Microplastics in gastrointestinal tracts of gentoo penguin (Pygoscelis papua) chicks on King George Island, Antarctica.

Microplastics (< 5 mm) have been found in marine ecosystems worldwide, even in Antarctic ecosystems. In this study, the stomach and upper intestines of 14 dead gentoo penguin (Pygoscelis papua) chicks were collected and screened for microplastics on King George Island, a gateway to Antarctic research and tourism. A total of 378 microplastics were identified by Fourier-transform infrared spectroscopy, with 27.0 ± 25.3 microplastics per individual. The detected number of microplastics did not increase with the mass of penguin chicks, suggesting no permanent accumulation of microplastics. However, the concentration of microplastics was much higher (9.1 ± 10.8 microplastics per individual within the size range 100-5000 µm) than the previously reported concentration in the penguin feces, and a greater number of smaller microplastics were found. Marine debris surveys near the breeding colony found various plastic (79.3%) to be the most frequent type of beached debris, suggesting that local sources of marine plastic waste could have contributed to microplastic contamination of penguin chicks being fed by parents that forage in nearby seas. This finding confirms the presence of microplastics in an Antarctic ecosystem and suggests the need for stronger waste management in Antarctica and a standardized scheme of microplastic monitoring in this once-pristine ecosystem.

Diversity of fecal parasitomes of wild carnivores inhabiting Korea, including zoonotic parasites and parasites of their prey animals, as revealed by 18S rRNA gene sequencing.

Consisting of diverse groups of organisms, parasites are among the least studied pathogens despite their enormous impacts on humans, livestock, and wildlife. In particular, little is known about their host specificity and diversity in wildlife. Here, using multiple primer pairs and sequencing 18S rRNA genes of diverse groups of parasites, we aimed to investigate fecal parasitomes of carnivorous wildlife in Korea, namely, the raccoon dog (Nyctereutes procyonoides), the leopard cat (Prionailurus bengalensis), and the Eurasian otter (Lutra lutra). A total of 5 host-specific parasite species were identified, including 2 from raccoon dogs, 2 from leopard cats, and 1 from Eurasian otters. In addition, numerous parasite species of their prey animals were detected in their feces. It was found that the parasitome composition varied between host animals, and it was thought that the difference was attributed to the difference in prey animals, as numerous small mammal parasites were detected from feces of leopard cats inhabiting inland areas and fish parasites from feces of Eurasian otters and raccoon dogs inhabiting waterside areas. Furthermore, 5 zoonotic parasites known to infect humans were identified at the species level. Wildlife-associated zoonoses are expected to increase as the proximity between humans and wildlife increases due to urbanization. Vigilance may be necessary, such as by monitoring parasites in wildlife feces, as was done in this study.

Combining vertebrate mitochondrial 12S rRNA gene sequencing and shotgun metagenomic sequencing to investigate the diet of the leopard cat (Prionailurus bengalensis) in Korea.

The leopard cat (Prionailurus bengalensis), an endangered species in South Korea, is a small feline widely distributed in Asia. Here, we investigated the diet of leopard cats in the inland areas of Korea by examining their fecal contents using vertebrate mitochondrial 12S rRNA gene sequencing and shotgun metagenomic sequencing. Shotgun metagenomic sequencing revealed that the feces were rich in DNA not only of vertebrates but also of arthropods and plants, but care should be taken when using shotgun metagenomic sequencing to identify vertebrates at low taxonomic levels (e.g., genus level), as it was often erroneous. Meanwhile, vertebrate mitochondrial 12S rRNA gene sequencing was found to be accurate in the genus-level identification, as the genera identified were consistent with the Korean fauna. We found that small mammals such as murids were their main prey. By using these two sequencing methods in combination, this study demonstrated that accurate information about the overall dietary content and vertebrate prey of leopard cats could be obtained. We expect that the continued community efforts to expand the genome database of wildlife, including vertebrates, will alleviate the problem of erroneous identification of prey at low taxonomic levels by shotgun metagenomic sequencing in the near future.

