Sterculia tragacantha Lindl Leaf Extract Ameliorates STZ-Induced Diabetes, Oxidative Stress, Inflammation and Neuronal Impairment

Figures & data

Table 1 Phytochemical Compositions and in vitro Antioxidants and Hypoglycemic Effects of Aqueous Extract of Sterculia tragacantha Leaf (AESTL)

Assays	AESTL	Standards
Flavonoids (mg/100g)	107.90±1.04	136.36±0.89
Phenolics (mg/100g)	12.12±0.03	67.26±2.34
Terpenoids (mg/100g)	31.29±0.94	151.29±1.90
FRAP (mmol/100g)	15.19±0.98	217.49±2.34
TAC (mg/100g)	43.38±0.96	49.74±0.23
ABTS (IC50)	63.03±2.57	3.38±0.05
DPPH (IC50)	117.49±2.35	41.57±1.03
AChE (IC50)	113.07±3.42	67.59±2.35
BChE (IC50)	87.50±4.32	47.02±2.34
α-Amylase (IC50)	77.21±4.35	18.45±0.34
α-Glucosidase (IC50)	443.25±12.35	106.88±3.24

Figure 1 In vitro antioxidants and anti-hypoglycemic effects of AESTL. Bar graphs of dose vs inhibition showing the effect of AESTL and standard drugs on (A) DPPH, (B) ABTS, (C) α-amylase and, (D) α-glucosidase activities. Values are mean ± SEM (n = 6).

Figure 2 The cholinesterase inhibitory activities of aqueous extract of Sterculia tragacantha leaf (AESTL). Bar graphs of dose vs inhibition showing the effects of AESTL on the (A) acetylcholinesterase and (B) butyrylcholinesterase activities of AESTL. Values are mean ± SEM (n = 6).

Table 2 Hypoglycaemic Effect of the Aqueous Extract of Sterculia tragacantha Leaf (AESTL) in Streptozotocin-Induced Diabetic Rats

	FBS (mg/dL)
Groups	Day 0	Day 2	Day 14	Day 21	Hypo Effect (%)
Normal Control	84.56 ± 4.07	85.26 ± 3.21***	83.18 ± 5.34***	85.08 ± 7.23***
Vehicle, 2.5 mL/kg	86.63 ± 3.80	289.54 ± 11.18	299.41 ± 11.34	310.09 ± 15.22	–
AESTL, 150 mg/kg	88.22 ± 4.44	314.21 ± 13.22	196.77 ± 10.56**	98.39 ± 10.49***	68.27±2.34
AESTL, 300 mg/kg	84.50 ± 3.22	298.24 ±11.29	110.88 ± 9.67***	87.06 ± 4.76***	71.92±2.45
Metformin, 200 mg/kg	85.33 ± 5.28	293.13 ± 10.32	156.45 ± 12.78**	84.99 ± 5.54***	72.59±3.45

Notes: Data expressed as mean ± SD (n = 6). *p < 0.05, **p < 0.01, ***p < 0.05. Hypo effect (%); percentage hypoglycaemic effect = FBS ((Vehicle control - Treatment)/Vehicle control) × 100.

Table 3 Effect of the Aqueous Extract of Sterculia tragacantha Leaf (AESTL) on Bodyweight Changes in Streptozotocin-Induced Diabetic Rats

	Day 0	Day 14	Day 21	Weight Changes (%)
Normal Control	150.89 ± 8.14	154 0.32 ± 7.10	165.98 ± 5.69	9.09 ± 2.4***
Vehicle, 2.5 mL/kg	160.89 ± 10.2	153.11 ± 10.1	140.10 ± 5.89	−14.84 ± 5.56
AESTL, 150 mg/kg	158.24 ± 6.80	159.19 ± 7.17	162.31 ± 6.16	2.51 ± 1.37**
AESTL, 300 mg/kg	150.34 ± 7.90	153.12 ± 8.14	156.19 ± 7.23	3.75 ± 1.50**
Metformin, 200 mg/kg	156.39 ± 7.56	157.59 ± 9.21	160.34 ± 9.31	2.46 ± 1.06**

Notes: Data expressed as mean ± SD (n = 6). * p < 0.05, ** p < 0.01, *** p < 0.05.

Figure 3 Aqueous extract of Sterculia tragacantha leaf (AESTL) attenuates the dysregulation of cholinesterase and neurotransmitters in brain tissue of streptozotocin-induced diabetic rats. Bar plots showing the effect of AESTL on the levels of (A) cholinesterases (AChE and BChE), (B) dopamine, serotonine, (C) epinephrine and norepinephrine in brain of streptozotocin-induced diabetic rats. Values are mean ± SEM (n = 6). *p<0.05, **p<0.01 or ***p<0.001.

Abbreviations: AChE, acetylcholinesterase; BCHE, butyrylcholinesterase.

Figure 4 AESTL regulates Na⁺-K⁺-ATPase anti-inflammatory response via inhibition of COX-2/NO signaling axis in brain of streptozotocin-induced diabetic rats. Bar plots showing the effect of AESTL on the activities of cyclooxygenase-2 (COX-2), (A), Na⁺-K⁺-ATPase (B) and the level of NO (C) in brain of streptozotocin-induced diabetic. Values are mean ± SEM (n = 6). **p<0.01 or ***p<0.001.

Figure 5 Aqueous extract of Sterculia tragacantha leaf (AESTL) attenuates oxidative stress in brain of streptozotocin-induced diabetic rats: Effect of the aqueous extract of S. tragacantha leaf extract (AESTL) on the level of enzymatic antioxidants including the (A) SOD, (B) GPx and (C) CAT, (D) level of non-enzymatic antioxidant (GSH) and (E) MDA in the brain of streptozotocin-induced diabetic rats. Values are mean ± SEM (n = 6). *p<0.05, **p<0.01 or ***p<0.001.

Abbreviations: CAT, catalase; SOD, superoxide dismutase; GSH, reduced glutathione; GPx, glutathione peroxidase; MDA, malondialdehyde.

Figure 6 Molecular docking profile of epicatechin and procyanidin B2 with cholinesterase. Two-dimensional (2 D) representations of the interaction occurring between epicatechin and procyanidin B2 and (A) butyrylcholinesterase and (B) acetylcholinesterase.

Abbreviations: AChE, acetylcholinesterase; BCHE, butyrylcholinesterase.

Figure 7 Molecular docking profile of epicatechin and procyanidin B2 with carbohydrate metabolizing enzymes. Two-dimensional (2 D) representations of the interaction occurring between epicatechin and procyanidin B2 and (A) α-amylase and (B) α-glucosidase.