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Aqueous Extract of Nypa fruticans Wurmb. Vinegar Alleviates Postprandial Hyperglycemia in Normoglycemic Rats.

Yusoff NA, Ahmad M, Al-Hindi B, Widyawati T, Yam MF, Mahmud R, Razak KN, Asmawi MZ - Nutrients (2015)

Bottom Line: Early work has shown that aqueous extract (AE) of NPV exerts a potent antihyperglycemic effect.One mg/mL of AE showed a comparable outcome to the use of phloridzin (1 mM) in vitro as it delayed glucose absorption through isolated rat jejunum more effectively than acarbose (1 mg/mL).Conversely, in spectrophotometric enzymatic assays, AE showed rather a weak inhibitory activity against both α-glucosidase and α-amylase when compared with acarbose.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia. namy11_pha015@student.usm.my.

ABSTRACT
Nypa fruticans Wurmb. vinegar, commonly known as nipa palm vinegar (NPV) has been used as a folklore medicine among the Malay community to treat diabetes. Early work has shown that aqueous extract (AE) of NPV exerts a potent antihyperglycemic effect. Thus, this study is conducted to evaluate the effect of AE on postprandial hyperglycemia in an attempt to understand its mechanism of antidiabetic action. AE were tested via in vitro intestinal glucose absorption, in vivo carbohydrate tolerance tests and spectrophotometric enzyme inhibition assays. One mg/mL of AE showed a comparable outcome to the use of phloridzin (1 mM) in vitro as it delayed glucose absorption through isolated rat jejunum more effectively than acarbose (1 mg/mL). Further in vivo confirmatory tests showed AE (500 mg/kg) to cause a significant suppression in postprandial hyperglycemia 30 min following respective glucose (2 g/kg), sucrose (4 g/kg) and starch (3 g/kg) loadings in normal rats, compared to the control group. Conversely, in spectrophotometric enzymatic assays, AE showed rather a weak inhibitory activity against both α-glucosidase and α-amylase when compared with acarbose. The findings suggested that NPV exerts its anti-diabetic effect by delaying carbohydrate absorption from the small intestine through selective inhibition of intestinal glucose transporters, therefore suppressing postprandial hyperglycemia.

No MeSH data available.


Related in: MedlinePlus

Inhibitory activities of aqueous extract (AE) of NPV on (A) α-glucosidase and (B) α-amylase. AE inhibitory activities were determined using the respective pNPG and starch as substrates. Acarbose was used as the positive control. Values are expressed as means ± S.E.M. of triplicates. Values with different letters of the alphabet were significantly different at p < 0.05, as analyzed using Tukey HSD (honest significant difference) as a post hoc test. The final concentration of acarbose was 6.25 mg/mL.
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nutrients-07-05320-f005: Inhibitory activities of aqueous extract (AE) of NPV on (A) α-glucosidase and (B) α-amylase. AE inhibitory activities were determined using the respective pNPG and starch as substrates. Acarbose was used as the positive control. Values are expressed as means ± S.E.M. of triplicates. Values with different letters of the alphabet were significantly different at p < 0.05, as analyzed using Tukey HSD (honest significant difference) as a post hoc test. The final concentration of acarbose was 6.25 mg/mL.

Mentions: AE inhibitory effects against α-lucosidase and α-mylase were respectively measured using p-nitrophenyl-α-d-glucopyranoside (pNPG) and starch as substrates (Figure 5). The inhibition of both enzyme activities was compared with that caused by a standard inhibitor, acarbose. Results indicated that AE inhibited the activity of α-glucosidase in a dose-dependent fashion: The percentages of activity were 0.85%, 6.36%, 15.93%, 40.28%, 69.64%, and 92.33% at the respective concentrations of 3.13, 6.25, 12.50, 25, 50, and 100 mg/mL (Figure 5A). Likewise, the inhibitory effect of AE against α-amylase activity occurred in a dose-dependent manner: The inhibition was intensified gradually as AE concentrations increased from 3.13 to 100 mg/mL (Figure 5B). At the concentration of 100 mg/mL, AE caused the maximum inhibition for both of the enzymes. Yet, with reference to the IC50 values of acarbose and AE, findings suggested that AE α-glucosidase and α-amylase inhibitory effects (28.92 ± 0.05 and 60.62 ± 0.32, respectively) were weaker than those of acarbose (1.11 ± 0.02 and 0.45 ± 0.07, respectively).


