Isoflavone formononetin from red propolis acts as a fungicide against Candida sp

Abstract

A bioassay-guided fractionation of two samples of Brazilian red propolis (from Igarassu, PE, Brazil, hereinafter propolis 1 and 2) was conducted in order to determine the components responsible for its antimicrobial activity, especially against Candida spp. Samples of both the crude powdered resin and the crude ethanolic extract of propolis from both locations inhibited the growth of all 12 tested Candida strains, with a minimum inhibitory concentration of 256 μg/mL. The hexane, acetate and methanol fractions of propolis 1 also inhibited all strains with minimum inhibitory concentration values ranging from 128 to 512 μg/mL for the six bacteria tested and from 32 to 1024 μg/mL for the yeasts. Similarly, hexane and acetate fractions of propolis sample 2 inhibited all microorganisms tested, with minimum inhibitory concentration values of 512 μg/mL for bacteria and 32 μg/mL for yeasts. The extracts were analyzed by HPLC and their phenolic profile allowed us to identify and quantitate one phenolic acid and seven flavonoids in the crude ethanolic extract. Formononetin and pinocembrin were the major constituents amongst the identified compounds. Formononetin was detected in all extracts and fractions tested, except for the methanolic fraction of sample 2. The isolated isoflavone formononetin inhibited the growth of all the microorganisms tested, with a minimum inhibitory concentration of 200 μg/mL for the six bacteria strains tested and 25 μg/mL for the six yeasts. Formononetin also exhibited fungicidal activity against five of the six yeasts tested. Taken together our results demonstrate that the isoflavone formononetin is implicated in the reported antimicrobial activity of red propolis.

Extraction and purification of formonometin from <i>Trifolium pratense</i> L: Physicochemical properties of its complex with lecithin

“…Since isoflavones, one of the four compounds it contained can be used as a natural replacement of estrogen, it is popular for its function to alleviate climateric symptoms in older women. Formononetin (7-Hydroxy-4′-methoxyisoflavone, C 16 H 12 O 4 , CAS: 485-72-3, MW: 268.3), one of the major substance in Red clover, has become a focus of study due to its various pharmacological and biological activities, such as anti-tumor [3], anti-oxidant [4], anti-bacterial [5], anti-inflammatory [6], anti-atherosclerosis [7], and anti-osteoporosis [8]. Therefore, it is widely used as an additive in the food and pharmaceutical industries.…”

Beekeeping in Brazil: A Bibliographic Review

“…HCA (hierarchical cluster analysis) and PLSDA (partial least squares discriminant analysis) were not able to classify the samples based on the chemical markers used. The analysis of vitamins confirmed that BP from this region can be a good source of antioxidant vitamins and that it can provide important nutritional information to food researchers and bioactive compounds for consumers 19 Neves et al [29] The botanical origin of propolis samples is difficult to ascertain on the basis of palynological analysis only, and a more definitive confirmation depends on analysis comparing the chemical profile of the samples with the chemical profile of resins and extracts from the plants found in close vicinity of the bee's hives. It should be stressed that red propolis has been suggested to be the only propolis type derived from a plant from the Leguminosae family (D. ecastaphyllum), rich in isoflavones such as genistein and formononetin.…”

Chemical characterization and pharmacological action of Brazilian red propolis

“…Neves et al (2016) studied the crude ethanolic extract of this substance in comparison to its fractionated derivatives in Candida albicans and Candida tropicallis species. The authors concluded that formononetin is an important compound for the antifungal activity demonstrated by red propolis.…”