Tag Archives: curcumin

Leptin and curcumin affect renal ischemia-reperfusion injury via modulation of P65 and Bax genes expression

M. M. Ragy1, M. M. Ramzy2*

1Physiology Department, Faculty of Medicine, Minia University, Misr-Aswan Road, Egypt;
2Biochemistry Department, Faculty of Medicine, Minia University, Misr-Aswan Road, Egypt;
*e-mail: maggiemaher24@gmail.com

Received: 01 June 2020; Accepted: 17 December 2020

Ischemia and reperfusion are natural steps during kidney transplantation, and ischemia-reperfusion injury is a critical condition in which physicians must preserve organ function and control cell damage. As leptin is thought to play an important role in the regulation of the immune system and inflammation and curcumin is a potent anti-fibrotic agent, both agents are promising to have therapeutic impact on renal damage. The present study was designed to evaluate the effects of leptin and curcumin on renal ischemia-reperfusion injury. Forty adult male albino rats were divided into four groups: control; ischemia-reperfusion (I/R), leptin-treated (leptin was injected intraperitoneally at a dose 100 μg/kg for 3 days prior to ischemia) and curcumin-treated (curcumin was given orally at a dose of 50 mg/kg/day for 5 days before ischemia). All rats were sacrificed 24 hours after reperfusion. Serum urea and creatinine, renal malondialdehyde and total antioxidant capacity were measured. Renal TNF-α was assayed by ELISA and P65 and Bax mRNA expression were determined using RT-PCR. Our results demonstrated a significant increase in P65 and Bax mRNA expression after renal ischemia-reperfusion injury compared to control group. Both leptin and curcumin prevented oxidative damage of the renal tissues as they lowered MDA and nitric oxide levels, increased antioxidant capacity and decreased TNF-α level. It was shown that protective leptin and curcumin effect against kidney IR-induced oxidative injury was associated with a down-regulation of P65 and Bax expression. These results show that ischemia-reperfusion leads to renal damage and also they reveal that both leptin and curcumin have protective implications which may be promising agents for avoiding various adverse effects.

Effect of curcumin on accumulation in mononuclear cells and secretion in incubation medium of Аβ(40) and cytokines under local excess of Аβ(42)-homoaggregates

V. V. Sokolik1, S. M. Shulga2

1SI “Institute of Neurology, Psychiatry and Narcology of NAMS of Ukraine”, Kharkiv;
2SI “Institute for Food Biotechnology and Genomics of NAS of Ukraine”, Kyiv;
e-mail:  sokolik67@rambler.ru

The aim of the work was to investigate accumulation of endogenous Aβ40 and cytokines (IL-1β, TNFα, IL-6, IL-10) in mononuclear cells and their secretion into incubation medium under Aβ42-aggregates’ toxicity and anti-inflammatory effects of curcumin. Mononuclear cells were isolated in Ficoll-Urografin density gradient from venous blood of healthy donors, resuspended and used for testing of homoaggregates of Aβ42 (15 nM), curcumin (54 pM) and their combinations on various timescales (0, 1, 2, 3, 6 and 24 hours). Endogenous Aβ40 and cytokines were detected in mononuclear cells and (separately) in incubation medium by ELISA. We demonstrated for the first time that homoaggregates of Aβ42 cause rapid accumulation of endogenous Aβ40 in mononuclear cells and accelerate its secretion into incubation medium. We found increased concentration of TNFα after 3 hours of incubation, and no changes in IL-1β concentration due to secretion of these pro-inflammatory factors into incubation medium. The concentrations of IL-6 in mononuclear cells were increased under effects of Aβ42 homoaggregates, and it was being secreted profoundly into incubation medium. Aβ42 did not affect IL-10 secretion, yet caused an increase in its intracellular concentration after 1 hour of incubation, which was subsequently suppressed. Curcumin prevented the increase in Aβ40 concentration in mononuclear cells and significantly decreased its secretion resulting from Aβ42 toxicity. Curcumin negated the activating effect of Aβ42 on pro-inflammatory cytokines, starting immediately for IL-1β and on 3-6 hours for TNFα, which resulted in decreased extracellular concentrations of these cytokines. The polyphenol also potentiated repleni­shing of intracellular IL-6 and IL-10 concentrations and their secretion into incubation medium.

Effect of β-amyloid peptide 42 on the dynamics of expression and formation of Аβ(40), IL-1β, TNFα, IL-6, IL-10 by peripheral blood mononuclear cells in vitro and its correction by curcumin

V. V. Sokolik1, O. K. Koliada2, S. M. Shulga3

1SI Institute of Neurology, Psychiatry and Narcology, National Academy
of Medical Sciences of Ukraine, Kharkiv;
2SI D. F. Chebotarev Institute of Gerontology, National Academy
of Medical Sciences of Ukraine, Kyiv;
3SI Institute for Food Biotechnology and Genomics, National Academy
of Sciences of Ukraine, Kyiv;
e-mail: sokolik67@rambler.ru

The toxic effect of Аβ-oligomers accompanies chronic inflammation, with cytokines as main mediators. Therefore, the cytokine link of inflammation becomes a new target on the way to restrain amyloidosis. The aim of the study was the effect of aggregated Аβ42 on the dynamics of expression and formation of endogenous Аβ40 and cytokines (IL-1β, TNFα, IL-6, IL-10) by peripheral blood mononuclear cells in vitro and its correction by curcumin. A suspension of mononuclear cells isolated ex tempore using ficoll-urografin gradient from venous blood samples of healthy volunteers were used to study the effects of Аβ42 (15 nM), curcumin (54 pM), and their combined action (at similar concentrations) in time dynamics: 0, 1, 3, 6 and 24 h incubation at 37 °C. Polymerase chain reaction with appropriate primers was used to determine the relative expression of mRNA for AβPP, TNFα, IL-1β, IL-6, IL-10 and enzyme-linked immunosorbent assay – to determine the content of Аβ40 and cytokines in mononuclear suspension during all periods of incubation. The individual dynamics AβPP and cytokine expression was shown under the action of the Aβ42, which had influence on the content of Aβ40, TNFα, IL-1β, IL-6 and IL-10 in mononuclear suspension. Curcumin displayed the inhibitory effect on gene expression of AβPP, TNFα and IL6, which resulted in the decrease of the level of these two cytokines and Aβ40. Thus, the dynamics of anti-inflammatory effect of curcumin in vitro for transcriptional and translational levels of cytokine’s formation by mononuclear cells was shown in the work. Direct inhibitory effect of curcumin on the concentration of endogenous Aβ40 during the 24 h incubation in conditions of toxic action of Aβ42 aggregates was established.