Anti-angiotensin Converting Enzyme Research Articles

Bioprospecting of Selected Species of Polypore Fungi from the Western Balkans.

Growing mushrooms means meeting challenges while aiming for sustainability and circularity. Wherever the producer is located, commercial strains are the same originating from several producers. Customized strains adapted to local conditions are urgently needed. Before introducing new species to the strain development pipeline, the chemical characterization and biological activity of wild ones need to be assessed. Accordingly, the mycoceutical potential of five polypore mushroom species from Serbia was evaluated including: secondary metabolite composition, oxidative damage prevention, anti-tyrosinase, and anti-angiotensin converting enzyme (ACE). The phenolic pattern was comparable in all samples, but the amounts of specific chemicals varied. Hydroxybenzoic acids were the primary components. All samples had varying quantities of ascorbic acid, carotene, and lycopene, and showed a pronounced inhibition of lipid peroxidation (LPx) and ability to scavenge HO•. Extracts were more potent tyrosinase inhibitors but unsuccessful when faced with ACE. Fomitopsis pinicola had the strongest anti-tumor efficacy while Ganoderma lucidum demonstrated strong selectivity in anti-tumor effect in comparison to normal cells. The evaluated species provided a solid foundation for commercial development while keeping local ecology in mind.

Dermatomyositis

Dermatomyositis is a heterogeneous disorder that can be classified into more homogeneous subsets. Autoantibodies are a useful tool in identifying such subsets because they correlate strongly with clinical phenotypes. In dermatomyositis, five disease-specific autoantibodies have been established to date, including antiMi-2, anti-melanoma differentiation-associated gene 5, anti-transcriptional intermediary factor 1, anti-nuclear matrix protein 2, anti-transcriptional intermediary factor 1, and anti-small-ubiquitin-like activating enzyme antibodies. In addition, several novel autoantibodies have recently been demonstrated in patients with dermatomyositis, including anti-four-and-a-half-LIM-domain 1, anti-cell division cycle and apoptosis regulator protein 1, anti-specificity protein 4, anti-cortactin, and IgM anti-angiotensin converting enzyme 2 antibodies.

Utilization of lactobacillus fermented proteins from meat processing wastewaters as a dietary protein source in poultry feed.

The present study aimed to evaluate the impact of fermented meat processing wastewater protein hydrolysate (FWMPH) prepared by Pediococcus lolii fermentation as an alternative protein source on growth performance, serum biochemistry, and hematological parameters of broiler chicks. FWMPH exhibited antioxidant, anti-angiotensin converting enzyme (ACE), and antimicrobial properties. A total of 60 one-day-old Vencobb broiler chicks were divided into five dietary groups on day 8 and a feeding trial was performed for 48days. Diets were prepared by replacing soya protein concentrate (SPC) at different levels of FWMPH as the protein source. These diets were denoted as SPSD (100% SPC), FMP-25 (25% FWMPH + 75% SPC), FMP-50 (50% FWMPH + 50% SPC), FMP-75 (75% FWMPH + 25% SPC), and FMP-100 (100% FWMPH). FMP-25 and FMP-100 diet group broiler chicks showed the highest and lowest feed consumption (P < 0.05), respectively. However, the highest body weight gain (1506.08 ± 52.52g) was observed in FMP-75 diet-fed chicks (P < 0.05). Furthermore, FMP-75 chicks displayed better feed conversion ratio (1.96), feed efficiency ratio (0.51), and protein efficiency ratio (2.32) values than other diet group chicks (P < 0.05), implying that the FMP-75 diet had better effect on the broiler growth. Also, the FMP-75 diet chicks showed better hematological values, serum biochemical parameters revealed no negative effect upon FWMPH consumption, and no pathological signs were observed in the histopathological examination as compared to the SPSD diet group (P < 0.05). Hence, the results could be helpful in the application of FWMPH at 75% level in the poultry feed as a potential protein ingredient in the countries looking for local feed protein products as soya bean meal replacement.

