Submitted to: International Journal of Food Sciences and Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2011
Publication Date: 4/21/2011
Citation: Park, J.B. 2011. Identification and quantification of a major anti-oxidant and anti-inflammatory phenolic compound found in basil, lemon, thyme, mint, oregano, rosemary, sage, and thyme. International Journal of Food Sciences and Nutrition. 62(6):577-584.
Interpretive Summary: Reactive oxygen species (ROS) are generated in the human body even under normal physiological conditions. If not properly controlled, ROS such as superoxides and hydroxyl radicals attack cellular components randomly and cause severe damage to lipids, proteins, and genes. The damage is believed to initiate signaling molecules that eventually lead to aging and several human chronic diseases or conditions such as atherosclerosis, myocardial infarction, hypertension, diabetes, liver damage, rheumatoid arthritis, Alzheimer's disease, and cancer. Therefore, major phenolic compounds from extracts of seven common culinary herbs---basil (Ocimum basilicum), lemon thyme (Thymus citriodorus), mint (Mentha sp), oregano (Origanum vulgare), perilla (Perilla frutescens), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), and thyme (Thymus vulgaris)---were isolated and investigated for their antioxidant and anti-inflammatory properties. Rosmarinic acid (RA) was identified and quantified as a major antioxidant and anti-inflammatory compound in all seven herbs because it was able to inactivate superoxide radicals and inhibit COX I and II enzymes that are involved in inflammation. The results of this study will provide researchers in nutrition, molecular biology, and medicine with new information about the potential antioxidant and anti-inflammatory effects of rosmarinic acid found culinary herbs used worldwide.
Technical Abstract: Basil, lemon thyme, mint, oregano, rosemary, sage, and thyme are in the mint family of plants that are used as culinary herbs world-wide. These herbs contain phenolic compounds that are believed to have strong antioxidant and anti-inflammatory activities. Therefore, the major phenolic compounds from these seven herbs were characterized using a HPLC profiling technique for phenolics commonly found in plants in combination with measurement of DPPH-radical scavenging activity. In order to isolate antioxidant and anti-inflammatory phenolic compounds from the seven herbs, MeOH extracts of the plants were prepared and the HPLC profiles compared to those of phenolic standards. In this study, fifteen plant-derived phenolic compounds were selected and their DPPH-radical scavenging activities were determined. Afterward, standard HPLC profiling of these phenolics was constructed using an HPLC method to separate them discretely and reproducibly. Rosmarinic acid (RA) was identified as a major antioxidant compound in all seven herbs, and its structure was confirmed using NMR spectroscopic methods. The RA concentration in all of these herbs ranged from between 0.22-0.97% with a decreasing order of concentration in sage = rosemary = thyme > thyme lemon > oregano > mint > basil. RA isolated from the herbs quenched superoxide radicals from xanthine oxidase and inhibited COX I and II enzymes. This study showed that RA found in herbs may provide significant antioxidant and anti-inflammatory effects via scavenging radicals and inhibiting COX enzymes. In addition, the RA content of perilla (Perilla frutescens) used as a culinary herb in many Asian countries was determined and compared to the herbs commonly found in American grocery stores.