Transboundary Cooperation in the Tumen River Basin Is the Key to Amur Leopard (Panthera pardus) Population Recovery in the Korean Peninsula.

The interconnected forest regions along the lower Tumen River, at the Sino-North Korean border, provide critical habitats and corridors for the critically endangered Amur Leopard (Panthera pardus orientalis). In this region, there are two promising corridors for leopard movement between China and North Korea: the Jingxin-Dapanling (JD) and Mijiang (MJ) corridors. Past studies have confirmed the functionality of the JD corridor, but leopards' utilization of the MJ corridor has not yet been established or confirmed. In this study, we assessed the functionality of the MJ corridor. The study area was monitored using camera traps between May 2019 and July 2021. We also analyzed 33 environmental and vegetation factors affecting leopard survival and analyzed leopard movement. In the Mijiang area, the Amur leopard was mainly active in the region adjacent to the Northeast China Tiger and Leopard National Park and did not venture into area near the North Korean border. The complex forest structure allowed leopards to move into the Mijiang area. However, the high intensity of human disturbance and manufactured physical barriers restricted further southward movement. Therefore, human-induced disturbances such as grazing, mining, farming, logging, and infrastructure development must be halted and reversed to make the Mijiang region a functional corridor for the Amur leopard to reach the North Korean forest. This necessitates inter-governmental and international cooperation and is essential for the long-term survival of the Amur leopard.

Callerya atropurpurea suppresses inflammation in vitro and ameliorates gastric injury as well as septic shock in vivo via TLR4/MyD88-dependent cascade.

BACKGROUND: Callerya atropurpurea is a traditional plant in a tropical zone discovered to have anti-inflammatory functions. PURPOSE: we want to investigate the mechanism related to anti-inflammation of C. atropurpurea ethanol extract (Ca-EE) both in vitro and in vivo. STUDY DESIGN: Murine macrophage cells and mouse models for gastritis and septic shock were conducted to evaluate the abilities of Ca-EE in anti-inflammation. METHODS: Ca-EE was tested by HPLC and LC-MS/MS. NO outcome was checked by Griess reagent test. Cell viabilities were evaluated using MTT assay. Inflammatory cytokines were determined via RT-PCR and ELISA. The mechanism of Ca-EE in anti-inflammation was investigated by luciferase reporter gene assay and immunoblot in transcription level and protein level respectively. Gastric injury and septic shock administrated with Ca-EE were studied by H&E, PCR, and immunoblot. RESULTS: Ca-EE significantly decreased LPS-induced NO production, but hardly stimulated the expression of NO itself. It not only showed no cytotoxicity, but also protected cells from LPS damage. Moreover, Ca-EE decreased TLR4 expression, altered MyD88 recruitment and TRAF6, and suppressed the phospho-Src/PI3K/AKT. Ca-EE inhibited downstream signaling P38, JNK and NF-κB. Finally, Ca-EE alleviated HCl/EtOH-induced gastritis and LPS/poly (I:C)-induced septic shock through the previously mentioned signaling cascades. CONCLUSION: Ca-EE exhibited an integrated and promising mechanism against TLR4-related inflammation, which shows potential for treating gastritis, septic shock, and other inflammatory diseases.

Using DNA metabarcoding and a novel canid-specific blocking oligonucleotide to investigate the composition of animal diets of raccoon dogs (Nyctereutes procyonoides) inhabiting the waterside area in Korea.

The raccoon dog (Nyctereutes procyonoides) is known to be an opportunistic generalist who feeds on a wide variety of foods. Historically, their diet has been investigated by morphological observation of undigested remains in feces, requiring specialized knowledge such as osteology, zoology, and phytology. Here, we used DNA metabarcoding of vertebrate 12S rRNA gene and invertebrate 16S rRNA gene to investigate their fecal contents. Additionally, we developed a blocking oligonucleotide that specifically inhibits the amplification of the canid 12S rRNA gene. We confirmed that the blocking oligonucleotide selectively inhibit the amplification of raccoon dog's DNA without significantly changing the composition of the preys' DNA. We found that the main foods of raccoon dogs in our study area, the waterside of paddy fields in Korea, were fishes such as Cyprinidae and insects such as mole crickets, which makes sense given the Korean fauna and their well-known opportunistic feeding behaviors. As a method to conveniently and objectively investigate feeding habits of raccoon dogs, this study provided baseline information on DNA metabarcoding. By using DNA metabarcoding, it is expected that the diet habits and ecology of raccoon dogs will be better understood by future research.

