Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Robert Y. Peng is active.

Publication


Featured researches published by Robert Y. Peng.


Bioscience, Biotechnology, and Biochemistry | 2007

Supercritical fluid extracts of rosemary leaves exhibit potent anti-inflammation and anti-tumor effects

Chiung-Huei Peng; Jeng-De Su; Charng-Cherng Chyau; Tzu-Ying Sung; Shin-Shien Ho; Chiung-Chi Peng; Robert Y. Peng

Supercritical fluid SF-CO2 treatment of Rosemarinus officinalis L. fresh leaves under optimum conditions (80 °C at 5,000 psi) yielded 5.3% of extract supercritical fluid extraction (SFE)-80, in which five major active principles were identified by liquid chromatography/mass spectrometry (LC/MS), viz., rosmarinic acid, carnosol, 12-methoxycarnosic acid, carnosic acid, and methyl carnosate. Total phenolic content was 155.8 mg/ gallic acid equivalent (GAE)/g in SFE-80, which showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging of 81.86% at 0.01 mg/ml. When treated in RAW 264.7, apparent dose-dependent NO inhibition occurred at dosages of 1.56 to 6.25 μg/ml, and more drastically at 12.5 and 25 μg/ml. At 0.5 to 5.0 μg/ml, SFE-80 exhibited dose-dependent viability suppression and significant tumor necrosis factor alpha (TNF-α) production in Hep 3B, whereas no effect was found in Chang liver cells. Furthermore, no effect was observed in RAW 264.7 at dosages of 3.13 to 25 μg/ml, indicating that SFE-80 exhibited a noncytotoxic character. Conclusively, rosemary can be considered an herbal anti-inflammatory and anti-tumor agent.


Journal of Agricultural and Food Chemistry | 2008

Optimization of bioactive compounds in buckwheat sprouts and their effect on blood cholesterol in hamsters.

Li-Yun Lin; Chiung Chi Peng; Ya Lu Yang; Robert Y. Peng

Nutrient levels in buckwheats that were maximized in day 8 sprouts (D8SP) included total phenolics, quercetin, and l-ascorbic acid, whereas those of oxalic, malic, tartaric, and citric acids, rutin, and gamma-aminobutyric acid (GABA) were found to reach maximum levels on day 10. Ethanolic extract of D8SP (2.5 mg/mL) revealed potent free-radical scavenging (FRS) and antioxidative (ANO) capabilities. However, its Fe2+-chelating capability was only moderate. To further study the hypolipidemic activity of D8SP, 36 Syrian hamsters were grouped into six groups and fed for 28 days, respectively, with (i) control meal, (ii) high fat plus high cholesterol meal, (iii) high fat plus high cholesterol plus 2.5% of buckwheat seeds, (iv) high fat plus high cholesterol plus 25% of buckwheat seeds, (v) high fat plus high cholesterol plus 2.5% of D8SP, and (vi) high fat plus high cholesterol plus 25% of D8SP. High seed meal prominently enhanced body weight gain, whereas high sprout meal exhibited the highest feed efficiency. Ratios of liver/body weight (L/B) were significantly lowered by all BS meals. Although low seed meal reduced serum total cholesterol (TC) levels (p<0.05), its effect was still inferior to the high seed and sprout meals (p<0.01). In contrast, serum triglyceride (TG) levels were lowered only by the high seed and sprout meals (p<0.05). Alternatively, levels of serum low-density lipoprotein cholesterol (LDL-C) were significantly suppressed by all buckwheat meals (p<0.01). Serum high-density lipoprotein cholesterol (HDL-C) levels were increased, however, insignificantly. Nutraceutically more meaningful is that both LDL-C/HDL-C and TC/HDL-C ratios were significantly lowered (p<0.01). Apparently, hepatic TC levels were significantly reduced, whereas hepatic TG levels were totally unaffected. Conclusively, sprouting triggers a variety of nutritional changes in buckwheats. Day 8 sprouts, consisting of high polyphenolic and moderate quercetin contents, are nutraceutically maximized when hypocholesterolemic, hypotriglyceridemic, and antioxidative activities are concerned.


