Studies on the possible mechanisms of antidiabetic activity of extract of aerial parts of Phyllanthus niruri

Figures & data

Table 1.  Thin layer chromatography finger-print of ME.

Spot number	Color	Retention factor (Rf)	Detection
1	Dark brown	0.92	H2SO4/Vanillin
2	Purple	0.78	UV365
3	Purple	0.72	UV365
4	Purple	0.66	Daylight, UV365
5	Purple	0.57	UV365
6	Dark brown	0.52	H2SO4/Vanillin

Mobile phase = Hex/EtOAc (3:2).

Table 2.  Effect of ME on blood glucose of treated diabetic rats.

Treatment	Dose (mg/kg)	Blood glucose level (mg/dL)
		Basal	Day 0	Day 3	Day 10	Day 17	Day 24
Control	-	62.0 ± 2.74	378.0 ± 75.8	448.4 ± 89.19 (NR)	367.6 ± 48.43 (2.75)	398.2 ± 90.34 (NR)	285.2 ± 80.88 (24.55)
ME	100	59.0 ± 6.42	418.0 ± 78.02	348.0 ± 100.2 (16.75)	294.75 ± 89.86 (29.49)	284.25 ± 101.7 (32)	264.25 ± 111.4 (36.78)
	200	76.0 ± 5.21	332.0 ± 56.75	443.75 ± 125.2 (NR)	411.25 ± 111.5 (NR)	348.25 ± 106.2 (NR)	254.5 ± 66.35 (23.34)
	400	67.33 ± 12.33	375.67 ± 121.2	340.0 ± 122.02 (9.50)	350.67 ± 115.2 (6.65)	209.33 ± 100.1 (44.28)	205.67 ± 107.2 (45.25)
Glibenclamide	0.5	61.00 ± 2.92	391.40 ± 80.50	383.8 ± 95.22 (1.94)	341.4 ± 83.07 (12.78)	313.6 ± 85.69 (19.88)	320.2 ± 78.94 (18.19)
NDNT	-	58.4 ± 5.49	58.4 ± 5.49	59.0 ± 3.13 (NR)	81.8 ± 3.77 (NR)	61.8 ± 3.44 (NR)	65.6 ± 4.76 (NR)
NDT	200	70.0 ± 5.23	70.0 ± 5.23	63.0 ± 6.23 (10)	76.0 ± 5.52 (NR)	75.2 ± 8.11 (NR)	74.0 ± 4.2 (NR)
	400	75.75 ± 4.89	75.75 ± 4.89	64.25 ± 3.07 (15.18)	73.75 ± 4.91 (2.64)	83.75 ± 10.09 (NR)	75.5 ± 5.91 (3.3)

n = 5; ME, methanol extract; NDNT, non-diabetic non-treated; NDT, non-diabetic treated with ME.

Values of blood glucose shown are Mean ± SEM; Values in parenthesis represent %reduction in blood glucose calculated relative to day 4; NR, no reduction.

Table 3.  Effect of ME on oral glucose tolerance in treated diabetic rats.

Treatment	Dose (mg/kg)	Blood glucose level (mg/dL)
		0 min	30 min	60 min	90 min	120 min
Control	-	304.8 ± 86.34	322.2 ± 81.92	316.0 ± 89.75 (1.92)	274.0 ± 88.86 (14.96)	326.2 ± 104.16 (NI)
ME	100	233.5 ± 97.95	253.0 ± 109.65	229.5 ± 102.36 (9.29)	272.0 ± 109.78 (NI)	295.0 ± 114.22 (NI)
	200	259.75 ± 85.91	312.0 ± 85.39	248.25 ± 56.89 (20.43)	232.0 ± 78.83 (25.64)	167.25 ± 58.36 (46.39)
	400	248.67 ± 101.47	310.67 ± 99.62	278.67 ± 126.24 (10.3)	175.33 ± 44.05 (43.56)	156.0 ± 37.31 (49.79)
Glibenclamide	0.5	234.2 ± 90.06	335.8 ± 88.5	315.2 ± 77.01 (6.14)	269.6 ± 88.34 (19.71)	243.6 ± 74.15 (27.46)
NDNT	-	62.0 ± 3.21	82.6 ± 5.00	76.2 ± 2.85 (7.75)	68.4 ± 4.16 (17.19)	70.0 ± 3.67 (15.25)
NDT	200	60.8 ± 6.18	96.8 ± 3.81	91.4 ± 6.45 (5.58)	75.0 ± 4.6 (22.52)	64.0 ± 4.24 (33.88)
	400	51.0 ± 1.92	91.5 ± 5.72	90.5 ± 5.17 (1.09)	76.0 ± 7.01 (16.94)	66.0 ± 2.35 (27.87)

