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

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.

Triterpenoid and Steroid Content of Lipophilic Extracts of Selected Medicinal Plants of the Mediterranean Region

The available phytochemical characteristics of the medicinal plants and derived herbal material often lack data concerning the content of steroids (including phytosterols) and triterpenoids, that can be responsible for various beneficial properties and therapeutic effects, either directly, or as a result of synergistic action with other bioactive constituents. The aim of the present work was the analysis of the content of these compounds in herbal material (leaves, aerial parts) derived from selected medicinal plants (Cistus ladanifer, Cistus monspeliensis, Erica arborea, Globularia alypum, Pistacia lentiscus, Rhamnus alaternus), widely used in folk medicine in the Mediterranean region. Results obtained by gas chromatography-mass spectrometry (GC-MS)-targeted profiling revealed the diversity in the profiles and contents of steroids and triterpenoids in the analyzed plant material, ranging from 5.7% d.w. in E. arborea to 0.1% in G. alypum. The obtained results supplement the existing phytochemical data of the investigated medicinal plants, pointing to the E. arborea aerial parts and P. lentiscus leaves as valuable resources of phytosterols and bioactive triterpenoids.

(Ericaceae) aerial parts

ETHNOPHARMACOLOGICAL RELEVANCE

Erica arborea known as Khlenj in Algeria is a small shrub belonging to Ericaceae family. E. arborea Aqueous extract (EAAE) is used in traditional medicine for anti-inflammatory, diuretic, antimicrobial, and antiulcer purposes.

AIM OF THE STUDY

To our knowledge, no data reveal the combination between in-vivo anti-inflammatory and toxicological studies of EAAE. For this purpose, the aim of this study is to evaluate the biological activity cited above and assess its safety.

MATERIAL AND METHODS

Anti-inflammatory activity was undergone using carrageenan-induced paw edema and croton oil-induced ear edema. The acute and sub-acute toxicity were conducted following the OECD guidelines 423 and 407, respectively. Phytochemical identification was carried out using HPLC-DAD-MS. Quantitative evaluation of polyphenols; flavonoids and antioxidant activity of EAAE were also determined.

RESULTS

Oral administration of EAAE (250 and 500 mg/kg) significantly (p < 0.05) reduced the edema induced by carrageenan. Administration of EAAE dosed at 250 and 500 mg/kg exhibited efficacy in reducing edema induced by croton oil. The acute administration of EAAE at doses of 2000 and 5000 mg/kg did not cause any mortality or adverse effects indicating that the LD50 is above 5000 mg/kg. The prolonged administration of EAAE (500 and 1000 mg/kg) showed a significant reduction in triglycerides levels in male and female rats whereas no significant changes in other biochemical and hematological parameters were observed. Histopathological damages were recorded in both liver and kidney animal's tissues of both sexes treated with medium and maximum doses of EAAE. Phytochemical characterization of EAAE revealed a high amount of phenolic compounds, HPLC-DAD-MS analysis led to the identification of chlorogenic acid and five flavonol glycosides: myricetin pentoside, quercetin-3-O-glucoside, myricetin-3-O-rhamnoside, quercetin-3-O-pentoside, and quercetin-3-O-rhamnoside.

CONCLUSION

In the light of the results obtained in this study, EAAE corroborates the popular use to treat the anti-inflammatory impairments. EAAE can be considered as non-toxic in acute administration and exhibited a moderate toxicity in sub-acute administration. High phenolic content and in-vitro antioxidant activity observed indicate that EAAE may reduce oxidative stress markers in-vivo.