The host-specific resistome in environmental feces of Eurasian otters (Lutra lutra) and leopard cats (Prionailurus bengalensis) revealed by metagenomic sequencing.

Investigation of feces of wildlife, which is considered as reservoirs, melting pots, vectors and secondary sources of antimicrobial resistance genes (ARGs), provides insights into the risks and ecology of ARGs in the environment. Here, we investigated microbiomes, virulence factor genes (VFGs) of bacterial pathogens, and resistomes in environmental feces of Eurasian otters (Lutra lutra) and leopard cats (Prionailurus bengalensis) using shotgun metagenome sequencing. As expected, the taxonomic compositions of bacteria were significantly different between the animals. Importantly, we found that the compositions of ARGs were also significantly different between the animals. We detected ARGs including iri, tetA(P), tetB(P), floR, sulII, strA, strB, tetW and tetY. Some of them were significantly more abundant in either of the host animals, such as strA, strB and tetY in Eurasian otters, and tetA(P), tetW and iri in leopard cats. We also found that some ARGs were selectively correlated to particular VFGs-related bacteria, such as tetA(P) and tetB(P) to Clostridium, and iri to Mycobacterium. We also found that there were positive correlations between Acinetobacter and ARGs of multiple antimicrobial classes. The host-specific resistomes and VFGs-related bacteria may be due to differences in the host's gut microbiome, diet and/or habitat, but further investigation is needed. Overall, this study provided important baseline information about the resistomes of the wildlife in Korea, which may help the conservation of these endangered species and assessment of human health risks posed by ARGs and bacterial pathogens from wildlife.

Cocculus hirsutus ameliorates gastric and lung injuries by suppressing Src/Syk.

BACKGROUND: Cocculus hirsutus (L.) W. Thedo., a traditionally well-known plant, has confirmed antitumor properties as well as acute and chronic diuretic effects. However, little is known about its inflammatory activities and the potential effect on inflammatory disease treatment. PURPOSE: Our aim in this study was to explore additional beneficial properties of C. hirsutus ethanol extract (Ch-EE) such as anti-inflammatory activity in vitro and in vivo as well as its underlying mechanisms and to provide a theoretical basis for its role as a candidate natural drug in clinical gastritis and lung disease therapy. STUDY DESIGN: RAW264.7 cells, HEK293T cells, peritoneal macrophages, and mouse models of acute gastritis and acute lung injury were used to assess the anti-inflammatory activity of Ch-EE. METHODS: Decreases in LPS-induced nitric oxide (NO) production and cytokine expression by RAW264.7 cells after Ch-EE treatment were evaluated by Griess assays and PCR, respectively. Transcription factor activity was assessed through luciferase reporter gene assay, and protein expression was determined by Western blotting analysis. Overexpression assays and cellular thermal shift assays were executed in HEK293T cells. Our two in vivo models were an HCl/EtOH-induced gastritis model and an LPS-induced lung injury model. Changes in stomach lesions, lung edema, and lung histology were examined upon treatment with Ch-EE. Components of Ch-EE were determined by liquid chromatography-mass spectrometry. RESULTS: LPS-induced nitric oxide production and Pam3CSK4- and L-NAME-induced NO production were inhibited by Ch-EE treatment of RAW264.7 cells. Furthermore, LPS-induced increases in transcript levels of iNOS, COX2, CCL12, and IL-1ß were reduced by Ch-EE treatment. Ch-EE decreased both MyD88- and TRIF-induced NF-κB promotor activity. Proteins upstream of NF-κB, namely p-p50, p-p65, p-IκBα, p-AKT1, p-Src, and p-Syk, were all downregulated by Ch-EE. Moreover, Src and Syk were targets of Ch-EE. Ch-EE treatment reduced the size of inflammatory stomach lesions induced by HCl/EtOH, lung edema, and accumulation of activated neutrophils caused by LPS. CONCLUSIONS: These results strongly suggest that Cocculus hirsutus can be developed as a promising anti-inflammatory remedy with Src- and Syk-inhibitory functions targeting diseases related to gastritis and lung injury.

