Search Results (157)

Consumer interest in vegetarian, ethical, and clean-label foods is reviving the use of plant-derived milk coagulants. Cardosins from Cynara cardunculus (“thistle”) are aspartic proteases with strong clotting activity, yet their technological impact in cheese remains under-explored. This study compared a commercial thistle extract (PC) with traditional bovine rennet rich in chymosin (AC) during manufacture and 60-day ripening of Caciotta cheese. Classical compositional assays (ripening index, texture profile, color, solubility) were integrated with scanning electron microscopy, three-dimensional surface reconstruction, and descriptive sensory analysis. AC cheeses displayed slower but sustained proteolysis, yielding a higher and more linear ripening index, softer body, greater solubility, and brighter, more yellow appearance. Imaging revealed a continuous protein matrix with uniformly distributed, larger pores, consistent with a dairy-like sensory profile dominated by milky and umami notes. Conversely, PC cheeses underwent rapid early proteolysis that plateaued, producing firmer, chewier curds with lower solubility and darker color. Micrographs showed a fragmented matrix with smaller, heterogeneous pores; sensory evaluation highlighted vegetal, bitter, and astringent attributes. The data demonstrate that thistle coagulant can successfully replace animal rennet but generates cheeses with distinct structural and sensory fingerprints. The optimization of process parameters is therefore required when targeting specific product styles. Full article

The HIV-1 aspartic protease is an effective target for the treatment of HIV/AIDS. Current therapy utilizes a selection of nine protease inhibitors (PIs) in combination with other classes of antiretroviral drugs. Although PIs were originally developed based on the knowledge of the HIV-1 subtype B protease, the existence of other HIV-1 subtypes and the effects of drug resistance on currently available PIs have become a major challenge in the treatment of HIV/AIDS. Specifically, the HIV-1 subtype C accounts for more than half of the global HIV infections. Considering the importance and relevance of the subtype C virus, in this timely review we discuss the effect of polymorphisms in the HIV-1 subtype C protease on drug resistance, flap flexibility, and hinge region dynamics. We discuss novel paradigms of protease inhibition that attempt to overcome the limitations of currently available inhibitors which fall short considering genetic diversity and resistance mutations. Full article

Drought stress poses a major constraint on global crop productivity. Although aspartic proteases (APs) are primarily characterized in plant disease resistance, their roles in abiotic stress adaptation remain largely unexplored. Here, we demonstrate that rice (Oryza sativa) OsAP4 critically regulates drought stress tolerance at the seedling stage. Genetic manipulation through overexpression (OsAP4-OE) or CRISPR knockout (OsAP4-KO) resulted in significantly reduced or enhanced stress tolerance compared to wild-type plants, respectively. Through integrated approaches including yeast two-hybrid, bimolecular fluorescence complementation, pull-down, co-immunoprecipitation, and protein degradation assays, we established that OsAP4 physically interacts with and destabilizes OsCATA/OsCATC, two catalase enzymes responsible for reactive oxygen species (ROS) scavenging. Importantly, OsAP4 modulates ROS production under drought stress treatment conditions. Together, these findings reveal a novel OsAP4-OsCATA/OsCATC regulatory module governing rice drought stress responses. Full article

The objective of this study was to evaluate the effects of dietary supplementation with different levels of Rhodotorula mucilaginosa (0.0 g/kg, 0.1 g/kg, 1.0 g/kg, and 10.0 g/kg) on resistance to Aeromonas veronii infection in red claw crayfish (Cherax quadricarinatus) (initial body weight of 0.13 ± 0.06 g). The investigation combined a 56-day feeding trial with a subsequent 7-day infection challenge to assess cumulative mortality, immune and antioxidant enzyme activities, and the relative expression of immune-related genes. During the A. veronii infection test, the cumulative mortalities for the 0.1 g/kg, 1.0 g/kg, and 10.0 g/kg groups were 44.44%, 38.89%, and 38.89%, respectively, all significantly lower (p < 0.05) than that of the control group (58.33%). Compared with the control group, after infection with A. veronii, the activities of acid phosphatase, alkaline phosphatase, catalase, and superoxide dismutase in the hepatopancreas and alkaline phosphatase, lysozyme in the hemolymph of red claw crayfish in the 1.0 g/kg group significantly increased (p < 0.05). The activities of aspartate aminotransferase and alanine aminotransferase in the hemolymph of red claw crayfish in the 1.0 g/kg group significantly decreased (p < 0.05). The relative expression levels of serine protease inhibitor, crustacean hyperglycemic hormone, anti-lipopolysaccharide factor, and superoxide dismutase genes in the hepatopancreas of red claw crayfish in the 1.0 g/kg group were significantly upregulated (p < 0.05). In conclusion, R. mucilaginosa could significantly improve the antibacterial ability of red claw crayfish against A. veronii. In this experimental context, the ideal addition level of R. mucilaginosa is determined to be 1.0 g/kg. Full article

