Antioxidant activity and chemical composition of essential oils of three aromatic plants from La Rioja province.

CONTEXT: The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, which is essential to identify the bioactive compounds present in it. The essential oils (EOs) of three native species from the La Rioja province were analyzed: Lippia turbinata Griseb and Lippia integrifolia (Griseb.) Hieron (Verbenaceae), and Clinopodium gilliesii (Benth.) Kuntze (Lamiaceae). OBJECTIVE: The aim of this study was to evaluate their EOs antioxidant activity (AA) and their chemical composition. MATERIALS AND METHODS: EOs were analyzed by gas chromatography-mass spectrometry (GC-MS). To enhance the aqueous solubilization of the EOs, EO-water emulsions were prepared (concentration range of 0.1-6 mg mL(-1)). AA was determined using ABTS, DPPH, and peroxyl radical scavenging assays, as well as by the ß-carotene bleaching test. RESULTS: Piperitenone oxide was a major constituent in L. turbinata, pulegone and piperitenone oxide in C. gilliesii, and ß-caryophyllene in L. integrifolia. Lippia turbinata EO was the most active ABTS and DPPH radical scavenger (SC50 values of 0.40 ± 0.14 and 0.74 ± 0.08 mg mL(-1), respectively). Clinopodium gilliesii EO exhibited the highest hydrogen peroxide scavenging activity (SC25 value = 1.52 ± 0.27 mg mL(-1)). In the ß-carotene assay, L. turbinata EO was more effective at inhibiting lipid peroxidation than the other two oils (IC25 value = 0.15 ± 0.04 mg mL(-1)). CONCLUSION: Our results suggest that the AA observed can be justified by the presence of oxygenated monoterpenes, mainly piperitenone oxide. Finally, L. turbinata EO might be used as a safe natural antioxidant and food preservative in the food and cosmetic industries.

Chemical constituents, anti-inflammatory and antioxidant activities of bark extracts from Prunus tucumanensis Lillo.

The anti-inflammatory, antioxidant, antimicrobial and cytotoxic activities of the hexane (HE), chloroform (CE) and methanol (ME) extracts obtained from the bark of Prunus tucumanensis Lillo were investigated. Both ME and CE extracts displayed a significant in vitro anti-inflammatory activity similar to dexamethasone and to a commercial formulation (Pygeum) used for the treatment of benign prostatic hyperplasia (BPH). ME exhibited powerful antioxidant (67.6% relative to BHT) and free radical scavenging (RC50 = 5 ppm) activities, antimicrobial activities against Staphylococcus aureus and Mycobacterium smegmatis and did not show any cytotoxic effect on human-derived macrophage cells. Chemical analyses showed that (2 R,3 R)-3,5,7,3',5'-pentahydroxyflavan, ß-sitosterol and ß-sitosterol-3-O-ß-D-glucopyranoside (daucosterol) are relevant components of ME.

Virucidal activity and chemical composition of essential oils from aromatic plants of central west Argentina.

The essential oils of seven aromatic plants from central west Argentina were isolated by steam distillation and analyzed by a gas chromatography/mass spectrometry technique. The oils were screened for cytotoxicity and in vitro inhibitory activity against herpes simplex virus type 1 (HSV-1), dengue virus type 2 (DENV-2) and Junin virus (JUNV). The oils showed a variable virucidal action according to the virus. JUNV was the least susceptible virus in comparison with HSV-1 and DENV-2. The better relationship between cytotoxicity and inhibitory activity was observed for the essential oil of Lantana grisebachiii (Seckt.) var. grisebachii against DENV-2 and HSV-1 with IC50 (inhibitory concentration 50%) values of 21.1 and 26.1 ppm, respectively. This effect was specific since the selectivity indices (ratio cytotoxicity/virucidal activity) were > 23.7 and > 19.1 for DENV-2 and HSV-1, respectively. Furthermore, the oil from L. grisebachii was also an effective inhibitor of HSV-2 and acyclovir resistant variants of herpes virus. This study demonstrates the effective and selective inhibitory activity of the essential oil from Lantana grisebachii against HSV and DENV by direct virus inactivation.