Phytochemical study and evaluation of some biological actiivities of three plants used as toothrub sticks In Togo: Terminalia avicennioides, Prosopis africana and Pseudocedrola kotschyi

Abstract

In Togo, the use of tooth-rubbing sticks, commonly referred to as "toothpicks," is a traditional practice for managing oral ailments. However, scientific data on their therapeutic potential remain limited. The objective of this study was to evaluate the biological and phytochemical properties of three plants traditionally used as tooth-rubbing sticks. Qualitative phytochemical analysis of the plant extracts was carried out using staining and/or precipitation tests. Total flavonoid content was determined by the metal chelation method, with rutin as the standard. Antioxidant activity was assessed using the FRAP method and the phosphomolybdate reduction method. The antimicrobial potential of the extracts was evaluated in vitro using the 96-well plate microdilution method combined with spreading. Acute toxicity was assessed in rats according to OECD Test Guideline 423. Phytochemical screening revealed the presence of tannins, reducing sugars, triterpenes, sterols, flavonoids, and polyphenols in the extracts of the three plants. The flavonoid assay showed a high concentration of flavonoids in the hydroalcoholic extract of the roots of Terminalia avicennioides (300.96 ± 6.73 μg ER/mg) and lower concentrations in the other two plants. Regarding antioxidant activity, the hydroalcoholic extract of the stems of Prosopis africana exhibited strong antioxidant power (380.50 ± 10.80 μmol Eq FeSO₄/mg), while the hydroalcoholic extract of the stems of Pseudocedrola kotschyi also demonstrated strong antioxidant capacity (92.67 ± 1.20 mg EAY/g extract). The hydroethanolic extracts of the three plants inhibited the in vitro growth of the tested microbial strains to varying degrees, with MIC values ranging from 3.125 to 6.25 mg/mL and CMB values ranging from 3.125 to 12.5 mg/mL. In the acute toxicity study, the LD₅₀ was greater than 5000 mg/kg body weight. These findings provide baseline data that may guide the development of novel therapeutic agents for the treatment of oral diseases.

Keywords: Terminalia avicennioides, Prosopis africana, Pseudocedrola kotschyi, acute toxicity, antimicrobial activity.