Phytochemical Analysis, Antioxidant and Antibacterial Capacities of a Congolese Traditional Recipe and Medicinal Plants Commonly Used in Prostate Diseases

Root barks of Morinda lucida, Psorospermum febrifugum, and trunk barks of Alstonia congensis are the three medicinal plants that make up a traditional recipe (JK recipe) used to treat prostate diseases in the Democratic Republic of Congo. This study aimed to evaluate the antioxidant, antibacterial and anti-inflammatory activities of the JK recipe as well as extracts from the selected parts of these three herbal medicines. Additionally, to better characterize the different parts of plants investigated, their microscopic histological features and their phytochemical fingerprints were determined. Powdered micrographic examination showed specific microscopic features for each botanical that constitute the database useful for the identification and authentication of these plants. The phytochemical study also focused on the reconstituted formulation. The TLC phytochemical analysis revealed the presence of various compounds, including coumarins, terpenoids, tannins, phenolic acids, and flavonoids, in both the reconstituted formulation and the individual plants. All three plants displayed important ABTS and DPPH radical-scavenging activities connected with their IC50 values with P. febrifugum as the most potent (IC50 = 18.410 ± 2.920 μg/mL for ABTS and IC50 = 92.5 ± 4.25 μg/mL for DPPH). Root barks of M. lucida exhibited a strong effect on the germ mostly involved in bacterial prostatitis, Escherichia coli (MIC = 250 μg/mL) followed by trunk barks of A. congensis (MIC = 500 μg/mL). The traditional formulation exhibited moderate antioxidant activity (IC50 = 50.8 ± 2.8 μg/mL for ABTS and IC50 = 107.2 ± 7.9 μg/mL for DPPH) and excellent anti-inflammatory activity. The antioxidant and antibacterial capacities of the three studied species and the anti-inflammatory activity of the formulation may have potential therapeutic interest and could justify their utilization in traditional medicine for the treatment of prostate diseases, but further studies are needed, especially in vitro and in vivo anti-cancer activities to demonstrate their efficacy on prostate cancer.