Garcinia vilersiana bark extract activates the Nrf2/HO-1 signaling pathway in RAW264.7 cells

Anti-inflammatory effects of Peucedanum japonicum Thunberg leaves extract in Lipopolysaccharide-stimulated RAW264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Peucedanum japonicum Thunberg are perennial herbaceous plants known to be cultivated for food and traditional medicinal purposes. P. japonicum has been used in traditional medicine to soothe coughs and colds, and to treat many other inflammatory diseases. However, there are no studies on the anti-inflammatory effects of the leaves.

AIM OF THE STUDY

Inflammation plays an important role in our body as a defense response of biological tissues to certain stimuli. However, the excessive inflammatory response can lead to various diseases. This study aimed to investigate the anti-inflammatory effects of P. japonicum leaves extract (PJLE) in LPS-stimulated RAW 264.7 cells.

MATERIAL AND METHODS

Nitric Oxide (NO) production assay measured by NO assay. Inducible NO synthase (iNOS), COX-2, MAPKs, AKT, NF-κB, HO-1, Nrf-2 were examined by western blotting. PGE₂, TNF-α, and IL-6 were analyzed by ELSIA. Nuclear translocation of NF-κB was detected by immunofluorescence staining.

RESULTS

PJLE suppressed inducible nitric oxygen synthase (iNOS) and prostaglandin-endoperoxide synthase 2 (cyclooxygenase-2, COX-2) expression, increased heme oxygenase 1 (HO-1) expression, and decreased nitric oxide production. And PJLE inhibited the phosphorylation of AKT, MAPK, and NF-κB. Taken together, PJLE down-regulated inflammatory factors such as iNOS and COX-2 by inhibiting the phosphorylation of AKT, MAPK, and NF-κB.

CONCLUSIONS

These results suggest that PJLE can be used as a therapeutic material to modulate inflammatory diseases.

Anti‑inflammatory effect of Chrysanthemum zawadskii, peppermint, Glycyrrhiza glabra herbal mixture in lipopolysaccharide‑stimulated RAW264.7 macrophages

The normal inflammatory reaction protects the body from harmful external factors, whereas abnormal chronic inflammation can cause various diseases, including cancer. The purpose of the present study was to investigate the anti‑inflammatory activity of a mixture of Chrysanthemum zawadskii, peppermint and Glycyrrhiza glabra (CPG) by analyzing the expression levels of inflammatory mediators, cytokines and transcription factors in lipopolysaccharide (LPS)‑stimulated Raw264.7 cells. A nitric oxide assay, ELISA, western blotting and immunofluorescence staining were performed to investigate the anti‑inflammatory activity of the CPG mixture. Pretreatment of Raw264.7 cells with CPG inhibited the increase of inflammatory mediators (inducible nitric oxide synthase, cyclooxygenase‑2 and IFN‑β) induced by LPS. Additionally, it inhibited the production of pro‑inflammatory cytokines (TNF‑α, IL‑6 and IL‑1β). CPG suppressed LPS‑induced phosphorylation of STAT1, AKT, Iκb and NF‑κB. Furthermore, CPG inhibited the translocation of NF‑κB into the nucleus. In summary, CPG could inhibit LPS‑induced inflammation, which occurs primarily through the AKT/Iκb/NF‑κB signaling pathway in RAW264.7 cells.

In vitro Anti-Inflammatory and Anti-Oxidative Stress Activities of Kushenol C Isolated from the Roots of Sophora flavescens