Assessment of angiotensin converting enzyme inhibitory activity and quality attributes of yoghurt enriched with Cinnamomum verum, Elettaria cardamomum, Beta vulgaris and Brassica oleracea

The new concept of functional foods has led to the varieties in the production of foods that provide not only basic nutrition, but can also warrant good health and longevity. This study deals with the production and evaluation of fortified yogurts’ with Cinnamomum verum, Elettaria cardamomum, Beta vulgaris and Brassica oleracea. The qualitative and quantitative phytochemical analysis of above mentioned plant extracts before using them into the preparation of functional yoghurt was carried out. The sensory evaluation of enriched yogurts with plant extracts carried out using 9 point hedonic scale. Comparative analysis between enriched yogurts and plain yogurt was carried. The results indicated increase in ash contents, water holding capacity, titratable acidity, total soluble solids, total phenolic content, tannin content, and total flavonoid content in fortified yogurt as compared to plain yogurt. In addition to this fortified yogurts showed greater antioxidant and antibacterial activity in contrast to plain yogurt. However, moisture contents, pH and susceptibility to syneresis of yogurt decreases with the addition of plant extracts. Shelf life of plain and fortified yogurt was determined both at room and refrigerated temperature. The results revealed that shelf life of fortified yogurt was greater as compared to plain yogurt. In silico analysis was carried out by using the galaxy web software. The results indicated that bioactive compounds including ascorbic acid, sinapinic acid, cinnamaldehyde and linalool acetate present in the flavored yogurts binds with angiotensin converting enzyme. All enriched yogurts showed higher anti-Angiotensin converting enzyme activity as compared to plain-yogurt.

Supplementation with rice bran hydrolysates reduces oxidative stress and improves lipid profiles in adult dogs.

Oxidative stress is defined as an imbalance between reactive oxygen species (ROS) production and antioxidant defense mechanisms of the body. An overproduction of ROS leads to lipid and protein oxidation, injuring the cells both in normal and pathological conditions. Rice bran protein hydrolysates (RBH) has potent antioxidant, anti-inflammatory, anti-angiotensin converting enzyme (ACE) and hypolipidemic effects. Little is known, however, about the effects of RBH in dogs. The present study evaluated the antioxidative, anti-ACE and metabolic effects of RBH in adult dogs. Eighteen adult dogs were divided into 2 groups: control (n=7) and RBH supplemented groups (n=11), received a diet with the same nutritional compositions. The RBH supplemented group was fed with RBH 500 mg/kg body weight (BW) mixed with food for 30 days. BW, blood glucose, lipid profiles, liver enzymes, electrocardiography (ECG), plasma ACE activity, oxidative stress and antioxidant biomarkers were determined on day 0 and day 30 of supplementation periods. Results showed that RBH decreased oxidative stress and increased antioxidant biomarkers by significantly reducing plasma malondialdehyde (MDA) and protein carbonyl, enhanced blood glutathione (GSH) and improved the GSH redox ratio. Moreover, decreased LDL-C and increased HDL-C levels were found after RBH supplementation whereas BW, blood glucose, liver enzymes, plasma ACE activity, plasma catalase (CAT) and superoxide dismutase (SOD) activity and cardiac function were not significantly changed. These results suggest that RBH may help to lower the risk of oxidative stress and dyslipidemia in adult dogs.

Identification of Gastrointestinal Digestion Stable Antihypertensive Fish Peptides from Atlantic Mackerel (Scomber scombrus).

