Graciela Ferraro

Phenolic constituents of four Achyrocline species

Four species of Achyrocline were analysed for flavonoids and caffeic acid derivatives, each showing a typical pattern of distribution. Among the identified substances, only two groups characterize a given species: the epoxybutoxy derivatives and the calleryanins.

Effect of Tilia x viridis flower extract on the proliferation of a lymphoma cell line and on normal murine lymphocytes: contribution of monoterpenes, especially limonene.

Tilia species are widely used in Europe as medicinal plants. The selective antiproliferative activity of a Tilia cordata flower dichloromethane extract (DME) on a lymphoma cell line has been reported previously and in order to extend this to other unstudied Tilia species, the effect of Tilia × viridis DME on the proliferation of tumor and normal murine lymphocytes was investigated. The bioguided fractionation of DME yielded a fraction rich in limonene (L), α‐pinene and β‐pinene, which presented a selective antiproliferative action on tumor lymphocytes (EC50 on tumor cells: 3.8 ± 0.2 µg/mL; EC50 on normal cells: 205 ± 1.8 µg/mL). While all monoterpenes exhibited this activity, limonene proved to be the most active (EC50 on tumor cells: 35 ± 2.0 µg/mL; EC50 on normal cells: 72 ± 5.0 µg/mL) also exerting a stimulatory effect on non‐mitogen stimulated lymphocytes proliferation (% of stimulation respect to control) (mean ± SEM): L 10 µg/mL: 25 ± 1.0%; 20 µg/mL: 38.5 ± 2.5%; L 40 µg/mL: 41 ± 0.9%; L 60 µg/mL: 58.5 ± 3%. T. × viridis may thus constitute a potential source of monoterpenes with immunomodulatory activity. Copyright

Mechanism of the antiproliferative action of limonene on a lymphoma cell line: participation of nitric oxide. antiproliferative action of limonene on a lymphoma cell line

Previously limonene demonstrated antiproliferative action on a lymphoma cell line (BW5147). The objective of this study was to investigate the mechanism of the antiproliferative action of limonene on BW 5147 cells. The induction of apoptosis and arrest in cell cycle phases, both phenomena related to nitric oxide (NO) production, was analyzed, as well as NO production. Results showed that limonene exhibited antiproliferative action on tumoral lymphocytes exerting a decrease in cell viability that was related to apoptosis induction and to the increase in NO levels at long incubation times. At short times and depending on its concentration, limonene arrested cells in different phases of the cell cycle, related to NO production. Copyright

HPLC fingerprint of a flower extract of Tilia × viridis and correlation with antiproliferative and antioxidant activity.

Tilia species have been used in Europe and in America to treat anxiety and also for the treatment of colds, influenza, bronchitis, fever and inflammation. Tilia × viridis is a Tilia species distributed widely in Buenos Aires, Argentina. The flavonoids present in Tilia species have antioxidant properties, acting as reactive oxygen species (ROS) scavengers, principally on hydrogen peroxide (H2O2) and the superoxide anion (O2.‐), which are involved in many diseases, including cancer. The aim of this study was to determine the phytochemical pattern of the ethanol extract of Tilia × viridis, principally the flavonoid content, and to evaluate the antiproliferative effects on both normal and tumoral cells, and the antioxidant activity in relation to H2O2 modulation. The extract was found to present a selective antiproliferative activity on a lymphoma cell line and this was related to free radical scavenging activity. In addition, one of its main compounds, rutin, showed antioxidant effects related to peroxidase activity. T. × viridis may therefore be a source of antioxidant compounds that contribute to a selective antiproliferative action on tumoral cells, acting by modulation of H2O2 levels. Copyright

Comparative antioxidant activity of an extract of Lithraea molleoides and an isolated 5-alkyl resorcinol derivative. Effects on the proliferation of normal and tumoral lymphocytes.

Lithraea molleoides (Vell.) Engl. (Anacardiaceae), is known in South America for its medicinal properties: antiarthritic, haemostatic, diuretic, tonic and useful for the treatment of respiratory diseases. Previously the isolation of a new cytotoxic 5‐alkyl resorcinol derivative, 1,3‐dihydroxy‐5‐(tridec‐4′,7′‐dienyl) benzene, from a dichloromethane extract (DM) was reported. The aim of this work was to determine and to compare the antioxidant activity of DM and the isolated compound, 1,3‐dihydroxy‐5‐(tridec‐4′,7′‐dienyl) benzene. Moreover, the activity of both on the proliferation of tumoral and normal lymphocytes was determined. The compound was isolated and quantified by HPLC. The compound represented 0.036% of DM. The extract and the compound exerted antioxidant activity by DPPH and FTC methods. On tumoral cells, both exerted antiproliferative action but the compound was more active (EC50: 17.4 ± 1 µg/mL). On normal lymphocytes, both exerted a stimulatory effect on cell proliferation inversely related to concentration, the extract was more active than the compound (maximum effect: 300 ± 20% of stimulation). Most of the effects observed with the extract were independent of the isolated compound. DM could be an important source of antioxidant and immunomodulatory compounds to be studied on cancer diseases. Copyright

Insecticidal Activity of the Essential Oil and Extracts of Gutierrezia mandonii and G. repens (Asteraceae) Growing in Argentina

Abstract The insecticidal activities of essential oils (EO), the remaining water phase (RW) from the hydrodistillation, and the dichloromethane and methanolic extracts from Gutierrezia repens Griseb. and Gutierrezia mandonii (Sch. Bip.) Solbrig were evaluated. The GC and GC/MS analyses of the oils resulted in the identification of 52 compounds from G. mandonii and 17 compounds from G. repens comprising 88.7% and 98.5% of the oils, respectively. Sabi- nene (0–13.1%), β-pinene (6.4–17.8%) limonene (0.7–13.3%), (E)-β-ocimene (1.3–7.0%), terpinen-4-ol (0.7–4.1%), spathulenol (0–4.1%) and, the isomers (6R,7R)-bisabolone (6.6–58.0%) and (6S,7R)-bisabolone (0–1.6%) were the main components of the oils. Mortality and development delays of Ceratitis capitata larvae, reared using a treated artificial diet, were recorded. Gutierrezia mandonii methanolic extracts and the oil produced lethal effects (p≤0.05). Methanolic and dichloromethane extracts, the oil and the remaining water from distillation (RW) produced sublethal effects. Meanwhile dichloromethane and methanolic extracts, the oil and RW from G. repens resulted in significant mortality (p≤0.05), and all causing also significant development delays. The required concentration of G. repens oil to avoid development in 50% of C. capitata larvae (EC50) was significantly lower than G. mandonii

In vivo immunomodulatory effect of Tilia x viridis extracts on normal lymphocyte proliferation: a direct and an indirect action.

The flowers of Tilia species have been used in Europe for many years to treat colds, bronchitis, fever, inflammations and influenza. It is well known that lymphocytes play a role in acquired immunity related to pathogens and tumor cells attachment. The aim of this study was to determine the effect of an aqueous (AE) and a dichloromethane extract (DM) from Tilia x viridis which is widely used and distributed in Argentina, on normal murine lymphocyte proliferation after being administered to mice. Both extracts presented a stimulatory effect on normal murine lymphocyte proliferation. The effect exerted by DM was principally related to macrophage activation, meanwhile AE exerted an important direct effect on lymphocytes related to the rutin presence. The stimulating effect, exerted on normal lymphocytes was due to a protective effect of apoptosis and also to cell IL2 production. Copyright