Table 2 System review results of Pu-erh tea inhibition effects on alpha glucosidase

From: Inhibitory effects of pu-erh tea on alpha glucosidase and alpha amylase: a systemic review

Study Experiment subjects outcome
Li et al.11 Alpha glucosidase inhibition assay 1. (−)-epigallocatechingallate (EGCG) and (−)-epicatechingallate (ECG), as potent alpha glucosidase inhibitors, were found in pu-erh tea. 2. The IC50 values of EGCG and ECG on alpha-glucosidase were 175.1 and 246.9 μM, respectively, and both were lower than that of acarbose (IC50 = 3553.0 μM), a commercial alpha glucosidase inhibitor. 3. Different concentrations have different Inhibition rates (1.0 17.1 + −1.3).
Yang et al.12 Alpha glucosidase inhibition assay In the concentration 2.5 mg/ml, the inhibition rate of acarbose: 60.16%, ethyl acetate fraction: 82.52%, n-butanol fraction: 65.84%, water fraction: 58.22%, water extract: 52.29%.
Du et al.4 Alpha glucosidase inhibition assays for the WEPT were conducted using rat small intestinal sucrose and maltase in vitro WEPT showed inhibitory effects on rat intestinal sucrose, maltase, and porcine pancreatic amylase, as shown in Table 3, but are less potent compared to acarbose (IC50 = 4.35 ± 0.59, 6.63 ± 0.70, and 64.19 ± 6.77 μmol/L for sucrose, maltase, and amylase, respectively).
Huang et al.13 Alpha glucosidase inhibition assay 1. EP exhibited the strongest inhibitory potential, which increased from 25.96% to 87.2% when the concentration increased from 4 μg/ml to 125 μg/ml. 2. EF, the inhibitory effect increased from 20.43% to 84.77% at the same range of concentrations. 3. Meanwhile, AE, R and SF also showed a great inhibition on a-glycosidase with an inhibitory effect of 78.85%, 69.94% and 69.47% at a concentration of125ug/ml, which were higher than that of acarbose at the same concentration (40.84%).
Deng et al.10 Enzyme assay of α-glucosidase activity 1. The IC50 of acarbose and the IC50s of TPSs from Feng Huang Dan Cong, Da Hong Pao and pu-erh tea (1-year old, 3-year old and 5-year old) on alpha glucosidase activity were 207.195, 5.653, 2.286, 2.192, 0.583, and 0.438 μg/ml. 2. PTPS had more significant effects on α-glucosidase than acarbose did.
Wang et al.14 Alpha glucosidase inhibition assay 1. The results showed that EtOAc fraction had a moderate inhibitory activity with IC50 values of 14.4 μg/mL against sucrose and 11.4 μg/mL against maltase, respectively. 2. The inhibitory effects of compounds 1–17 were also measured using the same methods. (–)-Epigallo-catechin-3-O-gallate (15) showed a moderate activity with IC50 values of 32.5 μmol/L against sucrose and 1.3 μmol/L against maltase, respectively.