High blood pressure has been recognized as one of the main risk factors of cardiometabolic syndrome by health organizations. Hypertension is medicated by various classes of synthetic drugs; however, adverse effects have repeatedly been reported. Moreover, natural alternatives such as fish peptides have been effective in the treatment and prevention of hypertension. The aim of our study was to fractionate and identify antihypertensive peptides. Fractions were produced using different techniques of solid-phase extraction (SPE), pressure-driven ultrafiltration (UF), and electro04dialysis with UF membrane. According to our results, the hydrophobic fraction of SPE (IC50 5 μg) was the most potent anti-angiotensin converting enzyme (ACE) product. Findings of the study suggest that the separation technique plays an important role in the isolation efficiency of antihypertensive biopeptides. Importantly, the hydrophobic fraction's activity was retained through a static model of an in vitro gastrointestinal digestion system. In conclusion, polarity regardless of charge and size was the most important factor for anti-ACE activity of an Atlantic mackerel biopeptide. In addition, the presence of leucine at either of the extremities (C- or N-terminal) and/or leucine-rich motifs could well explain the hypotensive effect of our active fraction.

Inhibition of angiotensin converting enzyme by phytochemicals in Cucurbita pepo L.: In silico Approach

Diabetes mellitus remains one of the dreaded diseases that affect both man and woman. It also causes a disorder which incapacitates human body from producing and exhausting insulin. In this work, in silico method was used to explore the anti-angiotensin converting enzyme activities of selected phytochemicals obtained from Cucurbita pepo L. The optimization of the phytochemicals obtained from Cucurbita pepo L. resulted to series of descriptors which exactly describe anti-angiotensin converting enzyme activities of Cucurbita pepo L.. Also, 3-[( Z )-3-(3,4- dihydroxyphenyl ) prop ‑2- enoyl ]oxy-1,4,5-trihydroxycyclohexane-1-carboxylic acid (Compound 3 ) with -7.7 kcal/mol proved to have better tendency to inhibit angiotensin converting enzyme than compound 1,2,4–8 as well as the referenced drug (Metformin) thereby dowregulating diabetes. The ADMET (absorption, distribution, metabolism excretion and toxicity) were examined and reported.

Seafood Paramyosins as Sources of Anti-Angiotensin-Converting-Enzyme and Anti-Dipeptidyl-Peptidase Peptides after Gastrointestinal Digestion: A Cheminformatic Investigation

Paramyosins, muscle proteins occurring exclusively in invertebrates, are abundant in seafoods. The potential of seafood paramyosins (SP) as sources of anti-angiotensin-converting-enzyme (ACE) and anti-dipeptidyl-peptidase (DPP-IV) peptides is underexplored. This in silico study investigated the release of anti-ACE and anti-DPP-IV peptides from SP after gastrointestinal (GI) digestion. We focused on SP of the common octopus, Humboldt squid, Japanese abalone, Japanese scallop, Mediterranean mussel, Pacific oyster, sea cucumber, and Whiteleg shrimp. SP protein sequences were digested on BIOPEP-UWM, followed by identification of known anti-ACE and anti-DPP-IV peptides liberated. Upon screening for high-GI-absorption, non-allergenicity, and non-toxicity, shortlisted peptides were analyzed via molecular docking and dynamic to elucidate mechanisms of interactions with ACE and DPP-IV. Potential novel anti-ACE and anti-DPP-IV peptides were predicted by SwissTargetPrediction. Physicochemical and pharmacokinetics of peptides were predicted with SwissADME. GI digestion liberated 2853 fragments from SP. This comprised 26 known anti-ACE and 53 anti-DPP-IV peptides exhibiting high-GI-absorption, non-allergenicity, and non-toxicity. SwissTargetPrediction predicted three putative anti-ACE (GIL, DL, AK) and one putative anti-DPP-IV (IAL) peptides. Molecular docking found most of the anti-ACE peptides may be non-competitive inhibitors, whereas all anti-DPP-IV peptides likely competitive inhibitors. Twenty-five nanoseconds molecular dynamics simulation suggests the stability of these screened peptides, including the three predicted anti-ACE and one predicted anti-DPP-IV peptides. Seven dipeptides resembling approved oral-bioavailable peptide drugs in physicochemical and pharmacokinetic properties were revealed: AY, CF, EF, TF, TY, VF, and VY. In conclusion, our study presented in silico evidence for SP being a promising source of bioavailable and safe anti-ACE and anti-DPP-IV peptides following GI digestions.

