Kwok-Pui Fung

Publications of Kwok-Pui Fung

• Ethyl Acetate Fraction of Radix Rubiae Inhibits Cell Growth and Promotes Terminal Differentiation in Cultured Human Keratinocytes.

  Authors: Lin-Li Zhou, Zhi-Xiu Lin, Kwok-Pui Fung, Chun-Tao Che, Ming Zhao, Christopher H K Cheng, Zhong Zuo

  Journal of ethnopharmacology. 05/2012;

  ETHNOPHARMACOLOGICAL RELEVANCE: In Chinese medicine practice, Radix rubiae, the dry root of Rubia cordifolia L. is commonly used for the treatment of psoriasis. AIM OF THE STUDY: Psoriasis is aETHNOPHARMACOLOGICAL RELEVANCE: In Chinese medicine practice, Radix rubiae, the dry root of Rubia cordifolia L. is commonly used for the treatment of psoriasis. AIM OF THE STUDY: Psoriasis is a chronic inflammatory skin disorder characterized by hyperproliferation and aberrant differentiation of epidermal keratinocytes. Our previous studies identified Radix rubiae to have potent antiproliferative action on cultured HaCaT keratinocytes and to induce keratinocyte differentiation in mouse tail model. The present study aimed to investigate whether Radix rubiae could also induce terminal differentiation in cultured human keratinocytes. METHODS AND RESULTS: The cornified envelope (CE) formation assay showed that ethyl acetate (EA) fraction of Radix rubiae significantly accentuated the CE formation, a well-recognized marker of terminal differentiation, in cultured HEK and HaCaT cells in a dose and time dependent manner. Western blot analyses demonstrated that EA fraction of Radix rubiae at a concentration of 3.2μg/ml significantly increased transglutaminase type I and involucrin expression in both HEK and HaCaT keratinocytes after 96h treatment, a response similar to that of Ca(2+) positive control. Moreover, the expression level of cytokeratin 5/14, which is specifically related to cell proliferation, was significantly downregulated while terminal differentiation markers cytokeratin 1/10 were markedly increased by Radix rubiae treatment in both HEK and HaCaT cells. CONCLUSION: The present experimental findings unequivocally confirmed the keratinocyte terminal differentiation promoting capacity of Radix rubiae, and strongly suggest that Radix rubiae is a promising antipsoriatic agent warranting further clinical development for psoriasis treatment.

• Eriocalyxin B induces apoptosis and cell cycle arrest in pancreatic adenocarcinoma cells through caspase- and p53-dependent pathways.

  Authors: Lin Li, Grace G L Yue, Clara B S Lau, Handong Sun, Kwok Pui Fung, Ping Chung Leung, Quanbin Han, Po Sing Leung

  Toxicology and applied pharmacology. 04/2012;

  Pancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated fromPancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated from the Isodon eriocalyx plant, is an ent-kaurane diterpenoid with promise as a broad-spectrum anti-cancer agent. The anti-leukemic activity of EriB, including the underlying mechanisms involved, has been particularly well documented. In this study, we demonstrated for the first time EriB's potent cytotoxicity against four pancreatic adenocarcinoma cell lines, namely PANC-1, SW1990, CAPAN-1, and CAPAN-2. The effects were comparable to that of the chemotherapeutic camptothecin (CAM), but with much lower toxicity against normal human liver WRL68 cells. EriB's cytoxicity against CAPAN-2 cells was found to involve caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Moreover, the p53 pathway was found to be activated by EriB in these cells. Furthermore, in vivo studies showed that EriB inhibited the growth of human pancreatic tumor xenografts in BALB/c nude mice without significant secondary adverse effects. These results suggest that EriB should be considered a candidate for pancreatic cancer treatment.

• Isolation, structure characterization and immunomodulating activity of a hyperbranched polysaccharide from the fruiting bodies of Ganoderma sinense.

  Authors: Xiao-Qiang Han, Ben Chung Lap Chan, Cai-Xia Dong, Yin-Hua Yang, Chun Hay Ko, Grace Gar-Lee Yue, Dan Chen, Chun-Kwok Wong, Clara Bik-San Lau, Pengfei Tu, Pang-Chui Shaw, Kwok-Pui Fung, Ping Chung Leung, Quan-Bin Han

  Journal of agricultural and food chemistry. 04/2012;

  A polysaccharide (GSP-6B) with a molecular weight of 1.86 ×106 Da was isolated from the fruiting bodies of Ganoderma sinense. Chemical composition analysis, methylation analysis, infra-redA polysaccharide (GSP-6B) with a molecular weight of 1.86 ×106 Da was isolated from the fruiting bodies of Ganoderma sinense. Chemical composition analysis, methylation analysis, infra-red spectroscopy, and nuclear magnetic resonance spectroscopy were conducted to elucidate its structure. GSP-6B contains a backbone of (1→6)-linked-β-D-glucopyranosyl residues, bearing branches at O-3 position of every two sugar residues along the backbone. The side chains contain (1→4)-linked-β-D-glucopyranosyl residues, (1→3)-linked-β-D-glucopyranosyl residues and non-reducing end β-D-glucopyranosyl residues. In vitro immunomodulating activity assay revealed that GSP-6B could significantly induce the releasing of IL-1β and TNF-in human PBMC and showed no toxicity to either PBMC or a human macrophage cell line THP-1. GSP-6B could also activate DC by stimulating the secretion of IL-12 and IL-10 from DC.

