Extraction optimization, antioxidants, and lipid-lowering activities of polygonatum cyrtonema Hua polysaccharides

Figures & data

Table 1. Single-factor experimental design.

Level	Extraction temperature (°C)	Liquid-to-solid ratio (mL/g)	Extraction time (min)	Number of extractions
1	50	10	30	1
2	60	15	60	2
3	70	20	90	3
4	80	25	120
5	90	30	150

Figure 1. Effects of (a) extraction temperature, (b) liquid-to-solid ratio, (c) extraction time, and (d) number of extraction rounds on polygonatum cyrtonema Hua polysaccharide (PCP) extraction yield. Data are shown as mean ± standard deviation (S.D.).

Table 2. Box – Behnken design and response value of polygonatum cyrtonema Hua polysaccharide (PCP) extraction.

Run	X1 extraction temperature (°C)	X2 liquid-to-solid ratio (mL/g)	X3 extraction time (min)	Yield (%)
1	60	15	90	6.23
2	80	15	90	8.39
3	60	25	90	7.63
4	80	25	90	8.63
5	60	20	60	6.52
6	80	20	60	7.91
7	60	20	120	7.28
8	80	20	120	8.92
9	70	15	60	9.44
10	70	25	60	8.62
11	70	15	120	8.75
12	70	25	120	9.84
13	70	20	90	10.95
14	70	20	90	10.04
15	70	20	90	10.88
16	70	20	90	11.89
17	70	20	90	11.06

Table 3. Analysis of variance (ANOVA) of a fitted response-surface quadratic polynomial model.

Source	Sum of squares	Degrees of freedom	Mean squares	F-value	p-value
Model	40.68	9	4.52	13.58	.0012
X1	4.79	1	4.79	14.39	.0068
X2	0.456	1	0.456	1.37	.2801
X3	0.6613	1	0.6613	1.99	.2015
X1X2	0.3364	1	0.3364	1.01	.3482
X1X3	0.0156	1	0.0156	0.0469	.8346
X2X3	0.912	1	0.912	2.74	.1418
X1^2	23.92	1	23.92	71.87	<.0001
X2^2	3.25	1	3.25	9.76	.0167
X3^2	3.73	1	3.73	11.2	.0123
Residual	2.33	7	0.3328
Lack-of-fit	0.4289	3	0.143	0.3009	.8243
Pure error	1.9	4	0.4752
Cor total	43.01	16

Figure 2. Response-surface three-dimensional (3D) plots and corresponding two dimensional (2D) contour plots of the effects of various variables on polygonatum cyrtonema Hua polysaccharide (PCP) yield.

Figure 3. Isolation, purification, and homogeneity analysis of polygonatum cyrtonema Hua polysaccharide 1 (PCP1). (A) DEDE-52 elution curve, (b) sephadex-G-75 elution curve, and (c) high performance gel permeation chromatography (HPGPC) spectrogram.

Figure 4. In vitro antioxidant activity analysis of polygonatum cyrtonema Hua polysaccharide 1 (PCP1). (a) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. (b) Hydroxyl radical-scavenging activity. (c) 2, 2'-azino-bis 3-ethylbenzthiazo-line-6-sulfonic acid (ABTS) radical-scavenging activity. Data are shown as mean ± standard deviation (S.D.).

Figure 5. Lipid-lowering effect of polygonatum cyrtonema Hua polysaccharide 1 (PCP1) in vitro. (a) Effect of palmitic acid (PA) concentration on the activity of HepG2 cells. (b) Effect of PCP1 on the activity of HepG2 cells incubated with PA. (c) Intracellular triglycerides (TG) level. (d) Intracellular total cholesterol (TC) level. (e) Intracellular alanine transaminase (ALT) level. (f) Intracellular aspartate transaminase (AST) level. (g) Oil red O staining diagram. Data are shown as mean ± standard deviation (S.D.) **p < .01 versus normal group, ^##p < .01 versus PA incubation group.