Recent advances on the beneficial use and health implications of Pu-Erh tea L.K. Lee a, b , K.Y. Foo b, c, ⁎ a Nutrition Programme, School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia b River Engineering and Urban Drainage Research Centre (REDAC), Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia c Environment and Occupational Health Programme, School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia abstract article info Article history: Received 31 August 2012 Received in revised form 18 February 2013 Accepted 21 February 2013 Keywords: Adsorption Antimicrobial Antimutagenic Antioxidative Hypocholesterolemic Pu-Erh tea Pu-Erh tea (PET) is a fully fermented tea cultivated in the Yunnan Province of China. It is widely appreciated and consumed as the healthful beverage. In vivo, in vitro and clinical studies have suggested the health benefits of PET for a variety of hypolipidemic, antiobesity, antimutagenic, antioxidative, antitumor, free radical scavenging and toxicity suppressing activities. Many of these beneficial impacts are related to its bioactive compounds, particu- larly theabrownin and gallic acid. However, there are some scientific evidences underlying the risk of patholog- ical abnormalities associated with the high doses of PET extracts. Confirming the assertion, this paper presents a state of art review of PET, its tasting, sensory evaluation and aroma characterization. The key advances of its wide implications in the adsorption engineering, toxicological, pharmacological and medical science development are laconically elucidated. Furthermore, the challenges and future prospects for the integration of PET practice are outlined. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction Taxonomically, Pu-Erh (Camellia sinensis var. Assamica), locally revered as “historical tea”, is a dicotyledonous tropical and subtropical seasonal plant species belonging to the family theaceae and genus of Camellia (Zhao, Zhang et al., 2011). Pu-Erh refers to the processed leaves and buds from a broad-leaf variety of tea plant native to the Upper Mekong River Region of China (Ming & Zhang, 1996). Histori- cally, the socio-linguistic groups in Yunnan Province, Bulang (Blang), Wa, Akha (Hani), Lahu, Yao, Hmong (Miao), Jinuo, De'ang, Dai, and Han, believed that this tea plant was left to them by the Prime Minister of Shu, Zhugeliang, during the Three Kingdoms period (A.C. 220 to 280). Since then, tea leaves were harvested from tea forests found on the Six Famous Tea Mountains of southern Yunnan. The customary use of Pu-Erh tea (PET) as salad, vegetables and snacks eaten together with betel nut, core foods during the annual harvest celebration has been widely documented (Ahmed et al., 2010). Today, PET tasting has become a social practice that emphasizes shared sensory experience, wellbeing, and alertness. This practice has developed prominence over the past two decades in response to Food Research International 53 (2013) 619–628 Abbreviations: AGE, Advanced glycation end products; AFB 1 ,Aflatoxin B 1 ; ALT, Alanine aminotransferase; ANOVA, Analysis of variance; AST, Aspartate amino-transferase; BMI, Body mass index; BW, Body weight; CCl 4 , Carbon tetrachloride; CVD, Cardiovascular disease; CHO, Chinese hamster ovary; CHD, Coronary heart disease; COX-2, Cyclo-oxygenase-2; EDDI, Daily dietary intake; DMEM, Dulbecco/Vogt modified Eagle's minimal essential; ELISA, Enzyme-linked immunosorbent assay; EC, Epicatechin; EGC, Epigallocatechin; ECG, Epicatechin 3-gallate; EGFR, Epidermal growth factor receptor; EGCG, Epigallocatechin gallate; FAS, Fatty acid syntase; FRAP, Ferric Reducing Antioxidant Power; GA, Gallic acid; GC, Gallocatechin; GCMS, Gas chromatography mass spectrometry; GC-O, Gas chromatography olfactometry; GOT, Glutamate oxaloacetate transaminase; GPT, Glutamate pyruvate transaminase; GSH, Glutathione; GPX, Glutathione peroxidase; GR, Glutathione reductase; GST, Glutathione transferase; IC 50 , Half maximal inhibitory concentration; HSSPME, Headspace-solid phase microextraction; HL, Hepatic lipase; HBeAg, Hepatitis B “e” antigen; HBV, Hepatitis B Virus; HDL, High density lipoprotein; HFD, High-fat-diet; HPLC, High performance liquid chromatography; HMEC, Human micro-vascular endothelial cell; H 2 O 2 , Hydrogen peroxide; iNOS, Inducible nitric oxide synthase; ICP-AES, Inductively coupled plasma atomic emission spectrometry; IL-6, Interleukine-6; ISE, Ion-selective electrode; KA, Kainic acid; LD 50 , Lethal dose of 50; LPS, Lipopolysaccharide; LC-DAD-MS/ MS-BCD, Liquid chromatography-diode array detection-tandem mass spectrometry and biochemical detection; LDL, Low-density lipoprotein; MDA, Malondialdehyde; MV, Methyl violet; MAPKs, Mitogen-activated protein kinases; MEFs, Mouse embryo fibroblasts; NO, Nitric oxide; NOAEL, No-observed-adverse-effect-level; PC12, Pheochromacytoma 12; PI3K, Phosphatidylinositol-3-kinase; PVA-PET, Polyvinyl alcohol-extract of PET; PVA-PTP, Polyvinyl alcohol-PET powder; PET, Pu-Erh tea; QCT, Quinocetone; RhoA, Ras homolog gene family member A; ROS, Reactive oxygen species; RT-PCR, Real-time polymerase chain reaction; SAM, Senescence-accelerated mouse; SD, Sprague–Dawley; SOD, Superoxide dismutase; t-BHP, Tert-butyl-hydroperoxide; TB, Theabrownin; TFs, Theaflavins; TBARS, Thiobarbituric acid reactive substances; TCC, Total catechin content; TC, Total cholesterol; TMC, Total methylxanthine content; TQS, Total quality score; TVBN, Total volatile base nitrogen; TG, Triglyceride; WHR, Waist hip ratio; GABA, γ-aminobutyric acid; DPPH, 1,1-diphenyl-2-picrylhydrazyl radical; ABTS, 2,2′-azinobis (3 ethylbenzthiazolinesulfonic acid) diammonium salt; MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide; NQNO, 4-nitroquinoline-N-oxide; 8-OHdG, 8-hydroxy 2-deoxyguanosine. ⁎ Corresponding author at: Environment and Occupational Health Programme, School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia. Tel.: +60 97677824, +6045945874; fax: +60 97677515, +60 45941011. E-mail addresses: k.y.foo@kk.usm.my, redacfoo@eng.usm.my (K.Y. Foo). 0963-9969/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodres.2013.02.036 Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres