Comparison of Antioxidant and α-Glucosidase Inhibitory Activities in Different Cultivars of Five Mango (Mangifera Indica L.) Leaf Extracts

Abstract

The objectives of study were to evaluate and compare the antioxidant, total phenolic, total flavonoid, mangiferin content and antidiabetic activities of five young mango cultivars leaf extract, namely, ‘Apple’, ‘Nam Dok Mai’, ‘Bao’, ‘OkRong’ and ‘Kiew Savoey’. Antioxidant effect was investigated by DPPH, ABTS radical scavenging activity, and ferric reducing power (FRAP) assays. Inhibitory on α-glucosidase activity and type of enzyme inhibition were evaluated by using Lineweaver Burk plot analysis. Mangiferin, major active compound, was quantified by HPTLC method. Furthermore, the hypoglycemic effect was determined using streptozotocin (STZ) –nicotinamide (NA) -induced type 2 diabetic mice. Young mango cv. ‘Apple’ leaf extract demonstrated the strongest antioxidant activity in all assays. Moreover, it contains highest amounts of total phenolic and mangiferin to the values of 311 mg GAE/g extract and 197 mg/g extract, respectively. It possessed potent α-glucosidase inhibitory activity with IC50 value of 0.50 µg/mL. Lineweaver-Burk plot analysis demonstrated a non-competitive inhibition of αglucosidase activity with the inhibition constant (Ki) of 2.98 µg/mL. Coadministration of young mango cv. ‘Apple’ leaf extract at dose of 1,000 mg/kg significantly reduced the total blood glucose level by 13.43% in STZ-NA-induced type 2 diabetic mice when compared with control diabetic mice in oral glucose tolerance test (OGTT) model. Inhibition of glucose absorption may be one of the possible mechanism of its hypoglycemic effect. In conclusion, young mango cv. ‘Apple’ leaf extract possesses the strongest antioxidant and antidiabetic activities which has a potential to develop as nutraceutical products.

Effects of Maturation on Antibacterial Properties of Vietnamese Mango (Mangifera indica) Leaves

“…From Table 1, we observed that the yields of mango leaves varied between 26.39 and 43.66%. These results were in accordance with the previous research of Chewchinda et al [28], who determined yields of crude ethanol extracts from mango leaves within a range from 25.26 to 47.44% depending on plant variety. When converted to dried weights of initial materials, contents of mangiferin were identified within a range from 8.71 to 81.82 mg/g dried powder, which is equal to 0.87 to 8.18%.…”

“…In young light green leaves, mangiferin content was determined to be 60.23 mg/g dried powder and 137.96 mg/g extract, similar to the results of Barreto et al [31] and Chewchinda et al [28], who, respectively, reported this content to be 58.12 mg/g dried powder and 105.18 to 197.32 mg/g extract. The higher contents observed in our studies for dark reddish brown and young yellow leaves might be partly explained by the fact that Chewchinda et al [28] and Barreto et al [31] classified all newly generated leaves as one group of young leaves, while our study further divided them into three smaller groups to examine separately. Mangiferin contents in old dark green leaves were determined at 13.36 mg/g dried weight, being lower than the study of Das et al [32], who reported this concentration to be 36.9 mg/g.…”

“…In young yellow leaves, the mangiferin content was determined to be 73.12 mg/g, which is higher than that reported by Barreto et al [31], who determined the content of generally young leaves to be 58.12 mg/g. Similarly, when converted to the weight of crude extracts, mangiferin contents in young dark reddish brown and young yellow leaves were 310.06 and 220.71 mg/g extract, respectively; these values are higher than the results of Chewchinda et al [28], who determined that these contents ranged from 105.18 to 197.32 mg/g extract. In young light green leaves, mangiferin content was determined to be 60.23 mg/g dried powder and 137.96 mg/g extract, similar to the results of Barreto et al [31] and Chewchinda et al [28], who, respectively, reported this content to be 58.12 mg/g dried powder and 105.18 to 197.32 mg/g extract.…”

“…Similarly, when converted to the weight of crude extracts, mangiferin contents in young dark reddish brown and young yellow leaves were 310.06 and 220.71 mg/g extract, respectively; these values are higher than the results of Chewchinda et al [28], who determined that these contents ranged from 105.18 to 197.32 mg/g extract. In young light green leaves, mangiferin content was determined to be 60.23 mg/g dried powder and 137.96 mg/g extract, similar to the results of Barreto et al [31] and Chewchinda et al [28], who, respectively, reported this content to be 58.12 mg/g dried powder and 105.18 to 197.32 mg/g extract. The higher contents observed in our studies for dark reddish brown and young yellow leaves might be partly explained by the fact that Chewchinda et al [28] and Barreto et al [31] classified all newly generated leaves as one group of young leaves, while our study further divided them into three smaller groups to examine separately.…”

Phenolic compounds in mango fruit: a review

“…"Apple" leaf extracts demonstrated potent α-glucosidase inhibitory activity with an IC50 value of 0.50 µg/mL. In addition, the co-administration of this extract at a dose of 1,000 mg/kg significantly reduced the total blood glucose level by 13.43% in STZ-NA-induced type 2 diabetic mice [140]. Besides, 5 benzophenones and 17 flavonoids from the extracts of mango leaves were isolated and identified, and some of them showed significant anti-inflammatory, antioxidant and antidiabetic activities [141].…”