Natural Product Research | 2008

Relevance of phenolic diterpene constituents to antioxidant activity of supercritical CO2 extract from the leaves of rosemary

Chi-Huang Chang; Charng-Cherng Chyau; Chiu-Lan Hsieh; Yen-ying Wu; Yaw-Bee Ker; Hau-Yang Tsen; Robert Y. Peng

Isolation of phenolic diterpene constituents from the freeze-dried leaves of Rosmarinus officinalis has been obtained by supercritical extraction with carbon dioxide. To determine the ideal conditions for the maximum yield of extract, nine different conditions using three levels of pressures (3000, 4000 and 5000 psi) in combination with three temperatures at 40, 60 and 80°C, respectively, in combination with the analyses of the corresponding antioxidant activities and constituents which existed in extracts has been investigated. The antioxidant activity of each obtained extract was determined by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals test. GC/MS method was used as an alternative to conventional HPLC method for the determination of the principal antioxidant constituents in extract, including phenolic diterpenes carnosic acid (CA) and carnosol (CAL). The confirmation of CA and CAL in extract was forward performed by subjecting HPLC isolates from extract into an ion trap mass spectrometer through an electrospray ionization (ESI) interface for MS/MS analysis. These results indicate that an ideal extraction process was obtained at 5000 psi and 80°C with an extraction yield of 4.27% (w/w) and rich in phenolic antioxidants CA and CAL as contents of 35.23 and 0.46 mg g−1 in extract, respectively.


Journal of Agricultural and Food Chemistry | 2009

Insulin secretagogue bioactivity of finger citron fruit (Citrus medica L. var. Sarcodactylis Hort, Rutaceae).

Chiung-Huei Peng; Yaw-Bee Ker; Ching-Feng Weng; Chiung-Chi Peng; Chien-Ning Huang; Li-Yun Lin; Robert Y. Peng

Finger citron [Citrus medica L. var. Sarcodactylis Hort, Rutaceae] (FC) fruits, widely cultivated in Japan, the southern provinces of China and Taiwan, are commonly used as functional vegetables and preserved as sweetmeats. Previously we identified the major compounds in essential oils (% in EO) of FC fruits to be d-limonene (51.24), gamma-terpenene (33.71), alpha-pinene (3.40), and beta-pinene (2.88). Documented evidence on its insulin secretion characteristics is still lacking. In parallel to compositional analysis, we performed in vivo the safety, hypoglycemic, and antidiabetic tests in Sprague-Dawley-SPF rats and Wistar DIO rats respectively. By kinetic analysis on the hypoglycemic patterns of the intraperitoneal glucose tolerance (IPGTT) and the insulin-glucose tolerance tests (IGTT), its insulin secretagogue effect was confirmed. In conclusion, FC fruits that concomitantly possess insulin secretagogue and slimming effects would be very beneficial to type 2 diabetes mellitus patients.


Nutrition and Cancer | 2007

Brain Derived Metastatic Prostate Cancer DU-145 Cells Are Effectively Inhibited In Vitro by Guava (Psidium gujava L.) Leaf Extracts

Kuan Chou Chen; Chiu Lan Hsieh; Chiung Chi Peng; Hsiu Mei Hsieh-Li; Han Sun Chiang; Kuan Dar Huang; Robert Y. Peng

Abstract: The aqueous extract of Psidium guajava L. (PE) inhibited the cancer cell DU-145 in a dose- and time-dependent manner. At 1.0 mg/mL, PE reduced the viability of PCa DU-145 (the androgen independent PCa cells) to 36.1 and 3.59%, respectively after 48 h and 72 h of incubations. The absolute cell viability suppressing capability (VSC)AC could reach 262.5 cells-mL-h/mg on exposure to PE for 72 h, corresponding to the safe ranges, i.e. the percent viability suppressing rates (PVSR) of 2.72 and 2.41 folds for DU-145 comparing to PZ-HPV-7 cells when treated with PE at 0.5 and 1.0 mg/mL respectively for 72 h. In addition, the colony forming capability of DU-145 cells was apparently lowered. The suppressing rates of which reached 8.09 and 5.96 colony/mg/day for D-145 and PZ-HPV-7 cells, respectively within the concentration range of PE at 0.1 ∼ 0.25 mg/mL. Cell cycle arrests at G0/G1 phase in both cells were observed by TUNEL assay and flow cytometric analysis, yet more prominently evident in DU-145. In addition, suppression of the matrix metalloproteinases MMP-2 and MMP-9, and the upregulation of active caspase-3 at 0.10 to 1.0 mg/mL in DU-145 were also effected in a dose-dependent manner by PE at 0.25 to 1.0 mg/mL, implicating a potent anti-metastasis power of PE. Conclusively, we ascribe the anticancer activity of PE to its extraordinarily high polyphenolic (165.61 ± 10.39 mg/g) and flavonoid (82.85 ± 0.22 mg/g) contents. Furthermore, PE might be useful for treatment of brain derived metastatic cancers such as DU-145, acting simultaneously as both a chemopreventive and a chemotherapeutic.