• Reversal of P-glycoprotein-mediated multidrug resistance in human hepatoma cells by hedyotiscone A, a compound isolated from Hedyotis corymbosa.

  Authors: Grace Gar-Lee Yue, Julia Kin-Ming Lee, Ling Cheng, Ben Chung-Lap Chan, Lei Jiang, Kwok-Pui Fung, Ping-Chung Leung, Clara Bik-San Lau

  Xenobiotica; the fate of foreign compounds in biological systems. 02/2012;

  Multidrug resistance is a major problem in hepatocellular carcinoma. Hedyotiscone A, a compound isolated from Chinese herbal medicine Hedyotis corymbosa (HC, family Rubiaceae), was used as theMultidrug resistance is a major problem in hepatocellular carcinoma. Hedyotiscone A, a compound isolated from Chinese herbal medicine Hedyotis corymbosa (HC, family Rubiaceae), was used as the chemical marker to distinguish between HC and an anticancer herb Hedyotis diffusa (HD) in our previous study. The present study aimed to investigate whether HA exhibited antiproliferative activities in multidrug-resistant hepatocellular carcinoma cells R-HepG2 and the parental cells HepG2 using MTT assay and [(3)H]-thymidine incorporation assay. Our results showed that HA could significantly inhibit cell proliferation in R-HepG2 and HepG2 (IC(50) = 43.7 and 56.3 µg/mL, respectively), but not in normal human liver cells WRL-68 (IC(50) > 100 µg/mL) cells, suggesting its selective cytotoxic effects. Besides, HA induced apoptosis in R-HepG2 cells, as confirmed by annexin-V & propidium iodide staining, and DNA fragmentation assay. The caspase cascade was activated as shown by a significant increase of cleaved caspases-3, -7 and -9 in HA-treated R-HepG2 cells. The activities and protein expression of P-glycoprotein as well as mRNA expression of MDR1 were also decreased in HA-treated R-HepG2 cells. Our study demonstrated for the first time the antiproliferative activities of hedyotiscone A in multidrug-resistant R-HepG2 cells. The findings revealed the potential of this compound in treating multidrug-resistant tumor.

• Synergistic interaction between Astragali Radix and Rehmanniae Radix in a Chinese herbal formula to promote diabetic wound healing.

  Authors: Kit-Man Lau, Kwok-Kin Lai, Cheuk-Lun Liu, Jacqueline Chor-Wing Tam, Ming-Ho To, Hin-Fai Kwok, Ching-Po Lau, Chun-Hay Ko, Ping-Chung Leung, Kwok-Pui Fung, Simon Kar-Sing Poon, Clara Bik-San Lau

  Journal of ethnopharmacology. 02/2012;

  ETHNOPHARMACOLOGICAL RELEVANCE: Astragali Radix (AR) and Rehmanniae Radix (RR) are two traditional Chinese medicines widely used in China for treating diabetes mellitus and its complications, such asETHNOPHARMACOLOGICAL RELEVANCE: Astragali Radix (AR) and Rehmanniae Radix (RR) are two traditional Chinese medicines widely used in China for treating diabetes mellitus and its complications, such as diabetic foot ulcer. AIM OF STUDY: In our previous study, a herbal formula NF3 comprising AR and RR in the ratio of 2:1 was found effective in enhancing diabetic wound healing in rats through the actions of tissue regeneration, angiogenesis promotion and inflammation inhibition. The aims of the present study were to investigate the herb-herb interaction (or the possible synergistic effect) between AR and RR in NF3 to promote diabetic wound healing and to identify the principal herb in the formula by evaluating the potencies of individual AR and RR in different mechanistic studies. MATERIALS AND METHODS: A chemically induced diabetic foot ulcer rat model was used to examine the wound healing effect of NF3 and its individual herbs AR and RR. For mechanistic studies, murine macrophage cell (RAW 264.7) inflammation, human fibroblast (Hs27) proliferation and human endothelial cell (HMEC-1) migration assays were adopted to investigate the anti-inflammatory, granulation formation and angiogenesis-promoting activities of the herbal extracts, respectively. RESULTS: In the foot ulcer animal model, neither AR nor RR at clinical relevant dose (0.98g/kg) promoted diabetic wound healing. However, when they were used in combination as NF3, synergistic interaction was demonstrated, of which NF3 could significantly reduce the wound area of rats when compared to water group (p<0.01). For anti-inflammation and granulation formation, AR was more effective than RR in inhibiting lipopolysaccharide (LPS)-induced nitric oxide production from RAW 264.7 cells and promoting Hs27 fibroblast proliferation. In the aspect of angiogenesis promotion, only NF3 promoted cell migration of HMEC-1 cells. CONCLUSIONS: AR plays a preeminent role in the anti-inflammatory and fibroblast-proliferating activities of NF3. The inclusion of RR, however, is crucial for NF3 to exert its overall wound-healing as well as the underlying angiogenesis-promoting effects. The results of present study justified the combined usage of AR and RR in the ratio of 2:1 as NF3 to treat diabetic foot ulcer and illustrated that AR is the principal herb in this herbal formula.

