AEO imparted the smart film with a favorable oxygen barrier, UV protection, mechanical properties, and antioxidant and pH/NH₃-sensitive functions. Interestingly, the PVA/CNC-AEO-PPA film achieved 45.41% and 48.25% bactericidal efficacy against S. putrefaciens and V. parahaemolyticus, respectively. Furthermore, a visual observation confirmed that the target film (PVA/CNC-AEO-PPA) changed color significantly during mantis shrimp spoilage: rose red—light red—pink—light gray—dark gray. Meanwhile, the PVA/CNC-AEO-PPA film retarded the quality deterioration of the mantis shrimp effectively. The PVA/CNC-AEO-PPA film shows great application potential in mantis shrimp preservation and freshness monitoring; it is expected to become a rapid sensor for detecting seafood quality non-destructively and a multifunctional film for better preservation of product quality.

Alpinia officinarum Hance, a well known agricultural product in the Lei Zhou peninsula, is generally rich in polysaccharides. In order to enhance the use of A. officinarum Hance polysaccharides (AOP) in functional food, AOP was extracted using an ultrasonic-assisted extraction method, and the ultrasonic extraction parameters of AOP was optimized. Furthermore, this study investigated the physicochemical and antioxidant activities of AOPs. In addition, the structural properties were preliminarily determined using Fourier-transform infrared spectroscopy (FTIR), high performance size exclusion chromatography, and a Zetasizer. Ultimately, this study explored the mechanism underlying the antioxidant activities of AOP. The results showed that the optimal ultrasonic-assisted extraction parameters were as follows: ultrasonic time, 6 min; ratio of water to material, 12 mL/g; and ultrasonic power, 380 W. Under these conditions, the maximum yield of AOPs was 5.72%, indicating that ultrasonic-assisted extraction technology is suitable for extracting AOPs due to the reduced time and water usage. Additionally, AOPs were purified using graded alcohol precipitation, resulting in three fractions (AOP30, AOP50, and AOP70). AOP30 had the lowest molecular weight of 11.07 kDa and mainly consisted of glucose (89.88%). The half inhibitory concentration (IC₅₀) value of AOP30 and AOP70 was lower than that of AOP50 in the ability to scavenge the ABTS radical, while a reverse trend was observed in reducing ferric ions. Notably, the antioxidant activities of AOPs were highly correlated with their polydispersity index (Mw/Mn) and Zeta potential. AOP30, a negatively charged acidic polysaccharide fraction, exhibited electron donating capacities. Additionally, it displayed strong antioxidant abilities through scavenging 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radicals and reducing ferric ions. In conclusion, the present study suggests that AOP30 could be developed as an antioxidant ingredient for the food industry.