Cissus subtetragona Planch. Ameliorates Inflammatory Responses in LPS-induced Macrophages, HCl/EtOH-induced Gastritis, and LPS-induced Lung Injury via Attenuation of Src and TAK1.

Several Cissus species have been used and reported to possess medicinal benefits. However, the anti-inflammatory mechanisms of Cissus subtetragona have not been described. In this study, we examined the potential anti-inflammatory effects of C. subtetragona ethanol extract (Cs-EE) in vitro and in vivo, and investigated its molecular mechanism as well as its flavonoid content. Lipopolysaccharide (LPS)-induced macrophage-like RAW264.7 cells and primary macrophages as well as LPS-induced acute lung injury (ALI) and HCl/EtOH-induced acute gastritis mouse models were utilized. Luciferase assays, immunoblotting analyses, overexpression strategies, and cellular thermal shift assay (CETSA) were performed to identify the molecular mechanisms and targets of Cs-EE. Cs-EE concentration-dependently reduced the secretion of NO and PGE2, inhibited the expression of inflammation-related cytokines in LPS-induced RAW264.7 cells, and decreased NF-κB- and AP-1-luciferase activity. Subsequently, we determined that Cs-EE decreased the phosphorylation events of NF-κB and AP-1 pathways. Cs-EE treatment also significantly ameliorated the inflammatory symptoms of HCl/EtOH-induced acute gastritis and LPS-induced ALI mouse models. Overexpression of HA-Src and HA-TAK1 along with CETSA experiments validated that inhibited inflammatory responses are the outcome of attenuation of Src and TAK1 activation. Taken together, these findings suggest that Cs-EE could be utilized as an anti-inflammatory remedy especially targeting against gastritis and acute lung injury by attenuating the activities of Src and TAK1.

Age-dependent shifts and spatial variation in the diet of endangered Black-faced Spoonbill (Platalea minor) chicks.

The endangered Black-faced Spoonbill (Platalea minor) strictly breeds in marine environments and is threatened by the rapid loss of coastal wetlands within its breeding range. Adults with chicks are thought to gradually switch feeding sites from freshwater wetlands to coastal mudflats as the chicks' osmoregulatory system develops. We investigated age-dependent shifts in the diet of Black-faced Spoonbill chicks at four breeding colonies with varying freshwater habitat availability by examining stable isotopes (δ13C, δ15N) between the tip (grown at the age of 10 days) and middle (grown at the age of 22 days) portions of their primary feathers. The δ13C value of the middle portions was significantly higher than that of the tips, which suggested that the ratio of marine resources increased with the growth and development of chicks. A Bayesian isotope mixing model revealed that the diet proportion of marine prey in the early-chick rearing season was slightly higher than in the late-chick rearing season at three colonies in inshore areas, although this proportion was approximately 60% even in the early chick-rearing period. In contrast, isotopic values and reconstructed diet composition suggested that chicks in an offshore colony with limited freshwater wetlands relied more heavily on freshwater diets for both chick-rearing periods (>80%). Our results suggest that the shifts in feeding sites seen in previous studies might be related to the age-dependent dietary shift of chicks, highlighting the importance of freshwater wetlands for spoonbills on offshore islands without an inflow of freshwater in nearby intertidal mudflats. These findings emphasize the importance of freshwater prey and wetlands even for the endangered marine-breeding spoonbills, even though the negative impact of salt stress remains inconclusive.

Health Surveillance of Penguins in the Barton Peninsula on King George Island, Antarctica.

