Planta Med 2014; 80 - LP29
DOI: 10.1055/s-0034-1395085

3-methoxy quercetin isolated from mistletoe parasitic on Garcinia kola exhibits potent anti-inflammatory activities in vitro

E Omeje 1, 2, 3, C Nworu 2, P Osadebe 1, L Onugwu 1, R Maurya 4, N Chattopadhyay 3
  • 1Department of Pharmaceutical and Medicinal Chemistry Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Nigeria
  • 2Department of Pharmacology and Toxicology Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Nigeria
  • 3Division of Endocrinology and Center for Research on Anabolic Skeletal Targets in Health and Illness (ASTHI) CSIR-Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226 031, India
  • 4Division of Medicinal & Process Chemistry, CSIR-Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226 031, India

We investigated the folkloric anti-inflammatory activities of the extracts from the mistletoes parasitic on five different host trees using rat paw edema and leukocytes migration inhibition models. The extracts were administered at 50, 100 and 200 mg/kg body weight of rats in both models. At 200 mg/kg dose, mistletoes extract from Garcinia kola (GKM) inhibited rat paw oedema approximately 3 times stronger than the positive control, indomethacin (17.50 ± 0.04% versus 6.02 ± 0.03% respectively) and also significantly inhibited leukocyte migration at the same dose to emerge the most potent extract. Consequently, the most abundant constituent from the most potent ethyl acetate fraction was isolated in pure form (yield = 9.7%) using gradient elution of ethyl acetate: methanol and characterized as 3-methoxy quercetin (3-MQ), a known flavonoid. The effect of the compound on the viability of RAW 264.7 cells was investigated and an IC50 of 8.7 mM was obtained. The effects of 3-MQ on LPS-evoked release of nitric oxide (NO) and TNFα were studied in cultures of RAW 264.7 macrophages cell line. The scavenging of reactive oxygen species (ROS) and reactive nitrogen species (RNS) by 3-MQ was studied using luminol chemiluminescence. LPS-induced release of NO was inhibited by as much as 72.62 ± 1.15% and 98.88 ± 1.11% at 25µM and 125µM, respectively while TNFα production was inhibited by as much as 97.83 ± 0.73% at 125µM. Similarly, the 3-MQ inhibited the generation of ROS/RNS in response to phorbol-12 myrstate-13-acetate (PMA) stimulation. 3-MQ inhibited the levels of ROS/RNS by as much as 99.84 ± 0.32 at 125µM. The present findings support previous data on quercetin and its derivatives. Taken together; these data suggest a highly potent anti-inflammatory and relatively safe profile for the 3-methoxy quercetin isolated from Nigerian mistletoes parasitic on Garcinia kola.

Fig. 1: Inhibition of LPS-evoked production of TNFa by 3-MQ.

Acknowledgements: Authors acknowledge the awards of: Fulbright fellowship to Dr. C.S. Nworu and CV Raman fellowship to Dr. E. O. Omeje in the course of the Research work.

Keywords: 3-methoxy quercetin, anti-inflammatory, mistletoes, Nigerian

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