Opium poppy (Papaver somniferum L.) is an ancient medicinal plant producing pharmaceutically important benzylisoquinoline alkaloids. In the present work we focused on the study of enzyme lipoxygenase (LOX, EC 1.13.11.12) from opium poppy cultures. LOX is involved in lipid peroxidation and lipoxygenase oxidation products of polyunsaturated fatty acids have a significant role in regulation of growth, development and plant defence responses to biotic or abiotic stress. The purpose of this study was to isolate and characterize LOX enzyme from opium poppy callus cultures. LOX was purified by ammonium sulphate precipitation followed by hydrophobic chromatography using Phenyl-Sepharose CL-4B and hydroxyapatite chromatography using HA Ultrogel sorbent. SDS-PAGE analysis and immunoblotting revealed that LOX from opium poppy cultures was a single monomeric protein showing the relative molecular weight of 83 kDa. To investigate the positional specificity of the LOX reaction, purified LOX was incubated with linoleic acid and the products were analysed by high-performance liquid chromatography. LOX converted linoleic acid primarily to 13-hydroperoxy-(9Z,11E)-octadecadienoic acids (78%) and to a lesser extent to 9-hydroperoxy-(10E,12Z)-octadecadienoic acids (22%). Characterization of LOX from opium poppy cultures provided valuable information in understanding of LOX involvement in regulation of signalling pathways leading to biosynthesis of secondary metabolites with significant biological activity.

Lipoxygenases are non-heme iron-containing enzymes that catalyze the oxidation of polyunsaturated fatty acids, resulting in the production of lipid hydroperoxides, which are precursors of inflammatory lipid mediators. The enzymes are widely distributed in humans, other eukaryotes, and cyanobacteria. Lipoxygenases hold promise as therapeutic targets for several human diseases, including cancer and inflammation-related disorders. Inhibitors of lipoxygenase have potential applications in pharmaceuticals, cosmetics, and food. Bioactive peptides are short amino acid sequences embedded within parent proteins, which can be released by enzymatic hydrolysis, microbial fermentation, and gastrointestinal digestion. A wide variety of bioactivities have been documented for protein hydrolysates and peptides derived from different biological sources. Recent findings indicate that protein hydrolysates and peptides derived from both edible and non-edible bioresources can act as lipoxygenase inhibitors. In this review, we explore current knowledge on the production of anti-lipoxygenase protein hydrolysates and peptides from millet grains, chia seeds, insects, milk proteins, fish feed, velvet antler blood, fish scales, and feather keratins. We delve into the anti-lipoxygenase activities and modes of action of these protein hydrolysates and peptides, while also highlighting the strengths and shortcomings of previous research. Additionally, we propose potential research directions and areas of improvement that can propel the discovery of anti-lipoxygenase peptides in the near future.

Oxidative stress is defined as an imbalance between the production of free radicals and reactive oxygen species (ROS) and the ability of the body to neutralize them by antioxidant defense systems. Cells produce ROS as a control of physiological processes, but increasing ROS becomes pathological leading to non-specific and irreversible damage to biological molecules, such as DNA, lipid, and protein. Endogenous ROS are mainly produced by mitochondria during both physiological and pathological conditions, and enzymes, such as nicotinamide adenine dinucleotide phosphate oxidase (NOX), xanthine oxidase (XO), lipoxygenase (LOX), myeloperoxidase (MPO) and monoamine oxidase (MAO). To neutralize ROS, the body employs enzymatic and non-enzymatic defense systems. The dietary intake of bioactive phenols, such as quercetin (Que), is a non-enzymatic system that can quench ROS and protect from pro-oxidative damage. In this review, we evaluate the ability of Que to target endogenous oxidant enzymes involved in ROS production and explore the mechanisms of action underlying its antioxidant properties. Que not only acts as a free radical scavenger by donating electrons through the negative charges in its phenolic and ketone groups, but it can effectively inhibit the activity of several endogenous oxidative enzymes, binding them with high affinity and specificity. Among all targets, Que showed the best results in molecular docking simulations with XO, followed by MAO-A, 5-LOX, NOX, and MPO. Taken together, these findings highlight the potential of Que as a natural antioxidant therapy for oxidative stress-related diseases.

