D

Ding‐Fung Toh

National University of Singapore

Publishes on Ginseng Biological Effects and Applications, Traditional Chinese Medicine Analysis, Metabolomics and Mass Spectrometry Studies. 4 papers and 478 citations.

4Publications
478Total Citations

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Top publicationsby citations

Ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry based metabolomics of raw and steamed <i>Panax notoginseng</i>
Eric Chun Yong Chan, Swee‐Lee Yap, Aik Jiang Lau et al.|Rapid Communications in Mass Spectrometry|2007
Cited by 170

At present, metabolite profiling is of growing importance in herbal medicine fields such as breeding, formulation, quality control and clinical trials. This preliminary study indicated that ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOFMS)-based metabolomics allows direct detection of down-stream derivatives of metabolites, arising from the herbal formulation process. This analytical approach allows the discrimination and tentative authentication of unique biomarkers related to different herbal extracts using unsupervised multivariate principal component analysis (PCA). The tentative identification of biomarkers is complemented significantly by the accurate mass measurement of TOFMS and the high resolution and high retention time reproducibility rendered by UPLC. The application of this approach in herbal extract discrimination and ginsenoside biomarker discovery of raw and steamed Panax notoginseng (Burk.) F.H. Chen is demonstrated and discussed.

Anti-proliferative effects of raw and steamed extracts of Panax notoginseng and its ginsenoside constituents on human liver cancer cells
Ding‐Fung Toh, D Patel, Eric Chun Yong Chan et al.|Chinese Medicine|2011
Cited by 69Open Access

BACKGROUND: Panax notoginseng is a potential source of anticancer compounds. This study aims to investigate the effects of steaming on the chemical profile of P. notoginseng and the anti-proliferative effects of P. notoginseng on liver cancer cells. METHODS: Samples of powdered raw P. notoginseng roots were steamed for various durations. Extracts of the raw and steamed samples were subjected to ultra-high pressure liquid chromatography/mass spectrometry (UHPLC-MS) analysis for chemical profiling. The anti-proliferative effects on three human liver cancer cells, namely SNU449, SNU182 and HepG2, were evaluated using colorimetric WST-1 assay. RESULTS: Steaming changed chromatographic and pharmacological profiles of P. notoginseng, causing differences in activities such as inhibition of cancer growth. Steamed P. notoginseng exhibited greater anti-proliferative effects against liver cancer cells (SNU449, SNU182 and HepG2) than its raw form; steaming up to 24 hours increased bioactivities. Steaming increased the concentrations of ginsenoside Rh2, Rk1, Rk3 and 20S-Rg3 and enhanced growth inhibition of liver cancer cells. CONCLUSION: Steaming changes the chemical profile as well as anti-cancer biological activities of P. notoginseng. Steamed P. notoginseng contains potential compounds for the treatment of liver cancer.