n = 5; ME, methanol extract; NDNT, non-diabetic non-treated; NDT, non-diabetic treated with ME.

Values of blood glucose shown are Mean ± SEM; Values in parenthesis represent % inhibition of elevation in blood glucose calculated relative to 30 min; NI, no inhibition.

Table 4.  Effect of ME on α-amylase activity.

Treatment	Concentration (mg/mL)	Concentration of maltose generated (mg/mL)
		0 min	1 min	2 min	3 min	Inhibition (%)
Control	-	0.46 ± 0.07	0.55 ± 0.09	0.63 ± 0.18	0.95 ± 0.03	-
ME	2.5	0.16 ± 0.01*	0.27 ± 0.01*	0.34 ± 0.03*	0.4 ± 0.01*	58.95 ± 1.22
	5	0.07 ± 0.03*	0.42 ± 0.04	0.29 ± 0.01*	0.29 ± 0.02*	69.47 ± 2.43
	10	0.20 ± 0.02*	0.18 ± 0.05*	0.27 ± 0.02*	0.21 ± 0.05*	77.54 ± 4.56
	20	−0.08 ± 0.03*	−0.13 ± 0.1*	−0.0 ± 0.01*	0.13 ± 0.11*	86.32 ± 11.39

*P <0.05 compared to control (ANOVA; LSD post hoc); ME, methanol extract. Concentration of generated maltose shown are Mean ± SEM; Inhibition (%) was calculated relative to control; IC₅₀ = 2.15 ± 0.1 mg/mL.

Table 5.  Effect of ME on α-glucosidase activity.

Treatment	Concentration(mg/mL)	α-Glucosidase inhibition
		p-Nitrophenol (absorbance)	Inhibition(%)
Control	-	0.99 ± 0.1	-
ME	0.3125	0.088 ± 0.02*	91.11 ± 1.54
	0.625	0.094 ± 0.01*	90.47 ± 0.51
	1.25	0.103 ± 0.01*	89.52 ± 0.81
Acarbose	0.05	0.76 ± 0.02	23.23 ± 0.84

*P <0.05 compared to control (ANOVA; LSD post hoc); ME, methanol extract.

Values of absorbance and inhibition (%) shown are Mean ± SEM; Inhibition (%) was calculated relative to control; IC₅₀ = 0.2 ± 0.02 mg/mL.

Table 6.  Effect of ME on hemoglobin glycosylation in treated diabetic rats.

Treatment	Dose (mg/kg)	Hemoglobin glycation (Absorbance of 5-HMF)	Inhibition (%)
Control	-	1.38 ± 0.44	-
ME	100	1.15 ± 0.48	16.67
	200	1.47 ± 0.47	NI
	400	0.86 ± 0.62	37.68
Glibenclamide	0.5	0.88 ± 0.39	36.23
NDNT	-	0.64 ± 0.54	NC
NDT	200	0.96 ± 0.37	NC
	400	0.47 ± 0.36	NC

n = 5; ME, methanol extract; NDNT, non-diabetic non-treated; NDT, non-diabetic treated with ME.

Inhibition (%) of hemoglobin glycation was calculated relative to control; Values of hemoglobin glycation (absorbance of 5-HMF) shown are Mean ± SEM; NI, no inhibition; NC, not calculated.

Table 7.  Effect of ME on liver weight and liver glycogen in treated diabetic rats.