Samples from 29 adult Gentoo (Pygoscelis papua), Chinstrap (Pygoscelis antarcticus), and Adélie Penguins (Pygoscelis adeliae) at the King Sejong Station on NarÌ¢ ebski Point, King George Island, Antarctica, were investigated to detect antibodies to avian influenza, Newcastle disease virus, infectious bursal disease virus, infectious bronchitis virus, Mycoplasma, and Salmonella. Antibodies were identified from one Gentoo Penguin and one Chinstrap Penguin against infectious bronchitis virus; from one Gentoo Penguin against Newcastle disease virus; from one Gentoo Penguin against Mycoplasma synoviae; and from two Chinstrap Penguins against Salmonella pullorum. Thirty-three dead penguin chicks were collected from the breeding colony for necropsy, histopathological examination, and polymerase chain reaction. Pulmonary hemorrhage and congestion were the main necropsy findings.

DNA-based detection of Leptospira wolffii, Giardia intestinalis and Toxoplasma gondii in environmental feces of wild animals in Korea.

Leptospira, Giardia intestinalis and Toxoplasma gondii infections are reported in humans and animals worldwide, but molecular surveillance of these pathogens in Korean wildlife is still limited. Here, we examined the prevalence of these pathogens in environmental feces of Eurasian otters, leopard cats and raccoon dogs using nested PCR followed by DNA sequencing. G. intestinalis was detected in all of three animals, while T. gondii was detected only in leopard cats. Leptospira wolffii was detected in raccoon dog and Eurasian otter. Our results suggest that these animals can act as a reservoir of these zoonotic pathogens. Consistent monitoring of these pathogens in wildlife is needed to prevent from their infections in humans and livestock in Korea.

Home Range Estimates and Habitat Use of Siberian Flying Squirrels in South Korea.

Conservation measures or management guidelines must be based on species' ecological data. The home range of the target species was studied to understand its spatial ecology, in order to protect it. The Siberian flying squirrel is the only flying squirrel species present and is considered as a protected species in South Korea. In this study, we investigated the home range, habitat use, and daily movement of Siberian flying squirrels from February 2015 to June 2016 at Mt. Baekwoon, Gangwon Province, South Korea. We tracked 21 flying squirrels using radio transmitters and analyzed the home range of 12 individuals. Flying squirrels appeared to have an overall mean home range of 18.92 ± 14.80 ha with a core area of 3.54 ha ± 3.88 ha. Movement activity peaked between 18:00-19:00 with the longest distance traveled, coinciding with sunset. In addition, we observed the preference of Siberian flying squirrels to the old deciduous forest with dense crowns. The results of the present study indicate that it is important to manage their habitat; for instance, preserving an appropriate size of mature deciduous forest is essential for Siberian flying squirrels. While our study provides needed baseline information on the spatial activity of the species, further research on topics such as the national distribution, behavior, and population dynamics of Siberian flying squirrels is needed in South Korea.

DNA metabarcoding-based diet survey for the Eurasian otter (Lutra lutra): Development of a Eurasian otter-specific blocking oligonucleotide for 12S rRNA gene sequencing for vertebrates.

The Eurasian otter (Lutra lutra) is an endangered species for which diet analyses are needed as part of its conservation efforts. Eurasian otters feed on vertebrates, such as fishes, and invertebrates, such as crustaceans, but their detailed taxonomies are not fully understood in part due to limited resolving power of traditional morphological identification methods. Here, we used high-throughput sequencing (HTS)-based DNA metabarcoding approaches to analyze diet profiles of Eurasian otters inhabiting a marshy estuary area in Korea. We investigated their diet profiles based on spraint sampling followed by DNA metabarcoding analyses targeting 12S rRNA gene region for vertebrates, 16S rRNA gene region for invertebrates, and cytochrome c oxidase 1 (COI) gene region for fishes. For the vertebrate analysis, a blocking oligonucleotide (OBS1) was designed to suppress amplification of DNA fragments derived from the otters. The 12S rRNA gene sequencing assay detected species belonging to fishes (95%) and amphibians (3.3%). Fishes detected by 12S rRNA gene sequencing included crucian carp (Carassius auratus), mullets (Mugil spp.), bluegill (Lepomis macrochirus), and northern snakehead (Channa argus), which were also detected by COI gene sequencing. Among invertebrates, mud flat crabs (Helicana spp.) and shrimps (Palaemon spp.) were abundant. The designed blocking oligonucleotide OBS1 effectively inhibited amplification of the otter's DNA, with only up to 0.21% of vertebrate sequence reads assigned to the otter. This study demonstrated that HTS-based DNA metabarcoding methods were useful to provide in-depth information regarding diet profiles of the otters at our sampling site. By using HTS-based DNA metabarcoding approaches, future research will explore detailed taxonomies of their diets across locations and seasons.