Nutrition and Cancer | 2007

Unique formosan mushroom Antrodia camphorata differentially inhibits androgen-responsive LNCaP and -independent PC-3 prostate cancer cells.

Kuan Chou Chen; Chiung Chi Peng; Robert Y. Peng; Ching-Hua Su; Han Sun Chiang; Jr Hung Yan; Hsiu Mei Hsieh-Li

Abstract Antrodia camphorata (AC), a precious and unique folkloric medicinal mushroom enriched in polyphenolics, isoflavonoids, triterpenoids, and polysaccharides, has been diversely used in Formosa (Taiwan) since the 18th century. In this study, prostate cancer (PCa) cell lines PC-3 (androgen independent) and LNCaP (androgen responsive) were treated with AC crude extract (ACCE) at 50–200 μ g/mL, respectively, for 48 h. At the minimum effective dose 150 μ g/mL, LNCaP showed a G 1 /S phase arrest with significant apoptosis. Such dose-dependent behavior of LNCaP cells in response to ACCE was confirmed to proceed as Akt → p53→ p21→ CDK4/cyclin D1→ G 1 /S-phase arrest→ apoptosis, which involved inhibiting cyclin D1 activity and preventing pRb phosphorylation. In contrast, being without p53, PC-3 cells showed a G 2 /M-phase arrest mediated through pathway p21→ cyclin B1/Cdc2→ G 2 /M-phase arrest, however, with limited degree of apoptosis, implicating that ACCE is able to differentially inhibit the growth of different PCa cells by modulating different cell cycle signaling pathways. We conclude that this unique Formosan mushroom, A. camphorata, due to its nontoxicity, might be used as a good adjuvant anticancer therapy for prostate cancers despite its androgen-responsive behaviors, which has long been a serious drawback often encountered clinically in hormonal refractory cases treated by antihormonal therapies and chemotherapeutics. *These two authors have contributed equally.


Journal of Agricultural and Food Chemistry | 2008

Alpinia zerumbet potentially elevates high-density lipoprotein cholesterol level in hamsters

Li-Yun Lin; Chiung Chi Peng; Yu Jing Liang; Wan Ting Yeh; Hui Er Wang; Tung Hsi Yu; Robert Y. Peng

In folkloric plant medicines, Alpinia zerumbet (AZ) has been popularly recognized as an exellent hepatoprotector. To search for a good high-density lipoprotein cholesterol (HDL-C) elevating herbal preparation, we examined AZ for its antioxidant and hypolipidaemic bioactivities, especially its HDL-C elevating activity. AZ seeds contain 0.51% essential oils (SO), which are comprised of monoterpenoids, oxygenated monoterpenoids, sesquiterpenoids, oxygenated sesquiterpenoids, aldehydes, acid, and esters. Gas chromatography/mass spectrometry analysis indicated that most of the monoterpenes and sesquiterpenes were recoverable in pentane eluent, whilst the oxygenated monoterpenoids and sesquiterpenoids remained in ether eluent. The high contents of rutin, quercetin, and polyphenolics in ethanolic extract of AZ seeds exhibit moderate antilipoperoxidative but potent DPPH free radical scavenging bioactivities. Conclusively, both seed powder (SP) and SO are effective hypolipidaemics with amazingly potent HDL-C elevating capabilities. On the basis of hepatoprotectivity, SP is a more feasible hypolipidemic agent as well as a promising HDL-C elevating plant medicine.


BioMed Research International | 2013

Cytotoxicity of Ferulic Acid on T24 Cell Line Differentiated by Different Microenvironments

Chiung Chi Peng; Charng Cherng Chyau; Hui Er Wang; Chi Huang Chang; Kuan Chou Chen; Kuang Yu Chou; Robert Y. Peng

