In Silico Analysis and In Vitro Characterization of the Bioactive Profile of Three Novel Peptides Identified from 19 kDa α-Zein Sequences of Maize.

In this study, we characterized three novel peptides derived from the 19 kDa α-zein, and determined their bioactive profile in vitro and developed a structural model in silico. The peptides, 19ZP1, 19ZP2 and 19ZP3, formed α-helical structures and had positive and negative electrostatic potential surfaces (range of -1 to +1). According to the in silico algorithms, the peptides displayed low probabilities for cytotoxicity (≤0.05%), cell penetration (10-33%) and antioxidant activities (9-12.5%). Instead, they displayed a 40% probability for angiotensin-converting enzyme (ACE) inhibitory activity. For in vitro characterization, peptides were synthesized by solid phase synthesis and tested accordingly. We assumed α-helical structures for 19ZP1 and 19ZP2 under hydrophobic conditions. The peptides displayed antioxidant activity and ACE-inhibitory activity, with 19ZP1 being the most active. Our results highlight that the 19 kDa α-zein sequences could be explored as a source of bioactive peptides, and indicate that in silico approaches are useful to predict peptide bioactivities, but more structural analysis is necessary to obtain more accurate data.

Antioxidant Activity of Zein Hydrolysates from Zea Species and Their Cytotoxic Effects in a Hepatic Cell Culture.

In recent years, food proteins with bioactivity have been studied for cancer treatment. Zein peptides have shown an important set of bioactivities. This work compares the cytotoxic activity of zein hydrolyzed, extracted from four Zea species: teosinte, native, hybrid, and transgenic (Teo, Nat, Hyb, and HT) in a hepatic cell culture. Zein fraction was extracted, quantified, and hydrolyzed. Antioxidant capacity and cytotoxicity assays were performed on HepG2 cells. The levels of expression of caspase 3, 8, and 9 were evaluated in zein-treated cell cultures. Zea parviglumis showed the highest zein content (46.0 mg/g) and antioxidant activity (673.40 TE/g) out of all native zeins. Peptides from Hyb and HT showed high antioxidant activity compared to their native counterparts (1055.45 and 724.32 TE/g, respectively). Cytotoxic activity was observed in the cell culture using peptides of the four Zea species; Teo and Nat (IC50: 1781.63 and 1546.23 ng/mL) had no significant difference between them but showed more cytotoxic activity than Hyb and HT (IC50: 1252.25 and 1155.56 ng/mL). Increased expression of caspase 3 was observed in the peptide-treated HepG2 cells (at least two-fold more with respect to the control sample). These data indicate the potential for zein peptides to prevent or treat cancer, possibly by apoptosis induction.

Biomedical applications of synthetic peptides derived from venom of animal origin: A systematic review.

Development of therapeutic agents that have fewer adverse effects and have higher efficacy for diseases, such as cancer, metabolic disorders, neurological diseases, infections, cardiovascular diseases, and respiratory diseases, are required. Recent studies have focused on identifying novel sources for pharmaceutical molecules to develop therapies against these diseases. Among the sources for potentially new therapies, animal venom-derived molecules have generated much interest. Various animal venom-derived proteins and peptides have been isolated, identified, synthesized, and tested to develop drugs. Venom-derived peptides have several biomedical properties, such as proapoptotic, cell migration, and autophagy regulation activities in cancer cell models; induction of vasodilation by nitric oxide and regulation of angiotensin II; modification of insulin response by controlling calcium and potassium channels; regulation of pain receptor activity; modulation of immune cell activity; alteration of motor neuron activity; degradation or inhibition of ß-amyloid plaque formation; antibacterial, antifungal, antiviral, and antiprotozoal activities; increase in sperm motility and potentiation of erectile function; reduction of intraocular pressure; anticoagulation, fibrinolytic, and antithrombotic activities; etc. This systematic review compiles these biomedical properties and potential biomedical applications of synthesized animal venom-derived peptides reported in the latest research. In addition, the limitations and areas of opportunity in this research field are discussed so that new studies can be developed based on the data presented.

Anti-Cancer Activity of Maize Bioactive Peptides.

Cancer is one of the main chronic degenerative diseases worldwide. In recent years, consumption of whole-grain cereals and their derivative food products has been associated with a reduced risk of various types of cancer. The main biomolecules in cereals include proteins, peptides, and amino acids, all of which are present in different quantities within the grain. Some of these peptides possess nutraceutical properties and exert biological effects that promote health and prevent cancer. In this review, we report the current status and advances in knowledge regarding the bioactive properties of maize peptides, such as antioxidant, antihypertensive, hepatoprotective, and anti-tumor activities. We also highlight the potential biological mechanisms through which maize bioactive peptides exert anti-cancer activity. Finally, we analyze and emphasize the potential applications of maize peptides.