ABSTRACT
Melissa officinalis L. (Lamiaceae) is consumed as a traditional herbal tea in the Mediterranean region. The cytotoxic effect of the 50% ethanolic and aqueous extract, determined by the MTT and NR assays, was evaluated in vitro on Human Colon Cancer Cell Line (HCT-116), using Triton 10% as positive control. The 50% ethanolic extract showed significant differences after 72 h of treatment, reducing cell proliferation to values close to 40%, even the lowest dose tested (5 µg/ml). In the MTT assay, the same extract caused the lowest cell viability with 13% at a concentration of 1,000 µg/ml after 72 h of treatment, being a value lower than Triton 10%. The antioxidant activity was also confirmed evaluating the capacity of the extracts to scavenge ABTS and DPPH radicals, and IC(50) values were highly correlated with the total phenolic and flavonoid content. Bioassay guided fractionation led to the isolation of an anti-proliferative compound, rosmarinic acid. Its structural elucidation was performed by HPLC/DAD/ESI/MS analysis. High dose of rosmarinic acid (1,000 µg/ml) was clearly cytotoxic against HCT-116 cells, with a significant decrease in cell number since the earliest time point (24 h).
Subject(s)
Antioxidants/pharmacology , Cinnamates/pharmacology , Depsides/pharmacology , Flavonoids/pharmacology , Melissa/chemistry , Phenols/pharmacology , Plant Extracts/pharmacology , Antioxidants/chemistry , Antioxidants/isolation & purification , Beverages , Cell Proliferation/drug effects , Cell Survival/drug effects , Cinnamates/chemistry , Cinnamates/isolation & purification , Depsides/chemistry , Depsides/isolation & purification , Flavonoids/chemistry , Flavonoids/isolation & purification , HCT116 Cells , Humans , Phenols/chemistry , Phenols/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Leaves/chemistry , Plants, Medicinal/chemistry , Time Factors , Rosmarinic AcidABSTRACT
A new formulation of bologna-type sausage enriched in ω-3 polyunsaturated fatty acids (PUFA) (8.75% linseed oil) was developed, using a lyophilized aqueous-ethanolic extract of Melissa officinalis. A comparison with the effectiveness of butylhydroxy anisole (BHA) synthetic antioxidant to decrease the oxidation of PUFAs was performed. The formulation increased the ω-3 PUFAs content, especially α-linolenic acid, decreasing significantly the ω-6/ω-3 ratio from 17.3 to 1.9, and also the Atherogenic Index and Thrombogenic Index (0.38-0.31 and 1.03-0.54, respectively). Modified sausages with BHA and Melissa extract showed significantly lower peroxides value (2.62 and 6.11 meq O2/kg) and thiobarbituric acid value (0.26 and 0.27 mg malondialdehyde/kg) and higher antioxidant capacity (hydrophilic fraction ABTS: 0.45 and 0.74 meq Trolox/g product; lipofilic fraction ABTS: 0.44 and 0.37 meq Trolox/g product) than those without these ingredients (16.49 meq O2/kg, 2.08 mg malondialdehyde /kg, 0.26 and 0.27 meq Trolox/g product, respectively). Sensorial tests showed that acceptability of the new formulations was similar to control products.
Subject(s)
Meat Products/analysis , Melissa/chemistry , Plant Extracts/chemistry , alpha-Linolenic Acid/metabolism , Animals , Antioxidants/chemistry , Food Additives/metabolism , Food Handling , Freeze Drying/methods , Linseed Oil/chemistry , Oxidation-Reduction , Swine , Thiobarbiturates/analysis , alpha-Linolenic Acid/analysisABSTRACT
Previous work pointed out the possibility to enhance the nutritional value of meat products using long chain omega-3 PUFA enriched emulsions. Oil-in-water emulsions elaborated with a mixture of algae and linseed oils (15:10) in order to be used as functional ingredient were stabilized with BHA (butylhydroxyanisol) or with a lyophilized water extract of Melissa officinalis L. (Lemon balm). The lipid profile of the oil mixture showed a high amount of DHA (31.7%), oleic (25.4%) and alpha-linolenic acid (12.7%) resulting in a very low omega-6/omega-3 ratio (0.12). The lyophilized extract of M. officinalis showed a high antioxidant activity (being 62ppm of the lyophilized water extract of Melissa equivalent to 200ppm of BHA, using the DPPH assay as reference), and high total phenolic content. Studying the oxidation process in the emulsions during 15days at room temperature, it could be concluded that this extract was as efficient as BHA in order to control the thiobarbituric acid reactive substances (TBARS) formation.