• Inhibitory effects of salviae miltiorrhizae radix (danshen) and puerariae lobatae radix (gegen) in carbachol-induced rat detrusor smooth muscle contractility.

  Authors: Willmann Liang, Ivy Wen Jia Teong, Johnny Chi Man Koon, Clara Bik San Lau, Kwok Pui Fung, Ping Chung Leung

  International journal of physiology, pathophysiology and pharmacology. 01/2012; 4(1):36-44.

  Both danshen (D) and gegen (G) have proven relaxant effects on vascular smooth muscle, thus their potential bladder inhibitory effects have impending interests in urology. The aim of this study wasBoth danshen (D) and gegen (G) have proven relaxant effects on vascular smooth muscle, thus their potential bladder inhibitory effects have impending interests in urology. The aim of this study was to demonstrate the novel effects of D and G on detrusor smooth muscle contractility. Urothelium-intact (+UE) and urothelium-denuded (-UE) detrusor strips were isolated from the rat. Isometric tension was measured using a myograph system. Carbachol (CCh) was used to pre-contract the detrusor strips prior to stepwise relaxation by adding extracts of D, G, and a DG (7:3) formulation. Tonic relaxation level and phasic contractile activity under the herbal treatments were analyzed. There was no difference in the herbal effects between +UE and -UE strips. D alone induced a much smaller relaxation than G alone or DG. G alone also suppressed phasic amplitude but not phasic frequency while DG suppressed both parameters. D and G acted synergistically to yield the observed effects on detrusor smooth muscle. The findings showed that the DG formulation were able to relax the detrusor as well as suppress phasic contractions, both actions important in maintaining normal bladder filling and urine storage processes. Hence DG may have new application in the management of bladder disorders.

• The role of turmerones on curcumin transportation and p-glycoprotein activities in intestinal caco-2 cells.

  Authors: Grace G L Yue, Sau-Wan Cheng, Hua Yu, Zi-Sheng Xu, Julia K M Lee, Po-Ming Hon, Mavis Y H Lee, Edward J Kennelly, Gary Deng, Simon K Yeung, Barrie R Cassileth, Kwok-Pui Fung, Ping-Chung Leung, Clara B S Lau

  Journal of medicinal food. 12/2011; 15(3):242-52.

  Abstract The rhizome of Curcuma longa (turmeric) is often used in Asia as a spice and as a medicine. Its most well-studied component, curcumin, has been shown to exhibit poor bioavailability inAbstract The rhizome of Curcuma longa (turmeric) is often used in Asia as a spice and as a medicine. Its most well-studied component, curcumin, has been shown to exhibit poor bioavailability in animal studies and clinical trials. We hypothesized that the presence of lipophilic components (e.g., turmerones) in turmeric extract would affect the absorption of curcumin. The effects of turmerones on curcumin transport were evaluated in human intestinal epithelial Caco-2 cells. The roles of turmerones on P-glycoprotein (P-gp) activities and mRNA expression were also evaluated. Results showed that in the presence of α- and aromatic turmerones, the amount of curcumin transported into the Caco-2 cells in 2 hours was significantly increased. α-Turmerone and verapamil (a P-gp inhibitor) significantly inhibited the efflux of rhodamine-123 and digoxin (i.e., inhibited the activity of P-gp). It is interesting that aromatic turmerone significantly increased the rhodamine-123 efflux and P-gp (MDR1 gene) mRNA expression levels. The effects of α- and aromatic turmerones on curcumin transport as well as P-gp activities were shown here for the first time. The presence of turmerones did affect the absorption of curcumin in vitro. These findings suggest the potential use of turmeric extract (including curcumin and turmerones), rather than curcumin alone, for treating diseases.

• Quick identification of kuraridin, a noncytotoxic anti-MRSA (methicillin-resistant Staphylococcus aureus) agent from Sophora flavescens using high-speed counter-current chromatography.

  Authors: Ben Chung-Lap Chan, Hua Yu, Chun-Wai Wong, Sau-Lai Lui, Claude Jolivalt, Carine Ganem-Elbaz, Jean-Marc Paris, Barbara Morleo, Marc Litaudon, Clara Bik-San Lau, Margaret Ip, Kwok-Pui Fung, Ping-Chung Leung, Quan-Bin Han

  Journal of chromatography. B, Analytical technologies in the biomedical and life sciences. 12/2011; 880(1):157-62.

  Bacterial resistance to antibiotics has become a serious problem of public health that concerns almost all currently used antibacterial agents and that manifests in all fields of their application.Bacterial resistance to antibiotics has become a serious problem of public health that concerns almost all currently used antibacterial agents and that manifests in all fields of their application. To find more antibacterial agents from natural resources is all the time considered as an important strategy. Sophora flavescens is a popularly used antibacterial herb in Chinese Medicine, from which prenylated flavones were reported as the antibacterial ingredients but with a major concern of toxicity. In our screening on the antibacterial activities of various chemicals of this herb, 18 fractions were obtained from 8 g of 50% ethanol extract on a preparative high-speed counter-current chromatography (HSCCC, 1000 ml). The system of n-hexane/ethyl acetate/methanol/water (1:1:1:1) was used as the two-phase separation solvent. A chalcone named kuraridin was isolated from the best anti-MRSA fraction, together with sophoraflavanone G, a known active ingredient of S. flavescens. Their structures were elucidated by analysis of the NMR spectra. Both compounds exhibited significant anti-MRSA effects, compared to baicalein that is a well known anti-MRSA natural product. More important, kuraridin showed no toxicity on human peripheral blood mononuclear cells (PBMC) at the concentration up to 64 μg/ml while sophoraflavanone G inhibited over 50% of cellular activity at 4 μg/ml or higher concentration. These data suggested that opening of ring A of the prenylated flavones might decrease the toxicity and remain the anti-MRSA effect, from a viewpoint of structure-activity relationship.