Aspartic proteases (APs) are among the four primary families of proteolytic enzymes found in plants, and they are essential for both stress response mechanisms and developmental activities. While the AP gene family has been studied in model plants like Arabidopsis, its characterization in woody species-particularly in extremophytes like Populus euphratica, remains limited. Moreover, the potential involvement of APs in salt tolerance mechanisms in trees is yet to be explored. In this research, 55 PeAPs were discovered and categorized into three distinct classes based on their conserved protein structures. The phylogenetic analysis revealed potential functions of AP genes derived from Arabidopsis thaliana, V. vinifera, and P. euphratica. Our findings indicate that PeAP possesses a well-conserved evolutionary background and contains numerous highly variable regions, making it an excellent candidate for the identification and systematic examination of woody trees. Additionally, motifs frequently found in aspartic proteases within the genome of P. euphratica may be linked to functional PeAPs. It appears that PeAPs are associated with specific gene functions. These genes are influenced by cis-elements, which may play a role in their responsiveness to phytohormone, stress adaptation maybe changed to these genes are regulated by cis-elements that may mediate their responsiveness to phytohormones, abiotic stress, and developmental cues. Our research offers the initial comprehensive analysis of the AP family in P. euphratica, emphasizing its potential functions in adapting to salt conditions. The findings uncover candidate PeAPs for genetic engineering to enhance salinity tolerance in woody crops. Full article

Caspases are a family of cysteine-dependent aspartate-directed proteases implicated in programmed cell death. Humans have eleven proteolytically active caspases, namely caspase-1 through -10 and caspase-14. The latter is expressed exclusively in epithelial cells and constitutively resides in its active form in the cornified layer of the human epidermis. Molecular phylogenetics has revealed that caspase-14 belongs to a subfamily of caspases, which also includes caspase-15 and -16. The latter are evolutionarily more ancient than caspase-14 and have been lost in the phylogenetic lineage leading to humans. Here, we review the molecular properties, the species distributions, and the biological roles of caspase-14-like proteases in amniotes. In contrast to the prodomain-less caspase-14, caspase-15 contains a prodomain that is predicted to assume a pyrin fold, and caspase-16 features a prodomain with unique sequence similarity to the catalytic domain. Gene knockout in mice, evolutionary gene loss in aquatic mammals and the association of human CASP14 mutations with ichthyosis indicate that caspase-14 is associated with the barrier function of mammalian skin. Caspase-15 is able to induce apoptosis in cell culture, but its role in vivo and the role of caspase-16 are currently unknown. We propose directions for research to further characterize caspase-14-like proteases. Full article

Sunflower press cake (SPC), a by-product of the edible oil industry, represents a promising source of plant-based protein. This study aimed to investigate and optimize protein recovery from SPC using conventional (CE) and advanced extraction techniques, including Ultrasound and Microwave-Assisted Extraction (UMAE), Pressurized Liquid Extraction (PLE) and Enzyme-Assisted Extraction (EAE). The protein content both in extracts and in the precipitated mass was measured through Lowry assay, while the amino acid profile of the extracted proteins under optimal conditions was analyzed via High-Performance Liquid Chromatography (HPLC). Extraction parameters were optimized using response surface methodology (RSM) for each method. Among the novel methods studied, UMAE and PLE demonstrated superior efficiency over CE, yielding higher protein recovery in significantly shorter extraction times. Optimal UMAE conditions (10 min, 0.03 g/mL, 450 W microwave power, and 500 W ultrasound power) yielded a precipitation yield (PY) of 21.2%, protein recovery in extract (PR_E) of 79.9%, and protein recovery in precipitated mass (PR_P) of 66.3%, with a protein content (PC_P) of 902.60 mg albumin eq./g. Similarly, optimal PLE conditions (6 min, 0.03 g/mL, and 50 °C) resulted in PY, PR_E, and PR_P of 17.7, 68.9, and 47.4%, respectively, with a PC_P of 932.45 mg albumin eq./g. EAE using Aspergillus saitoi protease was comparatively less effective. The amino acid profiling confirmed SPC as a valuable protein source, with glutamic acid, arginine, and aspartic acid being the most abundant. These results highlight the potential of UMAE and PLE as efficient strategies for valorizing edible oil industry by-products into high-quality protein ingredients for food and biotechnological applications. Full article

