Inhibition of α-Glucosidase by Andrographis paniculata. Ethanol Extract in Rats

Figures & data

Figure 1 (A) HPLC chromatogram of the standard andrographolide (AGPH) and (B) 20% v/v ethanol extract of AP. HPLC was performed in an UV Shimadzu LC-10AT model using Nucleosil (Phenomenex) 5-µm C18 column (250 × 4.6 mm). Mobile phase was MeOH and H₂O (65:35) at a flow rate of 1 mL/min and injection volume 20 µL with SPD-10A UV detector set at 223 nm.

Table 1. Effect on PBG and AUC after starch loading in normal and diabetic rats treated with 250 (D1), 500 (D2), 1000 (D3) mg/kg ethanol extract of Andrographis paniculata., vehicle, and acarbose 10 mg/kg Starch was used at 3 g/kg.

Group	PBG (mmol/L)	p	AUC (mmol/L)	p
Normal rats
D1	7.2±0.85	0.036	12.8±1.39	0.443
D2	6.7±0.93	0.003*	12.2±1.74	0.122
D3	6.1±0.64	<0.001**	11.0±1.03	0.004*
Control	8.1±0.87	1.000	13.4±1.56	1.000
Acarbose	5.7±0.44	<0.001**	10.3±0.47	<0.001**
Diabetic rats
D1	21.5±1.33	0.220	40.7±2.41	0.382
D2	19.9±1.11	0.004*	38.5±1.96	0.018
D3	17.7±1.26	<0.001**	34.2±2.31	<0.001**
Control	22.4±1.89	1.000	41.9±3.16	1.000
Acarbose	16.5±1.02	<0.001**	32.5±1.77	<0.001**

PBG, peak blood glucose; AUC, area under the curve.

Values are the mean±SD (n = 6).

*p < 0.05 compared with the control; **p < 0.001 compared with the control (one-way ANOVA followed by LSD post hoc. analysis).

Figure 2 Blood glucose response during oral starch tolerance test in normal rats treated with 250 (D1), 500 (D2), 1000 (D3) mg/kg of ethanol extract of AP, vehicle, and acarbose 10 mg/kg. Starch used at 3 g/kg. Values are the mean±SD (n = 6). *p < 0.05 compared with the control; **p < 0.001 compared with the control. (ANOVA followed by LSD post hoc. test).

Figure 3 Blood glucose response during oral starch tolerance test in diabetic rats treated with 250 (D1), 500 (D2), 1000 (D3) mg/kg of ethanol extract of AP, vehicle, and acarbose 10 mg/kg. Starch used at 3 g/kg. Values are the mean±SD (n = 6). *p < 0.05 compared with the control; **p < 0.001 compared with the control. (ANOVA followed by LSD post hoc. test).

Table 2. Effect on PBG and AUC after sucrose loading in normal and diabetic rats treated with 250 (D1), 500 (D2), 1000 (D3) mg/kg ethanol extract of Andrographis paniculata., vehicle, and acarbose 10 mg/kg Sucrose was used at 4 g/kg.

Group	PBG (mmol/L)	p	AUC (mmol/L)	p
Normal rats
D1	7.9±0.74	0.119	13.0±1.50	0.370
D2	7.0±0.98	0.001*	12.0±1.71	0.045*
D3	6.5±0.66	<0.001**	11.4±1.14	0.009*
Control	8.7±1.11	1.000	13.7±1.81	1.000
Acarbose	6.0±0.43	<0.001**	10.1±0.91	<0.001**
Diabetic rats
D1	20.7±1.01	0.547	40.0±1.40	0.961
D2	19.9±1.01	0.064	38.7±1.47	0.207
D3	17.8±1.14	<0.001**	34.0±1.99	<0.001**
Control	21.1±1.07	1.000	40.0±1.71	1.000
Acarbose	16.8±1.05	<0.001**	32.1±2.00	<0.001**

PBG, peak blood glucose; AUC, area under the curve.

Values are the mean±SD (n = 6).

*p < 0.05 compared with the control; **p < 0.001 compared with the control (one-way ANOVA followed by LSD post hoc. analysis).

Figure 4 Blood glucose response during oral sucrose tolerance test in normal rats treated with 250 (D1), 500 (D2), 1000 (D3) mg/kg of ethanol extract of AP, vehicle, and acarbose 10 mg/kg. Sucrose used at 4 g/kg. Values are the mean±SD (n = 6). *p < 0.05 compared with the control; **p < 0.001 compared with the control. (ANOVA followed by LSD post hoc. test).

Figure 5 Blood glucose response during oral sucrose tolerance test in diabetic rats treated with 250 (D1), 500 (D2), 1000 (D3) mg/kg of ethanol extract of AP, vehicle, and acarbose 10 mg/kg. Sucrose used at 4 g/kg. Values are the mean±SD (n = 6). *p < 0.05 compared with the control; **p < 0.001 compared with the control. (ANOVA followed by LSD post hoc. test).