• The healing and anti-scar effects of astragaloside IV on the wound repair in vitro and in vivo.

  Authors: Xi Chen, Li-Hua Peng, Ni Li, Qi-Mei Li, Ping Li, Kwok-Pui Fung, Ping-Chung Leung, Jian-Qing Gao

  Journal of ethnopharmacology. 11/2011; 139(3):721-7.

  Astragaloside IV is the chief ingredient of Radix Astragali, which has been used in the Traditional Chinese Medicine as a major component of many polyherbal formulations for the repair andAstragaloside IV is the chief ingredient of Radix Astragali, which has been used in the Traditional Chinese Medicine as a major component of many polyherbal formulations for the repair and regeneration of injured organ and tissues. This study is to investigate the influence of astragaloside IV on both of the wound healing and scar formation. For the in vitro evaluation, the influence of the astragaloside IV in the wound scratch test of keratinocytes and the secretion of transforming growth factor-β1, a key factor contributing to scar formation were determined. With the rat skin excision model, the in vivo regulation of astragaloside IV on wound closure, angiogenesis and collagen disposition were also evaluated. Astragaloside IV was shown to significantly promote the migration of keratinocytes in wound scratching assay. The superior effect of Astragaloside IV was observed at 100 μmol/L, in which the recover rates was increased with 2 and 3 folds after 48 h and 96 h respectively than that of blank control (P<0.01). Animal skin closure measurement showed that astragaloside IV could stimulate the wound healing, e.g. with 21% recover in contrast to the 8% of blank control at the 6th day. Biomechanic and Masson's trichrome stain analysis indicated that astragaloside IV may improve the strength of the repaired skin and promoted the angiogenesis and collagen synthesis. Meanwhile, the picrosirius-sirus red stain and Elisa test definitely showed the anti-scar effects of astragaloside IV by decreasing the levels of collagen I/III and TGF-β1 secretion by firbroblasts with a dose-dependent manner (25-100 μmol/L). Astragaloside IV was shown a promising natural product with both healing and anti-scar effects for wound treatment. These results give the evidence for the application of astragaloside IV in the treatment of injury.

• Screening for Anti-inflammatory and Bronchorelaxant Activities of 12 Commonly Used Chinese Herbal Medicines.

  Authors: Grace G L Yue, Ben C L Chan, Hin-Fai Kwok, Ming-Ho To, Kam-Lun Hon, Kwok-Pui Fung, Clara B S Lau, Ping-Chung Leung

  Phytotherapy research : PTR. 11/2011;

  The use of health supplements derived from medicinal herbs as self-medication for the relief of respiratory tract pathology symptoms is increasing in Chinese communities as air pollution isThe use of health supplements derived from medicinal herbs as self-medication for the relief of respiratory tract pathology symptoms is increasing in Chinese communities as air pollution is worsening. Twelve herbs from two formulae of our previous studies were evaluated for their anti-inflammatory, immunomodulatory and bronchorelaxant activities in this study. Among the extracts tested, those of Herba Schizonepetae and Radix Glycyrrhizae showed significant inhibitory effects on LPS-induced nitric oxide production (p < 0.05) in mouse macrophage RAW264.7 cells, suggesting their anti-inflammatory activities. Radix Scutellariae and Radix Glycyrrhizae extracts showed significant inhibitory effects on phytohaemagglutinin-induced proliferation in human peripheral blood mononuclear cells (p < 0.05). These extracts also showed inhibition of TNF-α, IFN-γ and IL-10 production. For the bronchorelaxant assay, Rhizoma Cynanchi Stauntonii and Radix Glycyrrhizae extracts showed potent attenuation of the acetylcholine- and carbachol-induced contractions in rat trachea (p < 0.05), implying their relaxant activities. In conclusion, Herba Schizonepetae, Radix Glycyrrhizae, Radix Scutellariae and Rhizoma Cynanchi Stauntonii extracts were demonstrated to exert anti-inflammatory, immunomodulatory and bronchorelaxant activities, which may help to ameliorate the symptoms of respiratory tract pathologies. The findings have thus provided some scientific evidence on the efficacy and mechanisms of action of these herbs, which are useful for the further development of clinical applications. Copyright © 2011 John Wiley & Sons, Ltd.

• Photodynamic Therapy of Pheophorbide a Inhibits the Proliferation of Human Breast Tumour via Both Caspase-dependent and -independent Apoptotic Pathways in In Vitro and In Vivo Models.

