Phenolic content, antibacterial, antioxidant, and toxicological investigations of Erodium guttatum (Geraniaceae) collected from the Northeast of Morocco

Abstract

Erodium genus contains several medicinal traditionally used and pharmacologically explored. However, Erodium guttatum has not been well valorized. Therefore, the aim of the present study was to evaluate the antibacterial and antioxidant activities of E. guttatum extracts in addition to their toxicity. To achieve the objectives of this study, methanol and aqueous extracts of E. guttatum were prepared. Then, antibacterial activity was evaluated against Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 43816, Salmonella typhimurium ATCC 14028, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, and Listeria monocytogenes ATCC 13932 by disc diffusion and broth microdilution methods. The antioxidant activity was evaluated by DPPH scavenging assay, scavenging of hydrogen peroxide assay, and xanthine oxidase inhibition assay. The mineral composition was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Moreover, the polyphenol, flavonoids, and tannins contents were estimated using colorimetric methods. However, the safety of plant extracts was validated by performing acute and subacute acute toxicity. The results of this study showed that methanolic and aqueous extracts of E. guttatum contain important amounts of polyphenols (279.71 ± 0.31 and 142.03 ± 0.81 mg GAE/g extract), flavonoids (118.58 ± 0.14 and 68.25 ± 0.42 mg ER/ g extract), and tannins (61.81 ± 0.25 and 27.47 ± 0.62 mg CE/g extract) as well as a wide range of mineral elements. Additionally, the biological evaluation showed that plant extracts exhibit remarkable antioxidant, and antibacterial activities (MIC ranged between 6.25 and 100 mg/mL for aqueous extract and between 3.12 and 100 mg/mL for methanolic extract). Moreover, our findings showed that E. guttatum aqueous extract did not show toxicity. Therefore, E. guttatum could be a good source for the identification of antioxidant and antibacterial drugs. In addition, the observed findings could open new horizons on the ethnobotanical usages of E. guttatum. However, further investigations are required to identify and isolate bioactive compounds from this plant as well the investigations of their biological effects.