Calycosin, a Common Dietary Isoflavonoid, Suppresses Melanogenesis through the Downregulation of PKA/CREB and p38 MAPK Signaling Pathways.

Calycosin, a bioactive isoflavonoid isolated from root extracts of Astragalus membranaceus, has been reported to inhibit melanogenesis, the mechanism of which remains undefined. In this study, we interrogated the mechanistic basis by which calycosin inhibits melanin production in two model systems, i.e., B16F10 melanoma cells and zebrafish embryos. Calycosin was effective in protecting B16F10 cells from α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis and tyrosinase activity. This anti-melanogenic effect was accompanied by decreased expression levels of microphthalmia-associated transcription factor (MITF), a key protein controlling melanin synthesis, and its target genes tyrosinase and tyrosinase-related protein-2 (TRP-2) in calycosin-treated cells. Mechanistically, we obtained the first evidence that calycosin-mediated MITF downregulation was attributable to its ability to block signaling pathways mediated by cAMP response element-binding protein (CREB) and p38 MAP kinase. The protein kinase A (PKA) inhibitor H-89 and p38 inhibitor SB203580 validated the premise that calycosin inhibits melanin synthesis and tyrosinase activity by regulating the PKA/CREB and p38 MAPK signaling pathways. Moreover, the in vivo anti-melanogenic efficacy of calycosin was manifested by its ability to suppress body pigmentation and tyrosinase activity in zebrafish embryos. Together, these data suggested the translational potential of calycosin to be developed as skin-lightening cosmeceuticals.

Synthesis of Yakuchinone B-Inspired Inhibitors against Islet Amyloid Polypeptide Aggregation.

Type 2 diabetes mellitus (T2DM) is associated with pancreatic ß-cell dysfunction and insulin resistance. Islet amyloid polypeptide (IAPP) aggregation is found to induce islet ß-cell death in T2DM patients. Recently, we demonstrated that yakuchinone B derivative 1 exhibited inhibitory activity against IAPP aggregation. Thus, in this study, a series of synthesized yakuchinone B-inspired compounds were tested for their anti-IAPP aggregation activity. Four of these compounds, 4e-h, showed greater activity than the lead compound 1, in the sub-µM range (IC50 = 0.7-0.8 µM). The molecular docking analysis revealed crucial hydrogen bonds between the compounds and residues S19 and N22 and important hydrophobic interactions with residue I26. Notably, compounds 4g and 4h significantly protected ß-cells against IAPP-induced toxicity with EC50 values of 0.1 and 0.2 µM, respectively. In contrast, the protective activities of compounds 4e and 4f were weak. Overall, these results suggest that the compounds exhibiting IAPP aggregation-inhibiting activity have the potential to treat T2DM.

Hepatoprotective Effect of Ugonin M, A Helminthostachyszeylanica Constituent, on Acetaminophen-Induced Acute Liver Injury in Mice.

The present study aimed to discover the possible effectiveness of Ugonin M, a unique flavonoid isolated from Helminthostachys zeylanica-a traditional Chinese medicine used as anti-inflammatory medicine-and to elucidate the potential mechanisms of Ugonin M in the acute liver injury induced by acetaminophen (APAP). In this study, Ugonin M significantly ameliorated APAP-induced histopathological changes and the typical liver function biomarkers (i.e., alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (T-Bil)). It also affected APAP-induced abnormal lipid metabolism including total cholesterol (TC) and triglyceride (TG) in the serum. In inflammatory pharmacological action, Ugonin M suppressed the pro-inflammatory mediators such as nitric oxide (NO) and the lipid peroxidation indicator malondialdehyde (MDA). In addition, Ugonin M reinforced hemeoxygenase-1 (HO-1) protein expression and the production of antioxidant enzymes viz superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). Furthermore, inflammation-associated cytokines including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1ß as well as proteins such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were decreased by the pretreatment of Ugonin M. Moreover, this study found that pretreatment of Ugonin M apparently decreased nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) activation via inhibition of the degradation of NF-κB, inhibitory κB-α (IκB-α), extracellular regulated kinase (ERK), c-Jun-N-terminal (JNK), and p38 active phosphorylation. In conclusion, Ugonin M significantly showed a protective effect against APAP-induced liver injury by reducing oxidative stress and inflammation. Thus, Ugonin M could be one of the effective components of H. zeylanica that plays a major role in the treatment of inflammatory disorders.

