Therapeutic valorization of Ononis angustissima and Genista saharae : Biological activities

Abstract

Ononis angustissima and Genista saharae are endemic Algerian plants with Pharmacological potential,used for centuries in traditional medicine.Herein the efficiency of subcritical water extraction(SWE)of phenols and flavonoids from these plants was evaluated by spectrophotometric assays.Afterward,the optimal extracts were tested for its;biological activities(in vitro),and toxicity(in vivo).The most important operational parameters of the technique (temperature,pressure,time)were optimized for each plant based on phenols yield.At defined optimal extraction conditions(155°C,50 bars,15min),maximum contents of phenols in the extracts were 18.33, and 21.12mg GAE/g dry weight,for O.angustissima and G.saharae,respectively.The antioxidant activity of extracts was evaluated by different assays including, DPPH, and β-Carotene Bleaching Assays.The antidiabetic effect of the extracts wasinvestigated in vitro against α-amylase and α-glucosidase.Chemical profile of the tested extracts was defined by RP-HPLC-UV/Vis.Both chemical profiles and demonstrated bioactivities were comparable for O.angustissima and G.saharae.However,G.saharae exhibited slightly stronger antioxidant capacity and higher content of phenolic compounds.Three hydroxybenzoic acids(p-Hydroxybenzoic,protocatechuic,syringic)were the major phenolic compounds in the tested extracts.Tested extracts demonstrated inhibitory effects against both enzymes α-amylase and α-glucosidase.In both applied assays,O.angustissima exhibited stronger enzyme-inhibitory effects compared to G.saharae.The MTT assay to test the antiproliferative activity of extracts was performed with three different cell lines.The most effective cell growth inhibition activity IC50 value of 18.34 µg/mL was observed in fibroblast cell line from murine (L2OB)treated with G.saharae.The lowest IC50 value(28.27 µg/mL)was calculated in the same cell line treated with O.angustissima.The antimicrobial activity of our extracts was studied against six bacterial strains,as well as two fungal strains.Both plant extracts were equally strong against the Grampositive bacterial strains (Staphylococcus aureus and Bacillus subtilis)(MIC=78.13 μg /mL).However,G.saharae SW/extract showed better activity against Gram-negative bacterial strains.Whereas,in the case of fungi O.angustissima extract had stronger activity against Candida albicans(MIC=78.13 μg /mL),and equal against Aspergillus niger(MIC=78.13 μg/mL).The acute toxicity of extracts was carried out using mice.The LD50was found to be superior to 5000 mg/kg.Obtained results suggested that subcritical water extracts of G.saharae and O.angustissima could provide powerful natural;antioxidant,antimicrobial,and antiproliferative agents,to be used in the management of different diseases.