Total sesquiterpene lactones isolated from Inula helenium L. attenuates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in mice.

BACKGROUND: Inula helenium L. is an herb whose anti-inflammatory properties are attributed to its active components, the sesquiterpene lactones (SLs). Our previous study demonstrated that the total sesquiterpene lactones isolated from Inula helenium L. (TSL-IHL), consisting mainly of alantolactone (AL) and isoalantolactone (IAL), may have potential in the prevention and treatment of rheumatoid arthritis (RA). However, the effect of TSL-IHL on atopic dermatitis (AD) has not been studied yet. AIM OF THE STUDY: The present study evaluates the potential of TSL-IHL as a treatment for AD. METHODS/STUDY DESIGNS: The effects of TSL-IHL on the expression of inflammatory genes and the activation of NF-κB signaling pathway in HaCat cells were examined by quantitative real-time PCR and western blotting, respectively, and compared with those of AL and IAL. The protective effect of TSL-IHL against AD was tested in a mouse model induced by 2,4-dinitrochlorobenzene (DNCB), in which AD-like skin lesions were induced in ICR mice by sensitizing once with 100 µl of 7% DNCB painted on their shaved back skin and then challenging with 20 µl of 0.2% DNCB five times on their right ears at 3 day intervals starting on day 5 post-sensitization. RESULTS: TSL-IHL, as well as AL and IAL, could all inhibit TNF-α-induced activation of NF-κB and the expression of TNF-α, IL-1, and IL-4 in HaCat cells in a dose-dependent manner in the range of 0.6-2.4 µg/ml. The topical application of TSL-IHL (1% W/W in emollient cream) attenuated DNCB-induced dermatitis severity and right ear swelling. The serum levels of IgE, TNF-α and IFN-γ in TSL-IHL-treated mice were reduced by 81.39%, 89.69%, and 87.85%, respectively, while the mRNA levels of IL-4, IL-5 and IL-13, in the back-skin lesions of TSL-IHL-treated mice were reduced by 39.21%, 40.62% and 48.12%, respectively, compared with the untreated controls. Histopathological examination showed that TSL-IHL treatment reduced epidermis/dermis thickening and dermal inflammatory infiltration in both ear and back skins. CONCLUSIONS: We suggest that TSL-IHL inhibited the development of AD-like skin symptoms by regulating cytokine expression and may be an effective alternative therapy for AD.

Total sesquiterpene lactones prepared from Inula helenium L. has potentials in prevention and therapy of rheumatoid arthritis.

BACKGROUNDS: Inula helenium L. is an herb with anti-inflammatory properties. Sesquiterpene lactones (SLs), mainly alantolactone (AL) and isoalantolactone (IAL), are considered as its active ingredients. However, the anti-inflammatory effects of SL-containing extracts of I. helenium have not been explored. Here we prepared total SLs from I. helenium (TSL-IHL), analyzed its chemical constituents, and performed cellular and animal studies to evaluate its anti-inflammatory activities. MATERIALS AND METHODS: The chemical profile of TSL-IHL was analyzed by HPLC-UV. Its in vitro effects on the activation of signaling pathways and expression of inflammatory genes were examined by western blotting and quantitative real-time PCR, respectively, and compared with those of AL and IAL. Its in vivo anti-inflammatory effects were evaluated in adjuvant- and collagen-induced arthritis rat models. RESULTS: Chemical analysis showed that AL and IAL represent major constituents of TSL-IHL. TSL-IHL, as well as AL and IAL, could inhibit TNF-α-induced activation of NF-κB and MAPK pathways in b. End3 cells, suppress the expressions of MMP-3, MCP-1, and IL-1 in TNF-α-stimulated synovial fibroblasts, and IL-1, IL-6, and iNOS in LPS-activated RAW 264.7 cells in a dose-dependent manner in the range of 0.6-2.4µg/mL. Oral administration of TSL-IHL at 12.5-50mg/kg could dose-dependently alleviate the arthritic severity and paw swelling in either developing or developed phases of arthritis of rats induced by adjuvant or collagen CONCLUSIONS: These results indicated potentials of TSL-IHL in prevention and therapy of rheumatoid arthritis.

Bioactive compound reveals a novel function for ribosomal protein S5 in hepatic stellate cell activation and hepatic fibrosis.

UNLABELLED: Liver fibrosis and its endstage, cirrhosis, represent a major public health problem worldwide. Activation of hepatic stellate cells (HSCs) is a central event in hepatic fibrosis. However, the proteins that control HSC activation are incompletely understood. Here we show that (6aS, 10S, 11aR, 11bR, 11cS)-10-methylamino-dodecahydro-3a, 7a-diaza-benzo [de]anthracene-8-thione (MASM) exhibits potent inhibitory activity against liver fibrosis in vitro and in vivo associated with the reduction of Akt phosphorylation. Furthermore, ribosomal protein S5 (RPS5) was identified as a direct target of MASM, which stabilized RPS5 in cultured HSCs and in the liver of experimental animals after dimethylnitrosamine (DMN) or bile duct ligation (BDL). Functional studies revealed that RPS5 could prevent HSC activation. RPS5 overexpression in HSCs resulted in Akt dephosphorylation at both Ser473 and Thr308, and led to subsequent dephosphorylation of GSK3ß or P70S6K. Progression of DMN- and BDL-induced hepatic fibrosis was aggravated by Rps5 knockdown and alleviated by RPS5 overexpression, which correlated with the modulation of Akt phosphorylation and HSC number in the fibrotic livers. Moreover, RPS5 was substantially reduced in the transdifferentiated HSCs, experimental fibrotic livers, and human cirrhosis samples. CONCLUSION: These results demonstrate that RPS5 is implicated in hepatic fibrogenesis and may represent a promising target for potential therapeutic intervention in liver fibrotic diseases.