  Authors: Sandy Wan-Heng Hoi, Hoi Ming Wong, Judy Yuet-Wa Chan, Grace Gar Lee Yue, Gary Man-Kit Tse, Bonita Ka-Bo Law, Wing Ping Fong, Kwok Pui Fung

  Phytotherapy research : PTR. 11/2011;

  Breast cancer is conventionally treated by surgery and radiotherapy, with adjuvant chemotherapy and hormonotherapy as supplementary treatments. However, such treatments are associated with adverseBreast cancer is conventionally treated by surgery and radiotherapy, with adjuvant chemotherapy and hormonotherapy as supplementary treatments. However, such treatments are associated with adverse side effects and drug resistance. In this study, Pheophorbide a (Pa), a photosensitizer isolated from Scutelleria barbata, was analysed for its antiproliferative effect on human breast tumour cells. The IC (inhibitory concentration)(50) of the combined treatment of Pa and photodynamic therapy (Pa-PDT) on human breast tumour MCF-7 cells was 0.5 µm. Mechanistic studies in MCF-7 cells demonstrated that Pa was localized in the mitochondria, and reactive oxygen species were found to be released after Pa-PDT. Apoptosis was the major mechanism responsible for the tumour cell death, and mitochondrial membrane depolarization and cytochrome c release highlighted the role of mitochondria in the apoptotic mechanism. Up-regulation of tumour suppressor protein p53, cleavage of caspase-9 and poly (ADP-ribose) polymerase suggested that the caspase-dependent pathway was induced, while the release of apoptosis-inducing factors demonstrated that the apoptosis was also mediated by the caspase-independent mechanism. In vivo study using the mouse xenograft model showed a significant inhibition of MCF-7 tumour growth by Pa-PDT. Together, the results of this study provide a basis for understanding and developing Pa-PDT as a cure for breast cancer. Copyright © 2011 John Wiley & Sons, Ltd.

• Transcriptional profiling of human skin fibroblast cell line Hs27 induced by herbal formula Astragali Radix and Rehmanniae Radix.

  Authors: Qi Zhang, Fan Wei, Chi Chun Fong, Wai Kin Yu, Yao Chen, Chi Man Koon, Kit Man Lau, Ping Chung Leung, Clara Bik San Lau, Kwok Pui Fung, Mengsu Yang

  Journal of ethnopharmacology. 10/2011; 138(3):668-75.

  The herbs Astragali Radix (AR) and Rehmanniae Radix (RR) have long been used in traditional Chinese Medicine and serve as the principal herbs in treating diabetic foot ulcer. Chinese herbal formulusThe herbs Astragali Radix (AR) and Rehmanniae Radix (RR) have long been used in traditional Chinese Medicine and serve as the principal herbs in treating diabetic foot ulcer. Chinese herbal formulus comprising Astragali Radix (AR) and Rehmanniae Radix (RR) have been shown to improve the healing of diabetic foot ulcer through enhancing the viability of primary fibroblasts in diabetic patients suffering insulin resistance. Our previous study demonstrated that the herbal formula NF3 comprising of AR and RR in the ratio of 2:1 was effective in promoting wound healing in diabetic rats, and in vitro data indicated that the wound healing effects of NF3 might be due to the regulation and coordination of inflammation, angiogenesis and tissue regeneration. However, the underlying molecular mechanism has not been well investigated. In this study, we investigated the cellular and molecular effects of the herbal formula NF3 on human skin fibroblast cells. Human skin fibroblast cells Hs27 were treated with NF3 ranging from 0 to 8 mg/ml for 24h, and the cells without NF3 treatment were used as control. Cell proliferation assay and cell cycle analysis were performed. Transcriptional profiles of Hs27 cells upon NF3 treatment were acquired by using a human cDNA microarray containing 10,000 genes, and the signaling pathways differentially regulated by NF3 were identified and analyzed. NF3 promoted Hs27 cell proliferation and cell cycle progression. Microarray analysis revealed that 116 genes were differentially expressed upon NF3 treatment. Functional analysis of the genes indicated that NF3 mainly activated Wnt and angiogenesis related pathways, which are directly related to cell proliferation, angiogenesis, extracellular matrix (ECM) formation and inflammation during the process of wound healing. This study provides insight into the molecular mechanism of how the herbal formula Astragali Radix and Rehmanniae Radix may serve as potential therapeutics for wound healing.

• Development of a simple chromatographic method for distinguishing between two easily confused species, Hedyotis diffusa and Hedyotis corymbosa.

  Authors: Clara B S Lau, Ling Cheng, Bobby W H Cheng, Grace G L Yue, Eric C W Wong, Ching-Po Lau, Ping-Chung Leung, Kwok-Pui Fung

  Natural product research. 10/2011;

  Hedyotis diffusa Willd. and Hedyotis corymbosa (L.) Lam. are closely related species of Rubiaceae family and they can be easily confused. Although previous reports have been found in whichHedyotis diffusa Willd. and Hedyotis corymbosa (L.) Lam. are closely related species of Rubiaceae family and they can be easily confused. Although previous reports have been found in which ultraviolet spectrum, convolution spectrometry or X-ray diffraction are reported to be used for distinguishing between the two species, these methods require specialised equipment. Hence, this study aims to develop a simple chromatographic method for the purpose. Our results illustrate the use of a thin-layer chromatographic (TLC) profile to differentiate between the two species, with a blue zone appearing at around an R(f) of 0.36 in H. corymbosa but not in H. diffusa. The compound corresponding to this blue zone was later found to be hedyotiscone A. LC-MS with multiple reaction monitoring was used as a tool to identify and quantify hedyotiscone A in the test samples. In conclusion, a quick and simple TLC assay was conducted to distinguish between the two species H. diffusa and H. corymbosa.

