Distribution of Plasma One-Carbon Metabolism Factors and Amino Acids Profile in Depression State Treated with Paroxetine: A Model Study

OBJECTIVE

Stress may have an important role in the origin and progress of depression and can impair metabolic homeostasis. The one-carbon cycle (1-CC) metabolism and amino acid (AA) profile are some of the consequences related to stress. In this study, we investigated the Paroxetine treatment effect on the plasma metabolite alterations induced by forced swim stress-induced depression in mice.

MATERIALS AND METHODS

In this experimental study that was carried out in 2021, thirty male NMRI mice (6-8 weeks age, 30 ± 5 g) were divided into five groups: control, sham, paroxetine treatment only (7 mg/kg BW/day), depression induction, and Paroxetine+depression. Mice were subjected to a forced swim test (FST) to induce depression and then were treated with Paroxetine, for 35 consecutive days. The swimming and immobility times were recorded during the interventions. Then, animals were sacrificed, plasma was prepared and the concentration of 1-CC factors and twenty AAs was measured by spectrophotometry and high-performance liquid chromatography system (HPLC) techniques. Data were analyzed by SPSS, using One-Way ANOVA and Pearson Correlation, and P<0.05 was considered significant.

RESULTS

Plasma concentrations of phenylalanine, glutamate, aspartate, arginine, ornithine, citrulline, threonine, histidine, and alanine were significantly reduced in the depression group in comparison with the control group. The Homocysteine (Hcy) plasma level was increased in the Paroxetine group which can be associated with hyperhomocysteinemia. Moreover, vitamin B12, phenylalanine, glutamate, ornithine, citrulline, and glycine plasma levels were significantly reduced in the depression group after Paroxetine treatment.

CONCLUSION

This study has demonstrated an impairment in the plasma metabolites' homeostasis in depression and normal conditions after Paroxetine treatment, although, further studies are required.

The associations between high-density lipoprotein mean particle size and its fatty acid composition

AIM

High-density lipoprotein (HDL) particles are heterogeneous in their composition, structure and size and may differ in conferring protection against coronary artery disease. The aim of this study is to investigate the associations between HDL size and its fatty acid composition.

PATIENTS & METHODS

HDL mean particle size from 140 healthy men was detected by dynamic light scattering methodology and fatty acid composition of HDL was determined by gas chromatography.

RESULTS

HDL with smaller size had a higher proportion of saturated fatty acids and lower proportion of unsaturated fatty acids. HDL mean size indicated a negative correlation with palmitic acid (r = -0.17; p < 0.05) and a positive correlation with palmitoleic acid (r = 0.17; p < 0.05), oleic acid (r = 0.23; p < 0.01), arachidonic acid (r = 0.17; p < 0.05) and dihomogamalinoleic acid (r = -0.18; p < 0.05).

CONCLUSION

Saturated fatty acids of HDL are inversely assocaited and unsaturated fatty acids are directly associated with HDL mean size.

Protective effects of copper against aluminum toxicity on acetylcholinesterase and catecholamine contents of different regions of rat's brain

The probable protective effects of copper on the acetylcholinesterase activity and the catecholamine levels in cerebellum, cortex and mid-brain of rat, which was intoxicated by aluminum, were studied during short and long terms. In this respect, male Wistar rats weighing 200-250 g were received daily intraperitoneal doses of aluminum, copper and also combined doses of both metals for 15 days (Al 10 mg kg(-1) BW and Cu 1 mg kg(-1) BW), 30 days (Al 5 mg kg(-1) BW and Cu 0.5 mg kg(-1) BW) and 60 days (Al 1 mg kg(-1) BW and Cu 0.1 mg kg(-1) BW), respectively. The results obtained from the short period of exposure (15 days) showed that aluminum produced significant (P < 0.05) decreases in the acetylcholinesterase activity by 24.14, 23.30 and 25.81 %. Similarly, the catecholamine levels were reduced by 10.69, 12.25 and 12.64 % in cerebellum, cortex and mid-brain, respectively. Treatment with copper increases both acetylcholinesterase activity and catecholamine contents of cerebellum, cortex and mid-brain. Simultaneous injection of copper and aluminum increased both acetylcholinesterase activity and catecholamine contents in all three parts of rat brain when compared to aluminum-treated group. Same results were also observed following 30 and 60 days of exposures. In overall, it has been found that copper may have a protective-like ability to hinder aluminum toxicity in the brain.

