Résumé:
Here, an Ambrosia maritima and Bituminaria bituminosa were assessed for their phenolic profile
composition, their potential antioxidant activity in vitro, and their cytoprotective effect in primary
cultured human umbilical vein endothelial cells (HUVECs) treated with hydrogen peroxide (H2O2)
and sera from CD patients, besides their anti-inflammatory and immunostimulatory potential.
Extraction was performed using two methods: Maceration followed by liquid-liquid extraction and
low temperature extraction. The anti-antioxidant activity was assessed using chemical methods and
in HUVECs cell culture using HDCFDA probe method. The anti-inflammatory activity was tested
by performing the protein anti-denaturation assay. Acute toxicity and immunostimulatory effect were
performed in mice. BBA, AMA and AMC while were the richest in term of phenols were the richest
in terms of flavonoids content (193.39 ± 24.15, and 158.15 ± 3.8 µg QE/mg, respectively). The
evaluation of total phenols revealed that both A. maritima and B. bituminosa demonstrated an
important phenolic content, with BBA and BBB showing the highest amounts (323,11±0,76 and
198,31±0,76 µg QE/mg, respectively) Three di-caffeoylquinic acid isomers detected for the first time
in AMp while a common range of apigenin derivatives characterized the BBp extract. Using different
analytical methods, a significant in vitro antioxidant activity was reported for AMA, AMC and AMB
with IC50 values of 19.90 ± 0.01, 11.72 ± 0.79 and 19.90 ± 0.01 µg/mL, respectively, proving a
relevant antioxidant ability of A. maritima. Viability and ROS levels result obtained respectively with
MTT and H2DCFDA demonstrated CD sera's prooxidant and cytotoxic effect on HUVECs. In
contrast, the AM extract showed a biphasic dose-dependent effect on H2O2-treated cells, respectively
cytoprotective and antioxidant at low doses and cytotoxic and prooxidant at high doses while BBp
extract showed no appearing cytotoxicity or oxidative behaviour. Additionally, at the concentration
of 10µg/mL, AMp was able to counteract both CD sera-induced oxidative stress and cell death.. AM
and BB and BBB showed the best anti-denaturation effect in a dose-dependent manner with the
lowest IC50 values of 131.07 ± 0.027, 148.5 ± 0.034, and 151 ± 0.024 µg/mL, respectively. The
studied plants showed no toxicity or mortality in vivo. An overall immunostimulatory effect was
induced in a dose-dependent manner. We suggest A. maritima and B. bituminosa as potent source of
antioxidant agents for further assays to better elucidate their actions on the immune system and in
Crohn’s disease pathology.
