Prunus mume leaf extract lowers blood glucose level in diabetic mice

Figures & data

Figure 1. Extraction and fractionation of Prunus mume leaves (schematic diagram). CH₂Cl₂, dichloromethane-soluble fraction; EtOAc, ethyl acetate-soluble fraction; n-BuOH, butanol-soluble fraction.

Figure 2. Effects of PMLE fractions on 3T3-L1 preadipocyte differentiation. 3T3-L1 preadipocytes were treated with the indicated concentrations of Prunus mume leaf extract fractions for 9 d. Differentiation was determined using the AdipoRed Assay as described in the Materials and methods. Bars represent means of relative values (% non-treated control) ± standard error of the mean.

Table 1. α-Glucosidase inhibition activities of fractions from 70% ethanol extract of Prunus mume leaf.

Fraction	IC50 (μg/mL)^a
n-Hexane	–
CH2Cl2	–
EtOAc	68.2 ± 5.37
n-BuOH	75.8 ± 18.76
Water	–

^aIC₅₀: 50% α-glucosidase inhibition concentration. – indicates no effect.

Table 2. The yield, total polyphenol and total flavonoid contents of ethanol extract and various fractions of Prunus mume leaf ethanol extract.

	Yield (%, w/w)	Polyphenol content (mg of TAE/g plant extract)^a	Flavonoid content (mg of RE/g plant extract)^b
70% EtOH	27.4	428.0 ± 10.8	389.6 ± 7.2
n-Hexane	9.5	112.1 ± 8.2	87.0 ± 4.1
CH2Cl2	5.4	168.6 ± 4.6	134.0 ± 5.9
EtOAc	3.8	883.5 ± 14.9	820.1 ± 7.7
n-BuOH	11.7	557.2 ± 7.1	503.3 ± 8.3
Water	66.9	130.8 ± 6.6	115.5 ± 2.9

^aTannic acid equivalents.

^bRutin equivalent.

Table 3. Effects of Prunus mume leaf extract (PMLE) on plasma glucose, lipids and body weight in streptozotocin (STZ)/high-fat/high-cholesterol diet (HFD)-induced mice.

	STZ/HFD (mg/kg)
	CON	HFD	STZ	PMLE 0	PMLE 5	PMLE 25	PMLE 50
Glucose (mg/dL)	130.4 ± 9.24	207.8 ± 12.61	284.6 ± 10.98	447.6 ± 15.87	452.0 ± 22.20	323.3 ± 29.72*	264.2 ± 26.73**
Total cholesterol (mg/dL)	538.9 ± 5.62	946.4 ± 7.85	675.4 ± 6.88	1045.6 ± 12.63	1016.2 ± 47.60	949.1 ± 22.33	1035.2 ± 18.80
Triacylglycerol (mg/dL)	143.0 ± 15.55	246.8 ± 10.49	232.6 ± 8.98	494.9 ± 14.80	383.3 ± 17.82*	336.0 ± 23.58*	320.7 ± 20.73*
Body weight (g)	33.5 ± 1.49	40.3 ± 2.06	32.6 ± 1.14	37.8 ± 1.63	32.1 ± 0.95*	32.9 ± 1.90*	29.9 ± 0.56**
Food intake (g/day)	4.31 ± 0.52	5.86 ± 0.92	4.32 ± 0.53	5.37 ± 0.48	5.43 ± 0.68	5.30 ± 0.84	5.26 ± 0.91

Four-week-old ICR mice were injected with vehicle and fed normal diet (CON) or HFD (HFD), or injected with low-dose STZ and fed ND (STZ) or HFD (STZ/HFD), and blood glucose, total cholesterol, triacylglycerol and body weight were measured. All values are represented as the means ± standard error of the mean (n = 6).

* p < 0.05 and **p < 0.01, compared with PMLE 0.