Quality Control of the Root and Rhizome of Helminthostachys zeylanica (Daodi-Ugon) by HPLC Using Quercetin and Ugonins as Markers.

Daodi-Ugon is the dried root and rhizome of Helminthostachys zeylanica (L.) Hook. and has been used for centuries in the treatment of inflammation, fever, pneumonia, burns, and various disorders. However, the chromatographic methods to determine the phytochemical composition of H. zeylanica have never been reported. This study not only aims to develop a valid high-performance liquid chromatography (HPLC) method and to establish a chromatographic fingerprint for the quality control of H. zeylanica, it also establish the proposed content limits of Quercetin, Ugonin J, and Ugonin M. An HPLC method with a RP18 column (250 × 4.6 mm, 5 µm) was developed for the quantitative analysis of Quercetin, Ugonin J, and Ugonin M in H. zeylanica. A simple gradient of (A) methanol/(B) phosphoric acid in water (5-45 min, 70-80% A; 50-55 min, 80-70% A) was used and 360 nm was selected as the detection wavelength. The average contents and proposed content limits for H. zeylanica were calculated with a t-test and a measurement uncertainty test based on 20 batches of authentic H. zeylanica samples. Limits of detection (LOD), quantification (LOQ), linearity, precision, repeatability, stability, and recovery of the developed method were validated. All of the validation results of quantitative determination and fingerprinting methods were satisfactory. The developed method was then applied to assay the contents of Quercetin, Ugonin J, and Ugonin M and to acquire the fingerprints of all of the collected H. zeylanica samples. At the 99% confidence level, the calculated content limits were 56.45, 112.15, and 277.98 mg/kg for Quercetin, Ugonin J, and Ugonin M, respectively. Those validated HPLC quantitative method, fingerprinting profile, and the proposed content limits of three chemical markers that could be used in the quality control of H. zeylanica in the market.

Ugonin M, a Helminthostachys zeylanica Constituent, Prevents LPS-Induced Acute Lung Injury through TLR4-Mediated MAPK and NF-κB Signaling Pathways.

Helminthostachys zeylanica (L.) Hook. is plant that has been used in traditional Chinese medicine for centuries for the treatment of inflammation, fever, pneumonia, and various disorders. The aims of the present study are to figure out the possible effectiveness of the component Ugonin M, a unique flavonoid isolated from H. zeylanica, and to elucidate the mechanism(s) by which it works in the LPS-induced ALI model. In this study, Ugonin M not only inhibited the production of pro-inflammatory mediators such as NO, TNF-α, IL-1ß, and IL-6, as well as infiltrated cellular counts and protein content in the bronchoalveolar lavage fluid (BALF) of lipopolysaccharides (LPS)-induced acute lung injury (ALI) mice, but also ameliorated the severity of pulmonary edemas through the score of a histological examination and the ratio of wet to dry weight of lung. Moreover, Ugonin M was observed to significantly suppress LPS-stimulated protein levels of iNOS and COX-2. In addition, we found that Ugonin M not only obviously suppressed NF-κB and MAPK activation via the degradation of NF-κB and IκB-α as well as ERK and p38MAPK active phosphorylation but also inhibited the protein expression level of TLR4. Further, Ugonin M treatment also suppressed the protein levels of MPO and enhanced the protein expressions of HO-1 and antioxidant enzymes (SOD, GPx, and CAT) in lung tissue of LPS-induced ALI mice. It is anticipated that through our findings, there is strong evidence that Ugonin M may exert a potential effect against LPS-induced ALI mice. Hence, Ugonin M could be one of the major effective components of H. zeylanica in the treatment of inflammatory disorders.