Associations between high density lipoprotein mean particle size and serum paraoxonase-1 activity

BACKGROUND

High density lipoprotein (HDL) particles are heterogeneous in composition, structure, size, and may differ in conferring protection against cardiovascular disease. HDL associated enzyme, paraoxonase-1 (PON1), has an important role in attenuation of atherogenic low density lipoprotein (LDL) oxidation. The aim of this study was to investigate the associations between HDL particle size and PON1 activity in relation to serum HDL cholesterol (HDL-C) levels.

MATERIALS AND METHODS

One hundred and forty healthy subjects contributed to this study. HDL was separated by sequential ultracentrifugation and its size was estimated by dynamic light scattering. Paraoxonase activity was measured spectrophotometrically using paraoxon as substrate.

RESULTS

Results of this study showed that PON1 activity had negative correlations with HDL mean particle size (r = -0.22, P < 01), HDL2/HDL3 ratio, and serum HDL-C levels (r = -0.25, P < 0.01). HDL mean particle size and HDL2/HDL3 ratio had negative correlation with body mass index (BMI), waist hip ratio (WHR), and serum triglyceride (TG) levels, and positive correlation with serum HDL-C levels. Serum HDL-C levels had significant positive correlations with age, total cholesterol (TC), and apolipoprotein A-I (apo A-I) and significant negative correlation with BMI, WHR, and TG.

CONCLUSION

Based on the results of this study, determination of HDL mean particle size beside the serum PON1 activity may help to better understand the CAD risks, pathogenesis, and prognosis, and may also help to design therapeutic protocols toward beneficial modifications of HDL characteristics.

Increased leukocyte ABCA1 gene expression in post-menopausal women on hormone replacement therapy

OBJECTIVE

The ATP binding cassette A1 (ABCA1) is a key participant in the reverse cholesterol process whereby mediates cholesterol efflux directly to HDL particles. The aim of this study was to investigate whether long-term treatment with conventional hormone replacement therapy (HRT) in post-menopausal women could affect their leukocytes ABCA1 expression. Changes in various serum lipids and lipoprotein fractions were also investigated.

MATERIAL AND METHODS

A total of 60 non-obese normolipidaemic post-menopausal women treated with oral oestrogen together with progestin therapy for 3 months were selected. Leukocytes ABCA1 gene expression and serum lipid and lipoprotein concentrations were measured at the start and end of the HRT.

RESULTS

HRT led to significant increases in HDL cholesterol (P = 0.001) and apoA-I (P = 0.046) and significant decrease in apoB (P = 0.049) and LDL cholesterol (P = 0.022) when compared with the baseline levels. Analysis of leukocytes ABCA1 mRNA showed a significant increase in ABCA1 gene expression after HRT (P = 0.001). There was also a significant inverse association (r =  -0.28, P = 0.03) between ABCA1 gene expression and log TG/HDL cholesterol changes related to HRT.

CONCLUSION

The beneficial cardiovascular effects of HRT could be explained, at least in part, by increasing the ABCA1 gene expression.

Kinetic investigation of myeloperoxidase upon interaction with copper, cadmium, and lead ions

BACKGROUND

Myeloperoxidase (MPO), which is abundantly expressed in neutrophils, catalyzes the formation of a number of reactive oxidant species. However, evidence has emerged that MPO-derived oxidants contribute to tissue damage and initiation and propagation of inflammatory diseases, particularly, cardiovascular diseases. Therefore, studying the regulatory mechanisms of the enzyme activity is of great importance. For clarifying some possible mechanism of the enzyme activity, kinetic investigations of MPO in the presence of Copper (Cu), Cadmium (Cd), and Lead (Pb) ions were carried out in vitro.

