Biochemical Studies On Herbal Extract

In this study different extracts of chamomile (Matricaria recutita L.), geranium (Pelargonium inquinans L.) and lemon grass (Andropogon schoenantus L.) was studied for their phenolics profile and antioxidant activities. Antiradical properties of the plant extracts were compared using stable DPPH• (1,1-diphenyl-2-picrylhydrazyl) Lemon grass had the highest antiradical activities followed by geranium and chamomile. Generally, ethanol extracts had the strongest antiradical activities followed by ethyl acetate and finally hexane extracts. The ethanolic extracts of different plants were also markedly effective in inhibiting the oxidation of linoleic acid and the subsequent bleaching of β-carotene in comparison with the control. The content of phenolic compounds (mg/g) in different extracts expressed in gallic acid equivalents (GAE), varied between 1.2 and 15.3. In all plant samples ethanolic extracts contained the highest levels of total phenolics and total flavonoids followed by ethyl acetate extracts and finally hexane extracts.In addition, blends (10% and 20%, w/w) of geranium hexane extract (Ger) and lemon grass hexane extract (Lem) with corn oil (CO) were formulated. Oxidative stability (OS) and radical scavenging activity (RSA) of CO and blends stored under oxidative conditions (60°C) for 15 days were studied. By increasing the proportion of Ger and Lem in CO, levels of polyunsaturated fatty acids (PUFA) decreased, while monounsaturated fatty acids (MUFA) content increased. Progression of oxidation was followed by measuring peroxide value (PV), conjugated dienes (CD) and conjugated trienes (CT). Inverse relationships were noted between PV and OS as termination of storage. Levels of CD and CT in CO and blends increased with increase in time. CO:Ger and CO:LEm blends gave 12-22% and 26-36% inhibition of DPPH• radicals, respectively. Oxidative stability of oil blends were better than CO, most likely as a consequence of changes in fatty acids and tocopherols’ profile, and minor bioactive lipids (e.g., sterols and phenolics) found in Ger and Lem. The results are important for using those plants in different food and pharmaceutical applications.