Antimycobacterial and hypolipemiant activities of Bidens odorata (Cavanilles)

Abstract

Ethnopharmacological relevance: Bidens odorata Cavanilles is a medicinal and edible plant known as "mozote blanco, aceitilla, acahual, mozoquelite" which is traditionally used in Mexico as a diuretic, hypoglycaemic, anti-inflammatory, antipyretic, antitussive, to treat gastrointestinal disorders, kidney pain, and lung or respiratory diseases.

Aim of the study: This research study was aimed at phytochemical analysis of aerial extracts of B. odorata for antimycobacterial and lipid-lowering activities.

Materials and methods: Compounds 1 (((2R, 3R, 4S, 5S, 6R)-3,4,5-Tryhidroxy-6-(((E)-3-(4-hydroxyphenyl) acryloyl) oxy) tetrahydro-2H-pyran-2-yl) methyl-4-hydroxybenzoate) and 2 (3,5-Dihydroxybenzoic acid) were isolated from B. odorata aerial shoots and their structural elucidation was carried out using 1 and 2D NMR, infrared spectroscopy (IR) and mass spectrometry (ESI-MS). The antimycobacterial activity of various extracts and compounds 1 and 2 was determined using the Microplate Alamar Blue Assay (MABA). The evaluation of the hypolipidemic effect of the ethanolic extract and the glycosylated compound 1 was tested in a murine model of hypercholesterolemia induced by diet and by Triton WR-1339. On the other hand, the LD₅₀ of the ethanolic extract was evaluated in ICR mice by the OECD protocol TG 423.

Results: Antimycobacterial assay of hexane, CH₂Cl₂, EtOAc, ethanolic and aqueous extracts, as well as the new glycosidic compound 1 and benzoic acid derivative 2 isolated from B. odorata showed minimal inhibitory concentrations (MIC) of 100, 12.5, 12.5, 12.5, ≥200, 3.125 and 50 μg/mL, respectively, against Mycobacterium tuberculosis H37Rv. Only hexane and CH₂Cl₂ extracts were observed to be active against Mycobacterium smegmatis mc²155 at a concentration of 50 and 100 μg/mL, respectively. The ethanolic extract showed lipid-lowering activity at doses of 100 and 1000 mg/kg, while glycosidic compound 1 was active at doses of 50 and 100 mg/kg. In addition, the LD₅₀ of the ethanolic extract was >2000 mg/kg, meaning that this extract does not cause lethality or adverse effects, and no signs of organs alterations or tissue damage were observed.

Conclusion: The hexane, CH₂Cl₂, EtOAc, and ethanolic extracts of B. odorata, as well as their components 1 and 2, displayed antimycobacterial activity against M. tuberculosis. Moreover, the ethanolic extract and glycosidic compound 1 showed an important lipid-lowering effect, without lethality or secondary effect. The results of this study support the documented traditional use for B. odorata.

Keywords: Bidens odorata; Hypolipidemic; Mycobacterium; Phenolic compounds; Traditional Medicine.