METHODS

MPO was partially purified from human white blood cells using ion-exchange and gel-filtration chromatography techniques. Its activity was measured spectrophotometrically by using tetramethyl benzidine (TMB) as substrate.

RESULTS

Purified enzyme had a specific activity of 21.7 U/mg protein with a purity index of about 0.71. Cu inhibited MPO activity progressively up to a concentration of 60 mM at which about 80% of inhibition achieved. The inhibition was non-competitive with respect to TMB. An inhibitory constant (Ki) of about 19 mM was calculated from the slope of repot. Cd and Pb did not show any significant inhibitory effect on the enzyme activity.

CONCLUSION

The results of the present study may indicate that there are some places on the enzyme and enzyme-substrate complex for Cu ions. Binding of Cu ions to these places result in conformational changes of the enzyme and thus, enzyme inhibition. This inhibitory effect of Cu on the enzyme activity might be considered as a regulatory mechanism on MPO activity.

Effect of estrogen receptor β A1730G polymorphism on ABCA1 gene expression response to postmenopausal hormone replacement therapy

The estrogen receptor β (ERβ) mediates the action of estrogen on metabolism of lipids and lipoprotein. Therefore, its gene is a promising candidate gene for cardiovascular disease. The aim of the present study was to investigate whether the ERβ A1730G polymorphism modifies the metabolic response to hormone replacement therapy (HRT) in postmenopausal women. The population included 60 normolipidemic postmenopausal women with equal numbers of each A1730G genotype followed during a 90-day experimental period. All subjects received oral estrogen together with a progestin therapy during the HRT. ABCA1 gene expression and serum lipid and lipoprotein concentrations were measured at the beginning and end of the HRT trial. At baseline, ABCA1 gene expression, lipid or lipoprotein concentrations were not significantly different among the ERβ A1730G genotype groups. After HRT, however, subjects with GG genotype had a greater increase in ABCA1 gene expression (p = 0.002) and a trend toward greater increase in apoA-I (p = 0.058) than subjects carrying the A allele. An interaction effect between genotype and HRT effect was observed on ABCA1 gene expression. In conclusion, the positive changes of ABCA1 gene expression and apoA-I were affected by the ERβ A1730G polymorphism in women taking estrogen-progesterone therapy.

Effect of titanium on lipoprotein lipase activity in vivo and in vitro

SUMMARY

Lipoprotein lipase (LPL) is a major lipolytic enzyme in the intravascular metabolism of postprandial triglyceride-rich lipoproteins. This enzyme is synthesized and secreted by tissues and transported to the capillary endothelial surface. Decreased activity of this enzyme is suggested to be involved in arterial sequestration of lipoproteins and thus in the progression of atherosclerosis. Titanium salts are widely used in industry, medicine, and pharmacy for tablet coating, pharmaceuticals and cosmetic products. In this study the effect of titanium on post-heparin LPL activity is reported in vivo and in vitro.

METHODS

Groups of Male Wistar rats were administered (i.p) with an acute dose of 2.5 mg/kg titanium chloride for 10 days and a chronic dose of 0.75 mg/kg for 30 and/or 60 days. Blood samples were then collected for LPL assay. For in vitro study, plasma aliquots were incubated in the presence of up to 50 mM titanium and the enzyme activity was measured.

RESULTS

Animals exposed to acute dose of titanium showed about 20% reduction in LPL activity, whereas 31% and 36% reductions were observed in animals chronically exposed for 30 and/or 60 days, respectively. Titanium in vitro also led to enzyme inhibition, so that a decrease of 28-53% was seen in the presence of 0.1-50 mM titanium. This inhibition by titanium was potentiated when citrate and/or bicarbonate was present.

CONCLUSION

Although the mechanism of titanium effect on LPL activity in vivo and in vitro demands more investigations, the inhibitory effect of titanium ion in vivo should be considered seriously in subjects exposed to this metal ion. Changes in LPL activity may affect whole body lipid metabolism, a condition favorable for development and progression of atherosclerosis.

