Ethnopharmacology of Calotropis procera: Traditional knowledge and scientific insights from Dodoma Region, Tanzania

Abstract

Introduction

This study explored the integration of traditional knowledge and contemporary science in the ethnopharmacology of Calotropis procera in the Kongwa District, Dodoma region in Tanzania.

Method

A cross-sectional design combining qualitative interviews with 110 respondents from Lenjulu and Majawanga villages, alongside laboratory analyses, was employed. These included preliminary phytochemical screening, GC–MS complemented by LC-MS, and in vitro antimicrobial assays using the microdilution method in 96-well microtiter plates.

Results

Ethnobotanical data revealed that traditional knowledge of C. procera is predominantly held by older community members, with 41.8 % of respondents above 55 years, and is transmitted mainly through intergenerational transfer, apprenticeships, and gender-specific roles. Phytochemical screening confirmed the presence of key bioactive compounds such as phenols, flavonoids, alkaloids, tannins, saponins, terpenoids, and steroids, validating its traditional use in treating ailments. The chemical profiling of C. procera using LC-MS and GC-MS revealed several dominant bioactive compounds across multiple pharmacological classes. For example, LC-MS analysis identified amino acids L-Tyrosine (12.73 %) and L-Isoleucine (8.92 %) and a flavonoid Quercetin (9.65 %), indicating their abundance and potential biological significance. GC-MS results highlighted a sesquiterpene Caryophyllene (8.12 %), a diterpene Neophytadiene (4.92 %) and a triterpenoid Squalene (3.56 %), all are known for anti-inflammatory and antimicrobial activities. These findings underscore the phytochemical richness and therapeutic potential of C. procera. In vitro antimicrobial assays revealed pronounced antibacterial efficacy of the C. procera, with B.subtilis exhibiting the highest susceptibility (MIC: 7.03 mg/L), followed by S.typhi (MIC: 14.06 mg/L), E.coli (MIC: 28.13 mg/L), and S.aureus (MIC: 56.25 mg/L). The observed activity is attributed to the presence of bioactive phytochemical constituents, underscoring the plant’s ethnopharmacological relevance as a promising source of natural antibacterial compounds.

Conclusion

These findings support the therapeutic potential of C. procera and underscore the critical need to preserve traditional medical knowledge for future healthcare applications.

Take-home message

Preserving the traditional knowledge of C. procera in Kongwa District is essential for future pharmaceutical and medical breakthroughs, as scientific validation has confirmed its strong antibacterial properties.