Three - (-) Catechin-O-Rhamnosides from the Eastern Nigeria Mistletoe with Potent Immunostimulatory and Antioxidant Activities
- *Corresponding Author:
- Omeje Edwin Ogechukwu
Department of Pharmaceutical and Medicinal Chemistry
Faculty of Pharmaceutical Sciences
University of Nigeria, Nsukka. 410001, Enugu, Nigeria
Tel: +234- 803-549-5441
E-mail: [email protected]; [email protected]
Received date: December 19, 2011; Accepted date: February 21, 2012; Published date: February 25, 2012
Citation: Ogechukwu OE, Ogoamaka OP, Kawamura A, Hassan A, Debbab A, et al. (2012) Three - (-) Catechin-O-Rhamnosides from the Eastern Nigeria Mistletoe with Potent Immunostimulatory and Antioxidant Activities. Biomolecul 1:102. doi:10.4172/2167-7956.1000102
Copyright: © 2012 Ogechukwu OE, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
In an attempt to provide further convincing evidence for the variously reported immunomodulatory potentials of mistletoes, bioassay-guided fractionation of the eastern Nigeria mistletoe afforded three compounds: - (-) catechin- 7-O-rhamnoside (1), - (-) catechin-3-O- rhamnoside (2) and a 4′-methoxy-7-O-rhamnoside (3). Their effects on C57BL6 mice splenocytes proliferation and expression of CD69 molecule were determined using flow cytometry techniques and compared to Lipopolysaccharide (LPS; 10 μg/ml) and Concanavalin A (ConA; 2 μg/ml) as standards. The antioxidant study was by the DPPH model with ascorbic acid as standard. The compounds (1-3) at 100 μg/ml showed statistically significant (p<0.05) stimulatory activity with values of 91.49 Â± 0.22%, 95.17 Â± 0.01% and 94.23 Â± 0.07% respectively compared to 2.65 Â± 0.33% for the unstimulated control. However, the CD69 expression assay showed only moderate stimulation. Their measured antioxidant potentials (effective concentration; EC50) were high (≤ 55.42 Â± 0.99 mg/ml) when compared to ascorbic acid (17.6 Â± 1.78 mg/ml). Characterization of the compounds was achieved by chromatographic and spectroscopic methods.