Aqueous Extract of Nypa fruticans Wurmb. Vinegar Alleviates Postprandial Hyperglycemia in Normoglycemic Rats.

Yusoff NA, Ahmad M, Al-Hindi B, Widyawati T, Yam MF, Mahmud R, Razak KN, Asmawi MZ - Nutrients (2015)

Inhibitory activities of aqueous extract (AE) of NPV on (A) α-glucosidase and (B) α-amylase. AE inhibitory activities were determined using the respective pNPG and starch as substrates. Acarbose was used as the positive control. Values are expressed as means ± S.E.M. of triplicates. Values with different letters of the alphabet were significantly different at p < 0.05, as analyzed using Tukey HSD (honest significant difference) as a post hoc test. The final concentration of acarbose was 6.25 mg/mL.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555159&req=5

nutrients-07-05320-f005: Inhibitory activities of aqueous extract (AE) of NPV on (A) α-glucosidase and (B) α-amylase. AE inhibitory activities were determined using the respective pNPG and starch as substrates. Acarbose was used as the positive control. Values are expressed as means ± S.E.M. of triplicates. Values with different letters of the alphabet were significantly different at p < 0.05, as analyzed using Tukey HSD (honest significant difference) as a post hoc test. The final concentration of acarbose was 6.25 mg/mL.
Mentions: AE inhibitory effects against α-lucosidase and α-mylase were respectively measured using p-nitrophenyl-α-d-glucopyranoside (pNPG) and starch as substrates (Figure 5). The inhibition of both enzyme activities was compared with that caused by a standard inhibitor, acarbose. Results indicated that AE inhibited the activity of α-glucosidase in a dose-dependent fashion: The percentages of activity were 0.85%, 6.36%, 15.93%, 40.28%, 69.64%, and 92.33% at the respective concentrations of 3.13, 6.25, 12.50, 25, 50, and 100 mg/mL (Figure 5A). Likewise, the inhibitory effect of AE against α-amylase activity occurred in a dose-dependent manner: The inhibition was intensified gradually as AE concentrations increased from 3.13 to 100 mg/mL (Figure 5B). At the concentration of 100 mg/mL, AE caused the maximum inhibition for both of the enzymes. Yet, with reference to the IC50 values of acarbose and AE, findings suggested that AE α-glucosidase and α-amylase inhibitory effects (28.92 ± 0.05 and 60.62 ± 0.32, respectively) were weaker than those of acarbose (1.11 ± 0.02 and 0.45 ± 0.07, respectively).

Bottom Line: Early work has shown that aqueous extract (AE) of NPV exerts a potent antihyperglycemic effect.One mg/mL of AE showed a comparable outcome to the use of phloridzin (1 mM) in vitro as it delayed glucose absorption through isolated rat jejunum more effectively than acarbose (1 mg/mL).Conversely, in spectrophotometric enzymatic assays, AE showed rather a weak inhibitory activity against both α-glucosidase and α-amylase when compared with acarbose.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia. namy11_pha015@student.usm.my.

ABSTRACT
Nypa fruticans Wurmb. vinegar, commonly known as nipa palm vinegar (NPV) has been used as a folklore medicine among the Malay community to treat diabetes. Early work has shown that aqueous extract (AE) of NPV exerts a potent antihyperglycemic effect. Thus, this study is conducted to evaluate the effect of AE on postprandial hyperglycemia in an attempt to understand its mechanism of antidiabetic action. AE were tested via in vitro intestinal glucose absorption, in vivo carbohydrate tolerance tests and spectrophotometric enzyme inhibition assays. One mg/mL of AE showed a comparable outcome to the use of phloridzin (1 mM) in vitro as it delayed glucose absorption through isolated rat jejunum more effectively than acarbose (1 mg/mL). Further in vivo confirmatory tests showed AE (500 mg/kg) to cause a significant suppression in postprandial hyperglycemia 30 min following respective glucose (2 g/kg), sucrose (4 g/kg) and starch (3 g/kg) loadings in normal rats, compared to the control group. Conversely, in spectrophotometric enzymatic assays, AE showed rather a weak inhibitory activity against both α-glucosidase and α-amylase when compared with acarbose. The findings suggested that NPV exerts its anti-diabetic effect by delaying carbohydrate absorption from the small intestine through selective inhibition of intestinal glucose transporters, therefore suppressing postprandial hyperglycemia.

No MeSH data available.


Related in: MedlinePlus