Schizothorax prenanti is an economically important cold-water fish in China. Lipopolysaccharide (LPS) can induce an immune response in S. prenanti; however, little is known about the effects of LPS on oxidative stress (OS) and apoptosis in S. prenanti. In this study, S. prenanti fish were stimulated with LPS at a dose of 10 mg/kg of body weight. After 0 h, 12 h and 24 h, the tissue samples were collected. The OS- and apoptosis-related genes and enzymatic activities in the liver, head kidney (HK), and spleen of S. prenanti were analyzed by a two-way repeated-measures analysis of variance (ANOVA). Hematoxylin and eosin and terminal transferase uridyl nick end labeling staining were also performed. In S. prenanti, LPS administration downregulated the catalase (CAT) and B-cell lymphoma/Leukemia-2 (Bcl-2) expression levels, and upregulated BCL2-associated X (Bax) and cysteine-aspartic-specific protease-3 (caspase-3) expression levels. Meanwhile, superoxide dismutase and CAT enzymatic activities were inhibited and malondialdehyde (MDA) content was increased by LPS treatment. Additionally, LPS treatment induced OS damage and apoptosis in tissue sections. These results indicated that apoptosis in the liver, HK, and spleen of LPS-administered S. prenanti may be mediated by OS via the mitochondrial apoptotic signaling pathway. Our findings are expected to contribute to a better understanding of the responses of different tissues to bacterial challenges. In addition, we can increase the tolerance of fish to the OS through dietary manipulation in the future. Full article

Plastic pollution in aquatic ecosystems has become a global concern, and nanoplastics, due to their small size and high penetration potential, pose significant risks to aquatic organisms. This study aimed to evaluate the effects of polystyrene nanoplastics (PS-NPs) on oxidative stress biomarkers, blood biochemical parameters, and digestive enzyme activities in Goldfish (Carassius auratus). The experiment was conducted over 21 days, exposing fish to four different dietary concentrations of PS-NPs (0, 1, 10, and 100 mg/Kg). The results showed that chronic exposure to 50 nm PS-NPs significantly increased the activity of antioxidant enzymes (CAT, SOD, and GPx) and MDA activity in the gill, kidney, and liver tissues, indicating the induction of oxidative stress. Furthermore, notable alterations were observed in blood biochemical enzymes (alkaline phosphatase [ALP], alanine aminotransferase [ALT], aspartate aminotransferase [AST], and lactate dehydrogenase [LDH]), suggesting cellular damage and physiological disturbances. Additionally, PS-NP exposure affected the activity of digestive enzymes (amylase, lipase, and protease), which may impact nutrient digestion and absorption. These findings highlight that PS-NPs can adversely affect aquatic animal health and may influence the nutritional quality of fish. Therefore, further research is necessary to assess the long-term ecological and toxicological impacts of nanoplastics in freshwater ecosystems. Full article

