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Dive into the research topics where Janis Ya-Xian Zhan is active.

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Featured researches published by Janis Ya-Xian Zhan.


Journal of Agricultural and Food Chemistry | 2011

Flavonoids from Radix Astragali Induce the Expression of Erythropoietin in Cultured Cells: A Signaling Mediated via the Accumulation of Hypoxia-Inducible Factor-1α

Ken Y.Z. Zheng; Roy Chi Yan Choi; Anna Wing Han Cheung; Ava J. Y. Guo; Cathy W. C. Bi; Kevin Y. Zhu; Qiang Fu; Yingqing Du; Wendy L. Zhang; Janis Ya-Xian Zhan; Ran Duan; David Tai Wai Lau; Tina Ting Xia Dong; Karl Wah Keung Tsim

Radix Astragali (RA) is commonly used as a health food supplement to reinforce the body vital energy. Flavonoids, including formononetin, ononin, calycosin, and calycosin-7-O-β-d-glucoside, are considered to be the major active ingredients within RA. Here, we provided different lines of evidence that the RA flavonoids stimulated the expression of erythropoietin (EPO), the central regulator of red blood cell mass, in cultured human embryonic kidney fibroblasts (HEK293T). A plasmid containing hypoxia response element (HRE), a critical regulator for EPO transcription, was tagged upstream of a firefly luciferase gene, namely, pHRE-Luc, which was being transfected into fibroblasts. The application of RA flavonoids onto the transfected cells induced the transcriptional activity of HRE. To account for the transcriptional activation after the treatment of flavonoids, the expression of hypoxia-inducible factor-1α (HIF-1α) was markedly increased: The increase was in both mRNA and protein levels. In addition, the degradation of HIF-1α was reduced under the effect of flavonoids. The regulation of HIF-1α therefore could account for the activation of EPO expression mediated by the RA flavonoids. The current results therefore reveal the function of this herb in enhancing hematopoietic functions.


Journal of Agricultural and Food Chemistry | 2013

Chemical and Biological Assessment of Ziziphus jujuba Fruits from China: Different Geographical Sources and Developmental Stages

Jianping Chen; Zhonggui Li; Maitinuer Maiwulanjiang; Wendy L. Zhang; Janis Ya-Xian Zhan; Candy Ting Wai Lam; Kevin Y. Zhu; Ping Yao; Roy Chi Yan Choi; David Tai Wai Lau; Tina Ting Xia Dong; Karl Wah Keung Tsim

Chinese date, the fruit of Ziziphus jujuba Mill., has thousands of years cultivation history, and about 700 cultivars of dates in China. Two types of dates are commonly found in the market: (i) fresh immature dates consumed as fruits, and (ii) dried mature dates used as Chinese medicines. Here, chemical and biological properties of these dates were revealed. Different sources of dates showed similar chemical profiles; however, the amounts of identified chemicals showed a great variation. The amount of nucleotides, flavonoids and polysaccharides in dates could be affected by its maturity and drying process. In parallel, the antioxidative functions of their extracts were compared. The date extracts protected PC12 cells against tBHP-induced cytotoxicity, and which also stimulated the transcriptional activity of antioxidant response element. The antioxidative effects were varied among different dates. The current results suggested the optimization of sources and specific usage of different maturity dates.


Journal of Agricultural and Food Chemistry | 2011

Chemical and biological assessment of Angelicae Sinensis Radix after processing with wine: an orthogonal array design to reveal the optimized conditions.

Janis Ya-Xian Zhan; Ken Yu Zhong Zheng; Kevin Y. Zhu; Cathy W. C. Bi; Wendy L. Zhang; Crystal Ying Qing Du; Qiang Fu; Tina Ting Xia Dong; Roy Chi Yan Choi; Karl Wah Keung Tsim; David Tai Wai Lau

The roots of Angelica sinensis [Angelica Sinensis Radix (ASR)] have been used as a common health food supplement for womens care for thousands of years in China. According to Asian tradition, ASR could be processed with the treatment of wine, which subsequently promoted the biological functions of ASR. By chemical and biological assessments, an orthogonal array design was employed here to determine the roles of three variable parameters in the processing of ASR, including oven temperature, baking time, and flipping frequency. The results suggested that oven temperature and baking time were two significant factors, while flipping frequency was a subordinate factor. The optimized condition of processing with wine therefore was considered to be heating in an oven at 80 °C for 90 min with flipping twice per hour. Under the optimized processing conditions, the solubilities of ferulic acid and Z-ligustilide from ASR were markedly increased and decreased, respectively. In parallel, the biological functions of processed ASR were enhanced in both anti-platelet aggregation and estrogenic activation; these increased functions could be a result of the altered levels of ferulic acid and Z-ligustilide in wine-processed ASR. Thus, the chemical and biological assessment of the processed ASR was in full accordance with the Chinese old tradition.