Chemical compositions, chromatographic fingerprints and antioxidant activities of Andrographis Herba.

This paper describes the development of an HPLC-UV-MS method for quantitative determination of andrographolide and dehydroandrographolide in Andrographis Herba and establishment of its chromatographic fingerprint. The method was validated for linearity, limit of detection and quantification, inter- and intra-day precisions, repeatability, stability and recovery. All the validation results of quantitative determination and fingerprinting methods were satisfactory. The developed method was then applied to assay the contents of andrographolide and dehydroandrographolide and to acquire the fingerprints of all the collected Andrographis Herba samples. Furthermore, similarity analysis and principal component analysis were used to reveal the similarities and differences between the samples on the basis of the characteristic peaks. More importantly, the DPPH free radical-scavenging and ferric reducing capacities of the Andrographis Herba samples were assayed. By bivariate correlation analysis, we found that six compounds are positively correlated to DPPH free radical scavenging and ferric reducing capacities, and four compounds are negatively correlated to DPPH free radical scavenging and ferric reducing capacities.

Comparative study of Scleromitrion diffusum and Oldenlandia corymbosa: Microscopy, TLC, HPLC, and antioxidant activity.

Quality control of herbal medicines is crucial, especially the role of herbal drug identification. This is essential for preventing the misuse of herbs, which can affect efficacy or cause toxicity. Scleromitrion diffusum is a common herb, yet it is often mistaken for Oldenlandia corymbosa. This study analyzed the morphology, microscopy, thin-layer chromatography (TLC), and high-pressure liquid chromatography (HPLC) using two markers, asperuloside and scandoside methyl ester, to distinguish between S. diffusum and O. corymbosa with the analysis included 10 samples of S. diffusum and 10 samples of O. corymbosa collected from the Taiwan market. By quantifying the total polyphenols and flavonoids, we investigated the antioxidant activity, including the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging effect, 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+) scavenging effect, and reducing power to further elucidate the biological effects of the two herbs. The results of this study revealed notable differences in microscopy and suggested a TLC method for distinguishing between the two herbs in the market. In HPLC, the ratios of asperuloside and scandoside methyl ester differed between the two herbs. S. diffusum contained a higher asperuloside content. In contrast, O. corymbosa contained higher concentrations of scandoside methyl esters. With more total polyphenols and flavonoids in S. diffusum than those in O. corymbosa, the antioxidant activity of S. diffusum was superior to that of O. corymbosa. This study provides a comprehensive understanding for the identification and quality evaluation of S. diffusum in the market. RESEARCH HIGHLIGHTS: The study consolidates and clarifies the morphological and microscopic differences between Scleromitrion diffusum and Oldenlandia corymbosa - a common adulterant species of S. diffusum on the Taiwan markets. Using Asperuloside and Scandoside methyl ester as two chemical markers, the study proposes a TLC method for rapidly testing S. diffusum and O. corymbosa on the market. Through HPLC analysis, our results showed that S. diffusum and O. corymbosa had a clear difference in the ratio of two markers, Asperuloside and Scandoside methyl ester: Asperuloside/Scandoside methyl ester in S. diffusum is higher than that in O. corymbosa. Through phytochemicals contents, including total phenols content, flavonoids content, and antioxidant activity, including DPPH, ABTS•+ scavenging activity, and reducing power, S. diffusum showed slightly higher levels of phenols and flavonoids as well as a better antioxidant activity than O. corymbosa.

A non-invasive mouse model that recapitulates disuse-induced muscle atrophy in immobilized patients.