Effect of hormone replacement therapy on total serum anti-oxidant potential and oxidized LDL/β2-glycoprotein I complexes in postmenopausal women

Oxidative stress and consequent oxidized lipoprotein production is thought to play a central role in both the initiation and progression of atherosclerosis. Oxidized low-density lipoprotein (oxLDL)/β2-glycoprotein I (β2GPI) complexes are etiologically important in the development of atherosclerosis. The aim of the present study was to investigate whether long-term treatment with conventional hormone replacement therapy (HRT) in postmenopausal women could affect total serum antioxidant capacity (TAC) and serum levels of oxLDL/β2GPI complexes. A total of 60 normolipidemic postmenopausal women treated with oral estrogen together with progestin therapy for 3 months were selected. TAC and serum levels of oxLDL/β2GPI complexes were measured at the beginning and end of the HRT. HRT led to a significant increase in TAC (15%, P=0.02) and a minor but statistically nonsignificant decrease of oxLDL/β2GPI complexes (3%, P=0.30) when compared with the baseline control levels. There was also no significant association between TAC and oxLDL/β2GPI complexes changes related to HRT. This study indicates that, HRT in postmenopausal women leads to an increase in TAC without an equivalent change in serum levels of oxLDL/β2GPI complexes. It is concluded that beneficial effects of HRT could be explained, at least in part, by improving antioxidant status, but may not be directly associated with a change in oxidized lipoprotein production.

Protective effects of selenium and zinc on changes in catecholamine levels of brain regions in lead intoxified rat

Lead is a common environmental toxic element for almost all biological systems. The nervous system is the primary target for the lead exposure. In the past few years, increasing considerations have been given to investigate the interaction occurring between toxic metals and some essential metals including Se and Zn with Pb. It has been shown that some trace elements could reverse the toxicity of lead on tissue functions. In this study the protective effects of Zn and Se on lead toxicity were investigated. Results of short time study showed that, intrapritoneal administration of Pb (13.5 mg kg(-1)) daily for 2 weeks reduced the catecholamine levels of cortex by 25, mid-Brain by 21 and cerebellum by 25.6%, respectively. Administration of the same amount of lead in combination with either Zn (0.5 mg kg(-1)) or Se (0.4 mg kg(-1)) reduced catecholamine levels of cortex by 8.3 and 18.3, mid-brain by 6, 10.9 and cerebellum 23, 6% respectively. Daily administration of lead alone (4 mg kg(-1)) for 60 days reduced catecholamine level of cortex by 27.4 and mid-Brain by 47.8 and cerebellum by 39%, respectively. When the same amount of lead in combination with Zinc (0.5 mg kg(-1)) and/or Se (0.4 mg kg(-1)) was administration daily for 60 days, results showed that catecholamine level of cortex was reduced by 9, 20 and mid-brain by 22.6, 29 and cerebellum 25, 16%, respectively. It is concluded that lead reduced catecholamine levels in different brain regions and Zn or Se might be able to reverse this reduction and protect brain function to some extent from lead toxicity.

Comparative effects of copper, iron, vanadium and titanium on low density lipoprotein oxidation in vitro

INTRODUCTION

Oxidation of low density lipoprotein (LDL) has been strongly implicated in the phathogenesis of atherosclerosis. The use of oxidants in dietary food stuff may lead to the production of oxidized LDL and may increase both the development and the progression of atherosclerosis. The present work investigated the effects of some elements including: copper (Cu), iron (Fe), vanadium (V) and titanium (Ti) on in vitro LDL oxidation quantitatively.

METHODS

The first LDL fraction was isolated from fresh plasma by single vertical discontinuous density gradient ultracentrifugation. The formation of conjugated dienes and thiobarbituric acid reactive substances and increase in electrophoretic mobility of LDL were monitored as markers of the oxidation of LDL.

RESULTS

It was demonstrated that Cu, Fe, V and Ti exhibited strong oxidant activity in this respect (P<0.001). Oxidation of LDL in the presence of Cu was more and appeared to be in this order Cu>Fe>V>Ti.

