Antibacterial and cytotoxic triterpenoids from ! " ssp. ! " var. # "

Abstract

BACKGROUND:

ssp.

var. is used in traditional medicine as a mosquito repellent and sometimes chewed for treatment of gastrointestinal problems. Gastrointestinal problems are varied and may include microbial infections, parasitic infestation; inflammatory bowel disease, malignancies, peptic ulcers, or simply colic pains. This work seeks to establish proof of the concept on safety and efficacy for treatment of bacterial infections. METHODS: Root and stem bark ethanol extracts, extract fractions and two isolated compounds were tested for antibacterial activity against five standard Gram positive and two Gram negative bacteria using the broth micro-dilution method. The extracts and isolated compounds were also tested for cytotoxic activity against brine shrimp larvae (

). RESULTS: The stem and root bark ethanol extracts exhibited strong antibacterial activity against

(195.3 μg/ml) and

(390.6 μg/ml). Camaric acid (1), isolated from the dichloromethane fraction of root bark extract, exhibited antimicrobial activity against (MIC = 19.5 μg/ml)

(MIC = 19.5 μg/ml)

(MIC = 9.76 μg/ml),

(MIC = 4.88 μg/ml), and (MIC = 19.5 μg/ml), and was toxic to the shrimps (LC50 = 4.1 μg/ml). Betulinic acid (2) also from the same fraction exhibited poor anti-bacterial activity against all bacteria tested but showed high cytotoxic activity against brine shrimp larvae (LC50 = 2.4 μg/ml). CONCLUSION: Detection of antibacterial activity and isolation of an antibacterial compound, camaric acid, from extracts of

ssp.

var. supports the traditional use of extracts of the plant for treatment of gastrointestinal problems. Betulinic acid and camaric acid are already established to have anticancer activity.