In vitro inhibitor effect and molecular docking of thiamine (vitamin B1), riboflavin (vitamin B2), and reference inhibitor captopril on angiotensin-converting enzyme purified from sheep plasma.

OBJECTIVE: Angiotensin-converting enzyme (ACE, EC 3.4.15.1) is a very important factor in the regulation of blood pressure. Also, the inhibition of ACE with natural compounds has been a very important research area in the treatment of high blood pressure. ACE was purified and characterized from sheep plasma. Molecular docking studies and the inhibition effect of thiamine, riboflavin, and captopril on ACE were investigated. METHODS: Herein, ACE was purified from sheep plasma by affinity chromatography. The effect of thiamine and riboflavin on ACE was researched. Molecular docking studies were performed to understand the molecular interactions between thiamine, riboflavin, and captopril with ACE. RESULTS: The purification coefficient was found to be 8636 fold. The binding energy of thiamine, riboflavin, and captopril was found to be -6.7 kcal/mol, -8.1 kcal/mol, and -5.5 kcal/mol, respectively. Thiamine conformed to three conventional hydrogen bonds with ASP:415, HIS:513, and LYS:454. Riboflavin formed four conventional hydrogen bonds with GLN:281, GLU:376, THR:282, and TYR:520. Captopril formed two conventional hydrogen bonds with ARG:124, one conventional hydrogen bond with TYR:62 and ASN:85, and one carbon-hydrogen bond with ASN:66. Molecular docking results showed that thiamine, riboflavin, and captopril interacted with ACE through hydrogen bonding and hydrophobic interactions. Thiamine and riboflavin indicated significant inhibition effects on ACE. The IC50 values of thiamine, riboflavin, and captopril were found as 960.56 µM, 11.02 µM, and 1.60 nM, respectively. Ki values for thiamine, riboflavin, and captopril were determined as 1352.04 µM, 12.30 µM, and 1.06 nM, respectively. CONCLUSION: In this work, it was concluded that thiamine and riboflavin may have preventive and therapeutical impacts against high blood pressure with their ACE inhibitor effect. Thiamine and riboflavin showed a lower inhibitory effect with a higher IC50 than captopril. However, when the inhibitory effect of thiamine and riboflavin vitamins is compared to captopril, it is concluded that they may be natural inhibitors with fewer side effects.

The investigation of hawthorn (Crataegus orientalis) plant's inhibition effect on angiotensin converting enzyme and in silico studies.

Hawthorn plant is used among people due to its cardiovascular, anti-inflammatory, and antihistamine properties. But no scientific study has been done about Crataegus orientalis (Mill.) M.Bieb. The presented study was planned to determine the effects of ethanol and n-hexane extracts of Crataegus orientalis leaves on human plasma ACE enzyme. In the study, the effect of plant extracts on ACE was studied by the spectrophotometric method. The chemical composition of the plant extracts was determined by HPLC-DAD analyses. In addition, molecular doking and ADME prediction studies were carried out. As a result, the obtained data showed that Crataegus orientalis could have an important place in the pharmaceutical industry and drug discovery studies, as it supports the traditional use of Crataegus orientalis as hypotensive. The results of the molecular docking studies revealed that the interactions of the selected compounds with the human ACE enzyme caused inhibition.

In vitro Evaluation of Selective Cytotoxic Activity of Chaerophyllum macropodum Boiss. on Cultured Human SH-SY5Y Neuroblastoma Cells.

Neuroblastoma is the most common solid tumor in children. New treatment approaches are needed because of the harmful side effects and costs of the methods used in the treatment of neuroblastoma. Medicinal and aromatic plants are important for new treatment approaches due to their minimal side effects and economic advantages. Therefore, the present study was carried out to examine the cytotoxic effect of Chaerophyllum macropodum extract on human neuroblastoma (SH-SY5Y) and fibroblast (HDFa) cell lines. 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase release (LDH) assays were used to determine the cytotoxic effect of C. macropodum. The extracts were analyzed for their phenolic content by HPLC-PDA. Major components were determined as 63.600% o-coumaric acid, 15.606% catechine hydrate, 8.713% rosmarinic acid, 4.376% clorogenic acid, and 3.972% salicylic acid. The obtained results from cytotoxicity testing revealed that C. macropodum exerted a significant cytotoxic effect on human neuroblastoma cells at all tested concentrations (p < 0.05). But it did not lead to any cytotoxic potential on human fibroblasts. As a result, the obtained data clearly revealed C. macropodum exerted a selective cytotoxic action on neuroblastoma cells for the first time.

The effects of pretreatment with lithium metaborate dihydrate on lipid peroxidation and Ca, Fe, Mg, and K levels in serum of Wistar albino male rats exposed to Cd.

Boron and boron compounds have beneficial biological effects. Lithium metaborate dihydrate (LMBDH) is used in many branches of industry. Despite its wide industrial use, there is limited information about its biological effects on antioxidant defense system and trace element homeostasis. Therefore, the aim of this study was to evaluate the in vivo protective effects of LMBDH against CdCl2-induced oxidative stress and imbalance of some bioelements for the first time. In the study, totally 20 Wistar albino male rats were used. The rats were fed with pellet food and water ad libitum and divided into four groups including five rats in each. Group I was control group (standard pellet food + water + normal saline), Group II was CdCl2 (4.58 mg/kg/body weight/intraperitoneally/single dose), Group III was LMBDH (15 mg/kg/body weight/day orally, for 5 days), Group IV was CdCl2 (4.58 mg/kg/body weight/intraperitoneally/single dose in fifth day), and LMBDH (15 mg/kg/body weight/day orally for 5 days). The results showed that CdCl2 treatment increased blood MDA level and decreased antioxidant enzyme activities and the level of blood GSH compared to control group. Pretreatment with LMBDH significantly decreased MDA levels and increased SOD activity (p < 0.05). In addition, Ca, Fe, and K levels decreased in LMBDH pretreatment group in different statistically levels. However, Mg levels showed an increase in LMBDH pretreatment group. As a result, LMBDH pretreatment decreased MDA status and supported antioxidant system by increasing SOD activity. In addition, it did not exhibit an ameliorative effect on measured bioelement homeostasis.