Journal of Agricultural and Food Chemistry | 2014

A Standardized Extract of the Fruit of Ziziphus jujuba (Jujube) Induces Neuronal Differentiation of Cultured PC12 Cells: A Signaling Mediated by Protein Kinase A

Jianping Chen; Maitinuer Maiwulanjiang; Kelly Yin Ching Lam; Wendy L. Zhang; Janis Ya-Xian Zhan; Candy Ting Wai Lam; Sherry L. Xu; Kevin Y. Zhu; Ping Yao; David Tai Wai Lau; Tina Ting Xia Dong; Karl Wah Keung Tsim

The fruit of Ziziphus jujuba Mill., known as Chinese date or jujube, is consumed as a health supplement worldwide. To study the role of jujube in brain benefits, its effects on neuronal differentiation of PC12 cells were studied. Application of jujube water extract induced neurite outgrowth of PC12 cells, >25% of which were differentiated; this effect was similar to that of nerve growth factor. In parallel, the expressions of neurofilaments (NFs) in jujube-treated cultures showed a dose-dependent increase, with the highest inductions by ∼150% for NF68 and NF160 and by ∼100% for NF200. Application of H89, a protein kinase A inhibitor, attenuated jujube-induced neurite outgrowth of the cultures. Besides, using jujube extract induced the phosphorylation of cAMP responsive element binding protein on PC12 cells, which was blocked by H89. These results support the use of jujube as a food supplement for the prevention of neurodegenerative diseases in which neurotrophin deficiency is involved.


European Journal of Pharmacology | 2012

Salidroside stimulates the accumulation of HIF-1α protein resulted in the induction of EPO expression: A signaling via blocking the degradation pathway in kidney and liver cells

Ken Yuzhong Zheng; Zhenxia Zhang; Ava J. Y. Guo; Cathy Wen-Chuang Bi; Kevin Y. Zhu; Sherry Li Xu; Janis Ya-Xian Zhan; David T W Lau; Tina Ting Xia Dong; Roy Chi Yan Choi; Karl Wah Keung Tsim

Rhodiolae Crenulatae Radix et Rhizoma (Rhodiola), the root and rhizome of Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba, has been used as a traditional Chinese medicine (TCM) to increase the body resistance to mountain sickness in preventing hypoxia; however, the functional ingredient responsible for this adaptogenic effect has not been revealed. Here, we have identified salidroside, a glycoside predominantly found in Rhodiola, is the chemical in providing such anti-hypoxia effect. Cultured human embryonic kidney fibroblast (HEK293T) and human hepatocellular carcinoma (HepG2) were used to reveal the mechanism of this hematopoietic function mediated by salidroside. The application of salidroside in cultures induced the expression of erythropoietin (EPO) mRNA from its transcription regulatory element hypoxia response element (HRE), located on EPO gene. The application of salidroside stimulated the accumulation of hypoxia-inducible factor-1α (HIF-1α) protein, but not HIF-2α protein: the salidroside-induced HIF-1α protein was via the reduction of HIF-1α degradation but not the mRNA induction. The increased HIF-1α could account for the activation of EPO gene. These results supported the notion that hematopoietic function of Rhodiola was triggered, at least partially, by salidroside.


