Estimation and Action Mechanisms of Cinnamon Bark via Oxidative Enzymes and Ultrastructures as Antimicrobial, Anti-biofilm, Antioxidant, Anti-diabetic, and Anticancer Agents

Cinnamon is a plant with significant medicinal value and used extensively as a spice, flavoring, and fragrance ingredient. Phytochemical characterization via HPLC, antimicrobial activity against various microorganisms, anti-diabetic activity via α-amylase and α-glucosidase assessment, antioxidant activity via 2,2-diphenyl-1-picryl-hydrazyl-hydrate, total antioxidant capacity and Ferric reducing Antioxidant Power methods, besides anticancer activity against MCF-7 (human breast cancer cells) and WI-38 cells (human fetal lung fibroblast cells) of cinnamon bark extract were detected. A promising antimicrobial action towards Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Candida albicans, and Mucor circinelloides with inhibition zones of 25, 23, 18, 19, 29, and 16 mm, respectively was recorded. Cinnamon bark has IC50 of 5.01 and 2.58 µg/mL compared to standard acrobose with their IC50 values 4.32 and 1.99 µg/mL, for α-amylase and α-glucosidase inhibition, respectively. Cinnamon bark extract have IC50 of 77.39 ± 0.84 and 162.67 ± 0.28 μg/mL against MCF-7, and WI-38 cell lines, respectively. The protective effect of cinnamon in accelerating the apoptosis of MCF-7 cells has been verified by flow cytometric evaluation employing Annexin-V and cell cycle kits, besides increasing the amounts of malondialdehyde, hydrogen peroxide and nitric oxide with decreasing glutathione and catalase levels.