Anti-urolithiatic, antibacterial, anti-inflammatory and analgesic effects of Erica arborea flowers and leaves hydromethanolic extracts: An ethnopharmacological study

Abstract

Erica arborea L. is a medicinal plant vastly used in therapeutic purposes in several parts of the world for antimicrobial, anti-inflammatory, and diuretic purposes, and in treating urinary infections and kidney stones. The current investigation aimed to evaluate the medicinal use of E. arborea in Algeria's Bejaia region, and to examine the anti-urolithiatic, antibacterial, anti-inflammatory (in vivo), analgesic, and toxicity effects of E. arborea hydromethanolic extracts from leaves (EALE) and flowers (EALE) to give a justification for its use in the traditional medicine. The in vitro anti-urolithiathic activity of E. arborea leaf and flower hydromethanolic extracts nucleation and aggregation of crystals were measured using spectrophotometric methods. The agar disk diffusion assay and minimum inhibitory concentration (MIC) determination were employed to estimate the antibacterial effect of EAME against three Gram-positive and three Gram-negative bacterial strains in vitro. In addition, the xylene and croton oil-induced ear edema methods in mice were used to examine the topical and oral anti-inflammatory potential of the extracts. Similarly, the analgesic effect of the extract was assessed via the acetic acid-induced abdominal constriction in mice, whereas the acute toxicity of EAME was conducted following OECD guidelines. An ethnobotanical survey was conducted among 171 informants with 212 questionnaire cards. Results indicated that 28.04 % of people in the studied region used E. arborea in traditional folk medicine. Additionally, results revealed the presence of epicatechin, palmitic acid, and kaempferol-3-O-glucoside in the plant extracts. Results also showed that EAME exhibits significant and dose-dependent anti-urolithiatic activity in nucleation and aggregation assays. Furthermore, results revealed that the extracts exhibit significant antibacterial activity. The E. arborea flower extract (EAFE) showed maximum antibacterial activity, especially against P. aeruginosa, E. coli, S. gallinarum, and B. cereus. In addition, a greater minimum inhibitory concentration (MIC) in this extract was found at 1.60 mg/mL against M. luteus strain compared to the positive control. Moreover, the EAME caused a significant inhibition influence in the xylene and croton oil-induced edematous in mice. In contrast, the topical anti-inflammatory potential showed that extracts exhibit a considerable anti-edematogenic effect in both animal models. In the writhing reaction induced by the acetic acid model, the two extracts significantly reduced abdominal contractions. Finally, results of the toxicity assay showed that EAME is safe and no deaths or changes in mice behavior were observed even when doses as high as 5 g/kg DW were used. From the ethnopharmacological studies, our consequences endorse the benefit of E. arborea in folk medicine. Results of this investigation suggest that the leaf and flower extracts of E. arborea exhibit notable anti-urolithiatic, anti-inflammatory, analgesic, and antibacterial activities and are safe as a natural source of drugs with the above effects.

Keywords: Analgesic; Anti-inflammatory; Anti-urolithiatic; Antibacterial; Erica arborea; HPLC–MS.

Graphical abstract

Fig. 1

Distributions of traditional plant family use rates in the study area.

Fig. 2

Chromatograms of identified compounds revealed in hydromethanolic extracts from leaves (a) and flowers (b) of Erica arborea L. EALE: E. arborea leaf extract and EAFE: E. arborea flower extract. Major peaks labeled 1, 2, and 3 correspond to epicatechin, kaempferol-3-O-glucoside, and palmitic acid, respectively.

Fig. 3

Topical anti-inflammatory effect of EAME on croton oil-induced (CIOIE) and xylene-induced (XIE) ear edema in mice. Ind: indomethacin, EALE: E. arborea leaf extract, and EAFE: E. arborea flower extract.