J Food Bioact

Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online

Journal website www.isnff-jfb.com

Original Research

Volume 3, Number , September 2018, pages 124-132

α-Glucosidase inhibitory activities, functional properties, and safety of green tea polysaccharides as a potential source of dietary supplement

Figure 2.
Molecular weight distribution of green tea polysaccharides.

Figure 3.
FT-IR spectra of green tea polysaccharides.

Figure 4.
Percentage viability of green tea polysaccharides. Data are expressed as the mean ± SD (n = 3).

Figure 5.
The results of AMES microplate format test of green tea polysaccharides in TA 98 and TA 100 strains (— 2-fold induction over the baseline).

**Table 1.** Mutagenicity of compounds identified according to the evaluation criteria
Criteria	Description
If baseline is ≤ 3
2–3 times greater than baseline	weak mutagen
>3 times greater than baseline	mutagen
If baseline is > 3
1.5–2.5 times greater than baseline	weak mutagen
>2.5 times greater than baseline	mutagen

Table 1. Mutagenicity of compounds identified according to the evaluation criteria

Criteria

Description

If baseline is ≤ 3

2–3 times greater than baseline

weak mutagen

>3 times greater than baseline

mutagen

If baseline is > 3

1.5–2.5 times greater than baseline

weak mutagen

>2.5 times greater than baseline

mutagen

**Table 2.** Yields, compositional characteristics, and antioxidant activities of green tea polysaccharides
Parameters	Units	GTPS
Abbreviations: ABTS, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid); FRAP, ferric reducing antioxidant potential; GAE, gallic acid equivalents; GTPS, green tea polysaccharides; TE, trolox equivalents. Data are expressed as the mean ± SD (n = 3).
Yield	%	3.05 ± 0.15
Total carbohydrates	%	34.33 ± 2.00
Protein	%	2.21 ± 0.05
Uronic acid	%	15.11 ± 1.55
Total phenolics	g GAE/100 g GTPS	5.80 ± 0.52
ABTS	mg TE/100 mg GTPS	42.51 ± 1.03
FRAP	mg FeSO₄·7H₂O /100 mg of GTPS	19.86 ± 1.52
Monosaccharide composition
Mannose	mol ratio %	3.97 ± 0.00
Ribose	5.95 ± 0.00
Rhamnose	3.06 ± 0.00
Glucuronic	2.02 ± 0.26
Galacturonic	0.95 ± 0.23
Glucose	16.61 ± 0.00
Galactose	40.22 ± 0.02
Xylose	1.37 ± 0.02
Arabinose	24.13 ± 0.01
Fucose	1.72 ± 0.03

Table 2. Yields, compositional characteristics, and antioxidant activities of green tea polysaccharides

Parameters

Units

GTPS

Abbreviations: ABTS, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid); FRAP, ferric reducing antioxidant potential; GAE, gallic acid equivalents; GTPS, green tea polysaccharides; TE, trolox equivalents. Data are expressed as the mean ± SD (n = 3).

Yield

3.05 ± 0.15

Total carbohydrates

34.33 ± 2.00

Protein

2.21 ± 0.05

Uronic acid

15.11 ± 1.55

Total phenolics

g GAE/100 g GTPS

5.80 ± 0.52

ABTS

mg TE/100 mg GTPS

42.51 ± 1.03

FRAP

mg FeSO₄·7H₂O /100 mg of GTPS

19.86 ± 1.52

Monosaccharide composition

Mannose

mol ratio %

3.97 ± 0.00

Ribose

5.95 ± 0.00

Rhamnose

3.06 ± 0.00

Glucuronic

2.02 ± 0.26

Galacturonic

0.95 ± 0.23

Glucose

16.61 ± 0.00

Galactose

40.22 ± 0.02

Xylose

1.37 ± 0.02

Arabinose

24.13 ± 0.01

Fucose

1.72 ± 0.03

**Table 3.** Inhibitory effects of green tea polysaccharides on α-glycosidase activity
Concentration (mg/mL)	Inhibition (%)
Data are expressed as the mean ± SD (n = 3).
2.5	95.25 ± 3.13
1.25	93.41 ± 3.30
0.5	91.86 ± 0.04
0.125	43.77 ± 1.73
0.025	7.15 ± 5.25

Table 3. Inhibitory effects of green tea polysaccharides on α-glycosidase activity

Concentration (mg/mL)

Inhibition (%)

Data are expressed as the mean ± SD (n = 3).

2.5

95.25 ± 3.13

1.25

93.41 ± 3.30

0.5

91.86 ± 0.04

0.125

43.77 ± 1.73

0.025

7.15 ± 5.25

**Table 4.** The result of AMES microplate format genotoxicity test of green tea polysaccharides
Concentration (mg/mL)	Positive wells	Baseline	Mutagenicity
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.
0.156	2.83 ± 1.83	3.00 ± 1.00	4.67	4.37	0.50	0.69	4.33 ± 1.21	5.00 ± 1.00	5.54	4.59	0.66	1,09^*
0.313	2.33 ± 0.58	2.67 ± 0.58	0.93	0.61	3.67 ± 0.58	6.00 ± 1.73	1.02	1.31^*
0.625	4.33 ± 0.58	3.00 ± 2.00	0.57	0.69	5.67 ± 0.58	6.33 ± 2.89	1.20^***	1.38^*
1.250	2.67 ± 1.53	3.00 ± 1.73	0.57	0.69	6.67 ± 1.53	4.67 ± 1.53	0.60	1.02
2.500	4.67 ± 3.06	2.33 ± 0.58	1.00	0.53	3.33 ± 1.15	5.67 ± 2.08	1.14^*	1.24^*
5.000	6.67 ± 1.53	5.00 ± 0.00	1.43^***	1.14^*	7.33 ± 0.58	6.67 ± 0.58	1.32^***	1.45^***

Table 4. The result of AMES microplate format genotoxicity test of green tea polysaccharides

Concentration (mg/mL)

Positive wells

Baseline

Mutagenicity

TA 98

Positive wells

Baseline

TA 100

Fold increase (over the 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.

0.156

2.83 ± 1.83

3.00 ± 1.00

4.67

4.37

0.50

0.69

4.33 ± 1.21

5.00 ± 1.00

5.54

4.59

0.66

1,09^*

0.313

2.33 ± 0.58

2.67 ± 0.58

0.93

0.61

3.67 ± 0.58

6.00 ± 1.73

1.02

1.31^*

0.625

4.33 ± 0.58

3.00 ± 2.00

0.57

0.69

5.67 ± 0.58

6.33 ± 2.89

1.20^***

1.38^*

1.250

2.67 ± 1.53

3.00 ± 1.73

0.57

0.69

6.67 ± 1.53

4.67 ± 1.53

0.60

1.02

2.500

4.67 ± 3.06

2.33 ± 0.58

1.00

0.53

3.33 ± 1.15

5.67 ± 2.08

1.14^*

1.24^*

5.000

6.67 ± 1.53

5.00 ± 0.00

1.43^***

1.14^*

7.33 ± 0.58

6.67 ± 0.58

1.32^***

1.45^***