S. Ragusa

Hypolipemic and hypoglycaemic activity of bergamot polyphenols: From animal models to human studies

Bergamot juice produces hypolipemic activity in rats though the mechanism remains unclear. Here we investigated on the effect of bergamot extract (BPF) in diet-induced hyperlipemia in Wistar rats and in 237 patients suffering from hyperlipemia either associated or not with hyperglycaemia. BPF, given orally for 30 days to both rats and patients, reduces total and LDL cholesterol levels (an effect accompanied by elevation of cHDL), triglyceride levels and by a significant decrease in blood glucose. Moreover, BPF inhibited HMG-CoA reductase activity and enhanced reactive vasodilation thus representing an efficient phytotherapeutic approach in combating hyperlipemic and hyperglycaemic disorders.

Antiinflammatory, Analgesic and Antipyretic Activity in Rodents of Plant Extracts used in African Medicine

Antiinflammatory, analgesic and antipyretic activities and toxicity of different extracts (decoction, petroleum ether, ethanol and aqueous extracts) of: Afrormosia laxiflora (Benth. ex Bak.) Harms (leaves), Cyathula prostrata (L.) Blume (whole plant), Ficus glomerata Roxb. (leaves), Lantana camara L. (leaves), Lippia geminata H.B.K. (leaves), Lippia nodiflora (L.) Michx. (leaves) and Synedrella nodiflora (L.) Gaertn. (whole plant), were evaluated in pharmacological tests using rats and mice.

A drug used in traditional medicine: Harpagophytum procumbens DC. II: Cardiovascular activity

In conscious normotensive rats the dried crude methanolic extract of Harpagophytum procumbens secondary roots caused a significant dose-dependent reduction of arterial blood pressure. The decrease was significant only at higher doses given by gavage (dried extract = 400 mg/kg). At the same time a decrease of heart rate was observed. In the same experimental conditions, harpagoside presented an activity lower than doses of Harpagophytum procumbens extract containing corresponding quantities of harpagoside. In spontaneously beating Langendorff preparations of rabbit heart, the Harpagophytum procumbens methanolic extract caused a mild decrease in the heart rate with a concomitant mild positive inotropic effect at lower doses but a marked negative inotropic effect at higher doses. The coronary flow decreased at higher doses only. The negative chronotropic and positive inotropic effects of harpagoside were comparatively higher with respect to that of the extract, whereas harpagide had only a slight negative chronotropic effect and a considerable negative inotropic one. Both in experiments on intact rats and on isolated rabbit heart, the Harpagophytum procumbens extract also demonstrated a protective action with regard to arrhythmias induced by aconitine, and particularly to those provoked by calcium chloride and epinephrine--chloroform.

Bergamot polyphenolic fraction enhances rosuvastatin-induced effect on LDL-cholesterol, LOX-1 expression and protein kinase B phosphorylation in patients with hyperlipidemia

BACKGROUND Statins are the most commonly prescribed drugs to reduce cardiometabolic risk. Besides the well-known efficacy of such compounds in both preventing and treating cardiometabolic disorders, some patients experience statin-induced side effects. We hypothesize that the use of natural bergamot-derived polyphenols may allow patients undergoing statin treatment to reduce effective doses while achieving target lipid values. The aim of the present study is to investigate the occurrence of an enhanced effect of bergamot-derived polyphenolic fraction (BPF) on rosuvastatin-induced hypolipidemic and vasoprotective response in patients with mixed hyperlipidemia. METHODS A prospective, open-label, parallel group, placebo-controlled study on 77 patients with elevated serum LDL-C and triglycerides was designed. Patients were randomly assigned to a control group receiving placebo (n=15), two groups receiving orally administered rosuvastatin (10 and 20mg/daily for 30 days; n=16 for each group), a group receiving BPF alone orally (1000 mg/daily for 30 days; n=15) and a group receiving BPF (1000 mg/daily given orally) plus rosuvastatin (10mg/daily for 30 days; n=15). RESULTS Both doses of rosuvastatin and BPF reduced total cholesterol, LDL-C, the LDL-C/HDL-C ratio and urinary mevalonate in hyperlipidemic patients, compared to control group. The cholesterol lowering effect was accompanied by reductions of malondialdehyde, oxyLDL receptor LOX-1 and phosphoPKB, which are all biomarkers of oxidative vascular damage, in peripheral polymorphonuclear cells. CONCLUSIONS Addition of BPF to rosuvastatin significantly enhanced rosuvastatin-induced effect on serum lipemic profile compared to rosuvastatin alone. This lipid-lowering effect was associated with significant reductions of biomarkers used for detecting oxidative vascular damage, suggesting a multi-action enhanced potential for BPF in patients on statin therapy.

Implication of limonene and linalyl acetate in cytotoxicity induced by bergamot essential oil in human neuroblastoma cells.

