OBJECTIVE: The present novel study aims to evaluate and make a comparison of antioxidant and antiproliferative activities of different extractions of C. cassia bark using seven solvents having different polarities. Solvents polarity gradients start with the solvent of lower polarity, n-hexane, and end with water as the highest polar solvent. Among the extracts, acetone extract contains the highest phenolic and flavonoid contents; therefore, it is assessed for the ability to protect DNA from damage.
METHODS: The extracts are evaluated for total phenolic, flavonoid contents and antioxidant activities, using FRAP, DPPH, superoxide, and hydroxyl and nitric oxide radicals scavenging assays. DNA damage protecting activity of the acetone extract is studied with the comet assay. Each of the extracts is studied for its antiproliferative effect against, MCF-7, MDA-MB-231(breast cancer), and HT29 (colon cancer), using MTT assay.
RESULTS: The acetone extract exhibited the highest FRAP value, phenolic and flavonoids contents when compared to the other extracts and could protect 45% mouse fibroblast cell line (3T3-L1) from DNA damage at 30 μg/ml. The lowest IC50 value in DPPH, superoxide, and hydroxyl radicals scavenging was noticed in the ethyl acetate extract. IC50 value obtained for the hexane extract was the lowest compared to the other extracts in scavenging nitric oxide radicals. The hexane extract showed the highest antiproliferative effect against cancer cells followed by the chloroform extract. The ethyl acetate extract inhibited the proliferation of only MCF-7 by IC50 of 100 μg/ml, while the other extracts exhibited no IC50 in all the cancer cells.
CONCLUSION: C. cassia showed promising antioxidant and anticancer activities with significant DNA damage protecting effect.
DATA SYNTHESIS: We searched the following international databases from inception to January 2022: PubMed, Scopus, Web of Science and Embase, and Google Scholar. Our findings of eleven meta-analyses showed that cinnamon consumption can significantly improve total cholesterol (TC) (WMD = -1.01 mg/dL; 95% CI: -2.02, -0.00, p = 0.049), low-density lipoprotein-cholesterol (LDL-C) (WMD = -0.82 mg/dL; 95% CI: -1.57, -0.07, p = 0.032), and high-density lipoprotein-cholesterol (HDL-C) (WMD = 0.47 mg/dL; 95% CI: 0.17, 0.77, p = 0.002) levels but not triglyceride (TG) levels (WMD = -0.13 mg/dL; 95% CI: -0.58, 0.32, p = 0.570). Our results did not show any significant effect of cinnamon on malondialdehyde (MDA) levels (WMD = -0.47; 95% CI: -0.99, 0.05, p = 0.078) and C-reactive protein (CRP) levels (WMD = -1.33; 95% CI: -2.66, 0.00, p = 0.051) but there was enhanced total antioxidant capacity (TAC) in patients with type 2 diabetes (T2DM) and polycystic ovary syndrome (PCOS) (WMD = 0.34; 95% CI: 0.04, 0.64, p = 0.026) and increased levels of interleukin-6 (WMD = -1.48; 95% CI: -2.96, -0.01, p = 0.049).
CONCLUSIONS: Our results support the usefulness of cinnamon intake in modulating an imbalanced lipid profile in some metabolic disorders, particularly PCOS, as well as in improving TAC and interleukin-6. The review protocol was registered on PROSPERO as CRD42022358827.