Foliage-feeding fall armyworm (Spodoptera frugiperda) and root-feeding western corn rootworm (Diabrotica virgifera virgifera) are maize (Zea mays L.) pests that cause significant yield losses. Jasmonic acid (JA) play pivotal defense role against insects. 12-oxo-phytodienoic acid (12-OPDA) is converted into JA by peroxisome-localized OPDA reductases (OPR). However, little is known about the physiological functions of cytoplasmic OPRs. Here, we show that disruption of ZmOPR2 reduced wound-induced JA production and defense against FAW while accumulating more JA catabolites. Overexpression of ZmOPR2 in Arabidopsis enhanced JA production and defense against beet armyworm (Spodoptera exigua). In addition, lox10opr2 double mutants were more susceptible than either single mutant, suggesting that ZmOPR2 and ZmLOX10 uniquely and additively contributed to defense. In contrast to the defensive role of ZmOPR2 and ZmLOX10 in leaves, single mutants did not display any alteration in root herbivory defense against WCR. Feeding on lox10opr2 double mutants resulted in increased WCR mortality associated with greater herbivory-induced production of insecticidal death acids and ketols. Thus, ZmOPR2 and ZmLOX10 cooperatively inhibit synthesis of these metabolites during herbivory by WCR. We conclude that ZmOPR2 and ZmLOX10 regulate JA-mediated resistance in leaves against FAW while suppressing insecticidal oxylipin synthesis in roots during WCR infestation.

Background: Given the increasing request for natural pharmacological molecules, this study assessed the antimicrobial capacity of Pistacia lentiscus L. essential oil (PLL-EO) obtained from the leaves of wild plants growing in North Sardinia (Italy), toward a wide range of periodontal bacteria and Candida including laboratory and clinical isolates sp., together with its anti-inflammatory activity and safety; Methods: PLL-EO was screened by gas chromatography / mass spectrometry. The minimal inhibitory concentration (MIC) was determined. The anti-inflammatory activity was measured by cyclooxygenase (COX 1/2) and lipoxygenase (LOX) inhibition while the antioxidant capacity was determined electro-chemically and by the MTT assay. The WST-1 assay was used to ascertain cytotoxicity toward four line of oral cells; Results: According to the concentrations of terpens, PLL-EO is a pharmacologically active phytocomplex. MICs against periodontal bacteria ranged between 3.13 and 12.5 µg/ml, while against Candida sp. were between 6.25 and 12.5 µg/ml. Oxidation by COX 1/2 and LOX was inhibited by 80% and 20% µg/mL of the oil respectively. Antioxidant activity seemed negligible, and no cytotoxicity arose; Conclusions: PLL-EO exhibits a broad-spectrum activity against periodontal bacteria and Candida, with an interesting dual inhibitory capacity toward COX2 and LOX inflammatory enzymes and without side effects against oral cells.

In recent years there has been increasing interest in the discovery of new natural herbal remedies for the treatment of common conditions such as diabetes and inflammatory diseases. In this context, this paper analyzed the antidiabetic and anti-inflammatory potential of two plants of the genus Artemisia: Artemisia absinthium (wormwood) and Artemisia vulgaris (mugwort) and Trigonella foenum-graecum (fenugreek) plants less studied from this point of view. Thus, hydroal-coholic extracts (50% EtOH v/v, 10% mass) were made, which were processed by membrane technologies, micro- and ultrafiltration, in order to concentrate the biologically active principles. The extracts were then analyzed in terms of content in active principles of interest (polyphenols, flavones). The antidiabetic activity of the extracts was analyzed by testing their ability to inhibit α-amylase and α-glucosidase and the anti-inflammatory activity by testing the ability to inhibit hyaluronidase (HYA) and lipoxygenase (LOX). Thus, the T. foenum-graecum extracts showed a high inhibitory activity on α-amylase 3.22 ± 0.3 g / mL (compared to the standard used - IC50 acarbose = 3.5 g / mL) and a high inhibitory activity on LOX: 19.69 ± 0.52 g/mL (compared to all standards used). The concentrated extract of Artemisia vulgaris showed increased activity of inhibition of α-amylase - IC50 = 8.57 ± 2.31g/mL and moderate activity of inhibition of HYA - IC50 = 17.18 g/mL compared to ibuprofen, the standard used - IC50 = 5.73 g/mL. The concentrated extract of Artemisia absinthium showed a pronounced activity of inhibition of LOX - IC50 = 19.71 g / mL, compared to the standard - rutin - IC50 = 22.34 g/mL).