Antioxidant, antidiabetic, and antimicrobial efficacy of germinated Ocimum gratissimum and Ocimum basilicum seed.

Abstract

Background: The edible seeds of Ocimum gratissimum and Ocimum basilicum were found to be a potent source of phytochemicals with noteworthy antioxidant, antidiabetic, and antimicrobial properties. This study aimed to investigate the impact of germination and extraction solvents (ethanol (EtOH), distilled water) on the therapeutic properties exhibited and the ability of seed extracts to act as natural food preservatives.

Results: The EtOH extracts of germinated O. gratissimum and O. basilicum seeds exhibited more phytoconstituents content with significantly higher phenols (21.03 ± 0.01 mg gallic acid equivalent (GAE)/g and 21.46 ± 0.01 mg GAE/g respectively) and flavonoids (11.92 ± 0.03 mg quercetin equivalent (QE)/g and 14.45 ± 0.04 mg QE/g respectively) than other extracts did. Thus, they exhibited superior antioxidant potential with substantially lower half-maximal inhibitory concentration (IC₅₀) values for scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical (0.013 ± 0.00 mg mL^-1 and 0.007 ± 0.00 mg mL^-1 respectively) and superoxide anion radical (4.33 ± 0.01 mg mL^-1 and 4.14 ± 0.00 mg mL^-1 respectively) and for inhibiting lipid oxidation (2.57 ± 0.00 mg mL^-1 and 2.33 ± 0.00 mg mL^-1 respectively) compared with other extracts. Further, they exhibited better antidiabetic potential with substantially lower IC₅₀ values for inhibiting α-amylase activity (0.93 ± 0.01 mg mL^-1 and 1.01 ± 0.01 mg mL^-1 respectively) and α-glucosidase activity (0.60 ± 0.01 mg mL^-1 and 0.51 ± 0.01 mg mL^-1 respectively). Also, they showed superior antimicrobial potential with higher inhibition zones for Bacillus subtilis (13.98 ± 0.18 mm, 17.02 ± 0.18 mm respectively), Vibrio parahaemolyticus (19.00 ± 0.20 mm, 22.58 ± 0.45 mm respectively), Salmonella enterica (24.98 ± 0.18 mm, 22.17 ± 0.15 mm respectively), and Escherichia coli (23.50 ± 0.50 mm, 27.00 ± 0.20 mm respectively) and better inhibition of Aspergillus flavus growth (93.28% and 81.77% respectively) compared with other extracts.

Conclusion: Both the O. gratissimum and O. basilicum seed extracts can be utilized efficiently as therapeutic agents to manage inflammation-driven diseases and diabetes, or as natural preservatives in foods and in edible films or coatings. © 2025 Society of Chemical Industry.