Anti-oxidative and anti-inflammatory effects of Tagetes minuta essential oil in activated macrophages

Objective:To investigate antioxidant and anti-inflammatory effects of Tagetes minuta(T.minuta)essential oil.Methods:In the present study T.minuta essential oil was obtained from leaves of T.minuta via hydro-distillation and then was analyzed by gas chromatography-mass spectrometry.The antioxidant capacity of T.minuta essential oil was examined by measuring reactive oxygen,reactive nitrogen species and hydrogen peroxide scavenging.The anti-inflammatory activity of T.minuta essential oil was determined through measuring NADH oxidase,inducible nitric oxide synthase and TNF-αmRNA expression in lipopolysacharide-stimulated murine macrophages using realtime PCR.Results:Gas chromatography-mass spectrometry analysis indicated that the main components in the T.minuta essential oil were dihydrotagetone(33.86%),E-ocimene(19.92%).tagetone(16.15%),cis-β-ocimene(7.94%),Z-ocimene(5.27%).limonene(3.1%)and epoxyocimene(2.03%).The T.minuta essential oil had the ability to scavenge all reactive oxygen/reactive nitrogen species radicals with IC_(50)12-15μg/mL,which indicated a potent radical scavenging activity.In addition,T.minuta essential oil significantly reduced NADH oxidase,inducible nitric oxide synthaseand TNF-αmRNA expression in the cells at concentrations of 50μg/mL,indicating a capacity of this product to potentially modulate/diminish immune responses.Conclusions:T.minuta essential oil has radical scavenging and anti-inflammatory activities and could potentially be used as a safe effective source of natural anti-oxidants in therapy against oxidative damage and stress associated with some inflammatory conditions.

In vitro-derived insulin-producing cells modulate Th1 immune responses and induce IL-10 in streptozotocin-induced mouse model of pancreatic insulitis

Background: Insulitis is defined by the presence of immune cells infiltrating in the pancreatic islets that might progress into the complete β-cell loss. The immunomodulatory properties of bone marrow-derived mesenchymal stem cells(BM-MSCs) have attracted much attention. This study aimed to evaluate the possible immunomodulatory effects of rat BM-MSCs and MSCs-derived insulin-producing cells(IPCs) in a mouse model of pancreatic insulitis. Methods: Insulitis was induced in BALB/c mice using five consecuti ve doses of streptozotocin. MSCs or IPCs were directly injected into the pancreas of mice and their effects on the expression of Th subsetsrelated genes were evaluated. Results: Both BM-MSCs and IPCs significantly reduced the expression of pancreatic Th1-related IFN-γ( P < 0.001 and P < 0.05, respectively) and T-bet genes(both P < 0.001). Moreover, the expression of IL-10 gene was significantly increased in IPC-treated compared to BM-MSC-or PBS-treated mice( P < 0.001 both comparisons). Conclusions: BM-MSCs and IPCs could successfully suppress pathologic Th1 immune responses in the mouse model of insulitis. However, the marked increase in IL-10 gene expression by IPCs compared to BM-MSCs suggests that their simultaneous use at the initial phase of autoimmune diabetes might be a better option to reduce inflammation but these results need to be verified by further experiments.