Anti-inflammatory and anticholinesterase activity of six flavonoids isolated from Polygonum and Dorstenia species

Abstract

This study was aimed at investigating the anti-inflammatory and anticholinesterase activity of six naturally occurring flavonoids: (-) pinostrobin (1), 2',4'-dihydroxy-3',6'-dimethoxychalcone (2), 6-8-diprenyleriodictyol (3), isobavachalcone (4), 4-hydroxylonchocarpin (5) and 6-prenylapigenin (6). These compounds were isolated from Dorstenia and Polygonum species used traditionally to treat pain. The anti-inflammatory activity was determined by using the Griess assay and the 15-lipoxygenase inhibitory activity was determined with the ferrous oxidation-xylenol orange assay. Acetylcholinesterase inhibition was determined by the Ellman's method. At the lowest concentration tested (3.12 µg/ml), compounds 2, 3 and 4 had significant NO inhibitory activity with 90.71, 84.65 and 79.57 % inhibition respectively compared to the positive control quercetin (67.93 %). At this concentration there was no significant cytotoxicity against macrophages with 91.67, 72.86 and 70.86 % cell viability respectively, compared to 73.1 % for quercetin. Compound 4 had the most potent lipoxygenase inhibitory activity (IC of 25.92 µg/ml). With the exception of (-) pinostrobin (1), all the flavonoids had selective anticholinesterase activity with IC values ranging between 5.93 and 8.76 µg/ml compared to the IC 4.94 µg/ml of eserine the positive control. These results indicate that the studied flavonoids especially isobavachalcone are potential anti-inflammatory natural products that may have the potential to be developed as therapeutic agents against inflammatory conditions and even Alzheimer's disease.

Spectrophotometric versus spectrofluorometric assessment in the study of the relationships between lipid peroxidation and metabolic dysregulation

“…The reported concentrations of the FOX reagent components vary in literature for both the ferrous salt and xylenol orange (Dzoyem, Kuete, McGaw, & Eloff, ; Dzoyem, Nkuete, Ngameni, & Eloff, ; Gay & Gebicki, ; Orefice et al., ; Santas, Guzmán, Guardiola, Rafecas, & Bou, ; Timabud, Sanitchon, & Pongdontri, ). The acidic medium is crucial for the assay, with a value of 1.8 being reported as optimal (Gay, Collins, & Gebicki, ; Gay & Gebicki, ; Timabud et al., ), and usually, sulphuric acid 25 mM (Dzoyem et al., ; Gay et al., ; Nourooz‐Zadeh, ; Santas et al., ) or perchloric acid 110 mM (Gay & Gebicki, ; Orefice et al., ; Timabud et al., ) is chosen as reagent solvent. For the formation of the detectable complex, an incubation step is required, from 5 (Mehta et al., ) up to 30 min (Marasca, Greetham, Herring, & Fisk, ; Santas et al., ), being detectable at either 530 (Bilgili et al., ), 550 (Timabud et al., ), or 560 nm (Gay & Gebicki, ; Gay et al., ; Santas et al., ).…”

Pre-Clinical Pharmacokinetic and Pharmacodynamic Characterization of Selected Chiral Flavonoids: Pinocembrin and Pinostrobin

“…Previous studies have suggested some pharmacological activity for pinocembrin and pinostrobin including anti-cancer, antiinflammatory, anti-diabetic, and anti-oxidant activities (15)(16)(17)(18)(19)(20)(21)(22)(23). Understanding the role of each flavonoid enantiomer in the pharmacological activity described for the racemic mixtures is important as the combined effect of some enantiomers can be exaggerated or attenuated.…”

Natural Chalcones in Chinese Materia Medica: Licorice

“…Several compounds of chalcones were discovered to strongly inhibit nitric oxide (NO), IL-6, and prostaglandin E 2 (PGE 2 ) secretion. On one hand, echinatin, licochalcones A-E, isobavachalcone, morachalcone A, DTM, licoagrochalcone C, and 4-hydroxylonchocarpin have been demonstrated to show significant inhibitory activity on LPSinduced NO production [10,21,69,70,78,80]. On the other hand, these compounds also have other different anti-inflammatory mechanisms.…”