Discovery of Bifunctional Anti-DPP-IV and Anti-ACE Peptides from Housefly Larval Proteins After In silico Gastrointestinal Digestion

Proteins and peptides of housefly larvae (HFL) have potential applications in food and therapy. The fate of HFL proteins following human gastrointestinal (GI) digestion is unknown. This study adopted a computational approach to discover peptides released from HFL proteins upon GI digestion. In silico digestion of eight major HFL proteins released 783 peptides. This comprised 243 peptides exhibiting 13 types of bioactivities. Ninety-two single-function peptides exhibiting anti-dipeptidyl peptidase IV (anti-DPP-IV), anti-dipeptidyl peptidase III, anti-angiotensin converting enzyme (anti-ACE), or antioxidant activity were found. Sixty-three multi-function peptides, encompassing 32 bifunctional anti-DPP-IV and anti-ACE peptides, were found. Further screening led to five non-toxic, non-allergenic, high-GI-absorption bifunctional dipeptides: AF, GW, GY, PH, and VF. Molecular docking found the dipeptides to interact with the active site of DPP-IV through hydrophobic interactions. Only GW and VF could bind to the active site of ACE. Thus, the five dipeptides are competitive inhibitors of DPP-IV. GW and VF are potential competitive inhibitors of ACE, whereas AF, GY, and PH are non-competitive inhibitors. Overall, GI digestion could liberate numerous single- and multi-function peptides from HFL proteins. Hence, HFL proteins can be tapped for potential applications in antidiabetic and antihypertension functional food and therapy.

SARS-CoV-2 Spike Protein 1 Activates Microvascular Endothelial Cells and Complement System Leading to Thrombus Formation

Background: Microvascular thrombosis is associated with multiorgan failure and mortality in coronavirus disease 2019 (COVID-19). Although thrombotic complications may be ascribed to the ability of SARS-CoV-2 to infect and replicate in endothelial cells, it has been poorly investigated whether specific viral elements can induce endothelial damage. Methods: We performed an enzyme-linked immunosorbent assay (ELISA) to detect circulating spike protein in the sera of 23 severe COVID-19 patients, 9 mild disease patients, and 9 infection-naive subjects. In vitro experiments were performed on human microvascular endothelial cells (HMEC-1) exposed to SARS-CoV-2-derived spike protein 1 (S1) protein at the subtoxic concentration of 10 nM for 24 hours. The expression of adhesive molecules was studied by immunofluorescence on S1-primed HMEC-1 and, in parallel, leukocyte adhesion and thrombus formation were assessed under flow conditions. In selected experiments, S1-treated HMEC-1 were incubated anti-angiotensin converting enzyme 2 (ACE2) functional blocking antibody or different complement inhibitors. Findings: We show that the activation of HMEC-1 with S1 protein, via ACE2, induced robust leukocyte recruitment due to increased adhesive molecule expression and thrombomodulin loss. This S1-induced pro-inflammatory phenotype led to exuberant C3 and C5b-9 deposition on HMEC-1, along with C3a and C5a generation that further amplified S1-induced complement activation. Functional blockade of ACE2 or complement inhibition halted S1-induced platelet-thrombi formation by limiting von Willebrand factor exocytosis and deposition. Interpretation: Collectively, we demonstrate that SARS-CoV-2-derived S1 is sufficient per se to propagate inflammatory and thrombogenic processes in the microvasculature, amplified by the complement system, recapitulating the thromboembolic complications of COVID-19. Funding Information: The authors declare no conflicts of interest. Declaration of Interests: The present study was supported by generous contributions from: Associazione Calcio Monza, Monza; Barabino Immobiliare, Milano; Brembomatic Pedrali, Pontirolo Nuovo, Bergamo; Fondazione Aiutiamoli a vivere, Ranica, Bergamo; GF-ELTI, Sovere, Bergamo; Mrs. Mariella Guzzoni, Bergamo; Mrs. Hazzazi Malika El, Milano; Mr. Alberto Paccanelli, Bergamo; SMILAB Srl, San Pellegrino Terme, Bergamo; Mrs. Paola Suardi, Bergamo. Ethics Approval Statement: The study was approved by the Ethical Committee of the Azienda Sanitaria Locale Bergamo, Italy. Written informed consent was obtained from all enrolled patients.

