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Chu KO, Yip YWY, Chan KP, Wang CC, Ng DSC, Pang CP. Amelioration of Functional, Metabolic, and Morphological Deterioration in the Retina following Retinal Detachment by Green Tea Extract. Antioxidants (Basel) 2024; 13:235. [PMID: 38397833 PMCID: PMC10886023 DOI: 10.3390/antiox13020235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Retinal detachment (RD) can result in the loss of photoreceptors that cause vision impairment and potential blindness. This study explores the protective effects of the oral administration of green tea extract (GTE) in a rat model of RD. Various doses of GTE or epigallocatechin gallate (EGCG), the most active ingredient in green tea catechins, were administered to Sprague Dawley (SD) rats with experimentally induced retinal detachment. The rats received sub-retinal injections of hyaluronic acid (0.1%) to induce RD and were given different doses of GTE and EGCG twice daily for three days. Notably, a low dose of GTE (142.9 mg/kg) caused significantly higher signal amplitudes in electroretinograms (ERGs) compared to higher GTE doses and any doses of EGCG. After administration of a low dose of GTE, the outer nuclear layer thickness, following normalization, of the detached retina reduced to 82.4 ± 8.2% (Mean ± SEM, p < 0.05) of the thickness by RD treatment. This thickness was similar to non-RD conditions, at 83.5 ± 4.7% (Mean ± SEM) of the thickness following RD treatment. In addition, the number of TUNEL-positive cells decreased from 76.7 ± 7.4 to 4.7 ± 1.02 (Mean ± SEM, p < 0.0001). This reduction was associated with the inhibition of apoptosis through decreased sphingomyelin levels and mitigation of oxidative stress shown by a lowered protein carbonyl level, which may involve suppression of HIF-1α pathways. Furthermore, GTE showed anti-inflammatory effects by reducing inflammatory cytokines and increasing resolving cytokines. In conclusion, low-dose GTE, but not EGCG, significantly alleviated RD-induced apoptosis, oxidative stress, inflammation, and energy insufficiency within a short period and without affecting energy metabolism. These findings suggest the potential of low-dose GTE as a protective agent for the retina in RD.
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Affiliation(s)
- Kai On Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; (K.O.C.); (Y.W.Y.Y.); (K.P.C.)
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong, China;
| | - Yolanda Wong Ying Yip
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; (K.O.C.); (Y.W.Y.Y.); (K.P.C.)
| | - Kwok Ping Chan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; (K.O.C.); (Y.W.Y.Y.); (K.P.C.)
| | - Chi Chiu Wang
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong, China;
| | - Danny Siu Chun Ng
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; (K.O.C.); (Y.W.Y.Y.); (K.P.C.)
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; (K.O.C.); (Y.W.Y.Y.); (K.P.C.)
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Zhu L, Zhang C, Zhang W, Xia Q, Ma J, He X, He Y, Fu PP, Jia W, Zhuge Y, Lin G. Developing urinary pyrrole-amino acid adducts as non-invasive biomarkers for identifying pyrrolizidine alkaloids-induced liver injury in human. Arch Toxicol 2021; 95:3191-3204. [PMID: 34390356 PMCID: PMC8364305 DOI: 10.1007/s00204-021-03129-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/29/2021] [Indexed: 01/24/2023]
Abstract
Pyrrolizidine alkaloids (PAs) have been found in over 6000 plants worldwide and represent the most common hepatotoxic phytotoxins. Currently, a definitive diagnostic method for PA-induced liver injury (PA-ILI) is lacking. In the present study, using a newly developed analytical method, we identified four pyrrole-amino acid adducts (PAAAs), namely pyrrole-7-cysteine, pyrrole-9-cysteine, pyrrole-9-histidine, and pyrrole-7-acetylcysteine, which are generated from reactive pyrrolic metabolites of PAs, in the urine of PA-treated male Sprague Dawley rats and PA-ILI patients. The elimination profiles, abundance, and persistence of PAAAs were systematically investigated first in PA-treated rat models via oral administration of retrorsine at a single dose of 40 mg/kg and multiple doses of 5 mg/kg/day for 14 consecutive days, confirming that these urinary excreted PAAAs were derived specifically from PA exposure. Moreover, we determined that these PAAAs were detected in ~ 82% (129/158) of urine samples collected from ~ 91% (58/64) of PA-ILI patients with pyrrole-7-cysteine and pyrrole-9-histidine detectable in urine samples collected at 3 months or longer times after hospital admission, indicating adequate persistence time for use as a clinical test. As direct evidence of PA exposure, we propose that PAAAs can be used as a biomarker of PA exposure and the measurement of urinary PAAAs could be used as a non-invasive test assisting the definitive diagnosis of PA-ILI in patients.
