Radical-scavenging activities vary significantly in each type of test. The IC50 values of ABTS assay were weak than those of DPPH assay. This difference is attributed to the reaction mechanisms. Indeed, ABTS reacts simultaneously with hydrophilic and lipophilic compounds while DPPH reacts only with hydrophilic compounds of the analysed matrice. Extracts of Cannabis sativa and Pterocarpus soyauxii showed very low values, which testify to their more powerful scavenging radical effect. The flowering tops of Cannabis sativa were therefore shown to be more active, followed by the red wood of Pterocarpus soyauxii then the leaves of Chromolaena odorata, Senna alata, Mitracarpus villosus and Tetradenia riparia. This difference in activity can be explained by the qualitative and quantitative composition in phytochemicals of each extract. Previous studies reported the antioxidant capacities of some of studies plants. Chromolaena odorata was described to be a species with antioxidant capacities related to its flavanone compounds . Phenolic compounds such as astragalin, luteolin and diterpenoids compounds were identified to be responsible of antioxidant activity of Tetradenia riparia .
Certain constituents of Cannabis sativa, in particular cannabinoids are also responsible for this said activity. Cannabidiol is a major non-psychotropic phytocannabinoid that attracted a great attention for its therapeutic potential against different pathologies including skin disease by its many beneficial pharmacological effects, including anti-inflammatory and antioxidant effects.The extract from the trunk of Pterocarpus soyauxii which proved to be very active after Cannabis sativa had an abundance of phenolic acids far superior to those of the others. Saha et al. reported the antioxidant capacities of different fraction from the trunk of Pterocarpus soyauxii which showed the best radical-scavenging activities.The antioxidant activities of these different parts of the species studied could correlate with their chemical composition. The antioxidant activity could be attributed to polyphenols. Polyphenols represent the most widespread secondary metabolites in the plant kingdom. They have several biological properties including the antioxidant capacities for which they are indicated in the management of various pathologies including skin infectious diseases .
The antioxidant potency is one of the most important properties of plant extracts. Since our body may not be producing enough antioxidants, it is necessary to use these antioxidant-rich ones every day to get rid of reactive species and therefore, cannabis grow equipment oxidative stress. Reactive Oxygen Species induced by oxidative stress can ultimately lead to apoptotic or necrotic cell death, once accumulated they play a critical role in intrinsic aging and photoaging of human skin in vivo, thus suggested to be responsible for various cancers of the skin and other inflammatory skin disorders . Nowadays, the properties of polyphenols are widely studied in the field of cosmeceuticals where they are recognized as having antibacterial activities, the protective effects on skin aging.As antioxidants, polyphenols act by various mechanisms which are: the direct trapping of reactives oxygen species , the inhibition of the enzymes involved in oxidative stress and the chelation of the metallic traces responsible for the production of ROS as well as the protection of systems antioxidant defense . At present, UV irradiation is considered as one of the major threats to the biological populations worldwide. Indeed, it has been identified, that a long-term exposure to the UV radiation can cause pathogenesis of severe conditions on the skin, including photoaging, immunosuppression and skin cancers.
Therefore, phenolic compounds from marine and terrestre plants with specially UV inhibition properties and antioxidant properties may have a greater potential to incorporate as an ingredient in cos meceutical products . Radical-scavenging activity is an indicator of the antioxidant activity of the different forms of use in traditional cosmetopoeia of these plant species. To the best of our knowledge, few reports exist on the antioxidant capacities of the red wood of Pterocarpus soyauxii known in DR Congo under the vernacular name of Ngola, whose wood is largely used for skin care , to heal, to color the skin and hair . Given the extent of its wide use in the manufacture of skin care products, further studies are needed, especially on cell models and in vivo to demonstrate its benefit of antioxidant effects on skin pathologies and to enhance its value. The antibacterial activity although null for all plant extracts on Pseudomonas aeruginosa is nevertheless stronger for the extracts of Cannabis sativa on Staphylococcus aureus and Escherichia coli, which correlates with the results obtained by Ali et al..