Disuse muscle atrophy occurs consequent to prolonged limb immobility or bed rest, which represents an unmet medical need. As existing animal models of limb immobilization often cause skin erosion, edema, and other untoward effects, we here report an alternative method via thermoplastic immobilization of hindlimbs in mice. While significant decreases in the weight and fiber size were noted after 7 days of immobilization, no apparent skin erosion or edema was found. To shed light onto the molecular mechanism underlying this muscle wasting, we performed the next-generation sequencing analysis of gastrocnemius muscles from immobilized versus non-mobilized legs. Among a total of 55,487 genes analyzed, 787 genes were differentially expressed (> fourfold; 454 and 333 genes up- and down-regulated, respectively), which included genes associated with muscle tissue development, muscle system process, protein digestion and absorption, and inflammation-related signaling. From a clinical perspective, this model may help understand the molecular/cellular mechanism that drives muscle disuse and identify therapeutic strategies for this debilitating disease.

General Use of Chinese Herbal Products among Female Patients with Mastitis in Taiwan.

Objectives: Little information is available regarding the use of Chinese herbal medicine to treat mastitis. This study evaluated the prescription patterns of Chinese herbal medicine products in women with mastitis in Taiwan. Design: This is a population-based cross-sectional study. Setting. 8,531 women aged 20-49 years, who received a diagnosis of mastitis between 2004 and 2013, were identified from the Longitudinal Health Insurance Database in Taiwan. We collected data on demographic characteristics, including age, monthly insurance premium, and urbanization level. The ten most Chinese herbal medicines prescribed for mastitis were assessed, including frequency, percentage, average daily dose, and average duration of prescription. Main outcome measures. We analysed the ten most single Chinese herbs and Chinese herbal formulae prescribed for mastitis. Results: Overall, 437 (5.1%) women received Chinese herbal medicine to treat mastitis. Mai Men Dong (Ophiopogon japonicus (Thunb.) Ker Gawl.; 22.3%), Pu Gong Yin (Taraxacum mongolicum Hand.-Mazz.; 7.8%), and Wang Bu Liu Xing (Vaccaria hispanica (Mill.) Rauschert; 3.5%) were three of the most commonly prescribed single Chinese herbs for mastitis. Xian-Fang-Huo-Ming-Yin (18.2%), Jia-Wei-Xiao-Yao-San (9.1%), and Chai-Hu-Shu-Gan-San (8.4%) were three of the most commonly prescribed Chinese herbal formulae. Conclusion: Xian-Fang-Huo-Ming-Yin can clear heat, detoxify body, alleviate swelling, activate blood, and relieve pain. It was the most frequently prescribed Chinese herbal formula in patients with mastitis.

Development of a traditional Chinese medicine-based agent for the treatment of cancer cachexia.

BACKGROUND: Despite recent advances in understanding the pathophysiology of cancer cachexia, prevention/treatment of this debilitating disease remains an unmet medical need. METHODS: We developed an integrated, multi-tiered strategy involving both in vitro and in vivo muscle atrophy platforms to identify traditional Chinese medicine (TCM)-based anti-cachectic agents. In the initial screening, we used inflammatory cytokine-induced atrophy of C2C12 myotubes as a phenotypic screening platform to assess the protective effects of TCMs. The selected TCMs were then evaluated for their abilities to protect Caenorhabditis elegans from age-related reduction of mobility and contractility, followed by the C-26 colon adenocarcinoma mouse model of cachexia to confirm the anti-muscle atrophy effects (body/skeletal muscle weights, fibre size distribution, grip strengths, and serum IL-6). Transcriptome analysis, quantitative real-time polymerase chain reaction, and immunoblotting were performed to gain understanding of the potential mechanism(s) by which effective TCM protected against C26 tumour-induced muscle atrophy. RESULTS: Of 29 widely used TCMs, Dioscorea radix (DR) and Mu Dan Pi (MDP) showed a complete protection (all P values, 0.0002) vis-à-vis C26 conditioned medium control in the myotube atrophy platform. MDP exhibited a unique ability to ameliorate age-associated decreases in worm mobility, accompanied by improved total body contractions, relative to control (P < 0.0001 and <0.01, respectively), which, however, was not noted with DR. This differential in vivo protective effect between MDP and DR was also confirmed in the C-26 mouse model. MDP at 1000 mg/kg (MDP-H) was effective in protecting body weight loss (P < 0.05) in C-26 tumour-bearing mice without changing food or water intake, accompanied by the restoration of the fibre size distribution of hindleg skeletal muscles (P < 0.0001) and the forelimb grip strength (P < 0.05). MDP-treated C-26-tumour-bearing mice were alert, showed normal posture and better body conditions, and exhibited lower serum IL-6 levels (P = 0.06) relative to vehicle control. This decreased serum IL-6 was associated with the in vitro suppressive effect of MDP (25 and 50 µg/mL) on IL-6 secretion into culture medium by C26 cells. RNA-seq analysis, followed by quantitative real-time polymerase chain reaction and/or immunoblotting, shows that MDP's anti-cachectic effect was attributable to its ability to reverse the C-26 tumour-induced re-programming of muscle homoeostasis-associated gene expression, including that of two cachexia drivers (MuRF1 and Atrogin-1), in skeletal muscles. CONCLUSIONS: All these findings suggest the translational potential of MDP to foster new strategies for the prevention and/or treatment of cachexia. The protective effect of MDP on other types of muscle atrophy such as sarcopenia might warrant investigations.