• Celastrol-induced apoptosis in human HaCaT keratinocytes involves the inhibition of NF-κB activity.

  Authors: Lin-Li Zhou, Zhi-Xiu Lin, Kwok-Pui Fung, Christopher H K Cheng, Chun-Tao Che, Ming Zhao, Shi-Hua Wu, Zhong Zuo

  European journal of pharmacology. 09/2011; 670(2-3):399-408.

  Psoriasis is a chronic inflammatory skin disease affecting 1-3% of the world's population. Traditional Chinese medicines have been extensively used for treating psoriasis with promising clinicalPsoriasis is a chronic inflammatory skin disease affecting 1-3% of the world's population. Traditional Chinese medicines have been extensively used for treating psoriasis with promising clinical results. Celastrol, a triterpenoid isolated from a Chinese herb Celastrus orbiculatus caulis, has been known to have diverse pharmacological effects such as anti-inflammatory, anti-cancer and antioxidant activities. The present study aimed at evaluating the anti-proliferative action of celastrol on cultured HaCaT cells and elucidating the mechanisms of action involved. Celastrol was shown to inhibit HaCaT cells growth with an IC₅₀ value of 1.1 μM as measured by MTT assay. The ability of celastrol to induce apoptosis was studied by flow cytometric and western blot analyses. Celastrol was found to be capable of inducing apoptosis in HaCaT cells as characterized by phosphatidyl-serine (PS) externalization, depolarization of mitochondrial membrane potential and activation of caspase-3. The apoptosis induced by celastrol could be suppressed by Z-IETD-FMK and Z-LEHD-FMK, the respective caspase-8 and caspase-9 inhibitor. In addition, western blot analysis revealed a significant augmentation in the protein expression of Bax and attenuation in Bcl-2, suggesting that the celastrol-induced apoptosis acts through both death receptor and mitochondrial pathways. Moreover, western blot analysis on the expression of Rel/NF-κB demonstrated that the celastrol-mediated apoptosis on HaCaT cells was associated with the inhibition of the NF-κB pathway. Taken together, the present project has for the first time identified celastrol as a naturally occurring compound with potent apoptogenic action on cultured human keratinocytes, rendering it a promising candidate for further development into an anti-psoriatic agent.

• Cordyceps militaris extract stimulates Cl⁻ secretion across human bronchial epithelia by both Ca²⁺₋ and cAMP-dependent pathways.

  Authors: Jacky Chun-Kit Fung, Grace Gar-Lee Yue, Kwok-Pui Fung, Xin Ma, Xiao-Qiang Yao, Wing-Hung Ko

  Journal of ethnopharmacology. 09/2011; 138(1):201-11.

  The caterpillar fungus Cordyceps militaris (CM; Clavicipitaceae) is a well-known traditional Chinese medicine that can be artificially cultivated on a large scale. We have previously demonstratedThe caterpillar fungus Cordyceps militaris (CM; Clavicipitaceae) is a well-known traditional Chinese medicine that can be artificially cultivated on a large scale. We have previously demonstrated that its stimulatory action on ion transport in human airway epithelia is similar to Cordyceps sinensis (Clavicipitaceae), which has been traditionally used to treat respiratory diseases. To investigate the signal transduction mechanism(s) underlying CM-induced ion transport activity in cultured human bronchial epithelia. 16HBE14o-, a human bronchial epithelial cell line, was used to study the regulation of ion transport by the water extract of CM. CM extract was added to the apical or basolateral aspect of the epithelia. In subsequent experiments, different Cl(-) channel and K(+) channel blockers, adenylate cyclase and protein kinase A (PKA) inhibitors, and an intracellular Ca(2+) chelator were used to examine the involvement of apical Cl(-) and basolateral K(+) channels in mediating CM-induced Cl(-) secretion and the underlying signal transduction mechanism(s). PKA activity was also measured in 16HBE14o- cells. CM stimulated Cl(-) secretion across 16HBE14o- monolayers in a dose-dependent manner. Cl(-) secretion could be inhibited by apical application of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-)channel blocker and the calcium-activated Cl(-) channel (CaCC) blocker. Cl(-) secretion was sensitive to basolateral application of different K(+) channel blockers. Similar inhibitory patterns were obtained in nystatin-permeabilized epithelia. The CM-induced Cl(-) secretion could be inhibited by adenylate cyclase and PKA inhibitors as well as an intracellular Ca(2+) chelator. Data from the PKA assay suggested that CM extract caused a significant increase in PKA activity compared with untreated control epithelia. These results suggest that CM extract stimulated Cl(-) secretion across human bronchial epithelia, possibly via apical CFTR and CaCC, and the basolateral K(+) channels are involved in driving apical Cl(-) exit. The underlying signal transduction mechanisms involve both cAMP- and Ca(2+)-dependent pathways.

• Pro-bone and antifat effects of green tea and its polyphenol, epigallocatechin, in rat mesenchymal stem cells in vitro.

  Authors: Chun Hay Ko, Wing Sum Siu, Hing Lok Wong, Wai Ting Shum, Kwok Pui Fung, Clara Bik San Lau, Ping Chung Leung

  Journal of agricultural and food chemistry. 09/2011; 59(18):9870-6.

