Phenolic Profiling, Antioxidant, and Antibacterial Activities of Selected Medicinal Plants from Tunisia

Abstract

Phytochemical screening of aqueous extract from six medicinal wild plants grown in South‐eastern of Tunisia: Atriplex halimus, Teucrium polium, Moricandia arvensis, Deverra tortuoa, Haplophyllum tuberculatum and Polygonum equisetiforme were evaluated. Both decoction and ultrasound assisted extraction were used. Antioxidant, antibacterial proprieties, and phenolic profiling, using LC‐ESI‐MS method, were assessed. Total polyphenols, flavonoids, and condensed tannins contents ranged from 7.47±0.19 to 22.25±0.49 mg GAE/g Dw, 5.47±0.06 to 7.55±0.07 mg RE/g Dw, and 0.33±0.02 to 19.43±0.64 mg TAE/g Dw, respectively. Moreover, the reducing power and DPPH tests showed that P. equisetiforme (EC50: 12.50±0.50 μg/ml; DPPH⋅+: 213.49±4.24 mg TEAC/g DW), T. polium (EC50: 25.00±1.00 μg/ml; DPPH⋅+: 181.39±9.47 mg TEAC/g DW) as well as H. tuberculatum (EC50: 56.25±0.25 μg/ml; DPPH⋅+: 177.83±5.85 mg TEAC/g DW) extracts were the most effective natural antioxidants. For anti‐bacterial activity, the ultrasonic extract of H. tuberculatum showed the highest activity against both P. aeruginosa (13.50±0.71 mm) and S. aureus (13.00±0.00 mm) at 10 mg/ml. Furthermore 24 phenolic compounds were identified, with predominance of quinic acid, gallic acid, protocatechuic acid, syringic acid, p‐coumaric acid, trans‐ferulic acid, catechin (+), trans‐cinnamic and silymarin. These results were further consolidated by to heatmap clustering with P. equisetiforme, H. tuberculatum, T. polium as the main antioxidant and antibacterial sources which supports their domestication and industrial use.

Phytochemical analyses by LC‐HRMS, FTIR spectral analysis, antioxidant, antidiabetic and antityrosinase activity of Crataegus orientalis Pall. ex M. Bieb fruit extracted with various solvents

“…and biotic stress from their environment. 5 These compounds, unlike primary compounds, do not directly impact a plants biological functions but hold economic importance in the pharmaceuticals, food, and cosmetics industries. Given the bioactive potential of SMs, medicinal plants might aid in normalizing pre-disease states.…”

“…SMs are synthesized by medicinal plants as a response to abiotic stress (such as fluctuations in temperature, light exposure, water availability, soil salinity, etc.) and biotic stress from their environment 5 . These compounds, unlike primary compounds, do not directly impact a plants biological functions but hold economic importance in the pharmaceuticals, food, and cosmetics industries.…”