Production of Liquid Milk Protein Concentrate with Antioxidant Capacity, Angiotensin Converting Enzyme Inhibitory Activity, Antibacterial Activity, and Hypoallergenic Property by Membrane Filtration and Enzymatic Modification of Proteins

Liquid milk protein concentrate with different beneficial values was prepared by membrane filtration and enzymatic modification of proteins in a sequential way. In the first step, milk protein concentrate was produced from ultra-heat-treated skimmed milk by removing milk serum as permeate. A tubular ceramic-made membrane with filtration area 5 × 10−3 m2 and pore size 5 nm, placed in a cross-flow membrane house, was adopted. Superior operational strategy in filtration process was herein: trans-membrane pressure 3 bar, retention flow rate 100 L·h−1, and implementation of a static turbulence promoter within the tubular membrane. Milk with concentrated proteins from retentate side was treated with the different concentrations of trypsin, ranging from 0.008–0.064 g·L−1 in individual batch-mode operations at temperature 40 °C for 10 min. Subsequently, inactivation of trypsin in reaction was done at a temperature of 70 °C for 30 min of incubation. Antioxidant capacity in enzyme-treated liquid milk protein concentrate was measured with the Ferric reducing ability of plasma assay. The reduction of angiotensin converting enzyme activity by enzyme-treated liquid milk protein concentrate was measured with substrate (Abz-FRK(Dnp)-P) and recombinant angiotensin converting enzyme. The antibacterial activity of enzyme-treated liquid milk protein concentrate towards Bacillus cereus and Staphylococcus aureus was tested. Antioxidant capacity, anti-angiotensin converting enzyme activity, and antibacterial activity were increased with the increase of trypsin concentration in proteolytic reaction. Immune-reactive proteins in enzyme-treated liquid milk protein concentrate were identified with clinically proved milk positive pooled human serum and peroxidase-labelled anti-human Immunoglobulin E. The reduction of allergenicity in milk protein concentrate was enzyme dose-dependent.

Preliminary Assessment of the Antihypertensive and Antioxidative Activities of the Peptides from “Saba” Banana (Musa balbisiana Colla) Flesh

The crude proteins were isolated using 0.125 M Tris-HCl with 50 mM NaCl at pH 7.4. The protein content of the crude extract was determined using the Lowry assay and was found to be 4.28 mg/mL. The major band which corresponds to the major protein has an approximate molecular weight of 20 KDa. The isolated crude proteins were subjected to enzymatic digestion using pepsin, trypsin, chymotrypsin, and thermolysin for 3, 4, 12, and 24 hours. The 24-hour digest was found to have the highest percent anti-Angiotensin Converting Enzyme (ACE) activity (36.02%) while the 12-hour digest was found to have the highest anti-oxidative activity (33.14%) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The 24-hour digest was subjected to Ultra-Performance Liquid Chromatography (UPLC) to determine the peptide fraction responsible for the ACE inhibitory activity. Three peptide fractions (PF1, PF2 and PF3) were chosen and PF2 exhibited the highest percent inhibitory activity (32.21) against ACE. PF2 was subjected to thin layer chromatography (TLC) and the possible identity is EK based on the Rf value traveled by glutamic acid (E) (0.43) and Lysine (K) (0.13). In silico analysis was done to correlate the results with the presence of putative peptides with antioxidative and antihypertensive activities. Results showed that antihypertensive peptides EK, GS, TY, FNE, FP, LKA, PT, PP, FAL and antioxidative peptides IR and VPW were found based on the sequence of the protein in “Saba” banana. The presence of the antihypertensive peptide EK was verified using thin layer chromatography (TLC).

