In vitro antioxidant properties of the diterpenes Parvifloron D and 7α-acetoxy-6β- hydroxyroyleanone

Abstract

59 Biomedical and Biopharmaceutical Research J o r n a l d e I n v e s t i g a ç ã o B i o m é d i c a e B i o f a r m a c ê u t i c aIn vitro antioxidant properties of the diterpenes Parvifloron D and 7α-acetoxy-6β-hydroxyroyleanone AbstractThe involvement of oxidative stress in several pathological and toxicological phenomena supports the quest for novel antioxidants. Plants from the Plectranthus genus contain bioactive components, including antioxidant compounds. In this work, the antioxidant activity of two diterpene compounds extracted from Plectranthus plants, Parvifloron D (ParvD) and 7α-acetoxy-6β-hydroxyroyleanone (Roy) was evaluated. First, the DPPH assay was used to assess the reducing capacity of these compounds. ParvD was shown to have a much stronger antioxidant activity than Roy and was therefore selected for further studies. The ability of ParvD to degrade H 2 O 2 was evaluated, but no activity was found. To assess if ParvD is able to protect DNA from ROS-induced DNA breaks, a plasmid cleavage assay was conducted. Treatment with H2O2 + Fe(II) altered the plasmid DNA conformation. In contrast, plasmid DNA treated with ParvD + H 2 O 2 + Fe(II) retained its supercoiled conformation, suggesting that ParvD protects DNA from oxidative breakage. These findings support that ParvD has antioxidant activity. Further work is planned to assess the antioxidant and DNA protective effects in cell based assays in order to validate the results found in these in vitro tests.

Screening the dermatological potential of Plectranthus species components: antioxidant and inhibitory capacities over elastase, collagenase and tyrosinase

“…Moreover, P. grandidentatus and P. ecklonii showed the highest anti-tyrosinase activity in vitro, and these were also the plants that showed increased antioxidant activity. The observed results can be attributed to the abietane diterpenoids mainly present in the organic extracts of these two plants 23,33 .…”

“…extracts, which held high RSA values only for the methanolic extracts. Actually, P. ecklonii and P. grandidentatus had the highest antioxidant activity among the studied Plectranthus species, with RSA similar to that of quercetin (89.0 2.5%) used as positive control, which is a potent antioxidant flavonoid compound 23,33 .…”

“…The search for new and more effective molecules from different sources has clearly been focussed on these potential mechanisms, with the goal of preventing oxidation, thus reducing the production of ROS and protecting the tissues 14,21 . Plants from the genus Plectranthus, belonging to the Lamiaceae family, are widely distributed across the warm and tropical areas of Africa, Asia and Oceania, and were likely brought to Mediterranean areas in the 16th century during the period of Portuguese discoveries 22,23 . Rich in essential oils and in mono-and sesquiterpenes [24][25][26] , extracts from these plants are widely used in traditional medicine with different ethnopharmacological uses, including antimicrobial, analgesic, antipyretic, anti-inflammatory and antitumoral.…”

“…Organic and aqueous extracts of several Plectranthus spp. plants, as well as their isolated compounds ( Figure 2) were obtained, characterised and screened by our team, following the procedures described in previous phytochemical studies 23,[30][31][32][33][34][44][45][46] . Their antioxidant and specific anti-enzymatic activities were tested in support of their potential interest for application in preventive dermatology and/or synergistic therapeutics.…”

Development of Parvifloron D-loaded Smart Nanoparticles to Target Pancreatic Cancer

“…Parvifloron D was isolated from P. ecklonii and thus, this plant can be associated as a good source of this abietane diterpenoid. In addition, it was also found that Parvifloron D anti-proliferative effect is generally associated with an increase in the intracellular level of Reactive Oxygen Species (ROS) that seems to play a crucial role in the apoptotic process of cells [11].…”