Anti-inflammatory effects of Allium cepa L. peel extracts via inhibition of JAK-STAT pathway in LPS-stimulated RAW264.7 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Allium cepa L. (A. cepa) is one of the oldest cultivated plants in the world. A. cepa has been used in traditional folk medicine to treat inflammatory disease in several regions, such as Palestine and Serbia. A. cepa peel has a higher content of flavonoids, such as quercetin, than the edible parts. These flavonoids alleviate inflammatory diseases. However, the anti-inflammatory effects of A. cepa peel extract-obtained using various extraction methods-and their underlying mechanisms require further investigation. AIM OF THE STUDY: Although research to find safe anti-inflammatory substances in various natural products has been actively conducted for many years, it is important to continue identifying potential anti-inflammatory effects in natural materials. The purpose of this study was to investigate the ethnopharmacological properties of the A. cepa peel extract, whose efficacy when obtained through different extraction methods and underlying action mechanisms is not well known. The present study specifically aimed to observe the anti-inflammatory effects of the A. cepa peel extracts obtained using various extraction methods and the related detailed mechanisms of A. cepa peel extracts in lipopolysaccharide (LPS)-induced RAW264.7 cells. MATERIALS AND METHODS: The total flavonoid content of the A. cepa peel extracts was determined the diethylene glycol colorimetric method and measured using a calibration curve prepared using quercetin as a standard solution. The antioxidant activity was evaluated using the ABTS assay, and cytotoxicity was measured using the MTT assay. NO production was measured using Griess reagent. Protein levels were measured by western blotting, and mRNA expression was measured by RT-qPCR. Secreted cytokines were analyzed using ELISA or cytokine arrays. In the GSE160086 dataset, we calculated Z-scores for individual genes of interest and displayed using a heat map. RESULTS: Of the three A. cepa peel extracts obtained using different extraction methods, the A. cepa peel 50% EtOH extract (AP50E) was the most effective at inhibiting LPS-induced nitric oxide (NO) and inducible nitric oxide synthase (iNOS). Furthermore, AP50E significantly reduced the levels of pro-inflammation cytokines interleukin (IL)-1α, IL-1ß, IL-6, and IL-27. Additionally, AP50E directly inhibited the Janus kinase-signaling transducer and activator of transcription (JAK-STAT) pathway. CONCLUSIONS: These results showed that AP50E exhibited an anti-inflammatory effect in LPS-induced RAW264.7 mouse macrophages by directly inhibiting JAK-STAT signaling. Based on these findings, we propose AP50E as a potential candidate for the development of preventive or therapeutic agents against inflammatory diseases.

Pharmacological anti-tumor effects of natural Chamaecyparis obtusa (siebold & zucc.) endl. Leaf extracts on breast cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Chamaecyparis obtusa (C. obtusa, cypress species) is a plant that grows mainly in the temperate Northern Hemisphere and has long been used as a traditional anti-inflammatory treatment in East Asia. C. obtusa contains phytoncides, flavonoids, and terpenes, which have excellent anti-cancer effects and have been reported to prevent the progression of various cancers. However, the detailed mechanisms underlying the anti-cancer effects of C. obtusa extracts are unknown. AIM OF THE STUDY: We sought to confirm the anti-cancer effects of C. obtusa leaf extracts and to reveal the mechanism of action, with the possibility of its application in the treatment or prevention of cancer. MATERIAL &METHODS: The cytotoxicity of C. obtusa leaf extracts was confirmed using an MTT assay. Intracellular changes in protein levels were measured by immunoblotting, and mRNA levels were measured with qRT-PCR. Wound healing assay and transwell migration assay were used to evaluate the metastatic potential of breast cancer cells. The extract-induced apoptosis was observed using IncuCyte Annexin V Red staining analysis. A syngeneic breast cancer mouse model was established by injecting 4T1-Luc mouse breast cancer cells into the fat pad of female BALB/c mice, and the extract was administered orally. Luciferin solution was injected intraperitoneally to assess primary tumor development and metastasis by bioluminescence. RESULTS: C. obtusa leaf extracts were extracted with boiling water, 70% EtOH, and 99% EtOH. Among the extracts, the 99% EtOH extract of C. obtusa leaf (CO99EL) most clearly inhibited the tyrosine phosphorylation of Signal Transducer and Activator of Transcription 3 (pY-STAT3) in MDA-MB-231 breast cancer cells at a concentration of 25 and 50 µg/mL. In addition, CO99EL strongly inhibited not only endogenous pY-STAT3 levels but also IL-6-induced STAT3 activation in various types of cancer cells, including breast cancer. CO99EL inhibited metastatic potential by downregulating the expression of N-cadherin, fibronectin, TWIST, MMP2, and MMP9 in MDA-MB-231 breast cancer cells. CO99EL also induced apoptotic cell death by increasing cleaved caspase-3 and decreasing anti-apoptotic proteins Bcl-2 and Bcl-xL. In an in vivo syngeneic breast cancer mouse model, 100 mg/kg CO99EL suppressed tumor growth and induced apoptosis of cancer cells. Moreover, CO99EL significantly inhibited lung metastasis from primary breast cancer. CONCLUSIONS: Our study demonstrated that 100 mg/kg CO99EL has potent anti-tumor effects against breast cancer, thus suggesting that 100 mg/kg CO99EL has potential applications in the treatment and prevention of breast cancer.

