The Democratic Republic of the Congo is a country of great biological diversity and these natural products should therefore be upgraded so that they can also serve the entire rural population.It is an innovative concept, which should be developed due to the fact that currently this subject is very almost not documented and the writings are little available. Cosmetopoeia is to cosmetics what pharmacopoeia is to pharmacy, constituting an encyclopedia of plants and their traditional uses intended to maintain health or care . It aims to promote and safeguard biodiversity and traditional knowledge by carrying out an inventory of existing cosmetic plants before they disappear . While the pharmacopoeia that lists plants for therapeutic purposes has experienced considerable development for a long time, work in the field of cosmetopoeia products is still little documented in the literature. The skin considered as the body’s largest organ is the main barrier of the body against the external environment.
Human skin infections, especially those involving soft skin and mucous surfaces, are a serious problem, especially in tropical and subtropical Low-Income Countries. The most common skin pathogens are methicillin resistant Staphylococcus aureus , Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans . In some Asian and African countries, up to 80% of the population relies on traditional medicine for their primary health care needs and in the DR Congo, several plants are traditionally used for the management of skin and skin appendages pathologies. World Health Organization recognizes that traditional, complementary and alternative medicine has many benefits and Africa has a long history of traditional medicine and practitioners that play an important role in providing care to populations . Then assessing and guaranteeing their safety and efficacy such as herbal cosmeceuticals constitutes an important challenge. In addition, the main benefits reported for cosmeceutical herbal extracts, vertical grow system used in skin care, include antioxidant and antimicrobial activities and the tyrosinase inhibiting effect . The aim of this study was to evaluate the antioxidant and antibacterial activities of extracts from leaves of Chromolaena odorata R. King & H. Rob., Mitracarpus villosus DC., Senna alata Roxb., Tetradenia riparia Codd, flowering tops of Cannabis sativa L. and red wood powders of Pterocarpus soyauxii Taub. used in the Congolese cosmetopoeia as natural cosmeceuticals agents.
Additionally, to better characterize the different parts of plants investigated, their microscopical characteristics and their chromatographic fingerprints were determined. To the best of our knowledge, there is no existing work which describes the microscopic histological characters of studied plants except for Cannabis sativa. Medicinal plant materials are categorized according to sensory microscopic and macroscopic characteristics. Microscopical inspection of crude drugs of plant origin is essential for the identification of ground or powdered materials.Adulteration in the plant samples is a serious issue that involves the deliberate or inadvertent mixture of a plant species by other inferior species, plants of other genera, or even toxic materials. Microscopic analysis is one of the cheapest methods to correctly identify the drugs and the raw materials from herbal medicines.The microscopical examination of crude drugs aims to determine the chemical nature of the cell wall along with a determination of the form and chemical nature of the cell contents. Thus, it determines the size, shape, and relative structure of the different cells and tissues in a plant drug .
Hence, the knowledge of microscopic details of the studied species is one of the most valuable tools for the evaluation of the quality and identity of these plant species. However, in-depth microscopic examinations should be carried out mainly to determine the dimensions of certain characteristic elements such as size of starch grains, calcium oxalate prisms and length of fibres and sclereids. Though microscopy alone cannot provide a complete evaluation profile of an herbal drug, it can still provide supporting evidence, which, when combined with other analytical parameters such as chromatographic fingerprints, can be used to obtain the full evidence for the standardization and evaluation of herbal drugs . The evaluation of antioxidant activity using ABTS and DPPH assays showed that all the extracts have shown the ability to inhibit radicals connected with their IC50 values .