Publications by authors named "Kit-Man Lau"

High prevalence rates of methicillin-resistant (MRSA) and lack of effective antibacterial treatments urge discovery of alternative therapeutic modalities. The advent of antibacterial photodynamic therapy (aPDT) is a promising alternative, composing rapid, nonselective cell destruction without generating resistance. We used a panel of clinically relevant MRSA to evaluate hypericin (Hy) and pheophobide a (Pa)-mediated PDT with clinically approved methylene blue (MB).

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Background: We report herein the synthesis of a novel dicationic boron dipyrromethene derivative (compound 3) which is symmetrically substituted with two trimethylammonium styryl groups.

Methods: The antibacterial photodynamic activity of compound 3 was determined against sixteen methicillin-resistant Staphylococcus aureus (MRSA) strains, including four ATCC type strains (ATCC 43300, ATCC BAA-42, ATCC BAA-43, and ATCC BAA-44), two mutant strains [AAC(6')-APH(2") and RN4220/pUL5054], and ten nonduplicate clinical strains of hospital- and community-associated MRSA. Upon light irradiation, the minimum bactericidal concentrations of compound 3 were in the range of 1.

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The plant Scutellaria barbata (SB) is commonly used as herbal medicines for treating cancer. The present pre-clinical study aimed to validate the Chinese Pharmacopoeia (CP) recommended dosages of SB water extract (SBW) in treating colon tumors. The content of chemical marker scutellarin in SBW was quantified using UPLC.

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Antimicrobial photodynamic therapy (aPDT) is an innovative approach to combat multi-drug resistant bacteria. It is known that cationic Zn(II) phthalocyanines (ZnPc) are effective in mediating aPDT against methicillin-resistant (MRSA). Here we used ZnPc-based photosensitizer named ZnPcE previously reported by our research group to evaluate its aPDT efficacy against broad spectrum of clinically relevant MRSAs.

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The high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) causing skin and soft tissue infections in both the community and healthcare settings challenges the limited options of effective antibiotics and motivates the search for alternative therapeutic solutions, such as antibacterial photodynamic therapy (aPDT). While many publications have described the promising anti-bacterial activities of PDT in vitro, its applications in vivo and in the clinic have been very limited. This limited availability may in part be due to variabilities in the selected photosensitizing agents (PS), the variable testing conditions used to examine anti-bacterial activities and their effectiveness in treating MRSA infections.

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A series of cationic boron dipyrromethene (BODIPY) derivatives were synthesized and characterized with various spectroscopic methods. Having the ability to generate singlet oxygen upon irradiation, these compounds could potentially serve as photosensitizers for antimicrobial photodynamic therapy. Of the five BODIPYs being examined, the dicationic aza-BODIPY analogue (compound ) demonstrated the highest potency against a broad spectrum of clinically relevant methicillin-resistant (MRSA), including four ATCC-type strains (ATCC 43300, ATCC BAA-42, ATCC BAA-43, and ATCC BAA-44), two strains carrying specific antibiotic resistance mechanisms [-AAC(6')-APH(2") and RN4220/pUL5054], and ten non-duplicate clinical strains from hospital- and community-associated MRSAs of the important clonal types ST239, ST30, and ST59, which have previously been documented to be prevalent in Hong Kong and its neighboring countries.

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Acanthopanacis Senticosi Radix et Rhizoma seu Caulis, the dried root and rhizome or stem of , is commonly known as Siberian ginseng or Ciwujia in Chinese. It is used all over the world as an adaptogen to enhance physical and mental performance for the sake of normal physiological functioning of human bodies under stress. In the theory of traditional Chinese medicine, Ciwujia can strengthen the spleen that is an essential organ for immunological response.

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Quality surveillance on authentication, safety and efficacy of proprietary Chinese medicines (pCm) are certainly the top priorities for the industries. Nowadays, the quality control system adopted is mainly chemical marker-oriented, concerning basically the correct use of raw material and safety issues, while the biological activities of the chemical marker(s) are seldom considered. Hence, there is an undefined relationship between the amount of chemical markers and the claimed pharmacological activities.

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Background: Metabolic syndrome is the cluster of risk factors that leads to increased episodes of cardiovascular disease (CVD). These risk factors include but are not limited to obesity, non-alcoholic fatty liver (NAFLD), dyslipidemia, and type 2 diabetes. Since the pathogenesis of metabolic syndrome has multiple metabolic origins, there is no single treatment for it.

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Despite being a potent hypolipidemic drug, atorvastatin (AS) possesses certain adverse effects. Using AS and an herbal formula (Danshen and Gegen, DG) in combination may achieve potentiated hypolipidemic effects and also reduce its adverse effects. Hence, this study aimed to investigate the efficacy and safety of an AS and DG combination on high-fat diet-induced hyperlipidemia.