  Green tea has been demonstrated recently as a potent bone supportive agent. Our previous studies showed that green tea and its polyphenolic constituents can promote bone-forming osteoblast activitiesGreen tea has been demonstrated recently as a potent bone supportive agent. Our previous studies showed that green tea and its polyphenolic constituents can promote bone-forming osteoblast activities and inhibit the bone-resorpting osteoclast formation. The objective of the present study was to investigate whether green tea and its components can regulate the osteogenic and adipogenic differentiation in pluripotent rat mesenchymal stem cells (MSCs). The rat MSCs were isolated from the bone marrow of tibiae and femora. The cells were treated with decaffeinated green tea extract (GTE) and six tea polyphenols under osteogenic induction. The alkaline phosphatase (ALP) activities and matrix calcium (Ca) deposition were assessed after 7 and 14 days of treatment. Our results demonstrated that GTE could significantly increase ALP dose dependently in the concentrations without cytotoxicity (0-100 μg/mL). Among six tested tea polyphenols, epigallocatechin (EGC) was shown to be the most effective in promoting osteogenic differentiation. At 20 μM, EGC increased ALP levels and Ca deposition significantly by 2.3- and 1.7-fold, respectively, when compared with the control group. EGC also increased the mRNA expression of bone formation markers runt-related transcription factor 2, ALP, osteonectin, and osteopontin. Furthermore, EGC demonstrated its antiadipogenicity by decreasing the adipocyte formation and inhibiting the mRNA expression levels of the adipogenic markers peroxisome proliferator-activated receptor γ, ccaat/enhancer-binding protein β, and fatty acid binding protein 4. In conclusion, this is the first report of the dual action of green tea polyphenol EGC in promoting osteogenesis and inhibiting adipocyte formation in MSCs. Our results provide scientific evidence to support the potential use of green tea in supporting the bone against degenerative diseases such as osteoporosis.

• Danshen-Gegen decoction exerts proliferative effect on rat cardiac myoblasts H9c2 via MAPK and insulin pathways.

  Authors: Chi Chun Fong, Fan Wei, Yao Chen, Wai Kin Yu, Chi Man Koon, Ping Chung Leung, Kwok Pui Fung, Clara Bik San Lau, Mengsu Yang

  Journal of ethnopharmacology. 09/2011; 138(1):60-6.

  Danshen (root of Salvia miltiorrhiza) and Gegen (roots of Pueraria lobata) are traditional Chinese medicines that have been used in combination for cardiovascular disease treatment. The present studyDanshen (root of Salvia miltiorrhiza) and Gegen (roots of Pueraria lobata) are traditional Chinese medicines that have been used in combination for cardiovascular disease treatment. The present study was performed to investigate the effect of Danshen-Gegen decoction on rat myocardium cell line H9c2 and the possible molecular mechanisms. Rat heart myocardium H9c2 cells were treated with or without Danshen-Gegen decoction (DG) ranging from 10 to 1000μg/ml for 24h. Cell viability was measured by Alarma blue assay and cell proliferation assay was performed by BrdU Cell Proliferation ELISA kit. The activation of mitogen-activated protein kinase and insulin pathways was analyzed by Luminex technology and the growth factors and cytokine expression of H9c2 cells induced by DG was evaluated by protein array. Moreover, a rat functional specific cDNA microarray was constructed to study the gene expression profiles of H9c2 cells upon the DG treatment at 50μg/ml for 24h. DG promoted H9c2 cell viability and cell proliferation at dose-dependent manner within the range between 0 and 250μg/ml. A Bio-Plex assay kit (Bio-Rad Bioscience) was used to detect the expression level of phosphoprotein as well as total proteins involved in the MAPK and insulin pathways. Significant phosphorylation of ERK, c-Jun, JNK, p38, AKT, IGF-IR, IRS-1and I kappa B were observed after DG treatment at 2h or 4h. A rat cytokine antibody array was used to detect and quantify 22 growth factors and cytokines in samples collected from the control and DG treated H9c2 cells. In the category of growth factors, GM-CSF, CNIF and b-NGF were stimulated by DG, while the expression of TIMP-1 was suppressed. For cytokine expression, it was found that DG stimulated three interleukin subclasses, IL-1α, 1X and 6, respectively. However, the expression of pro-inflammatory factors such as TNF-α and IFN-γ were down-regulated significantly. Moreover, the microarray analysis revealed that DG significantly up-regulated anti-apoptosis related genes such as Cdkn2c and Ppp3ca, and several cardiovascular disease suppressers and anti-inflammatory mediators; on the other hand, pro-apoptotic related genes including Caspase and Tnf-α were down-regulated by DG. Based on the results, a tentative scheme was proposed to show that the activation of the MAPK and insulin pathways are involved in the bioactive effect of Danshen-Gegen decoction on cardiomyocytes. Our study suggested that Danshen-Gegen decoction has proliferative effect on myocardium cells via MAPK and insulin signaling pathways. The molecular mechanism of the action may include the up-regulation of IRS/AKT and JNK pathways as well as the inhibition of TNF and p38 pathways.

• Development of a novel mouse model of severe glucose-6-phosphate dehydrogenase (G6PD)-deficiency for in vitro and in vivo assessment of hemolytic toxicity to red blood cells.