Kushenol C (KC) is a prenylated flavonoid isolated from the roots of Sophoraflavescens aiton. Little is known about its anti-inflammatory and anti-oxidative stress activities. Here, we investigated the anti-inflammatory and anti-oxidative stress effects of KC in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages, and tert-butyl hydroperoxide (tBHP)-induced oxidative stress in HaCaT cells. The results demonstrated that KC dose-dependently suppressed the production of inflammatory mediators, including NO, PGE₂, IL-6, IL1β, MCP-1, and IFN-β in LPS-stimulated RAW264.7 macrophages. The study demonstrated that the inhibition of STAT1, STAT6, and NF-κB activations by KC might have been responsible for the inhibition of NO, PGE₂, IL-6, IL1β, MCP-1, and IFN-β in the LPS-stimulated RAW264.7 macrophages. KC also upregulated the expression of HO-1 and its activities in the LPS-stimulated RAW264.7 macrophages. The upregulation of Nrf2 transcription activities by KC in the LPS-stimulated RAW264.7 macrophages was demonstrated to be responsible for the upregulation of HO-1 expression and its activity in LPS-stimulated RAW264.7 macrophages. In HaCaT cells, KC prevented DNA damage and cell death by upregulating the endogenous antioxidant defense system involving glutathione, superoxide dismutase, and catalase, which prevented reactive oxygen species production from tert-butyl hydroperoxide (tBHP)-induced oxidative stress in HaCaT cells. The upregulated activation of Nrf2 and Akt in the PI3K-Akt signaling pathway by KC was demonstrated to be responsible for the anti-oxidative stress activity of KC in HaCaT cells. Collectively, the study suggests that KC can be further investigated as a potential anti-inflammatory candidate for the treatment of inflammatory diseases.

A bypass mechanism of abiraterone-resistant prostate cancer: Accumulating CYP17A1 substrates activate androgen receptor signaling

BACKGROUND

Intratumoral steroidogenesis and its potential relevance in castration-resistant prostate cancer (CRPC) and in cytochrome P450, family 17, subfamily A, polypeptide 1 (CYP17A1)-inhibitor treated hormone-naïve and patients with CRPC are not well established. In this study, we tested if substrates for de novo steroidogenesis accumulating during CYP17A1 inhibition may drive cell growth in relevant preclinical models.

METHODS

PCa cell lines and their respective CRPC sublines were used to model CRPC in vitro. Precursor steroids pregnenolone (Preg) and progesterone (Prog) served as substrate for de novo steroid synthesis. TAK700 (orteronel), abiraterone, and small interfering RNA (siRNA) against CYP17A1 were used to block CYP17A1 enzyme activity. The antiandrogen RD162 was used to assess androgen receptor (AR) involvement. Cell growth was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. AR-target gene expression was quantified by reverse transcription polymerase chain reaction (RT-PCR). Nuclear import studies using cells with green fluorescent protein (GFP)-tagged AR were performed to assess the potential of precursor steroids to directly activate AR.

RESULTS

Preg and Prog stimulated cell proliferation and AR target gene expression in VCaP, DuCaP, LNCaP, and their respective CRPC sublines. The antiandrogen RD162, but not CYP17A1 inhibition with TAK700, abiraterone or siRNA, was able to block Preg- and Prog-induced proliferation. In contrast to TAK700, abiraterone also affected dihydrotestosterone-induced cell growth, indicating direct AR binding. Furthermore, Prog-induced AR translocation was not affected by treatment with TAK700 or abiraterone, while it was effectively blocked by the AR antagonist enzalutamide, further demonstrating the direct AR activation by Prog.

CONCLUSION

Activation of the AR by clinically relevant levels of Preg and Prog accumulating in abiraterone-treated patients may act as a driver for CRPC. These data provide a scientific rationale for combining CYP17A1 inhibitors with antiandrogens, particularly in patients with overexpressed or mutated-AR.

Aqueous extract of Dipsacus asperoides suppresses lipopolysaccharide-stimulated inflammatory responses by inhibiting the ERK1/2 signaling pathway in RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Dipsaci Radix, which is the dried root of Dipsacus asperoides C. Y. Cheng and T. M. Ai (Dipsacaceae), is used to treat back pain and blood stasis syndrome in Korean traditional medicine.

AIM OF THE STUDY

To understand the mechanisms responsible for the pharmacological activities of D. asperoides, we investigated the inhibitory effect of D. asperoides on lipopolysaccharide (LPS)-induced inflammation in mouse macrophages RAW 264.7 cells.

