Antioxidant and Antidiabetic Activities of Fresh Aqueous Pink Petals of Indian Lotus-Nelumbo nucifera Gaertn.

Abstract

The genus Nelumbo is endowed with a number of medicinally important activities antidiabetic, antipyretic, anti-inflammatory, anti-cancerous, antimicrobial, antiviral and anti-obesity properties. Furthermore, Nelumbo nucifera flowers are served as healthy beverages to treat hypertension, cancer, diarrhea, fever, weakness, infection and body heat imbalance. It has been widely used in folk medicine for the treatment of various inflammatory and infectious diseases. Current research studies were carried out for evaluating the antioxidant, antidiabetic and antibacterial activities of fresh aqueous pink petals of Nelumbo nucifera. Antioxidant activities such as DPPH˙ radical, Superoxide (O2.-) radical, ABTS●+ radical cation, phosphomolybdenum reduction and Fe3+ reduction were carried out for fresh aqueous pink petals of Nelumbo nucifera. The maximum DPPH˙ radical scavenging activity was 88.33±0.47% at 300 µg/mL concentration and the IC50 value was 131.68 µg/mL concentration. The maximum superoxide (O2.-) radical scavenging activity was 86.76±0.31% at 120 µg/mL concentration and the IC50 value was 21.31 µg/mL concentration. The maximum ABTS●+ radical cation scavenging activity was 69.55±0.26% at 30 µg/mL concentration and the IC50 value was 10.82 µg/mL concentration respectively. The maximum Mo6+ reduction was 84.54±0.21% at 45 µg/mL concentration and the RC50 value of Mo6+ reduction was 25.79 µg/mL concentration. The maximum Fe3+ reduction was 56.00±0.38% at 300 µg/mL concentration and the RC50 value of Fe3+ reduction was 177.30 µg/mL concentration respectively. The maximum alpha amylase enzyme inhibition was 66.37±0.10% at 300 µg/mL concentration and the IC50 value was 63.84 µg/mL concentration respectively. The antibacterial activity of fresh aqueous pink petals of Nelumbo nucifera showed maximum zone of inhibition of 14 mm for B. subtilis and minimum zone of inhibition of 10 mm for E. coli at 375 µg/mL concentration. 
 Keywords: Antioxidant, Superoxide (O2.-) radical, ABTS●+ radical cation, Fe3+ reduction and alpha-amylase.