Bergamot (Citrus bergamia, Risso et Poiteau) essential oil (BEO) is a widely used plant extract showing anxiolytic, analgesic and neuroprotective effects in rodents; also, BEO activates multiple death pathways in cancer cells. Despite detailed knowledge of its chemical composition, the constituent/s responsible for these pharmacological activities remain largely unknown. Aim of the present study was to identify the components of BEO implicated in cell death. To this end, limonene, linalyl acetate, linalool, γ-terpinene, β-pinene and bergapten were individually tested in human SH-SY5Y neuroblastoma cultures at concentrations comparable with those found in cytotoxic dilutions of BEO. None of the tested compounds elicited cell death. However, significant cytotoxicity was observed when cells were cotreated with limonene and linalyl acetate whereas no other associations were effective. Only cotreatment, but not the single exposure to limonene and linalyl acetate, replicated distinctive morphological and biochemical changes induced by BEO, including caspase-3 activation, PARP cleavage, DNA fragmentation, cell shrinkage, cytoskeletal alterations, together with necrotic and apoptotic cell death. Collectively, our findings suggest a major role for a combined action of these monoterpenes in cancer cell death induced by BEO.

The protective effect of bergamot oil extract on lecitine-like oxyLDL receptor-1 expression in balloon injury-related neointima formation

Lectin-like oxyLDL receptor-1 (LOX-1) has recently been suggested to be involved in smooth muscle cell (SMC) proliferation and neointima formation in injured blood vessels. This study evaluates the effect of the nonvolatile fraction (NVF), the antioxidant component of bergamot essential oil (BEO), on LOX-1 expression and free radical generation in a model of rat angioplasty. Common carotid arteries injured by balloon angioplasty were removed after 14 days for histopathological, biochemical, and immunohistochemical studies. Balloon injury led to a significant restenosis with SMC proliferation and neointima formation, accompanied by increased expression of LOX-1 receptor, malondialdehyde and superoxide formation, and nitrotyrosine staining. Pretreatment of rats with BEO-NVF reduced the neointima proliferation together with free radical formation and LOX-1 expression in a dose-dependent manner. These results suggest that natural antioxidants may be relevant in the treatment of vascular disorders in which proliferation of SMCs and oxyLDL-related endothelial cell dysfunction are involved.

Chapter 27 Prevention of Glutamate Accumulation and Upregulation of Phospho‐Akt may Account for Neuroprotection Afforded by Bergamot Essential Oil against Brain Injury Induced by Focal Cerebral Ischemia in Rat

The effects of bergamot essential oil (BEO; Citrus bergamia, Risso) on brain damage caused by permanent focal cerebral ischemia in rat were investigated. Administration of BEO (0.1-0.5 ml/kg but not 1 ml/kg, given intraperitoneally 1 h before occlusion of the middle cerebral artery, MCAo) significantly reduced infarct size after 24 h permanent MCAo. The most effective dose (0.5 ml/kg) resulted in a significant reduction of infarct extension throughout the brain, especially in the medial striatum and the motor cortex as revealed by TTC staining of tissue slices. Microdialysis experiments show that BEO (0.5 ml/kg) did not affect basal amino acid levels, whereas it significantly reduced excitatory amino acid, namely aspartate and glutamate, efflux in the frontoparietal cortex typically observed following MCAo. Western blotting experiments demonstrated that these early effects were associated, 24 h after permanent MCAo, to a significant increase in the phosphorylation and activity of the prosurvival kinase, Akt. Indeed, BEO significantly enhanced the phosphorylation of the deleterious downstream kinase, GSK-3beta, whose activity is negatively regulated via phosphorylation by Akt.

A drug used in traditional medicine: harpagophytum procumbens dc. iii. effects on hyperkinetic ventricular arrhythmias by reperfusion

In Langendorff preparations of rat heart, hyperkinetic ventricular arrhythmias (HVA) have been induced by an ischaemic perfusion (coronary flux 0.5 ml/min; pressure 8 mmHg) and following reperfusion at basal conditions (coronary flux 8 ml/min; pressure 50 mmHg). Crude methanolic extracts of Harpagophytum procumbens secondary roots and harpagoside showed a significant, dose-dependent, protective action toward HVA induced by reperfusion.

A drug used in traditional medicine: harpagophytum procumbens DC. IV. effects on some isolated muscle preparations

Effects of the crude methanolic extract of Harpagophytum procumbens secondary roots and two of its active principles, harpagoside and harpagide, on some smooth muscle in vitro have been studied. The results obtained show how the action of H. procumbens is due to a complex interaction between the various active principles contained in the drug and suggest that they, especially harpagoside, interfere with the mechanisms that regulate the influx of calcium in the cells.

Characterization of Artemisia arborescens L. (Asteraceae) leaf-derived essential oil from Southern Italy

Abstract Leaf-derived essential oils isolated from Artemisia arborescens L. (Asteraceae) were analyzed by using GC/MS and GC-FID (for compound quantification); a total of 82 components were determined. The oils were derived from plants collected at the vegetative stage and originating from three locations in southern parts of Italy: Calabria, Sicily and the island of Lipari (Eolian Islands). In general, the chemical compositions were rather similar with some major differences regarding, in particular, the amounts of oxygenated compounds, such as camphor, chamazulene and α- and β-thujones. The research work was extended to the determination of a series of chiral compounds, as also the olfactive analysis of the aroma-active compounds, with the aim of acquiring an enlargened view on this specific sample-type.