MATERIALS AND METHODS

Aqueous extract of D. asperoides (AEDA) was prepared by boiling D. asperoides in water and then administered to LPS treated RAW 264.7 cells. Cell viabilities were measured using an MTT assay, and protein levels were determined by western blotting. The ROS scavenging activity of AEDA was measured using a DCFH-DA assay and levels of nitric oxide (NO) were determined using a NO assay. The nuclear translocations of NF-κB and Nrf2 were investigated immunocytochemically, and pro-inflammatory cytokines in supernatant were evaluated by ELISA.

RESULTS

Treatment with AEDA suppressed the expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 macrophages. AEDA also reduced ROS, pro-inflammatory cytokine (IL-6 and IL-1β) levels, and iNOS-derived NO and COX-2-derived prostaglandin E2 release to medium, and suppressed the phosphorylation and degradation of IκB and the activation of NF-κB in macrophages. Furthermore, treatment with AEDA inhibited the ERK1/2 pathway but not the JNK or p38 MAPK pathways. In addition, AEDA significantly promoted Nrf2 translocation from cytoplasm to nucleus and up-regulated the expression of HO-1.

CONCLUSION

These results suggest that AEDA has anti-inflammatory and anti-oxidative effects through the inhibition of NF-κB and ERK1/2 and the activation of Nrf2/HO-1 in macrophages.

Antioxidant and Anti-Inflammatory Effects of Herbal Formula SC-E3 in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

SC-E3 is a novel herbal formula composed of five oriental medicinal herbs that are used to treat a wide range of inflammatory diseases in Korean traditional medicine. In this study, we sought to determine the effects of SC-E3 on free radical generation and inflammatory response in lipopolysaccharide- (LPS-) treated RAW 264.7 macrophages and the molecular mechanism involved. The ethanol extract of SC-E3 showed good free radical scavenging activity and inhibited LPS-induced reactive oxygen species generation. SC-E3 significantly inhibited the production of the LPS-induced inflammatory mediators, nitric oxide and prostaglandin E₂, by suppressing the expressions of inducible nitric oxide synthase and cyclooxygenase-2, respectively. SC-E3 also prevented the secretion of the proinflammatory cytokines, IL-1β, TNF-α, and IL-6, and inhibited LPS-induced NF-κB activation and the mitogen-activated protein kinase (MAPK) pathway. Furthermore, SC-E3 induced the expression of heme oxygenase-1 (HO-1) by promoting the nuclear translocation and transactivation of Nrf2. Taken together, these results suggest that SC-E3 has potent antioxidant and anti-inflammatory effects and that these effects are due to the inhibitions of NF-κB and MAPK and the induction of Nrf2-mediated HO-1 expression in macrophages. These findings provide scientific evidence supporting the potential use of SC-E3 for the treatment and prevention of various inflammatory diseases.

Anti-inflammatory activity of myricetin from Diospyros lotus through suppression of NF-κB and STAT1 activation and Nrf2-mediated HO-1 induction in lipopolysaccharide-stimulated RAW264.7 macrophages

Diospyros lotus is traditionally used for the treatment of diabetes, diarrhea, tumor, and hypertension. The purpose of this study was to investigate the anti-inflammatory effect and underlying molecular mechanisms of myricetin in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Myricetin dose-dependently suppressed the production of pro-inflammatory mediators (NO, iNOS, PGE2, and COX-2) in LPS-stimulated RAW264.7 macrophages. Myricetin administration decreased the production of NO, iNOS, TNF-α, IL-6, and IL-12 in mice. Myricetin decreased NF-κB activation by suppressing the degradation of IκBα, nuclear translocation of p65 subunit of NF-κB, and NF-κB DNA binding activity in LPS-stimulated RAW264.7 macrophages. Moreover, myricetin attenuated the phosphorylation of STAT1 and the production of IFN-β in LPS-stimulated RAW264.7 macrophages. Furthermore, myricetin induced the expression of HO-1 through Nrf2 translocation. In conclusion, these results suggest that myricetin inhibits the production of pro-inflammatory mediators through the suppression of NF-κB and STAT1 activation and induction of Nrf2-mediated HO-1 expression in LPS-stimulated RAW264.7 macrophages.