As suggested by Khalid Rahman the oxidation
As suggested by Khalid Rahman , the oxidation of LDL begins once the endogenous lipophilic anti-oxidants such as α-tocopherol, α-carotene and ubiquinol levels get completely exhausted. Therefore, additional sources of natural antioxidants would be required. Thus, we derived the main objectives of this study as: (1) extraction of essential oil from C. citratus (2) FT-IR analysis to find the presence of functional groups in the essential oil (3) in vitro anti-oxidant assays and (4) cytoprotective effect of essential oil from C. citratus in PBMC induced with modified LDL (OxLDL and H2O2 LDL).
Materials and methods
Discussion The utilization of medicinal plants has relied largely on long-term clinical experience with little or no scientific data on their efficacy or safety after long-term treatment (Zhu et al., 2002; Ernst, 2004). As is the case in relation to many other medicinal plant species, there are few toxicological/toxicogenetic studies on the safety of C. citratus. Degenerative disorders, such as cancer, cardiovascular diseases and neurodegenerative diseases progress due to high levels of ROS or free radicals Yen et al. (2002). Plant based antioxidants can elicit increased synthesis of endogenous antioxidant defenses or by themselves act directly as antioxidants . The cardioprotective effect of C. citratus in isoproterenol-induced cardiotoxicity has been reported by Gayathri et al. (2010) who showed that lemon grass administration decreases the toxic effects of lipid peroxidation in both serum and heart tissue by increasing the levels of antioxidants. Costa et al. (2011) showed that oral intake of C. citratus essential oil for 21days showed reduction in cholesterol and genotoxicity. DPPH radical scavenging ability of EOC was comparable with standard L-ascorbic purchase thapsigargin suggesting the presence of proton donating ability of EOC that could serve as free radical inhibitor. The reducing power of EOC suggested that the strong antioxidant activity of EOC might be due to the presence of phenolic compounds which absorb and neutralize free radicals and quench peroxides, due to their redox properties (Gordan, 1990; Osawa et al., 1994). The total antioxidant capacity of EOC was assessed by phosphomolybdenum method. Luximon-Ramma et al. (2005). In the present study, the obtained results demonstrate that the highest antioxidant activity was at the highest concentration of EOC used (100μg/mL). The difference in the antioxidant capacity of EOC is because of the presence of phytochemicals such as tannins, triterpenoids, steroids and flavonoids [33,34]. Our results indicate that EOC has good antioxidant potential. Superoxide and hydroxyl radical are the two major ROS produced during the reduction of oxygen to water. Superoxide radicals are formed by one electron reduction of molecular oxygen [35,36]. Superoxide scavenging activity of EOC was comparable with the known antioxidant L-ascorbic acid, thus EOC also possesses superoxide scavenging activity. Nitric oxide can be described as a pleiotropic inhibitor of physiological process because it plays a vital role in smooth muscle relaxation, neural signalling, inhibition of platelet aggregation and regulation of cell mediated toxicity . Our results exhibit that EOC could increase the demand for NO under oxidative stress and since heart diseases can occur in a background of oxidative stress, the EOC may be considered to contain cardioprotective property. Lee et al.  have stated that H2O2 is poorly reactive because of its weaker oxidizing and reducing capabilities. Hence, biologically it can be a cytotoxic agent by converting itself into hydroxyl radical in the presence of metal ions and superoxide anion and produces singlet oxygen through reaction with superoxide anion or with hypochlorous acid. In this study, EOC was less effective at lower concentration, whereas at 100μg/mL the H2O2 scavenging activity was more as compared to L-ascorbic acid.