## 4 Discussion  
Reactive oxygen species (ROS) are generated in aerobic metabolism processes and are capable of controlling many pathways through direct reaction with proteins, controlling gene expression and transcription factors [35]. An imbalance between the antioxidant production and the production of free radical generation causes various types of pathogenesis. In this perspective, previous studies reported that medicinal plants or its active compounds prevent the pathogenesis through regulation of oxidative stress, inflammation and enhancement of antioxidant levels [11; 12; 13]. In this study, antioxidant and anti-inflammatory activity of _Tamarix aphylla_ leaf extract were examined, and it was reported that the extract showed free radical scavenging effects through DPPH assay-based findings. These leaves are a rich source of various ingredients, including polyphenols, which are responsible for scavenging the free radical formation. Previous findings were in accordance with the current finding, as _T. aphylla_ leaf and stem extracts were evaluated for antioxidant potential. It was reported that enhanced activity was noticed against DPPH radicals, superoxide anion radicals and nitric oxide radicals [36]. Other findings also reported free radical scavenging and antioxidant potential of _Tamarix aphylla_ bark and _A. javancia_ (aerial parts), respectively [37]. Current findings show that heat-induced albumin denaturation inhibition was concentration-dependent, and the % inhibition of denaturation is enhanced by an increase in extract concentration. Acute lung injury (ALI) shows high mortality and morbidity among patients and effective drugs are not available in the clinical practice [38; 39]. LPS is measured to be one of the vital aspects leading to ALI, which causes entrance of fluid to the lung tissue, as well as microvascular permeability increases, triggering the signs of acute inflammation in the tissue [40; 41]. Moreover, it causes inflammatory cell infiltration and alveolar epithelial permeability, which in turn causes in an accumulation of inflammatory cytokines in lung and BALF [42], similar to the pathology of ALI/ARDS in humans [43; 44]. After being challenged with LPS, macrophages are activated, and numerous cytokines and pro-inflammatory factors released; too much release can result in a lot of tissue damage and pathological changes [45; 46]. The treatment module in the treatment of ALI is still limited. Effective treatments with fewer side effects are still of central importance to health sciences. _Tamarix aphylla_, grown in Saudi Arabia, has been shown to have anti-inflammatory and antipyretic properties [47]. In this study, it was reported that treatment of RAW 264.7 macrophages with LPS caused a significant increase in IL-6 and TNF-\(\alpha\). Meanwhile, the extract significantly decreased the LPS-induced production of TNF-\(\alpha\) and IL-6 in a concentration-dependent manner. A previous study based on _Tamarix aphylla_ reported that its extracts inhibited the production of TNF-\(\alpha\) by LPS-activated THP-1 cells and extracts inhibited TNF-\(\alpha\) production with IC\({}_{50}\) = 3.7 \(\pm\) 0.3 and 44.9 \(\pm\) 8.9 \(\mu\)g/mL, respectively [48]. Cytotoxicity of the extract was evaluated, and it was reported that a low concentration did not show any cytotoxicity and high concentration showed mild cytotoxicity. An earlier study also reported that a mild cytotoxic effect was noticed at high concentrations of _T. aphylla_ leaf extract on the Vero cell line with a 50% cytotoxicity concentration >100 g/mL. Moreover, findings of the cytotoxicity test of extracts on Vero cells designated that this plant is possibly nontoxic [49]. In the current study, it was reported that mice induced with LPSs only showed a significant increase in inflammatory markers (TNF-\(\alpha\) and IL-6), whereas treatment with the extract significantly decreased the levels of inflammatory markers induced by LPS.