Predicting climate-driven shifts in the breeding phenology of Varied Tits (Sittiparus various) in South Korean forests.

Phenological shifts of plants and animals due to climate change can vary among regions and species, requiring study of local ecosystems to understand specific impacts. The reproductive timing of insectivorous songbirds in temperate forests is tightly synchronized with peak prey abundance, and thus they can be susceptible to such shift in timing. We aimed to investigate the effect of future climate change on the egg-laying phenology of the Varied Tit (Sittiparus various), which is common and widely distributed in South Korean forests. We developed the predictive model by investigating their egg-laying dates in response to spring temperatures along geographical gradients, and our model indicated that the tits lay eggs earlier when the average of daily mean and daily maximum temperatures rise. We predicted future shifts in egg-laying dates based on the most recent climate change model published by the Intergovernmental Panel on Climate Change (IPCC), under a scenario with no climate change mitigation and under a scenario with moderate mitigation. Under this outcome, this species might be unable to adapt to rapid climate change due to asynchrony with prey species during the reproductive period. If no mitigation is undertaken, our model predicts that egg-laying dates will be advanced by more than 10 days compared to the present in 83.58% of South Korea. However, even moderate mitigation will arrest this phenomenon and maintain present egg-laying dates. These results demonstrate the first quantitative assessment for the effect of warming temperatures on the phenological response of insectivorous songbirds in South Korea.

A new southern distribution limit for Sorex mirabilis Ognev, 1937 (Eulipotyphla, Soricidae).

Sorex mirabilis, a small insectivorous mammal, is a very rare, poorly known species distributed at high latitudes and altitudes of northeastern Asia. The occurrence of this species in the Republic of Korea was known from late 1990s. We found a new specimen from a location of a 50' lower latitude and 400 m lower altitude than the previously known locations of the first record in the Republic of Korea. This finding may imply that S. mirabilis is distributed in a wider range than previously considered and that their distribution might be related to eoreumgols, or ice valleys, where there are potential insular refugia due to micro-meteorological characteristics.

Two new phenolic glucosides from Lagerstroemia speciosa.

Two new phenolic glucosides, 1-O-benzyl-6-O-E-caffeoyl-ß-d-glucopyranoside and 1-O-(7S,8R)-guaiacylglycerol-(6-O-E-caffeoyl)-ß-d-glucopyranoside, were isolated from the aerial parts of Lagerstroemia speciosa, along with ten known compounds. The structures of the isolated compounds were determined based on 1D- and 2D-NMR, Q-TOF MS and optical rotation spectroscopic data. All of the compounds showed moderate inhibitory activities against nitric oxide production in lipopolysaccharide-treated RAW264.7 cells, with IC50 values of 69.5-83.3 µM.

Flavonoids from Symplocos racemosa.

A novel isoflavone glycoside, peseudobatigenin 7-O-[ß-d-apiofuranosyl-(1''''→5''')-O-ß-d-apiofuranosyl-(1'''→6'')]-ß-d-glucopyranoside, namely sympracemoside (1), was isolated from the aerial parts of Symplocos racemosa along with 15 known flavonoids (2-16). Their structures were characterized by Q-TOF mass, optical rotation, UV, 1D and 2D-NMR spectroscopic data. Compounds 3, 9, 16 showed moderate inhibitory activities against NO production with IC50 value of 88.2, 42.1 and 74.3 µM, respectively.

