Effect of In Vitro Digestion on the Total Antioxidant Capacity and Phenolic Content of 3 Species of Oregano (Hedeoma patens, Lippia graveolens, Lippia palmeri).

Oregano phenolic compounds have been studied for their anti-inflammatory properties. Nonetheless, after ingestion, the gastrointestinal environment can affect their antioxidant stability and thus their bioactive properties. To evaluate the effect of in vitro gastrointestinal (GI) digestion on the phenolic compounds of 3 species of oregano (Hedeoma patens, Lippia graveolens, and Lippia palmeri), the total reducing capacity, total flavonoid content, and antioxidant capacity were evaluated before and after in vitro GI digestion. In addition, the phenolic compounds of the 3 oregano species were identified and quantified by UPLC-PDA before and after in vitro GI digestion. It was shown that the reducing capacity, flavonoid content and antioxidant capacity were affected by the GI digestion process. Moreover, the phenolic compounds identified were apigenin-7-glucoside, scutellarein, luteolin, luteolin-7-glucoside, phloridzin and chlorogenic acid, and their levels were affected by the in vitro GI process. Our results showed that the phenolic compounds from these 3 species of oregano are affected by the in vitro digestion process, and this effect is largely attributable to pH changes. These changes can modify the bioavailability and further anti-inflammatory activity of oregano phenolics, and thus, further research is needed. PRACTICAL APPLICATION: Oregano is a rich source of polyphenols that have shown bioactive properties like anti-inflammatory potential. However, little is known of the gastrointestinal fate of oregano polyphenols which is imperative to fully understand its bioaccessibility. Our results are important to develop new administration strategies which could help protect the antioxidant and anti-inflammatory potential and bioaccessibility of such compounds.

Extraction of volatile oil from aromatic plants with supercritical carbon dioxide: experiments and modeling.

An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE) of volatile oils from seven aromatic plants: pennyroyal (Mentha pulegium L.), fennel seeds (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.), savory (Satureja fruticosa Béguinot), winter savory (Satureja montana L.), cotton lavender (Santolina chamaecyparisus) and thyme (Thymus vulgaris), is presented. A flow apparatus with a 1 L extractor and two 0.27 L separators was built to perform studies at temperatures ranging from 298 to 353 K and pressures up to 30.0 MPa. The best compromise between yield and composition compared with hydrodistillation (HD) was achieved selecting the optimum experimental conditions of extraction and fractionation. The major differences between HD and SFE oils is the presence of a small percentage of cuticular waxes and the relative amount of thymoquinone, an oxygenated monoterpene with important biological properties, which is present in the oils from thyme and winter savory. On the other hand, the modeling of our data on supercritical extraction of volatile oil from pennyroyal is discussed using Sovová's models. These models have been applied successfully to the other volatile oil extractions. Furthermore, other experimental studies involving supercritical CO(2) carried out in our laboratories are also mentioned.

Antimicrobial activity of Hedeoma drummondii against opportunistic pathogens.

Hedeoma drummondii is a medicinal plant with diverse properties; however, validations of its medicinal uses are scarce. To evaluate its antimicrobial properties H. drummondii, was tested against opportunistic pathogens of medical importance. Antimicrobial tests were performed by the microdilution method in order to determine the Minimal Inhibitory Concentration (MIC) for each extract. Extracts of this plant showed relevant antimicrobial activity, results revealed that the hexanic extract has stronger activity and broader spectrum compared to acetone and methanol extracts. The activity of hexanic extract may be attributed mainly to the presence of the monoterpenes pulegone and menthol. In conclusion, the hexanic extract possess relevant antibacterial properties which suggests that H. drummondii have bioactive principles; these new data provide scientific support for the use of this plant in traditional medicine, particularly for gastrointestinal diseases.

Antioxidant and cytotoxic properties of an aqueous extract from the Argentinean plant Hedeoma multiflorum.

CONTEXT: Hedeoma multiflorum Benth. (Lamiaceae) is widely used in Argentinean popular medicine for digestive and anti-spasmodic purposes. However, knowledge about its pharmacological properties has been poorly investigated. OBJECTIVE: The antioxidant and cytotoxic properties of an aqueous extract from the plant were investigated for the first time. MATERIAL AND METHODS: Scavenging of stable free radicals of 2,2-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS(+)) and 2,2-diphenyl-1-picryl hydrazyl (DPPH), reducing of ferric (III) iron of ferric reducing ability of plasma (FRAP) reagent, and inhibition of lipid peroxidation (LP) of human plasma and rat brain homogenates were assessed. Cytotoxicity was tested on human polymorphonuclear (PMN) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cytotoxicity was assessed by flow cytometric techniques. RESULTS: Extract scavenged ABTS(+) and DPPH (1.78 and 0.78 µmol Trolox equivalent/mg dry extract, respectively) and reduced FRAP reagent (0.66 µmol ascorbic acid equivalent/mg dry extract). LP of human plasma and rat brain was also inhibited in a dose-dependent way (inhibitory concentration 50%=27.0 and 86.0 µg/mL, respectively). Extract is rich in polyphenol compounds (0.96 ± 0.08 µmol equivalent caffeic acid/mg dry matter). Treatment of PMN decreased significantly the cell ability to reduce the MTT salt and increased the hypodiploid nuclei from 4 to 18% quantified using propidium iodide (PI). In the annexin V-Fluorescein isothiocyanate (annexin V-FITC) assay, 26% of treated cells were annexin V-FITC positive and PI negative. Using the 3,3'-dihexyloxacarbocyanine iodide uptake method, the negative fraction of cells was calculated as 29%. DISCUSSION AND CONCLUSION: H. multiflorum extract was found to have a significant antioxidant and pro-apoptotic activities, and a great potential as a source of healthy products.

Antiproliferative effect from the Mexican poleo (Hedeoma drummondii).

Hedeoma drummondii (poleo) has been used by Mexicans to prepare a tea for its pleasant taste. The methanolic extract, polar fractions, and major antioxidant compounds of the Mexican herbal tea obtained from aerial parts of H. drummondii ("poleo") showed antiproliferative effects against the cancer cell lines MCF-7 (human breast) and HeLa (human cervix). Phenolic acids isolated from poleo have significant antiproliferative effects with caffeic acid the most potent. This evidence suggests that herbal poleo tea may have chemopreventive properties.

Free radical scavengers from the Mexican herbal tea "poleo" (Hedeoma drummondii).

The aerial parts of the Lamiaceae Hedeoma drummondii (Benth.) are used in Mexico to prepare a herbal tea and by North American Amerindians as a spice. The methanolic extract of the aerial parts exhibited a strong antioxidant effect measured by the scavenging of the free diphenyl picrylhydrazyl (DPPH) radical. Assay-guided fractionation of the crude methanolic extract allowed the identification of three major active constituents, chlorogenic, caffeic and rosmarinic acid, as well as sideritoflavone derivatives and simple phenolics. The TEAC, FRAP, total phenolic and flavonoid content were determined. The high content of caffeic acid and rosmarinic acid relates to the antioxidant activity of H. drummondii.