Journal of Ethnopharmacology | 2014

Prevention of UV radiation-induced cutaneous photoaging in mice by topical administration of patchouli oil

Rong-Feng Lin; Xue-Xuan Feng; Chu-Wen Li; Xiao-Jun Zhang; Xiu-Ting Yu; Jiu-Yao Zhou; Xie Zhang; You-Liang Xie; Zi-Ren Su; Janis Ya-Xian Zhan

ETHNOPHARMACOLOGICAL RELEVANCE Pogostemon cablin has been widely used in traditional Chinese medicine for the treatment of many diseases, including skin disorders. In the skin beauty and care prescriptions, Pogostemon cablin is one of the top ten frequently used traditional Chinese medicines. AIM OF THE STUDY The present study was aimed to investigate the protective effects of the essential oil of Pogostemon cablin (patchouli oil, PO) against UV-induced skin photoaging in mice. MATERIALS AND METHODS To ensure the quality of PO, the chemical compositions of PO were identified, and the content of its chemical marker patchouli alcohol was determined, which was around 28.2% (g/g) in PO. During the experiment period, the dorsal depilated skin of mice was treated with PO for two hours prior to UV irradiation. Then the protective effects of PO on UV-induced skin photoaging were determined by macroscopic and histological evaluations, skin elastic test, collagen content determination and biochemical assays of malondiaidehyde (MDA) content, activities of anti-oxidative indicators including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT). RESULTS Compared to UV exposure groups, present results showed that topical administration of PO, especially at dose of 6mg/mouse and 9mg/mouse, significantly inhibited the increase in skin wrinkle formation, alleviated the reduction in skin elasticity and increased the collagen content by about 21.9% and 26.3%, respectively. We also found that application of 6-9mg/mouse PO could not only decrease the epidermal thickness by about 32.6%, but also prevent the UV-induced disruption of collagen fibers and elastic fibers. Furthermore, the content of MDA was decreased by almost 26.5% and activities of SOD, GSH-Px and CAT were significantly up-regulated after the treatment of PO. CONCLUSION Results of present study revealed that PO was capable of maintaining skin structural integrity caused by UV irradiation and it was useful in preventing photoaging. These protective effects of PO were possibly due to its anti-oxidative property. Therefore, we suggested that PO should be viewed as a potential therapeutic agent for preventing photoaging.


Chemico-Biological Interactions | 2010

PRiMA directs a restricted localization of tetrameric AChE at synapses.

Heidi Qunhui Xie; K. Wing Leung; Vicky P. Chen; Gallant K. L. Chan; Sherry L. Xu; Ava J. Y. Guo; Kevin Y. Zhu; Ken Y.Z. Zheng; Cathy W. C. Bi; Janis Ya-Xian Zhan; Wallace K.P. Chan; Roy Chi Yan Choi; Karl Wah Keung Tsim

Acetylcholinesterase (AChE), a highly polymorphic enzyme with various splicing variants and molecular isoforms, plays an essential role in the cholinergic neurotransmission by hydrolyzing acetylcholine into choline and acetate. The AChE(T) variant is expressed in the brain and muscle: this subunit forms non-amphiphilic tetramers with a collagen tail (ColQ) as asymmetric AChE (A(12) AChE) in muscle, and amphiphilic tetramers with a proline-rich membrane anchor (PRiMA) as globular AChE (G(4) AChE) in the brain and muscle. During the brain development, the expression of amphiphilic G(4) AChE is up regulated and becomes the predominant form of AChE there. This up-regulation of G(4) AChE can be attributed to the increased expressions of both AChE(T) and PRiMA. A significant portion of this membrane-bound G(4) AChE is localized at the membrane rafts of the cell membranes derived from the brain. This raft association could be directed by PRiMA via its CRAC (cholesterol recognition/interaction amino acid consensus) motif and C-terminus. In cultured cortical neurons and muscles, the PRiMA-linked AChE was clustered and partially co-localized with synaptic proteins. The restricted localizations suggest that the raft association of PRiMA-linked AChE could account for its synaptic localization and function.


Planta Medica | 2014

The Extract of Ziziphus jujuba Fruit (Jujube) Induces Expression of Erythropoietin Via Hypoxia-Inducible Factor-1α in Cultured Hep3B Cells

Jianping Chen; Candy Ting Wai Lam; Ava Y.Y. Kong; Wendy L. Zhang; Janis Ya-Xian Zhan; Cathy W. C. Bi; Gallant K. L. Chan; Kelly Yin Ching Lam; Ping Yao; Tina Ting Xia Dong; Karl Wah Keung Tsim