Effects of alkaline hydrolysis and storage conditions on the biological activity of ostrich egg white

This study aimed to improve the biological activity of ostrich egg white (OEW) using alkaline hydrolysis (0.25 M NaOH at 40°C for 8 hr), and studied the effects of packing materials and temperature on biological and physical properties of OEW hydrolysate (hOEW). The results show that alkaline hydrolysis clearly enhanced several biological activities, including ABTS radical scavenging (61.35%), anti-microbial (51.66% against Bacillus subtilis and 38.58% against Escherichia coli) and anti-angiotensin converting enzyme activity (39.19%). The hydrolysate maintained biological activities after gastrointestinal digestion and showed non-toxicity toward human red blood cells. In storage study, the best storage conditions were packing hOEW powder in an Al-foil-laminated bag at 4°C, resulting in slightly decreased biological activity after 6 months storage and significantly lower moisture content than plastic zipper bag. Additionally, SEM revealed smooth surfaces of hOEW powder for the best condition, while air pores and bridges were found in the worst conditions. Practical applications The alkaline hydrolysis method (incubation in 0.25 M NaOH at 40°C for 8 hr) used in this study can be used to enhance the antioxidant, antimicrobial, and anti-ACE inhibition activity of egg white protein. This study also reports the optimal packaging and storage conditions for egg white hydrolysate powder, which are beneficial for maintaining the antioxidant, antimicrobial, and anti-angiotensin converting enzyme activity as well as the texture of the egg white hydrolysate powder.

Modification of ACE-inhibitory peptides from Acaudina molpadioidea using the plastein reaction and examination of its mechanism

The development of peptides derived from seafood, which have potential anti-angiotensin converting enzyme (ACE) activity and other bioactivities, are of scientific interest. However, the activity and thermal stability of these peptides are relatively poor, limiting their applications. The ACE-inhibitory peptides with high activity and stability prepared from sea cucumber (Acaudina molpadioidea) protein were modified using the plastein reaction. The mechanism of the plastein reaction was investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry. FTIR data suggested that the plastein products had a new absorption peak at 1250 cm−1, which suggested the occurrence of the plastein reaction. Two new diffraction peaks appeared at 7.9 and 13.6° in the XRD spectra, and they indicated that new products were obtained from the peptides. The thermal stability of peptides after the plastein reaction was enhanced, and the thermal transition temperature of the peptides increased from 120° to 134°C. Urea and SDS decreased the plastein stability, thus suggesting that non-covalent interactions, such as hydrophobic and hydrogen bonds, are important for the plastein reaction. Accordingly, the plastein reaction has the potential to enhance the activity of peptides. Therefore, it can possibly be used as an effective method for increasing the application of marine active peptides and possibly other bioactive peptides.

Lactobacillus paracasei CD4 as potential indigenous lactic cultures with antioxidative and ACE inhibitory activity in soymilk hydrolysate

The present study evaluates indigenous Lactic acid bacteria (LAB) isolated from different fermented foods for their fermentation efficiency in soymilk generating anti-oxidative and anti-angiotensin-converting enzyme (ACE) activity in soymilk hydrolysate. The efficiency of lactic cultures to ferment soymilk was evaluated by fermenting 100 mL of soymilk with 1% of lactic cultures, incubated for 24 h at 37 °C. The efficiency of fermentation was determined in terms of degree of hydrolysis of soymilk which ranged from 7.17 to 11.09% for different cultures. Further, the fermented hydrolysate fraction was evaluated for its free radical scavenging activity and ACE inhibitory activity. The fermented soymilk hydrolysate from Lactobacillus rhamnosus GG, Brevibacilllus aydinogluensis, Brevibacillus thermoruber resulted in higher free radical scavenging activity ranging from 62 to 67% as compared to unfermented control (18.4%). However, ACE inhibitory activity was observed only in the hydrolysate from the strains of Lactobacillus paracasei CD4 and B. thermoruber HM34. The principal component analysis of the antioxidative properties of different cultures indicated that the release of total phenolic content and increase in free radical scavenging activity is strain specific.

