Effects of Aphloia theiformis on key enzymes related to diabetes mellitus

Figures & data

Table 1. IC₅₀ values of crude methanol and aqueous extracts and fractions of AT against enzymes relevant to diabetes and related complications.

	Crude extract (μg/mL)		Fractions (μg/mL)
Enzyme	Methanol	Aqueous	Hexane	DCM	Ethyl acetate	n-Butanol	Water	Controls
α-amylase	67.71 ± 1.21^a	–	–	–	43.59 ± 1.59^d	22.94 ± 0.40^b	–	38.45 ± 1.36*^c
α-glucosidase	55.20 ± 1.64^a	77.63 ± 1.67^b	–	–	45.58 ± 0.89^a	23.44 ± 0.08^c		749.48 ± 1.726*^d
Pancreatic lipase	939.97 ± 49.34^b	–	–	–	202.31 ± 23.91^c	39.32 ± 1.32^a	279.31 ± 6.45^d	41.61 ± 6.08‡^a

Values are expressed as mean ± standard deviation of triplicate determinations. Values in the same row having different superscripts differ significantly (p < 0.05) compared to control. – Low activity observed. *: acarbose, ‡: Orlistat^®.

Table 2. Possible synergistic effect of ethyl acetate and butanol fractions on α-amylase, α-glucosidase and pancreatic lipase.

Sample	α-Amylase (IC50 μg/mL)	Interaction	α-Glucosidase (IC50 μg/mL)	Interaction	Pancreatic lipase (IC50 μg/mL)	Interaction
Ethyl acetate	43.59 ± 1.59^a	Synergistic	45.58 ± 0.89^a	None	202.31 ± 23.91^a	Synergistic
n-butanol	22.94 ± 0.40^b		23.44 ± 0.08^b		39.32 ± 1.32^b
Ethyl acetate/n-butanol mixture	15.72 ± 0.73^c		46.32 ± 0.60^a		157.03 ± 4.73^c

Values are expressed as mean ± standard deviation of triplicate determinations. Values in the same column having different superscripts differ significantly (p < 0.05) from the ethyl acetate/n-butanol mixture.

Figure 1. Double-reciprocal Lineweaver Burk plots of crude methanol extract of AT on (a) α-amylase, (b) α-glucosidase, and (c) pancreatic lipase.

Figure 2. Double-reciprocal Lineweaver Burk plots of the different concentrations of ethyl acetate fraction of AT on (a) α-amylase, (b) α-glucosidase, and (c) pancreatic lipase.

Figure 3. Double-reciprocal Lineweaver Burk plots of the different concentrations of n-butanol fraction of AT on (a) α-amylase, (b) α-glucosidase, and (c) pancreatic lipase.

Table 3. Antioxidant capacities of crude methanol and aqueous extracts and fractions of AT.

	Crude extract		Fractions
	Methanol	Aqueous	Hexane	DCM	Ethyl acetate	n-Butanol	Water	Controls
AC (μg GAE/mg crude  extract/fraction)	0.44 ± 0.02^a	0.17 ± 0.00^b	0.38 ± 0.01^a	0.43 ± 0.01^a	1.41 ± 0.17^c	0.93 ± 0.00^e	0.58 ± 0.05^d	ND
FRAP (μg TE/mg crude  extract/fraction)	1625.63 ± 5.00^a	580.23 ± 8.23^b	116.02 ± 0.94^c	337.42 ± 0.41^d	1553.10 ± 6.19^a	1087.39 ± 1.89^f	794.55 ± 5.75^e	ND
DPPH (IC50 μg/mL)	64.42 ± 5.35^e	290.60 ± 2.55^a	271.78 ± 12.56^a	110.89 ± 7.54^d	17.07 ± 3.40^b	13.30 ± 0.78^c	16.32 ± 2.38^b	189.91 ± 6.18^f
β-Carotene (IC50 μg/mL)	19.49 ± 3.69^d	31.55 ± 2.14^a	38.03 ± 3.76^a	10.50 ± 0.15^e	3.46 ± 0.26^b	4.60 ± 0.63^b	1.32 ± 0.05^c	23.92 ± 1.99^d

Values are expressed as mean ± standard deviation of triplicate determinations. Values in the same row having different superscripts differ significantly (p < 0.05). ND: Not determine.

Table 4. Phytochemical determination of crude methanolic and aqueous extracts and fractions of AT.

	Crude extract		Fractions
	Methanol	Aqueous	Hexane	DCM	Ethyl acetate	n-Butanol	Water
TPC (μg GAE/mg crude extract/fraction)	675.53 ± 0.57^a	438.48 ± 0.13^b	19.35 ± 0.12^c	43.05 ± 0.73^d	211.74 ± 2.26^e	293.13 ± 3.45^f	112.13 ± 0.99^g
TFC (μg RE/mg crude extract/fraction)	223.11 ± 4.12^a	170.91 ± 0.73^b	22.57 ± 1.21^c	45.30 ± 4.28^d	272.93 ± 2.51^e	174.64 ± 3.17^f	186.79 ± 0.98^g
TTC (μg catechin/mg crude extract/fraction)	1749.33 ± 33.31^a	922.67 ± 28.10^b	30.97 ± 0.00^c	40.00 ± 7.33^d	313.55 ± 3.35^e	210.32 ± 6.80^f	169.03 ± 9.93^g
TAC (mg cyanidin-3-glucoside/mL)	13.96 ± 1.95^a	12.01 ± 1.93^a	–	–	3.90 ± 0.10^b	11.05 ± 1.46^c	6.36 ± 0.52^d

Values are expressed as mean ± standard deviation of triplicate determinations. Values in the same row having different superscripts differ significantly (p < 0.05). – not present.