You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Changes in skeletal muscle proteolytic gene expression after prophylactic supplementation of EGCG and NAC and eccentric damage. PURPOSE: The impact of prophylactic supplementation of N-acetyl-cysteine (NAC) and epigallocatechin gallate (EGCG) on intramuscular expression of proteolytic genes after unaccustomed eccentric muscle contractions was investigated. METHODS: Thirty apparently healthy males (mean±SD: 20.0±1.8years, 175±7.1cm, 76.1±16.9kg) ingested daily either 1800mg of NAC or 1800mg of EGCG (98% total polyphenols, 80% total catechins, and 50% EGCG), or 1000mg of a glucomannan placebo (PLA) in a double blind, prophylactic fashion for 14days. Subjects then completed an unaccustomed eccentric exercise bout (100 repetitions at 30°s(-1)) using the dominant knee extensors. Skeletal muscle biopsies were collected from the vastus lateralis at baseline and both 6 and 24h after exercise. The expression of proteolytic genes [i.e., muscle ring-finger 1 (MuRF1), atrogin-1, α-type 20S subunit C2 (HC2), α-type 20S subunit C3 (HC3), ubiquitin protein ligase 3B (UBE3B), μ-calpain, and m-calpain] was quantified using real-time RT-PCR. Separate 3×3 (group×time) repeated measures ANOVAs were used to analyze changes in gene expression over time between groups. RESULTS: No significant group×time interactions were detected between groups for the expression of any of the atrogenes or calpains (p>0.05). Significant main effects for time identified increases in MuRF1 (6h: 5.3±10.8 fold; p=0.046), UBE3B (6h: 5.3±7.7 fold; p=0.006; 24h: 3.3±4.5 fold; p=0.005), and m-calpain expression (6h: 2.7±4.4 fold; p=0.045) in all participants following exercise. Increases approached significance in HC2 (6h: 1.9±2.4 fold; p=0.079; 24h: 1.6±1.9 fold; p=0.084) and m-calpain expression (24h: 1.8±2.3 fold; p=0.084) following exercise. CONCLUSIONS: Prophylactic supplementation of NAC and EGCG did not impact acute changes in skeletal muscle proteolytic gene expression following eccentric exercise. Eccentric muscle contractions elevated MuRF1 and UBE3B, while m-calpain and HC2 mRNA tended to increase.
{"Chemical": ["N-acetyl-cysteine", "NAC", "catechins", "epigallocatechin gallate", "polyphenols", "EGCG"]}