Bioactivity-guided isolation of anti-angiotensin converting enzyme constituents from Trichosanthis Pericarpium

To isolate the anti-angiotensin converting enzyme (ACE) constituents from Trichosanthis Pericarpium based on bioactivity-guided separation. Trichosanthis Pericarpium was extracted with boiling water and precipitated by ethanol, then its supernatant was collected and dialyzed. The retentate of the fractions above 1 000 was lyophilized to obtain GLP, which was then successively separated by DEAE Sepharose fast flow anion-exchange and Superdex-75 gel permeation chromatographic steps to achieve GLP-1-1. A combination of HPGPC, monosaccharide compositions determination and ACE inhibitory activity studies was performed to investigate the structure and bioactivity. The results showed that an anti-angiotensin converting enzyme oligosaccharide, GLP-1-1, was obtained from Trichosanthis Pericarpium based on activity tracking, whose average molecular weight was estimated to 1 367; mainly composed of arabinose, mannose, and glucose at a ratio of 0.2∶4.3∶10.0. GLP-1-1 showed potent anti-angiotensin converting enzyme effect with the IC₅₀of (113.4±8.6) mg•L⁻¹. In this study, an oligosaccharide with anti-angiotensin converting enzyme effect was isolated from Trichosanthis Pericarpium, which could lay the foundation for the substance basis study of Trichosanthis Pericarpium.

Effects of high doses of dexamethasone on hemodynamic and immunohistochemical characteristics of acute paraquat intoxication in rat kidneys

Paraquat (1,1’-dimethyl-4,4’-bipyridinium) (PQ), is a nonselective contact herbicide that is highly toxic to humans. The kidney is affected during PQ intoxication. Dexamethasone (Dexa) has anti-inflammatory effects and is used to treat cases of PQ poisoning. We investigated in rat kidney hemodynamic effects and immunohistochemical characteristics of Dexa treatment in acute PQ poisoning. Adult male rats were divided into four groups: 1, untreated control; 2, treated with 100 mg/kg Dexa; 3, treated with 25 mg/kg PQ; 4, treated with PQ + Dexa. Mean arterial pressure (MAP) and heart rate (HR) were recorded during the experimental period (2 h). Tissues were removed after 2 h and immunohistochemistry was performed after 24 h. Paraffin sections of kidney were prepared and anti-cyclo-oxygenase-1 (COX-1), anti-cyclo-oxygenase-2 (COX-2), anti-angiotensin converting enzyme (ACE), anti-aquaporin-1 (AQU-1), anti-vascular cell adhesion molecule (VCAM) primary antibodies were used for immunohistochemical examination. Immunoreactivities were scored as: (1) minimal, (2) weak, (3) mild, (4) moderate, (5) strong and (6) very strong. MAP and HR were measured at 10 min, 20 min, 1 h and 2 h. MAP at 10 and 20 min and 1 h was increased in the Dexa group. HR also was increased in all groups compared to controls at 2 h. Compared to groups 2 and 4, MAP values decreased significantly in group 3 at 1 h. The intensity of all of immunoreactivities was decreased in group 2. In group 3, immunoreactivities of COX-1, COX-2 and ACE were decreased compared to the control and the other groups, whereas AQU-1 and VCAM immunoreactivities were the same as the control group. ACE and VCAM immunoreactivities were decreased in group 4 compared to the control group, while COX-1, COX-2 and AQU-1 immunoreactivities were close to those of the control group. Dexa appears to be useful for treating PQ intoxication.