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Carbasugar sodium-glucose cotransporter 2 (SGLT2) inhibitors are highly promising drug candidates for the treatment of Type 2 diabetes mellitus (T2DM). However, the clinical usage of carbasugar SGLT2 inhibitors has been underexplored, due to the lengthy synthetic routes and the lack of structure-activity relationship (SAR) studies of these compounds. Herein, we report a concise and stereodivergent synthetic route towards some novel carbasugar SGLT2 inhibitors, featuring an underexploited, regioselective, and stereospecific palladium-catalyzed allyl-aryl coupling reaction.

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Delayed foot wound healing is a major complication attributed to hyperglycemia in type 2 diabetes mellitus (DM) patients, and these wounds may develop into foot ulcers. There are at least two types of DM wound models used in rodents to study delayed wound healing. However, clinically relevant animal models are not common.

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Selective inhibition of the transporter protein sodium-glucose cotransporter 2 (SGLT2) has emerged as a promising way to control blood glucose level in diabetes patients. Reported herein is a short and convergent synthetic route towards some small-molecule SGLT2 inhibitors by a chemo- and diastereospecific palladium-catalyzed arylation reaction. This synthetic strategy enabled the discovery of two highly selective and potent SGLT2 inhibitors, thereby paving the way towards the development of carbasugar SGLT2 inhibitors as potential antidiabetic/antitumor agents.

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Objectives: An anti-osteoporotic herbal formula ELP containing Epimedii Herba (E), Ligustri Lucidi Fructus (L) and Psoraleae Fructus (P) was studied to investigate the herb-herb interaction (or the possible synergistic effect) among each component and to identify the principal herbs in different modes of action.

Methods: Rat osteoblast-like UMR-106 cells proliferation, rat MSCs-derived osteoblastogenesis and RANKL-induced RAW 264.7 osteoclastogenesis were adopted to investigate the bone-forming activity and bone-degrading activity of the herbal extracts.

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Background: The fresh leaves of Eucalyptus globulus Labill. (Lan An) have been used in Chinese medicine for many years to treat dermatomycosis. Macrocarpal C was isolated from this herb and identified as its major antifungal component by bioassay-guided purification.

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Backbround: We investigated the effect of a Chinese 2-herb formula (NF3) on the enumeration and angiogenic differentiation of endothelial progenitor cells (EPCs) in diabetic foot ulcer rats.

Methods: EPCs and stromal cell-derived factor-1α (SDF-1α) were quantified by flow cytometry and ELISA, respectively. In vitro angiogenesis assays included proliferation, adhesion, migration and tube formation.

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Diabetic foot ulcer is closely associated with peripheral vascular disease. Enhancement of tissue oxidative stress, reduction of nitric oxide (NO) and angiogenic growth factors, and abnormal matrix metalloproteinase (MMP) activity are pathophysiological factors in post-ischemic neovascularization and diabetic wound healing. Our previous study demonstrated that the Chinese 2-herb formula, NF3, showed significant wound healing effects on diabetic foot ulcer rats.

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Bakuchiol was an active antifungal compound isolated from Psoraleae Fructus by means of bioassay-guided fractionation in our previous study. The present work aimed to investigate the underlying mechanisms and the therapeutic effect of bakuchiol in Trichophyton mentagrophytes-induced tinea pedis. After exposure to bakuchiol at 0.

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Background: Danshen (Salviae Miltiorrhizae Radix) and Gegen (Puerariae Lobatae Radix) have been used for treating heart disease for several thousand years in China. It has been found that a Danshen and Gegen decoction (DG) exhibiting an anti-atherosclerosis effect, which improves the patients' heart function recovery. Pre-treatment with DG was reported to have protective effects on myocardium against ischemia/reperfusion injury.

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Astragali Radix (AR) and Rehmanniae Radix (RR) have long been used in traditional Chinese Medicine and as the principal herbs in treating diabetic foot ulcer. In this study, we investigated the effect of NF3, which comprises of AR and RR in the ratio of 2:1(w/w), on skin fibroblast cell migration and the activation of selected genes and proteins related to wound healing. Human skin fibroblast cell line Hs27 was treated with NF3 at 4 mg/ml for 24h, and in vitro scratch wound healing and quantitative cell migration assays were performed, respectively.

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Danshen (Salviae Miltiorrhizae Radix) and Gegen (Puerariae Lobatae Radix) have been widely used in treating cardiovascular diseases for thousands of years in China. The present study was carried out to evaluate the effects of a Danshen and Gegen decoction (DG) on the vascular reactivity of a porcine isolated coronary artery and the underlying mechanisms involved. Porcine coronary rings were precontracted with 15 nM U46619.

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This study aimed to investigate and compare the fibroblast-proliferating activities of different Rehmanniae Radix (RR) samples and its chemical components using human normal fibroblast cells Hs27. Those active components were quantified in differently treated RR samples using UPLC so as to correlate activity with component content. Our results showed that dried RR aqueous extract exhibited the most potent fibroblast-proliferating activity.

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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 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.

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Ethnopharmacological Relevance: 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.

Aim Of The Study: 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.

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Ethnopharmacological Relevance: 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.

Aim Of The Study: 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.

Materials And Methods: 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.

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