Brazilian southeast brown propolis: gas chromatography method development for its volatile oil analysis, its antimicrobial and leishmanicidal activities evaluation

Abstract

Introduction Propolis is widely used in folk medicine, and many factors can affect its chemical composition, including abiotic factors that can influence plants and bees. Therefore, analytical methods are powerful techniques in the quality control of such products. Objective Develop and validate an analytical method for quantifying volatile compounds in Brazilian brown propolis, and evaluate its biological activities. Methods A gas chromatography flame ionisation detector (GC‐FID) analytical method was validated, attending the parameters of international validation guidelines as ANVISA 2017 and ICH 2005, for quantification of compounds present in volatile oils from propolis. Evaluation of cytotoxic, antimicrobial, and leishmanicidal activities of the oil. Results The compounds 1,8‐cineole, terpinen‐4‐ol, α‐copaene, β‐caryophyllene, γ‐muurolene, nerolidol, spathulenol, and γ‐palmitolactone were isolated from the volatile fraction of a Brazilian brown propolis and used in the method validation. All the validation parameters of the method were satisfactory. The volatile fraction displayed a significant leishmanicidal activity, with half maximal inhibition concentration (IC50) = 21.3 μg/mL against amastigote forms and IC50 = 25.1 μg/mL against promastigote forms of Leishmania amazonensis. The oil also displayed an antibacterial effect by inhibiting the growth of Streptococcus mutans and Staphylococcus aureus at 25 μg/mL and 50 μg/mL, respectively, but it was not cytotoxic against AGP‐01, He‐La and CHO‐K1cell lines, with IC50 > 100 μg/mL. Conclusion The GC‐FID method can be a useful tool in the quality control of propolis material. The southeast brown propolis showed a high chemical complexity in its volatile fraction, which displayed leishmanicidal activity and bactericidal activity.

Phytochemical, Antiplasmodial, Cytotoxic and Antimicrobial Evaluation of a Southeast Brazilian Brown Propolis Produced by Apis mellifera Bees

“…The identification of α‐pinene and β‐pinene reinforces the hypothesis that Pinus , Eucalyptus and Araucaria angustifolia are the primary botanical sources of this propolis. The propolis used in this study proved to be different in its volatile composition from other brown propolis evaluated in the same region, [8] thus demonstrating the tremendous chemical diversity of this bee product.…”

“…These compounds were not found in this brown propolis, revealing that B. dracunculifolia does not participate in its composition. In contrast to these findings, Ribeiro et al (2021) found markers of B. dracunculifolia in brown propolis from the southeastern region in Brazil [8] …”

“…In the propolis from the Paraná state, the most abundant compounds were α‐pinene and β‐pinene [41] . α‐Pinene and β‐pinene were also the main constituents of the volatile fraction of a southeast Brazilian brown propolis [8] . The volatile main compound manool was found in Greek propolis, and the compound 13‐epi‐manoyl oxide has not been reported in propolis samples [42] …”

“…Several biological properties were attributed to Brazilian brown propolis, such as leishmanicidal, [8] anti‐inflammatory and nociceptive, [9] mutagenic and antimicrobial, [10] and antimycoplasma [11] . Some studies attribute the antimicrobial activity of brown propolis to terpenic compounds present in its extract, [12] while its antioxidant effect is related to the cytotoxic activity, mediated via free radical‐scavenging activity by the phenolic compounds [13] .…”

How diverse is the chemistry and plant origin of Brazilian propolis?

“…Propolis with brown color is produced in several areas of the Brazilian territory. For example, brown propolis produced in the municipality of Cabo Verde (state of Minas Gerais, southeast Brazil) contains volatile oil with antimicrobial and leishmanicidal activities; the oil was shown to contain chiefly mono-and sesquiterpenes, in addition to γ-palmitolactone (Ribeiro et al 2020). However, the designation "brown propolis" refers mostly to products from the Brazilian south region (states of Paraná, Santa Catarina and Rio Grande do Sul), in areas with climate ranging from subtropical to temperate, dominated by Araucaria forests (Fig.…”