Inhibition of angiotensin-converting enzyme by aqueous extract of tomato

To investigate the presence of anti-angiotensin converting enzyme (ACE) factors in aqueous extract of tomato. The bio-guided fractionation of the aqueous extract of tomato produced a sugar-free, heat-stable fraction with molecular mass <1,000 Da from tomatoes. The sugar-free tomato extract (TE) was tested for its anti-ACE activity using human plasma and rabbit lung pure ACE. In addition, its effect on human platelet aggregation induced by ADP, collagen or arachidonic acid was determined. The mechanism of platelet inhibitory action of TE was investigated by measuring platelet factor 4 (PF4) release and cAMP synthesis by platelets. Typically, 100 g tomatoes produced 72.2 ± 4.7 mg of TE. This extract inhibited both platelet aggregation and plasma ACE activity in a dose-dependent manner. It inhibited platelet aggregation in response to ADP, collagen or arachidonic acid, and inhibitory action was mediated in part by reducing platelet PF4 release and by stimulating cAMP synthesis. The IC50 value of TE for ADP-induced platelet aggregation was 0.4 ± 0.02 mg/ml, whereas the IC50 value for ACE enzyme inhibition was 1.40 ± 0.04 mg/ml. Both the TE and commercially available sugar-free TE, Fruitflow(®)-2 had similar amount of catechin, and also had equal inhibitory potencies against platelet aggregation and plasma ACE activity. Together these data indicate that aqueous extract of tomatoes contain anti-ACE factors in addition to previously described anti-platelet factors.

Anti-angiotensin converting enzyme (ACE) proteins from mycelia of Ganoderma lucidum (Curtis) P. Karst

BackgroundGanoderma lucidum has been purported as a potent remedy in the treatment and prevention of several ailments, including hypertension. This study aimed to explore the anti-ACE potential of protein fractions from the mycelia of G. lucidum.MethodsGanoderma lucidum mycelia were cultivated by submerged fermentation in a liquid medium containing brown sugar and spent brewer’s yeast. Intracellular proteins were fractionated from mycelia crude water extract by ammonium sulphate precipitation, and their angiotensin converting enzyme inhibitory activity was evaluated. The potential anti-ACE protein fractions were further separated by RP-HPLC and characterised using proteomics platforms.ResultsPreliminary result demonstrated that the mycelia crude water extract inhibited ACE at IC50 value of 1.134 ± 0.036 mg/mL. Following protein fractionation and HPLC purification, the presence of highly potential anti-ACE proteins with the IC50 values less than 200 μg/mL was detected. Characterisation of these proteins demonstrated the presence of four different antihypertensive-related proteins involved in the regulation of blood pressure through different mechanisms.ConclusionsThis study suggests that the mycelia of G. lucidum has high potential in lowering blood pressure level due to the presence of several antihypertensive-related proteins such as cystathionine beta synthase-like protein, DEAD/DEAH box helicase-like protein, paxillin-like protein, and alpha/beta hydrolase-like protein.

Concentration and selective fractionation of an antihypertensive peptide from an alfalfa white proteins hydrolysate by mixed ion-exchange centrifugal partition chromatography

This article reports a promising use of the mixed ion-exchange centrifugal partition chromatography (MIXCPC) technique in the field of downstream processes. A complex alfalfa white protein concentrate hydrolysate (AWPC hydrolysate) showing anti-hypertensive properties was successfully fractionated by MIXCPC to yield a l-valyl-l-tryptophan (VW) enriched fraction in one run. This dipeptide shows an interesting anti-angiotensin converting enzyme (anti-ACE) activity. An analytical method based on RP-LC/MS-MS was developed to quantify the target VW peptide in both the starting material and the enriched fractions. The best results for the MIXCPC fractionation were obtained by the combined use of the quaternary biphasic solvent system, methyl-tert-butylether/acetonitrile/n-butanol/water (2:1:2:5, v/v) in the descending mode, of the lipophilic di(2-ethylhexyl)phosphoric acid (DEHPA) cation-exchanger with an exchanger (DEHPA)/peptides ratio of 15, and of two displacers: calcium chloride and hydrochloric acid. The complexity of the starting material involved the selectivity optimization by splitting the stationary phase into two sections that differed by their triethylamine concentration. From 1g of AWPC hydrolysate containing 0.26% of VW, 30.7mg of a VW enriched fraction were recovered with a purity of 10.9%, corresponding to a purification factor of 41 and a recovery of 97%.