Treatment	Dose (mg/kg)	Liver weight (g)		Liver glycogen (glucose g/g of wet tissue)
		Absolute	Relative
Control	-	6.38 ± 0.18	3.43 ± 0.36	0.35 ± 0.12
ME	100	8.32 ± 1.02* (30.41)	3.77 ± 0.06 (9.91)	0.49 ± 0.13 (40)
	200	7.88 ± 0.55 (23.51)	3.84 ± 0.15 (11.95)	0.48 ± 0.06 (37.14)
	400	7.01 ± 0.4 (9.87)	4.23 ± 0.56 (23.32)	0.55 ± 0.1 (57.14)
Glibenclamide	0.5	6.29 ± 0.8 (NI)	3.5 ± 0.29 (2.04)	0.36 ± 0.09 (2.86)
NDNT	-	6.01 ± 0.54 (NI)	3.26 ± 0.2 (NI)	0.44 ± 0.1 (25.71)
NDT	200	5.8 ± 0.21 (NI)	3.08 ± 0.13 (NI)	0.48 ± 0.08 (37.14)
	400	6.89 ± 0.26 (7.99)	3.28 ± 0.21 (NI)	0.46 ± 0.12 (31.43)

n = 5; *P <0.05 compared to control (ANOVA; LSD post hoc); ME, methanol extract; NDNT, non-diabetic non-treated; NDT, non-diabetic treated with ME.

Values of liver weight and liver glycogen shown are Mean ± SEM; Values in parenthesis represent % increase in liver weight and liver glycogen calculated relative to control; NI, no increase.

Table 8.  Effect of ME on body weight of treated diabetic rats.

Treatment	Dose (mg/kg)	Body weight (g)
		Basal	Day 0	Day 3	Day 10	Day 17	Day 24
Control	-	201.0 ± 8.84	181.6 ± 7.14	182.2 ± 8.39 (0.33)	190.6 ± 10.58 (4.96)	187.4 ± 13.46 (3.19)	191.8 ± 14.11 (5.62)
ME	100	218.25 ± 27.37	205.75 ± 28.22	204.0 ± 27.74 (NI)	217.5 ± 28.34 (5.71)	212.0 ± 25.03 (3.04)	220.25 ± 26.43 (7.05)
	200	191.5 ± 11.85	177.5 ± 7.19	184.25 ± 8.98 (3.8)	188.75 ± 8.21 (6.34)	187.75 ± 11.24 (5.77)	196.75 ± 10.77 (10.85)
	400	185.0 ± 8.15	167.0 ± 5.03	162.66 ± 7.54 (NI)	170.67 ± 11.1 (2.2)	149.0 ± 10.54* (NI)	166.0 ± 13.45 (NI)
Glibenclamide	0.5	187.4 ± 22.74	178.6 ± 21.27	183.0 ± 20.88 (2.46)	190.0 ± 22.96 (6.38)	188.0 ± 23.54 (5.26)	190.8 ± 26.94 (6.83)
NDNT	-	195.6 ± 13.67	195.6 ± 13.67	192.4 ± 13.77 (NI)	200.0 ± 15.66 (2.25)	202.0 ± 15.18 (3.27)	205.0 ± 15.21 (4.81)
NDT	200	188.8 ± 14.69	188.8 ± 14.69	183.8 ± 13.76 (NI)	184.6 ± 13.24 (NI)	179.8 ± 11.8 (NI)	189.4 ± 11.39 (0.32)
	400	193.5 ± 8.97	193.5 ± 8.97	193.5 ± 9.22 (NI)	195.0 ± 10.65 (0.78)	183.5 ± 11.02 (NI)	210.5 ± 9.22 (8.79)

n = 5; *P <0.05 compared to day 4 (ANOVA; LSD post hoc); ME, methanol extract; NDNT, non-diabetic non-treated; NDT, non-diabetic treated with ME.

Values of body weight shown are Mean ± SEM; Values in parenthesis represent % increase in body weight calculated relative to day 4; NI, no increase.