Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online
Journal website www.isnff-jfb.com

Original Research

Volume 13, March 2021, pages 93-101

In-vitro antidiabetic activities, chemical compositions, antioxidant activities, and toxicity of black tea polysaccharides as a potential source of dietary ingredients

Figures

Figure 1.
Figure 1. Gel permeation chromatogram (a), UV Spectra (b), and FT-IR spectra (c) of BTPS.
Figure 2.
Figure 2. The α-glucosidase inhibitory activity of BTPS (a), 2-deoxyglucose (2-DG) uptake in adipocytes in the absence (0 nM) and in the presence (1 µg/mL) of insulin at indicated concentrations of BTPS extract (0.5 and 1 mg/mL) (b), and percentage viability of BTPS (c). Abbreviations: GC, growth control; SC, solvent control. Data are expressed as the mean ± SD (n = 3). Means ± SD followed by different letters are significantly different (p < 0.05) for Figures 2a and b. For Figure 2c, a significant difference from GC (p < 0.001) and b significant difference from SC (p < 0.001).
Figure 3.
Figure 3. The results of AMES microplate format test of BTPS in TA 98 and TA 100 strains.

Tables

Table 1. Yield and compositional parameters of BTPS
 
Parameters
Data are expressed as the mean ± SD (n = 3). Abbreviations: ABTS, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid); FRAP, ferric reducing antioxidant potential; GAE, gallic acid equivalents; BTPS, black tea polysaccharide, TE, trolox equivalents.
Yield (%)3.26 ± 0.11
Total carbohydrates (%)51.8 ± 4.8
Uronic acid (%)4.35 ± 0.58
Insoluble dietary fibre (%)1.21 ± 0.11
Soluble dietary fibre (%)30.2 ± 0.1
Total phenolics (g GAE/100 g BTPS)10.9 ± 1.3
ABTS (mg TE/100 g BTPS)8.77 ± 0.67
FRAP (mg FeSO4.7H2O/100 g BTPS)3.01 ± 0.29

 

Table 2. Monosaccharide, amino acid, and mineral compositions of BTPS
 
Monosaccharidesmol ratio (%)Amino acidsmg/100 gMineralsmg/100 g
Data are expressed as the mean ± SD (n = 3). Abbreviation: nd, not detected.
D-mannose2.38 ± 0.02Aspartic acid446 ± 86Calcium41.2 ± 1.7
D-ribose2.72 ± 0.02Alanine114 ± 11Chromium0.78 ± 0.0
L-rhamnose2.86 ± 0.03Arginine89.5 ± 12Copper1.37 ± 0.0
D-glucuronic2.46 ± 1.01Glutamic acid822 ± 11Iron9.8 ± 0.2
D-galacturonic2.89 ± 1.02Glycine337 ± 60Magnesium815 ± 27
D-glucose7.00 ± 0.07Histidine9.50 ± 7.80Manganese423 ± 4
D-galactose47.5 ± 0.5IsoleucinendPhosphorus1,970 ± 50
D-xylose1.89 ± 0.02Leucine54.5 ± 3.5Potassium9,155 ± 47
D-arabinose28.5 ± 0.3Lysine182 ± 12Sodium15.3 ± 0.8
L-fucose1.45 ± 0.08MethioninendZinc6.22 ± 0.20
Proline85.0 ± 9.9
Phenylalanine20.0 ± 4.2
Serine144 ± 12
Threonine67.0 ± 0.0
Tyrosine40.0 ± 14.1
Valine37.5 ± 3.5
Total2,498 ± 1

 

Table 3. The result of AMES microplate format genotoxicity test of BTPS
 
Concentrations (mg/mL)Mutagenity
BaselineTA 98 (positive wells)TA 98 (Fold increase over baseline)BaselineTA 100 (positive wells)TA 100 (Fold increase over baseline)
S9+S9−S9+S9−S9+S9−S9+S9−S9+S9−S9+S9−
Data are expressed as the mean ± SD (n = 3). *p < 0.05, significant level according to the student-t test. ***p < 0.001, significant level according to the student-t test.
0.1563.824.182.00 ± 1.003.00 ± 1.730.520.725.554.896.33 ± 0.583.33 ± 1.151.14*0.68
0.3132.00 ± 2.003.00 ± 1.000.520.727.33 ± 0.586.67 ± 2.081.32***1.36*
0.6252.00 ± 1.003.33 ± 1.530.520.807.67 ± 0.587.00 ± 1.001.38***1.43***
1.2501.33 ± 0.581.00 ± 0.000.35*0.24***5.33 ± 3.063.67 ± 1.150.960.75
2.5000.33 ± 0.582.00 ± 1.000.09***0.48***4.00 ± 2.002.33 ± 1.530.720.48*
5.0001.00 ± 1.731.33 ± 0.580.26*0.32***6.67 ± 1.537.00 ± 1.001.20*1.43***