Antioxidant profile, acetylcholinesterase inhibition, and platelet aggregation of polyphenols and proteins from germinating green gram (Vigna radiata)

ABSTRACT

Germinating seeds tend to release a variety of bioactive compounds into the surrounding medium and their compositions vary depending on the type of seed and the temperature of the medium. During imbibition, green gram seeds exuded polyphenols and proteins, and their contents were higher at 45°C (warm seed) compared with that obtained from seeds soaked at room temperature. The total exudate from warm seeds also showed higher antioxidant activity compared with that of room-temperature exudate. Hence, the ethanol extract of the warm seed exudate was characterized for its health beneficial effects. Phenolic acids like gallic, ferulic, and sinapic acids, and flavonoids like vitexin and isovitexin were identified in the extract of the exudate. Among these, vitexin content was the highest compared to other bioactive compounds. DPPH radical scavenging activity and reducing power of the extract were comparable to those of butylated hydroxyanisole (BHA). Ethanol extract of warm seed exudate showed acetylcholinesterase (AChE) inhibition with an IC₅₀ value of 9.6 µg GAE/ml and 72% inhibition of platelet aggregation at 0.11 mg GAE/ml concentration. High MW protein (>150kDa) of the exudate showed 83% inhibition of platelet aggregation at a concentration of 1 mg/ml. Low MW proteins of 29 kDa and 12 kDa showed 50% AChE inhibition at 8 μg/ml and 6.82 μg/ml concentrations, respectively.

KEYWORDS:

• Green gram
• Exudate
• Antioxidant
• Acetylcholinesterase
• Platelet aggregation

Acknowledgements

Shaik Akbar Basha gratefully acknowledges the award of Senior Research Fellow by Indian Council of Medical Research Institute, New Delhi, India.