Syk/Src-targeted anti-inflammatory activity of Codariocalyx motorius ethanolic extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Codariocalyx motorius (Houtt.) H. Ohashi (Fabaceae) is one of several ethnopharmacologically valuable South Asian species prescribed as an herbal medicine for various inflammatory diseases. Due to the lack of systematic studies on this plant, we aimed to explore the inhibitory activity of Codariocalyx motorius toward inflammatory responses using its ethanolic extract (Cm-EE). MATERIALS AND METHODS: Lipopolysaccharide (LPS)-treated macrophages and a HCl/EtOH-induced gastritis model were used for evaluation of the anti-inflammatory activity of Cm-EE. HPLC and spectroscopic analysis were employed to identify potential active components. Mechanistic approaches to determine target enzymes included kinase assays, reporter gene assays, and overexpression of target enzymes. RESULTS: Cm-EE strongly suppressed nitric oxide (NO) and prostaglandin E2 (PGE2) release. Cm-EE-mediated inhibition was observed at the transcriptional level in the form of suppression of NF-κB (p65) translocation and activation. This extract also lowered the levels of phosphorylation of Src and Syk, their kinase activity, and their formation of signalling complexes by binding to the downstream enzyme p85/PI3K. In accord with these findings, the phosphorylation of p85 induced by overexpression of Src or Syk was also diminished by Cm-EE. Orally administered Cm-EE clearly inhibited gastritic ulcer formation and the phosphorylation of IκBα and Src in HCl/EtOH-treated stomachs of mice. By phytochemical analysis, luteolin and its glycoside, apigenin-7-O-glucuronide, and scutellarein-6-O-glucuronide were identified as major components of Cm-EE. Among these, it was found that luteolin was able to strongly suppress NO and PGE2 production under the same conditions. CONCLUSION: Syk/Src-targeted inhibition of NF-κB by Cm-EE could be a major anti-inflammatory mechanism contributing to its ethno pharmacological role as an anti-inflammatory herbal medicine.

Myrsine seguinii ethanolic extract and its active component quercetin inhibit macrophage activation and peritonitis induced by LPS by targeting to Syk/Src/IRAK-1.

ETHNOPHARMACOLOGICAL RELEVANCE: Myrsine seguinii H. LÉVEILLÉ (syn. Rapanea neriifolia) (Myrsinaceae) is a medicinal plants traditionally used in Myanmar to treat infectious and inflammatory diseases. Since none of reports have systematically demonstrated the anti-inflammatory activity of this plant, we aimed to mechanistically understand the regulatory roles of the plant in inflammatory responses using the ethanolic extract of Myrsine seguinii (Ms-EE). MATERIALS AND METHODS: Activated macrophages and peritonitis symptoms induced by lipopolysaccharide (LPS) were employed. HPLC analysis was used to identify active components. To characterize direct target enzymes, kinase assay was established. RESULTS: Ms-EE inhibited the production of nitric oxide (NO) and prostaglandin (PG)E2 in RAW264.7 cells and peritoneal macrophages stimulated by LPS. This extract suppressed the mRNA expression of the inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 genes by down-regulating the activation of nuclear factor (NF)-κB and activator protein (AP-1). Interestingly, it was found that Ms-EE can directly suppress the enzyme activities of Syk, Src, and interleukin-1 receptor-associated kinase-1 (IRAK-1). Similarly, orally administered Ms-EE inhibited the phosphorylation of Src and Syk in peritoneal exudate-derived cells prepared from peritonitis. Finally, HPLC analysis clearly demonstrated that quercetin is a major active component with suppressing activity on the release of inflammatory mediators (NO and PGE2), and the enzyme activities of Src, Syk, and IRAK-1. CONCLUSION: Ms-EE containing quercetin negatively modulates macrophage-mediated in vitro inflammatory responses and LPS-induced peritonitis by blocking the Src/Syk/NF-κB and IRAK-1/AP-1 pathways, which contributes to its major ethnopharmacological use as an anti-inflammatory herbal medicine.