Cytotoxic and antioxidant properties of essential oil of Centaurea behen L. in vitro.

Centaurea species of Asteraceae family are widely use in traditional medicine. Despite wide medicinal use of Centaurea sp., there is limited knowledge concerning Centaurea behen toxicity. Therefore, in this study, it is aimed to determine cytotoxic and oxidative effects of essential oil of C. behen on human blood cell cultures. 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release assays were performed to determine cytotoxic effects. In addition, total antioxidant capacity (TAC) and total oxidative status (TOS) were examined to determine oxidative potentials. The results indicated that all tested concentrations of essential oil of C. behen were cytotoxic and led to decreases of cell viability in both assays. Besides, C. behen led to significant increases of TOS levels and decreases of TAC levels. As a conclusion, the present study showed for the first time the cytotoxic and oxidant effects of essential oil of C. behen on cultured human whole blood cells.

An Investigation of Protective Effects of Litium Borate on Blood and Histopathological Parameters in Acute Cadmium-Induced Rats.

This study was carried out to determine the protective effects of lithium borate (LTB) on blood parameters and histopathological findings in experimentally induced acute cadmium (Cd) toxicity in rats. Twenty-eight male Wistar albino rats were used, weighing 200-220 g, and they were randomly divided into four groups, including one control and the following three experimental groups: a Cd group (0.025 mmol/kg), a LTB group (15 mg/kg/day orally for 5 days), and a LTB + Cd group (15 mg/kg/day orally for 5 days and Cd 0.025 mmol/kg by intraperitoneal injection on the fifth day). All the rats in the study were anesthetized with ketamine at the end of the sixth day, blood was taken from their hearts, and then the rats were decapitated. The values in the control and LTB group were usually close to each other. White blood cell (WBC), neutrophil %, and C-reactive protein (CRP) levels increased in the Cd and LTB + Cd groups while lymphocyte and monocyte levels decreased in a statistically significant manner, in comparison to the other groups. It was determined that the levels of red blood cells (RBCs), hematocrit (Htc), and hemoglobin (Hb) did not change in the groups. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the Cd and LTB + Cd groups significantly increased, in comparison to the other groups, while the glucose, alkaline phosphatase (ALP), albumin (ALB), and total protein (TP) levels decreased. According to histopathological findings in the control and LTB groups, the liver and kidney tissues were found to have normal histological structures. In the Cd group, severe necrotic hemorrhagic hepatitis, mild steatosis, and mononuclear cell infiltration were detected in the liver. In the LTB + Cd group, degeneration and mild mononuclear cell infiltration were found in the liver. Regarding the kidney tissue in the Cd group, severe intertubular hyperemia in both kidney cortex and medulla, as well as degeneration and necrosis in the tubulus epithelium, was observed. In the LTB + Cd group, mild interstitial hyperemia and mononuclear cell infiltration was detected. Resultantly, it can be said that LTB at this dose has non-toxic effects and some beneficial effects for liver and kidney damage caused by acute Cd toxicity.

Cytogenetic and oxidative alterations after exposure of cultured human whole blood cells to lithium metaborate dehydrate.

Boron compounds have an ability of supporting antioxidant properties in human and animal tissues. Lithium metaborate dihydrate (LiBO2·2H2O; LMD) is commonly used in nonlinear optic materials, cellular phones and pagers. But, there are limited data on the genotoxic and antioxidant effects of LMD in cultured human whole blood cells. The aim of this study was to evaluate for the genotoxicity and antioxidant/oxidant activity of LMD on human whole blood lymphocytes (n = 5). LMD was applied at various concentrations (0-1,280 µg/ml) to cultured blood samples. Antioxidant/oxidant activity was evaluated by measuring the total oxidant status (TOS) and total antioxidant capacity levels. Micronuclei and chromosomal aberration tests were used in genotoxicity studies. Our results clearly revealed that all tested concentrations of LMD were found to be non-genotoxic when compared to that of the control group. In addition, LMD exhibited antioxidant activities at low concentrations. In addition the TOS levels were not changed at all concentrations of LMD. Consequently, our results clearly demonstrated that LMD is non-genotoxic and it has an important antioxidant potential in vitro.

DNA damaging and biochemical effects of potassium tetraborate.

Potassium tetraborate (PTB) is a product resulting from the controlled reaction of potassium hydroxide, water and boric acid (BA). It is used in many areas of industry such as disinfectant, detergent and treatment of contact lenses. PTB is one of the boron compounds which is most commonly used in many areas of industry although very limited information is available concerning its toxicity. Therefore, in this study, it is aimed to determine genetic and biochemical effects of PTB in human blood cell cultures (n=4). PTB was added into culture tubes at various concentrations (0-1280 µg/ml). Micronucleus (MN) and chromosomal aberration (CA) tests were performed for genotoxic damage influences estimation. In addition, biochemical parameters (total antioxidant capacity (TAC) and total oxidative status (TOS) were examined to determine oxidative effects. The results indicated that all tested concentrations of PTB were found to be non-genotoxic. In addition, low concentrations (1.25, 2.5 and 5 µg/ml) of PTB caused increases of TAC levels. Furthermore, all concentrations of PTB were not changed the TOS levels in cultured human blood cells. Based on these results, in this study it has been reported for the first time that PTB is not genotoxic and it increases the antioxidant capacity in human peripheral blood lymphocytes.