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Affiliation(s)
- Lin Zhu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chunyuan Zhang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Wei Zhang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Qingsu Xia
- National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xin He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yisheng He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Peter P Fu
- National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Wei Jia
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Yuzheng Zhuge
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China.
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
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Wang N, Wang S, Li MY, Hu BG, Liu LP, Yang SL, Yang S, Gong Z, Lai PBS, Chen GG. Cancer stem cells in hepatocellular carcinoma: an overview and promising therapeutic strategies. Ther Adv Med Oncol 2018; 10:1758835918816287. [PMID: 30622654 PMCID: PMC6304707 DOI: 10.1177/1758835918816287] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/06/2018] [Indexed: 12/12/2022] Open
Abstract
The poor clinical outcome of hepatocellular carcinoma (HCC) patients is ascribed to the resistance of HCC cells to traditional treatments and tumor recurrence after curative therapies. Cancer stem cells (CSCs) have been identified as a small subset of cancer cells which have high capacity for self-renewal, differentiation and tumorigenesis. Recent advances in the field of liver CSCs (LCSCs) have enabled the identification of CSC surface markers and the isolation of CSC subpopulations from HCC cells. Given their central role in cancer initiation, metastasis, recurrence and therapeutic resistance, LCSCs constitute a therapeutic opportunity to achieve cure and prevent relapse of HCC. Thus, it is necessary to develop therapeutic strategies to selectively and efficiently target LCSCs. Small molecular inhibitors targeting the core stemness signaling pathways have been actively pursued and evaluated in preclinical and clinical studies. Other alternative therapeutic strategies include targeting LCSC surface markers, interrupting the CSC microenvironment, and altering the epigenetic state. In this review, we summarize the properties of CSCs in HCC and discuss novel therapeutic strategies that can be used to target LCSCs.
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Affiliation(s)
- Nuozhou Wang
- Department of Surgery, The Chinese University of
Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR,
China
| | - Shanshan Wang
- Department of Otorhinolaryngology, Head and Neck
Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Prince of
Wales Hospital, Hong Kong, China
| | - Ming-Yue Li
- Department of Surgery, Faculty of Medicine, The
Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong,
China
- Shenzhen Research Institute, The Chinese
University of Hong Kong, Shenzhen, Guangdong, China
| | - Bao-guang Hu
- Department of Gastrointestinal Surgery, The
Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong,
China
| | - Li-ping Liu
- Department of Hepatobiliary and Pancreas
Surgery, The Second Clinical Medical College of Jinan University (Shenzhen
People’s Hospital), Shenzhen, Guangdong Province, China
| | - Sheng-li Yang
- Cancer Center, Union Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, China
| | - Shucai Yang
- Department of Clinical Laboratory, Pingshan
District People’s Hospital of Shenzhen, Shenzhen, Guangdong Province,
China
| | - Zhongqin Gong
- Department of Surgery, The Chinese University of
Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR,
China
| | - Paul B. S. Lai
- Department of Surgery, The Chinese University
of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong
SAR, China
| | - George G. Chen
- Department of Surgery, The Chinese University
of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong
SAR, China
- Shenzhen Research Institute, The Chinese
University of Hong Kong, Shenzhen, Guangdong, China
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