Evaluations and Mechanistic Interrogation of Natural Products Isolated From Paeonia suffruticosa for the Treatment of Inflammatory Bowel Disease.

Mu Dan Pi (MDP), a traditional Chinese medicine derived from the root bark of Paeonia suffruticosa Andrews, is used to treat autoimmune diseases due to its anti-inflammatory properties. However, the impact of MDP on inflammatory bowel disease (IBD) and its principal active compounds that contribute to the anti-inflammatory properties are uncertain. Thus, this study systemically evaluated the anti-inflammatory effects of fractionated MDP, which has therapeutic potential for IBD. MDP fractions were prepared by multistep fractionation, among which the ethyl acetate-fraction MDP5 exhibited the highest potency, with anti-inflammatory activity screened by the Toll-like receptor (TLR)-2 agonist, Pam3CSK4, in a cell-based model. MDP5 (at 50 µg/ml, p < 0.001) significantly inhibited nuclear factor kappa-B (NF-κB) reporters triggered by Pam3CSK4, without significant cell toxicity. Moreover, MDP5 (at 10 µg/ml) alleviated proinflammatory signaling triggered by Pam3CSK4 in a dose-dependent manner and reduced downstream IL-6 and TNF-α production (p < 0.001) in primary macrophages. MDP5 also mitigated weight loss, clinical inflammation, colonic infiltration of immune cells and cytokine production in a murine colitis model. Index compounds including paeoniflorin derivatives (ranging from 0.1 to 3.4%), gallic acid (1.8%), and 1,2,3,4,6-penta-O-galloyl-ß-D-glucose (1.1%) in MDP5 fractions were identified by LC-MS/MS and could be used as anti-inflammatory markers for MDP preparation. Collectively, these data suggest that MDP5 is a promising treatment for IBD patients.

A systematic identification of anti-inflammatory active components derived from Mu Dan Pi and their applications in inflammatory bowel disease.

Mu Dan Pi (MDP), also known as Moutan Cortex Radicis, is a traditional Chinese medicine used to treat autoimmune diseases. However, the impact of MDP and its principal active compounds on inflammatory bowel disease (IBD) is uncertain. This study therefore systemically assessed the anti-inflammatory effects of MDP and its known active compounds in IBD. The anti-inflammatory activities of water extract and individual compounds were screened by NF-κB and interferon regulatory factor (IRF) reporter assays in THP-1 cells induced with either Toll-like receptor or retinoic acid inducible gene I/melanoma differentiation-associated gene 5 activators and further verified in bone marrow-derived macrophages. MDP water extract significantly inhibited the activation of NF-κB and IRF reporters, downstream signaling pathways and the production of IL-6 and TNF-α, in a dose-dependent manner. Among 5 known active components identified from MDP (1,2,3,4,6-penta-O-galloyl-ß-d-glucose [PGG], gallic acid, methyl gallate, paeoniflorin, and paeonol), PGG was the most efficient at inhibiting both reporters (with an IC50 of 5-10 µM) and downregulating IL-6 and TNF-α. Both MDP powder for clinical use and MDP water extract, but not PGG, reduced colitis and pathological changes in mice. MDP and its water extract show promise as a novel therapy for IBD patients.

Effects of Non-insulin Anti-hyperglycemic Agents on Gut Microbiota: A Systematic Review on Human and Animal Studies.

Background: As growing evidence links gut microbiota with the therapeutic efficacy and side effects of anti-hyperglycemic drugs, this article aims to provide a systematic review of the reciprocal interactions between anti-hyperglycemic drugs and gut microbiota taxa, which underlie the effect of the gut microbiome on diabetic control via bug-host interactions. Method: We followed the PRISMA requirements to perform a systematic review on human vs. animal gut microbiota data in PubMed, SCOPUS, and EMBASE databases, and used Cochrane, ROBIN-I, and SYRCLE tools to assess potential bias risks. The outcomes of assessment were trends on gut microbiota taxa, diversity, and associations with metabolic control (e.g., glucose, lipid) following anti-hyperglycemic treatment. Results: Of 2,804 citations, 64 studies (17/humans; 47/mice) were included. In human studies, seven were randomized trials using metformin or acarbose in obese, pre-diabetes, and type 2 diabetes (T2D) patients. Treatment of pre-diabetes and newly diagnosed T2D patients with metformin or acarbose was associated with decreases in genus of Bacteroides, accompanied by increases in both Bifidobacterium and Lactobacillus. Additionally, T2D patients receiving metformin showed increases in various taxa of the order Enterobacteriales and the species Akkermansia muciniphila. Of seven studies with significant differences in beta-diversity, the incremental specific taxa were associated with the improvement of glucose and lipid profiles. In mice, the effects of metformin on A. muciniphila were similar, but an inverse association with Bacteroides was reported. Animal studies on other anti-hyperglycemic drugs, however, showed substantial variations in results. Conclusions: The changes in specific taxa and ß-diversity of gut microbiota were associated with metformin and acarbose in humans while pertinent information for other anti-hyperglycemic drugs could only be obtained in rodent studies. Further human studies on anti-hyperglycemic drugs other than metformin and acarbose are needed to explore gut microbiota's role in their therapeutic efficacies and side effects.

Antiviral activity of Sambucus FormosanaNakai ethanol extract and related phenolic acid constituents against human coronavirus NL63.

Human coronavirus NL63 (HCoV-NL63), one of the main circulating HCoVs worldwide, causes respiratory tract illnesses like runny nose, cough, bronchiolitis and pneumonia. Recently, a severe respiratory illness outbreak of HCoV-NL63 has been reported in a long-term care facility. Sambucus FormosanaNakai, a species of elderberry, is a traditional medicinal herb with anti-inflammatory and antiviral potential. The study investigated the antiviral activity of Sambucus FormosanaNakai stem ethanol extract and some phenolic acid constituents against HCoV-NL63. The extract was less cytotoxic and concentration-dependently increased anti-HCoV-NL63 activities, including cytopathicity, sub-G1 fraction, virus yield (IC50 = 1.17 µg/ml), plaque formation (IC50 = 4.67 µg/ml) and virus attachment (IC50 = 15.75 µg/ml). Among the phenolic acid constituents in Sambucus FormosanaNakai extract, caffeic acid, chlorogenic acid and gallic acid sustained the anti-HCoV-NL63 activity that was ranked in the following order of virus yield reduction: caffeic acid (IC50 = 3.54 µM) > chlorogenic acid (IC50 = 43.45 µM) > coumaric acid (IC50 = 71.48 µM). Caffeic acid significantly inhibited the replication of HCoV-NL63 in a cell-type independent manner, and specifically blocked virus attachment (IC50 = 8.1 µM). Therefore, the results revealed that Sambucus Formosana Nakai stem ethanol extract displayed the strong anti-HCoV-NL63 potential; caffeic acid could be the vital component with anti-HCoV-NL63 activity. The finding could be helpful for developing antivirals against HCoV-NL63.