The fruit of Ziziphus jujuba Mill., known as jujube or Chinese date, is commonly consumed as health supplement or herbal medicine worldwide. To study the beneficial role of jujube in enhancing hematopoietic function, we investigated its roles on the expression of erythropoietin in cultured Hep3B human hepatocellular carcinoma cells. Application of chemically standardized jujube water extract stimulated erythropoietin expression in a dose-dependent manner, with the highest response by ~ 100 % of increase. A plasmid containing hypoxia response element, a critical regulator for erythropoietin transcription, was transfected into Hep3B cells. Application of jujube water extract onto the transfected cells induced the transcriptional activity of the hypoxia response element. To account for its transcriptional activation, the expression of hypoxia-inducible factor-1α was increased after treatment with jujube water extract: the increase was in both mRNA and protein levels. These results confirmed the hematopoietic function of jujube in the regulation of erythropoietin expression in liver cells.


Phytomedicine | 2014

The sulfur-fumigation reduces chemical composition and biological properties of Angelicae Sinensis Radix.

Janis Ya-Xian Zhan; Ping Yao; Cathy Wenchuan Bi; Ken Yuzhong Zheng; Wendy L. Zhang; Jianping Chen; Tina Ting Xia Dong; Zi-Ren Su; Karl Wah Keung Tsim

Angelica Sinensis Radix (roots of Angelica sinensis; ASR) is a popular herbal supplement in China for promoting blood circulation. Today, sulfur-fumigation is commonly used to treat ASR as a means of pest control; however, the studies of sulfur-fumigation on the safety and efficacy of ASR are very limited. Here, we elucidated the destructive roles of sulfur-fumigation on ASR by chemical and biological assessments. After sulfur-fumigation, the chemicals in ASR were significantly lost. The biological activities of anti-platelet aggregation, induction of NO production and estrogenic properties were compared between the water extracts of non-fumigated and sulfur-fumigated ASR. In all cases, the sulfur-fumigation significantly reduced the biological properties of ASR. In addition, application of water extract deriving from sulfur-fumigated ASR showed toxicity to cultured MCF-7 cells. In order to ensure the safety and to achieve the best therapeutic effect, it is recommended that sulfur-fumigation is an unacceptable approach for processing herbal materials.


Evidence-based Complementary and Alternative Medicine | 2013

Chemical and biological assessment of angelica roots from different cultivated regions in a chinese herbal decoction danggui buxue tang.

Wendy L. Zhang; Ken Y.Z. Zheng; Kevin Y. Zhu; Janis Ya-Xian Zhan; Cathy W. C. Bi; Jian-Nan Chen; Tina Ting Xia Dong; Roy Chi Yan Choi; David Tai Wai Lau; Karl Wah Keung Tsim

Roots of Angelica sinensis (Danggui) have been used in promoting blood circulation as herbal medicine for over 2000 years in China. Another species of Angelica roots called A. gigas is being used in Korea. To reveal the efficiency of different Angelica roots, the chemical and biological properties of Angelica roots from different cultivated regions were compared. Roots of A. sinensis contained higher levels of ferulic acid, Z-ligustilide, and senkyunolide A, while high amounts of butylphthalide and Z-butylenephthalide were found in A. gigas roots. The extracts deriving from A. gigas roots showed better effects in osteogenic and estrogenic properties than that of A. sinensis from China. However, this difference was markedly reduced when the Angelica roots were being prepared in a Chinese herbal decoction together with Astragali Radix as Danggui Buxue Tang. In contrast, the herbal decoction prepared from A. sinensis roots showed better responses in cell cultures. In addition, the extracts of A. gigas roots showed strong cell toxicity both as single herb and as Danggui Buxue Tang. This result revealed the distinct properties of Angelica roots from China and Korea suggesting the specific usage of herb in preparing a unique herbal decoction.

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Karl Wah Keung Tsim

Hong Kong University of Science and Technology

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Wendy L. Zhang

Hong Kong University of Science and Technology

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Tina Ting Xia Dong

Hong Kong University of Science and Technology

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Kevin Y. Zhu

Hong Kong University of Science and Technology

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Jianping Chen

Hong Kong University of Science and Technology

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David Tai Wai Lau

Hong Kong University of Science and Technology

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Roy Chi Yan Choi

Hong Kong University of Science and Technology

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Zi-Ren Su

Guangzhou University of Chinese Medicine

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Cathy W. C. Bi

Hong Kong University of Science and Technology

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Ping Yao

Hong Kong University of Science and Technology

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