The intestine is an important immune organ of aquatic animals and it plays an essential role in maintaining body health and anti-oxidative stress. To investigate the toxic effects of deltamethrin in intestinal tissue of Chinese mitten crabs (Eriocheir sinensis), 120 healthy crabs were randomly divided into two experimental groups (blank control group and deltamethrin-treated group), with three replicates in each group. After being treated with deltamethrin for 24 h, 48 h, 72 h, and 96 h, intestinal tissues were collected aseptically to assess the effects of deltamethrin on oxidative stress, immunity, apoptosis-related genes, and the structure of microflora in intestinal tissues. Additionally, correlations between gut microbiota composition and intestinal tissue damage-associated genes were analyzed. The results demonstrated that prolonged exposure to deltamethrin induced oxidative stress damage in intestinal tissue. Compared with the blank control group, the expression of autophagy-related genes B-cell lymphoma/Leukemia-2 (bcl-2), c-Jun N-terminal kinase (jnk), Microtuble-associated protein light chain 3 (lc3c), Cysteine-dependent Aspartate-specific Protease 8 (caspase 8), BECN1(beclin1), oxidative stress damage-related genes MAS1 proto-oncogene (mas), Glutathione Peroxidase (gpx), kelch-like ECH-associated protein 1 (keap1), Sequestosome 1 (p62), Interleukin-6 (il-6), and immune-related genes Lipopolysaccharide-induced TNF-alpha Factor (litaf), Heat shock protein 90 (hsp90) and prophenoloxidase (propo) in the deltamethrin treatment group were significantly up-regulated at 96 h (p < 0.05 or p < 0.01). Additionally, 16S rRNA sequencing showed that the diversity of intestinal flora in the deltamethrin-treated group was significantly higher compared with the blank control group (p < 0.01). Analysis of the differences in the composition of intestinal flora at the genus level showed that the relative abundance of Candidatus Bacilloplasma in the deltamethrin treatment group was significantly lower than that in the blank control group (p < 0.01). In contrast, the relative abundances of Flavobacterium, Lachnospiraceae_NK4A136_group, Acinetobacter, Chryseobacterium, Lacihabitans, Taibaiella, Hydrogenophaga, Acidovorax, and Undibacterium were significantly higher than those in the blank control group (p < 0.05 or p < 0.01). Pearson correlation analysis revealed that Malaciobacter, Shewanella, and Prevotella exhibited significant positive correlations with gene indicators (jnk, gpx, lc3c, litaf, hsp90), while Dysgonomonas, Vibrio, and Flavobacterium demonstrated significant negative correlations with multiple gene indicators (caspase 8, p62, il-16, keap1, jnk, etc). These results demonstrate that deltamethrin significantly impacts the gut microbiota, immune function, and antioxidant capacity of E. sinensis. The changes in gut microbiota have correlations with the biomarkers of intestinal tissue injury genes, indicating that gut microbiota plays a crucial role in deltamethrin-induced intestinal tissue damage. These insights contribute to a better understanding of the ecological risks associated with deltamethrin exposure in aquatic organisms. Full article

The increasing demand for poultry products has led to significant by-products, with chicken bones being a rich source of proteins and minerals. The protease hydrolysis of chicken bones has emerged as a key method for extracting chicken bone protein. The objective of this study was to optimize enzyme combinations and hydrolysis reaction conditions to enhance both the nutritional value and quality of the product. Through univariate experiments and response surface methodology, the optimal enzymatic hydrolysis conditions were determined as follows: 55 °C, 1.5 h, and composite enzymes comprising papain (2.53%), bromelain (4%), and flavorzyme (4%) (w/w). The peptide content of the hydrolysis product obtained with the composite enzyme reached 336.78 mg/g, with small molecular peptides (<500 Da) accounting for 95% of the composite enzyme hydrolysis product. These small molecular peptides are more readily absorbed by the human body. Additionally, the free amino acids significantly increased, particularly those more easily absorbed by the human body such as glutamic, glycine, and aspartic. Moreover, there was a notable increase in the volatile flavor compounds including aldehydes and alcohols, which enhanced the flavor profile by producing fatty or mushroom-like aromas. This method enhances protein recovery and sample quality, converting chicken bone waste into valuable ingredients, contributing to sustainable food practices and innovative consumables for both pet and human consumption. Full article

Herbal feed additives have benefits in aquaculture, as they can improve growth performance, welfare, and stress resistance. Hence, the effects of dietary Prosopis farcta extract (PFE) on the growth parameters, digestive enzyme activity, antioxidant defense, innate immunity responses, and resistance to ammonia stress in the common carp, Cyprinus carpio, were studied. Fish (15.14 ± 0.72 g) were fed on diets without the PFE (PFE0) or those fortified with 0.5% (PFE0.5), 1% (PFE1), or 2% (PFE2) PFE for 60 days and then subjected to ammonia stress for 24 h. The growth rate, feed efficiency, and amylase-, lipase-, and protease-specific activities in the PFE1 and PFE2 treatments showed significant elevations compared to these values in PFE0. The intestinal protease-specific activity significantly increased in all of the PFE treatments compared to that in the PFE0 treatment. Serum total protein and immunoglobulin significantly increased in the PFE1 treatment, whereas serum albumin and alternative complement activity significantly increased in the PFE2 treatment compared to these values in the PFE0 treatment. The PFE2 treatment significantly mitigated post-stress elevations in serum cortisol, glucose, malondialdehyde levels, alanine aminotransferase, and aspartate aminotransferase activities. The PFE1 treatment significantly mitigated post-stress elevations in CAT activity and decreases in SOD and lysozyme activity. In conclusion, 1–2% dietary PFE supplementation can improve the growth performance, health, and resilience to environmental stressors of the common carp. Full article