Chamaecyparis obtusa (Siebold & Zucc.) Endl. leaf extracts prevent inflammatory responses via inhibition of the JAK/STAT axis in RAW264.7 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Chamaecyparis obtusa (Siebold & Zucc.) Endl. (C. obtusa) has been used as folk medicine in East Asia and has been reported to alleviate inflammatory diseases. However, the detailed mechanisms for the anti-inflammatory effects of C. obtusa remain unclear. AIM OF THE STUDY: Although the anti-inflammatory mechanisms of natural products have been studied for decades, it is still important to identify the potential anti-inflammatory effects of natural sources. In this study, we investigated the anti-inflammatory effects and underlying mechanism of C. obtusa leaf extracts. MATERIAL &METHODS: The cell viability was determined by MTT and crystal violet staining. NO production in the supernatant was measured using Griess reagent. The cell lysates were analyzed by immunoblotting and RT-qPCR. Secreted cytokines were analyzed using ELISA kit and cytokine array kit. mRNA expression from the GSE9632 database set. Z-scores were calculated for each gene and visualized by heat map. RESULTS: Among the extracts of C. obtusa obtained with different extraction methods, the 99% ethanol leaf extract (CO99EL) strongly inhibited lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and Janus kinase/signaling transducer and activator of transcription (JAK/STAT) phosphorylation in RAW264.7 cells. In addition, CO99EL strongly inhibited LPS-induced interleukin (IL)-1ß, IL-6, IL-27, and C-C motif chemokine ligand (CCL)-1 production and directly inhibited LPS-induced JAK/STAT phosphorylation in RAW264.7 cells. CONCLUSIONS: These findings demonstrate that CO99EL significantly prevents LPS-induced macrophage activation by inhibiting the JAK/STAT axis. Therefore, we suggest the use of C. obtusa extracts as therapeutic approach for inflammatory diseases.

Ginsenoside 20(S)-Rh2 exerts anti-cancer activity through targeting IL-6-induced JAK2/STAT3 pathway in human colorectal cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax ginseng is one of the most well-known medicinal herbs in Korea and China, which has been used for treatment and prevention of cancer, obesity, diabetes, and cardiovascular diseases. Ginsenosides are the major components of P. ginseng, having a wide range of pharmacological activities. Among the ginsenosides, protopanaxadiol (PPD)-types reportedly have potent anti-cancer effects. Rh2 is PPD-type ginsenoside, and two stereoisomeric forms of Rh2 as 20(S)- and 20(R)-Rh2 were selectively isolated recently. AIM OF THE STUDY: The biological activities of Rh2 ginsenosides are known to depend on their differences in stereochemistry. Colorectal cancer (CRC) is one of the most lethal neoplasm, and cancer-related death is usually associated with metastasis to other organs. We aimed this study to investigate whether 20(S)- and 20(R)-Rh2 can suppress tumor invasion in human CRC cells. MATERIALS AND METHODS: 20(S)- and 20(R)-Rh2 were isolated from the roots of ginseng. Human CRC cells were incubated with 20(S)- or 20(R)-Rh2 in the presence or absence of interleukin-6. An MTT assay was used to measure cell viability. Western blot and quantitative real-time PCR analyses were performed to determine levels of expression and phosphorylation. An invasion assay was performed using a Boyden chamber system with the Matrigel-coated membrane to measure cancer cell invasion. RESULTS: 20(S)- and 20(R)-Rh2 showed differential cytotoxic activity. Only 20(S)-Rh2 decreased cancer cell viability. Additionally, 20(S)-Rh2 effectively inhibited IL-6-induced signal transducer and activator of transcription 3 (STAT3) phosphorylation and the expression of matrix metalloproteinases (MMPs), including MMP-1, -2, and -9, resulting in inhibition of cancer cell invasion. Interestingly, these pharmacological activities of 20(S)-Rh2 were more potent than those of 20(R)-Rh2. Furthermore, combination treatment showed that 20(S)-Rh2 enhanced the sensitization of doxorubicin-treated anti-cancer activities in CRC cells. CONCLUSION: Our results demonstrated that ginsenoside 20(S)-Rh2 has therapeutic potential for the treatment with CRC and may be valuable as a combination partner with more classic chemotherapeutic agents, such as doxorubicin, to treat CRC.

Isolation and characterization of the corticotropin-releasing factor-related diuretic hormone receptor in Rhodnius prolixus.

Rhodnius prolixus, the vector of human Chagas disease, is a hemipteran insect that undergoes rapid post-feeding diuresis following ingestion of a blood meal that can be up to 10 times its initial body weight. Corticotropin-releasing factor-related diuretic hormone (Rhopr-CRF/DH) and serotonin are neurohormones that are synergistic in increasing rates of fluid secretion by Malpighian tubules during this rapid post-feeding diuresis. A Rhopr-CRF/DH receptor transcript has now been isolated and characterized from fifth instar R. prolixus. The receptor is a family B1 (secretin) G protein-coupled receptor (GPCR) and was deorphaned in a heterologous cellular system using Chinese hamster ovary (CHO) cells stably expressing a promiscuous G-protein (Gα16). This assay was also used to demonstrate the presence of Rhopr-CRF/DH in the haemolymph of R. prolixus in response to blood-gorging. Two additional cell lines were used in this heterologous assay to verify that the cyclic adenosine monophosphate (cAMP) pathway and not the inositol triphosphate (IP3) pathway was stimulated upon activation of the receptor. Lastly, quantitative PCR demonstrated strong receptor expression in digestive tissues, upper Malpighian tubules and reproductive tissues. Identification of the Rhopr-CRF/DH receptor now provides tools for a more detailed understanding into the precise coordination of diuresis and other physiological processes in R. prolixus.