Anti-collagenase, anti-elastase and anti-oxidant activities of extracts from 21 plants

Background: Owing to their roles in tissue remodelling in health and disease, several studies have reported investigations on plant extracts as inhibitors of proteinases and as anti-oxidants. Methods: The anti-ageing and anti-oxidant properties of 23 plant extracts (from 21 plant species) were assessed as anti-elastase and anti-collagenase activities and in selected anti-oxidant assays along with phenolic content. Results: Anti-elastase activities were observed for nine of the extracts with inhibitory activity in the following order:white tea (similar to 89%), cleavers (similar to 58%), burdock root (similar to 51%), bladderwrack (similar to 50%), anise and angelica (similar to 32%). Anti-collagenase activities were exhibited by sixteen plants of which the highest activity was seen in white tea (similar to 87%), green tea (similar to 47%), rose tincture (similar to 41%), and lavender (similar to 31%). Nine plant extracts had activities against both elastase (E) and collagenase (C) and were ranked in the order of white tea (E:89%, C:87%) > bladderwrack (E:50%, C:25%) > cleavers (E:58%, C:7%) > rose tincture (E:22%, C:41%) > green tea (E:10%:C:47%) > rose aqueous (E:24%, C:26%) > angelica (E:32%, C:17%) > anise (E:32%, C:6%) > pomegranate (E:15%, C:11%). Total phenolic content varied between 0.05 and 0.26 mg gallic acid equivalents (GAE)/mL with the exception of white tea (0.77 mg GAE/mL). For anti-oxidant assessment, the Trolox equivalent antioxidant capacity (TEAC) assay revealed activity for all extracts. White tea had the highest activity equivalent to similar to 21 mu M Trolox for a 6.25 mu g aliquot. In addition, seven extracts exhibited activities = 10 mu M Trolox with witch hazel (6.25 mu g = 13 mu M Trolox) and rose aqueous (6.25 mu g = 10 mu M Trolox) showing very high activities at low concentrations. A high activity for white tea was also found in the superoxide dismutase (SOD) assay in which it exhibited similar to 88% inhibition of reduction of nitroblue tetrazolium. High activities were also observed for green tea (86.41%), rose tincture (82.77%), witch hazel (82.05%) and rose aqueous (73.86%). Conclusion: From a panel of twenty three plant extracts, some one dozen exhibit high or satisfactory anti-collagenase or anti-elastase activities, with nine having inhibitory activity against both enzymes. These included white tea which was found to have very high phenolic content, along with high TEAC and SOD activities.