DISCUSSION

Cu, Fe, V and Ti are redox-active transition metals that may cause oxidative damage to lipids, proteins and DNA molecules. We suggest that these elements may also influence the oxidation of LDL in vivo, which could increase both the development and progression of atherosclerosis.

Long Term Effects of Oral Vitamin E Supplement in Type II Diabetic Patients

This triple-blind, placebo-controlled clinical trial was conducted to determine the effect of the vitamin E on fasting blood sugar (FBS), serum insulin, and glycated hemoglobin (GHb) in type II diabetic patients (NIDDM). A total of 100 patients, with no complications, aged 20–60 years old were chosen from those consulting the Isfahan Social Security Service Diabetes Clinic and divided randomly into two treated and placebo groups, and matched for age, sex, level of education, and occupation. The treated and placebo groups were given vitamin E tablets (200 IU/day) and placebo respectively. Serum vitamin E, total cholesterol (TC), triglycerides (TG), FBS, insulin, and GHb were measured at the beginning and at the end of the study (a period of 27 weeks); FBS, GHb and insulin levels were also determined several times during the period. Blood lipids and FBS were measured using the ELAN 2000 autoanalyzer at the Isfahan Cardiovascular Research Center, while for measuring insulin the enzyme-linked immunosorbent assay (ELISA) method was used; GHb was determined calorimetrically (thiobarbituric acid), and for vitamin E measurements the Hansen and Warwick method was used, by which the vitamin E was determined fluorometrically. The findings of this study show no effect of vitamin E supplementation in the patients: GHb did not change appreciably, FBS was reduced nonsignificantly (–4.3% in the treated group vs. –14.0% in the placebo group, p < 0.05). In the case of insulin, no increase was seen; instead, a decrease was observed (slightly more than 17% in the two groups, p = 0.15). No changes were observed in the levels of blood lipids. It was concluded that a daily vitamin E supplement of 200 IU for a period of 27 weeks does not affect insulin, GHb, or FBS in type II diabetic patients. However, since this antioxidant vitamin is beneficial in other ways in these patients, it would seem justified to recommend its use. Certainly, more extensive research is necessary to draw definite conclusions.

Effect of some volatile oils on the affinity of intact and oxidized low-density lipoproteins for adrenal cell surface receptors

Extensive research has shown that a high plasma concentration and oxidation of low-density lipoproteins (LDL) has an important role in atherogenesis. The affinity of LDL to its classic receptor is reduced due to oxidation. Instead, it is taken up by scavenger molecules in macrophages, as a result of which foam cells are formed that have a major role in increasing the subendothelial fat layers of the blood vessels. In the present study the antioxidant effect of eight volatile compounds in plant essences, namely, anethol, eugenol, limonen, linalool, p-cymol, pulegon, thymol, and geraniol, and their effect on the affinities of intact and oxidized (with Cu(+2)) LDL for LDL receptor in sheep adrenal tissue cells in the presence of labeled LDL with fluorescein isothiocynate (FITC) were investigated. The results obtained show that eugenol and thymol have the highest antioxidant effect, on the uptake of LDL (intact and oxidized) by the adrenal cells. The order of the compounds studied with regard to their antioxidant effect on intact and oxidized LDL is as follows: On intact LDL: eugenol > or = thymol > linalool > p-cymol > limonen > geraniol > anethol; on oxidized LDL: thymol > or = eugenol > geraniol > p-cymol > linalool > pulegon. Our findings also show that the compounds, particularly thymol and eugenol, have an antioxidant property and can change the affinity of the LDL particles for the LDL receptor probably due to their lipophylic property. Further research may prove that these compounds can be used clinically, especially in atherosclerotic and hypercholesterolemic cases.

Vanadyl sulfate ameliorates insulin resistance and restores plasma dehydroepiandrosterone-sulfate levels in fructose-fed, insulin-resistant rats

OBJECTIVES

To elucidate whether vanadyl sulfate ameliorates the decreased dehydroepiandrosterone sulfate (DHEAS) in hyperinsulinemic rats, we evaluated plasma DHEAS, insulin and triglyceride (TG) levels in fructose-induced, insulin-resistant rats.

