The nuclei visible at the facing-down side of the membrane were counted

riments to monitor LC3 turnover confirmed that limonene enhanced autophagic flux. In fact, limonene induced a dramatic but transient BAY-41-2272 site increase in LC3II levels a finding consistent with the notion that LC3 itself is degraded by autophagy and its levels are reduced after a period of sustained autophagy. Under our experimental conditions, modulation of autophagic markers by 250750 mM d-limonene is not associated to nor it precedes cell death; in fact, we recently showed that incubation of SH-SY5Y cells with these concentrations of d-limonene for 1 h and 24 h does not affect SH-SY5Y cell viability. The latter findings are consistent with results obtained by other research groups showing that relatively high concentrations of limonene are required to affect proliferation of diverse cancer cell lines. The mechanisms underlying in vitro antiproliferative effects of limonene are not clearly defined and several mechanisms have been called into question including inhibition of protein isoprenylation and possibly alteration of Ras signaling, Ras-independent-mechanisms, increase in nitric oxide levels, ERK pathway activation, inactivation of Akt. Here we provide further insight into the biological activities of this naturally occurring monoterpene by showing that it rapidly modulates autophagic markers in vitro and this occurs at concentrations that can be found in breast tissue of women with early-stage breast cancer taking 2 grams of limonene daily for 26 PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19684114 weeks . Our present observations provide the basis for further investigations to characterize the mechanisms underlying modulation of autophagy by d-limonene. These mechanisms might be involved in its biological effects, including antinflammatory and chemopreventive activities, reported in preclinical animal models. In particular, autophagy might play a role in chemoprevention by limonene, since this pathway acts as a tumor suppressor in the early phases of tumorigenesis. The finding that linalyl acetate significantly enhanced LC3 lipidation triggered by d-limonene, highlights the inherent difficulties in dissecting the molecular 16 / 19 Bergamot Essential Oil and D-Limonene Induce Autophagy mechanisms underlying the effects of herbal drugs. Each constituent can contribute indeed to the overall effect PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19682619 of a phytocomplex and the latter might be not completely mirrored by any of each single ingredient given alone. Collectively, here we have provided evidence that BEO modulates autophagy in vitro and that d-limonene is implicated in this effect; these observations may stimulate further studies to identify the mechanisms involved and their relevance for the biological activities of these natural products. Such efforts might also be expected to lead to the identification of new targets/lead compounds for drug development. Vascular endothelial growth factor is a 43- to 46-kd glycoprotein and a major regulator of physiological and pathological angiogenesis. It increases vascular permeability and plays a vital role in endothelial cell migration, proliferation and survival. In the kidney, VEGF is highly expressed in presumptive as well as in mature podocytes and plays a critical role in glomerular development and function i.e. to establish the glomerular filtration barrier. Anti-VEGF-agents were first used in cancer treatment with some severe side effects in consequence of systemic administration. Concerning the kidneys, proteinuria and hypertension have been reported. In addition, thrombotic microangiop