Ferulic acid (4-hydroxy-3-methoxycinnamic acid) (FA) is a ubiquitous health beneficial phenolic acid. Although FA has shown a diversity of biological activities including anti-inflammatory, antihypercholesterolemic and anticancer bioactivities, studies revealing its adverse effects are accumulating. Recently, 3D-cultures are shown to exhibit uniquely biological behaviors different from that of 2D cultures. To understand whether the cytotoxicity of FA against the T24 cell line (a bladder cancer cell line) in 2D-culture could consistently retain similar bioactivity if cultured in the 3D-systems, we conducted this experiment with 2 mM FA. Much higher cytotoxicity was found for 3D- than 2D-culture, showing (2D vs. 3D): apoptotic rates, 64% and 76%; cell killing rates, 3.00 × 105 cells mmol−1·h−1 and 2.63 × 106 cells mmol−1·h−1, attaining a 8.77-fold. FA upregulated the activities at 72 h (2D vs. 3D in folds that of control): SOD, 1.73-folds (P < 0.05) versus 3.18 folds (P < 0.001); and catalase, 2.58 versus 1.33-folds. Comparing to the control (without FA), Bcl-2 was prominently downregulated while Bax, caspase-3 and cleaved caspase-9 were more upregulated in 3D-cultures (P < 0.05). Conclusively, different microenvironments could elicit different biological significance which in part can be ascribed to different mass transport rate.


Journal of Agricultural and Food Chemistry | 2010

Quercetin and ferulic acid aggravate renal carcinoma in long-term diabetic victims

Chiu Lan Hsieh; Chiung Chi Peng; Yu Ming Cheng; Li-Yun Lin; Yaw Bee Ker; Chi Huang Chang; Kuan Chou Chen; Robert Y. Peng

Many phytoantioxidants have therapeutic drawbacks due to their potent prooxidant bioactivity. It is hypothesized that phytoantioxidants (PAO) are beneficial only to the early-stage diabetes mellitus (DM) and will become ineffective once renopathy occurs. Gallic acid, rutin, EGCG, ferulic acid (FA), and quercetin were tried on the streptozotocin (STZ)-induced DM rat model for a 28 week experimental period. All of these PAO were shown to be ineffective for hypoglycemic action. The incidence of cataract (50%), injured glomerules, and renal cell carcinoma (RCC) was very common, among which the most severely affected involved the quercetin- and the FA-treated groups. The tumorigenicity of ferulic acid is still unclear. However, for quercetin, this can be attributted to (i) the prooxidant effect, (ii) the insulin-secretagogue bioactivity, and (iii) the competitive and noncompetitive inhibition on the O-methyltransferase to enhance the estradiol-induced tumorigenesis. Conclusively, quercetin and FA are able to aggravate, if not induce, nephrocarcinoma. It is time to reevaluate the tumorigenic detrimental effect of PAO, especially those exhibiting prooxidant bioactivity.


Clinical Nutrition | 2012

Ferulic acid is nephrodamaging while gallic acid is renal protective in long term treatment of chronic kidney disease

Chiung Chi Peng; Chiu Lan Hsieh; Hui Er Wang; Jin Yuan Chung; Kuan Chou Chen; Robert Y. Peng

BACKGROUNDS & AIMS The long term therapeutic effect of ferulic acid (FA) and gallic acid (GA) in treatment of chronic kidney disease (CKD) has been lacking. METHODS Doxorubicin (DR, Adriamycin)-induced CKD rat model was established for this study. RESULTS DR significantly reduced levels of serum albumin, GOT, GPT, RBC, TNF-α, and urinary creatinine and elevated serum cholesterol, TG, BUN, creatinine, uric acid, WBC, platelet count, and IL-6. In DRCKD rats, FA and GA significantly increased kidney weight and glomerular volume. FA reduced glomerular filtration rate but GA did not. FA enhanced more collagen deposition than GA in renal cortex and glomeruli. Both FA and GA showed crucial hyperlipidemic activity. The inhibitory effects of FA and GA on MMP-2 were very comparable. GA suppressed MMP-2 more effectively than FA in DRCKD rats. Both FA and GA induced SOD elevation and MDA elimination. In DRCKD rats, Western blot analysis indicated that FA further up-regulated CD34, α-SMA, tissue pDGFR, p-PDGFR, and TGF-β; and down-regulated p-PI3K, and p-Akt. Since both PDGF-BB and TGF-β are considered to induce kidney prefibrosis stage, GA was proved to be more beneficial in this regard. CONCLUSIONS GA tends to protect the CKD while FA is not recommended for the long term CKD therapy.

Collaboration


Dive into the Robert Y. Peng's collaboration.

Top Co-Authors

Avatar

Chiung Chi Peng

Taipei Medical University

View shared research outputs
Top Co-Authors

Avatar

Kuan Chou Chen

Taipei Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Chiu Lan Hsieh

National Changhua University of Education

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Chiu Lan Hsieh

National Changhua University of Education

View shared research outputs
Researchain Logo
Decentralizing Knowledge