DESIGN AND METHODS

Animals were divided into three groups: control (C), fructose fed (F-F), and vanadyl-treated fructose fed (F-T). Control animals were fed with standard chow; F-F and F-T groups fed with 66% fructose diet. F-F and C groups received tap water; F-T group received water supplemented with 0.2 mg/ml vanadyl sulfate.

RESULTS

Fasting plasma glucose levels of three groups were comparable. Vanadyl treatment prevented the increase in plasma insulin and TG in the F-T group (P < 0.001) compared with the F-F group. Fructose feeding led to a decrease in plasma DHEAS in the F-F group (P < 0.001) compared with the C group. Vanadyl treatment prevented the decrease in plasma DHEAS in the F-T group (P < 0.001) compared with the F-F group.

CONCLUSIONS

Our results indicated that the hyperinsulinemia in fructose-fed, insulin-resistant rats is associated with low levels of DHEAS. Vanadyl sulfate probably restores plasma DHEAS, due to the improved insulin action.

Comparative binding study of aluminum and chromium to human transferrin. Effect of iron

The characteristics of aluminum and chromium binding to apo-transferrin (apo-tf) have been investigated and compared. Both metal ions were taken up by human transferrin forming complexes with the maximum absorbances at 405 nm for chromium-transferrin (cr-tf) and 240 nm for aluminum-transferrin (Al-tf). In the presence of citric acid, chromium binding to transferrin is five times more than aluminum. The binding of aluminum or chromium to apo-transferrin was reduced by 18 and 22% in the presence of 200 ng/mL of iron. The binding of both metals to apo-tf appears to be pH dependent. In acidic pHs, less chromium and more aluminum binding occurred.

The effect of chromium on parameters related to iron metabolism

The effect of chromium on some parameters related to iron metabolism was investigated. Preliminary experiments showed that this metal ion was taken up by serum proteins and was dependent on the amount of chromium present in the medium. It was also shown that the uptake of iron was reduced significantly in the presence of chromium. In vivo study showed that the serum levels of iron and total iron binding capacity (TIBC) were reduced by 28 and 11%, respectively, following daily administration of chromium (1 mg/kg) for 45 d. Serum ferritin was reduced by 22% under this condition. Hematocrit and hemoglobin levels were also affected in chromium-treated animals and were both reduced by 17%. Spectrophotometric titration of each individual amino acid located in the iron binding site of transferrin revealed that tyrosine might be the most suitable ligand for the binding of chromium to transferrin. These results suggest that chromium may compete with iron in binding to apo-transferrin, and influence iron metabolism and its related biochemical parameters.

Effect of estradiol on neurotransmitter sensitive adenylate cyclase. Its possible role in 'sexual differentiation'

Adenylate cyclase activity is lower in the hypothalamus of 5-day-old male rats than in females. This may be due to the presence of estradiol (E2) in this area of the male but not in the female since castration of the newborn male leads to an enzyme activity in the hypothalamus that is indistinguishable from that of the female and androgenization of the newborn female causes an enzyme activity level comparable to that of the male. In the adult, enzyme activity is highest when the concentration of E2 is at its lowest level; adenylate cyclase activity in the hypothalamus-preoptic area was found to be higher in the metestrus female than in proestrus or in the adult male. In vitro E2 was shown to reduce enzyme activity and this reduction was found to be dependent on induction of protein biosynthesis. In addition, there appears to be a requirement for Ca2+ in the E2-induced reduction of cyclase activity. Although F- activates the enzyme in all of the cases studied, the reduction in enzyme activity brought about by E2 is not reversed by F-, suggesting that the effect of E2 is not on the receptor. As sexual differentiation is brought about by the action of E2 during the first week after birth, it seems plausible to suggest that this interaction between hormone and enzyme is an early step in the sexual differentiation of the brain.