Melanoma is one of the most lethal cancers originating from melanocytes. Its incidence and mortality have been rising rapidly for several decades and have posed a serious threat to human health. Current melanoma treatments are hindered by the scope of application, low efficiency, high cost, and toxic side effects. Due to their affordability and minimal side effects, natural bioactive compounds derived from plants are promising candidates for melanoma treatment. This study aims to delve into the isolation, purification, and characterization of potato proteins and to explore their potential in melanoma treatment. Two potato proteins, patatin PP-1 and aspartate protease inhibitor PP-2, were isolated and purified by a newly developed method in this work, and their physicochemical properties were systematically characterized. Both potato proteins showed great antiproliferative activities and migration inhibition effects on melanoma cells. Meanwhile, Western blotting results illustrated that they could induce endogenous cell apoptosis by regulating the Bax/Bcl-2 pathway. Notably, aspartate protease inhibitor PP-2 demonstrated the best performance in inhibiting the growth and migration of melanoma cells, which might be attributed to the combined effect of its significant antioxidative activity and the inhibition effect of certain necessary protease activities in melanoma. This study provides valuable insights for developing nutraceuticals and therapeutic strategies against melanoma, which can lead to breakthroughs in melanoma treatment. Full article

This study aims to explore the protective effects of Hong-bai-lan-shen (HBLS) extract, a traditional Chinese medicine compound, on myocardial injury based on metabolomics. H9C2 cells were cultured with HBLS extract for 12 h, and then the cells were cultured in a CoCl₂-containing medium, a model simulating the ischemic-hypoxic damage in myocardial cells, for an additional 12 h. The cell viability, cytotoxicity, intracellular metabolite and reactive oxygen species (ROS), mitochondrial membrane potential, apoptosis, and adenosine monophosphate-activated protein kinase (AMPK) signal pathway were determined. The results showed that HBLS extract significantly increased cell viability, stabilized cell morphology, reduced lactate dehydrogenase (LDH) release and ROS production, blocked cysteine-aspartic acid protease 3 (caspase-3) and bcl-2-associated X protein (Bax) expression and decreased apoptotic cell numbers. Meanwhile, HBLS increased membrane potential and the expression of B-cell lymphoma-2 (Bcl-2). Additionally, HBLS extract upregulated the expression of AMPK, PI3K, and protein kinase B (AKT) (p < 0.05, p < 0.01). These findings suggest that HBLS extract has a protective effect on myocardial cells by regulating the AMPK signal pathway and may be a promising therapeutic candidate for ischemic heart disease. Full article

Dalbergia odorifera is widely used to treat cardiovascular diseases. Our research group found that Dalbergia odorifera volatile oil has a good anti-myocardial ischemic effect, and its main pharmacodynamic components are trans-nerolol and its oxides. However, the exact mechanisms underlying this effect have not yet been elucidated. This study aimed to explore the potential myocardial protective effects of trans-nerolol and its underlying molecular mechanisms. Molecular docking was used to predict and visualize the possible mechanism of the anti-apoptotic myocardial protection by trans-nerolol. The myocardial protective effect of trans-nerolol was evaluated by observing pathological injury, myocardial enzyme levels, oxidation, antioxidant levels, and the expression of related proteins. Molecular docking results showed that trans-nerolol binds closely to cytochrome C (Cytc) and apoptosis-related proteins, suggesting that it may play a role in interacting with these target proteins. The results showed that pre-treatment with dose-dependent trans-nerolol significantly mitigated the myocardial histological damage; decreased lactate dehydrogenase (LDH), creatinine kinase (CK), alanine transaminase (ALT), and aspartate transaminase (AST) levels; reduced nitric oxide (NO) production, hydrogen peroxide (H₂O₂), and lipid peroxide (LPO); and increased the total antioxidant content (T-AOC), glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) activities compared with the model group. In addition, dose-dependent trans-nerolol significantly increased the Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase levels. Moreover, trans-nerolol markedly reduced the endogenous and external apoptotic pathways; downregulated the protein expression of Cytc, apoptotic protease activating factor-1 (Apaf1), Fibroblast-associated (Fas), Cysteine-aspartate protease 3 (Caspase3), Cysteine-aspartate protease 8 (Caspase8), and Cysteine-aspartate protease 9 (Caspase9); and upregulated the expression of Heat shock protein 70 (Hsp70) and B-cell lymphoma-2 (Bcl-2). These data indicate that trans-nerolol exerts protective effects against myocardial ischemia (MI), and its mechanism is associated with the suppression of the Cytc- and caspase-signaling pathways. Trans-nerolol has a therapeutic effect on MI, and its mechanism of action is related to its anti-apoptotic effect. These results suggest that Dalbergia odorifera has a potential role to be developed as an MI-promoting therapeutic agent. Full article