  Authors: Chun Hay Ko, Karen Li, Chung Leung Li, Pak Cheung Ng, Kwok Pui Fung, Anthony Edward James, Raymond Pui-On Wong, Goldie Jia-Shi Gu, Tai Fai Fok

  Blood cells, molecules & diseases. 08/2011; 47(3):176-81.

  Studies of hemolytic agents on G6PD-deficient subjects have been extensively performed on red blood cells obtained from donors, only using in vitro methods. However, there has been no adequateStudies of hemolytic agents on G6PD-deficient subjects have been extensively performed on red blood cells obtained from donors, only using in vitro methods. However, there has been no adequate G6PD-deficient animal model for in vivo assessment of potentially hemolytic agents. The objective of this study is to establish a novel mouse model of severe G6PD-deficiency, with high susceptibility to hemolytic damage upon oxidative agents. To create this model, G6PD mutant Gpdx allele was introduced into the C57L/J mouse strain background by breeding program. The hemolytic toxicity of naphthalene and its metabolite α-naphthol on G6PD-deficient red blood cells was evaluated. Our data showed that the F2 homozygous Gpdx mutant with C57L/J background exhibiting the G6PD activity was 0.9±0.1 U/g Hb, level similar to those of G6PD deficiency in human. A significantly negative correlation was demonstrated between GSH percentage reduction and G6PD activity (r=-0.51, p<0.001) upon challenge of the red blood cells with alpha-naphthol in vitro. Similar correlation was also found between GSSG elevation and G6PD activity. Our in vivo studies showed that the administration of naphthalene at 250 mg/kg inflicted significant oxidative damage to the G6PD-deficient mice, as illustrated by the decrease of the GSH-to-GSSG ratio (by 34.2%, p=0.005) and the increase of the methemoglobin level (by 1.9 fold, p<0.001). Hemolytic anemia was also found in G6PD-deficient mice at this dosage of naphthalene. In summary, this novel mouse model could be utilized as a screening platform to more accurately determine the hemolytic toxicity of pharmacological agents on G6PD-deficient subjects.

• Bioassay-guided isolation of norviburtinal from the root of Rehmannia glutinosa, exhibited angiogenesis effect in zebrafish embryo model.

  Authors: Cheuk-Lun Liu, Ling Cheng, Hin-Fai Kwok, Chun-Hay Ko, Tai-Wai Lau, Chi-Man Koon, Ming Zhao, Ching-Po Lau, Kit-Man Lau, Chun-Wai Wong, Ping-Chung Leung, Kwok-Pui Fung, Clara Bik-San Lau

  Journal of ethnopharmacology. 08/2011; 137(3):1323-7.

  The root of Rehmannia glutinosa (RR) is commonly used as a wound-healing agent in various traditional Chinese herbal formulae; while angiogenesis is one of the crucial aspects in wound-healing. TheThe root of Rehmannia glutinosa (RR) is commonly used as a wound-healing agent in various traditional Chinese herbal formulae; while angiogenesis is one of the crucial aspects in wound-healing. The objective of the present study was to investigate the angiogenesis effects of RR aqueous crude extract and its active component(s) using zebrafish model. The in vivo angiogenesis effect was studied using transgenic TG(fli1:EGFP)(y1)/+(AB) zebrafish embryos by observing the capillary sprouts formation in sub-intestinal vessel (SIV) of zebrafish embryos after 72 h post-fertilization under fluorescence microscopy. Our results indicated that RR aqueous crude extract (250 μg/ml) exhibited significant angiogenesis effect, with an increase in capillary sprouts formation in SIV. Following sequential solvent partition of the RR aqueous crude extract with dichloromethane, ethyl acetate and n-butanol successively, the dichloromethane fraction (DCM) was found to have the most sprouts formation in the SIV region. Subjected to column chromatography, DCM fraction was further fractionated into six sub-fractions and among these tested, the sub-fraction C2 exhibited the most potent angiogenesis effect. The major component, C2A, was isolated and identified as norviburtinal using nuclear magnetic resonance (NMR) and mass spectrometry (MS). The compound norviburtinal (at 50 μg/ml) was shown to possess significant angiogenesis effect in zebrafish model (p < 0.001). Norviburtinal was, for the first time, found in the extract of RR and possessed novel angiogenesis effect. Bioassay-guided fractionation suggested that norviburtinal was not the only active component responsible for the angiogenesis effect of RR.

• Genetically manipulated adult stem cells for wound healing.

  Authors: Li-Hua Peng, Kwok-Pui Fung, Ping-Chung Leung, Jian-Qing Gao

  Drug discovery today. 07/2011; 16(21-22):957-66.

  New knowledge of the signal controls and activities of adult stem cells (ASCs) involved in wound repair have led to extensive investigation of the topical delivery of biomacromolecules andNew knowledge of the signal controls and activities of adult stem cells (ASCs) involved in wound repair have led to extensive investigation of the topical delivery of biomacromolecules and multipotent stem cells to injured tissues for scar-less regeneration. The transplantation of genetically recombinant stem cells, which have roles as both therapeutics and carriers for gene delivery to wound sites, represents an attractive strategy for wound treatment. Here, we compare viral and non-viral vectors and three-dimensional scaffold-based transfection strategies in terms of their biosafety, recombinant efficiency and influence on the differentiation of ASCs, to indicate the future direction of the application of recombinant ASCs in wound treatment.