Pharmacognostic Standardization, Morphometric Analysis, and Multivariate Analysis of Croton lobatus L. and Croton zambesicus Mull. Arg.

Croton lobatus L. and Croton zambesicus Mull. Arg. from the family Euphorbiaceae has been used traditionally in West tropical Africa for the treatment of rheumatism, arthritis, malaria, female infertility, and dysentery. This present study was performed to generate data for quality control, standardization, and morphometrics of C. lobatus and C. zambesicus. Macroscopic and microscopic evaluations were carried out on the plants using standard procedures. Powdered samples of the leaves were used for fluorescence analysis. Chemomicroscopy and phytochemical screening were also done according to standard procedures. The 25 accessions used for morphometrics were obtained from the herbarium specimens of the Forest Herbarium Ibadan (FHI) using 23 morphological characters. The macro- and microscopic studies of the plants showed confirmation of the species identity and also showed differences in features such as leaf apex, margin, trichome type, and anticlinal walls, which can be used in differentiating C. lobatus from C. zambesicus. For the physicochemical parameters, the moisture content was above 10.0%, and total ash ranged from 9.6% ± 0.0% to 11.7% ± 0.02%, indicating low contamination of the plant samples. Acid insoluble ash values for the two plants were below 2.0%. The phytochemical screening showed the presence of alkaloids, saponins, tannins, steroids, and cardiac glycoside in both plants. The result of the multivariate analyses (Principal Component Analysis (PCA) and Cluster Analysis) revealed that six out of the 23 parameters utilized accounted for differences among C. lobatus and C. zambesicus accessions studied. The pharmacognostic features established from the evaluation of the two species of Croton could be used for their identification, thus providing appropriate characters for their standardization.