Hepatoprotective effect of the ethanol extract of Polygonum orientale on carbon tetrachloride-induced acute liver injury in mice.

Polygonum orientale L. (Polygonaceae) fruits have various medicinal uses, but their hepatoprotective effects have not yet been studied. This study investigated the hepatoprotective activity of the ethanolic extract of P. orientale (POE) fruits against carbon tetrachloride (CCl4)-induced acute liver injury (ALI). Mice were pretreated with POE (0.1, 0.5, and 1.0 g/kg) or silymarin (0.2 g/kg) for 5 consecutive days and administered a dose of 0.175% CCl4 (ip) on the 5th day to induce ALI. Blood and liver samples were collected to measure antioxidative activity and cytokines. The bioactive components of POE were identified through high-performance liquid chromatography (HPLC). Acute toxicity testing indicated that the LD50 of POE exceeded 10 g/kg in mice. Mice pretreated with POE (0.5, 1.0 g/kg) experienced a significant reduction in their serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), and alkaline phosphatase (ALP) levels and reduction in the extent of liver lesions. POE reduced the malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) levels, and increased the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GRd) in liver. HPLC revealed peaks at 11.28, 19.55, and 39.40 min for protocatechuic acid, taxifolin, and quercetin, respectively. In summary, the hepatoprotective effect of POE against CCl4-induced ALI was seemingly associated with its antioxidant and anti-proinflammatory activities.

Chemical compositions, chromatographic fingerprints and antioxidant activities of Citri Exocarpium Rubrum (Juhong).

BACKGROUND: Citri Exocarpium Rubrum (CER), which is known as Juhong in Chinese, is the dried exocarp of Citrus reticulata Blanco and its cultivars (Fam. Rutaceae) and is currently used in Chinese medicine to protect the stomach and eliminate dampness and phlegm. The main aim of this study was to develop a high-performance liquid chromatography ultraviolet mass spectrometry (HPLC-UV-MS) method for determining the chemical compositions and fingerprint of CER. We also evaluated the antioxidant properties of CER based on its 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, ferric ion reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays. METHODS: Ten CER samples were collected from Hong Kong and mainland China. Each CER sample was extracted using an ultrasonic extraction method. Chromatographic separation was achieved using a conventional Dikma Inspire C18 column with photo diode array detection (190-400 nm). Hesperidin, nobiletin and tangeretin were quantified based on the UV signal observed at 330 nm. The column was eluted with a mobile phase consisting of water and acetonitrile (15-55%) over 55 min. Fingerprints combined with similarity and principal component analyses were used to classify the herbs. The DPPH free radical scavenging activity, FRAP and ABTS properties of the different CER samples were assayed. Bivariate correlation analysis was performed to investigate the correlation between the characteristic peaks and their antioxidant capacities. RESULTS: Limit of detection (LOD), limit of quantification (LOQ), linearity, inter-day precision, intra-day precision, repeatability, stability and recovery of the developed method were validated, and the method was subsequently used to determine the contents of hesperidin, nobiletin and tangeretin, and to acquire the fingerprints of the CER samples. Seventeen characteristic peaks were found in the fingerprints, and eleven of them were identified. Bivariate correlation analysis revealed correlations between the characteristic peaks and the antioxidant activities of the samples. CONCLUSION: An HPLC-UV-MS method was developed and validated after a detailed investigation on extraction of chemical compounds from CER using different solvents and extraction times. None of the peaks was correlated with the DPPH free radical scavenging activity or ferric reducing capacity. Most of the peaks were correlated well with the ABTS radical scavenging capacity.