Explore the vast range of titles available.

Iridoids are a class of active compounds that widely exist in the plant kingdom. In recent years, with advances in phytochemical research, many compounds with novel structure and outstanding activity have been identified. Iridoid compounds have been confirmed to mainly exist as the prototype and aglycone and Ι and II metabolites, by biological transformation. These metabolites have been shown to have neuroprotective, hepatoprotective, anti-inflammatory, antitumor, hypoglycemic, and hypolipidemic activities. This review summarizes the new structures and activities of iridoids identified locally and globally, and explains their pharmacokinetics from the aspects of absorption, distribution, metabolism, and excretion according to the differences in their structures, thus providing a theoretical basis for further rational development and utilization of iridoids and their metabolites.

Iridoid glycosides are natural products occurring widely in many herbal plants. Geniposide (C17H24O10) is a well-known one, present in nearly 40 species belonging to various families, especially the Rubiaceae. Along with this herbal component, dozens of its natural derivatives have also been isolated and characterized by researchers. Furthermore, a large body of pharmacological evidence has proved the various biological activities of geniposide, such as anti-inflammatory, anti-oxidative, anti-diabetic, neuroprotective, hepatoprotective, cholagogic effects and so on. However, there have been some research articles on its toxicity in recent years. Therefore, this review paper aims to provide the researchers with a comprehensive profile of geniposide on its phytochemistry, pharmacology, pharmacokinetics and toxicology in order to highlight some present issues and future perspectives as well as to help us develop and utilize this iridoid glycoside more efficiently and safely.

The leaves of the olive plant ( Olea europaea ) are rich in polyphenols, of which oleuropein and hydroxytyrosol (HT) are most characteristic. Such polyphenols have been demonstrated to favourably modify a variety of cardiovascular risk factors. The aim of the present intervention was to investigate the influence of olive leaf extract (OLE) on vascular function and inflammation in a postprandial setting and to link physiological outcomes with absorbed phenolics. A randomised, double-blind, placebo-controlled, cross-over, acute intervention trial was conducted with eighteen healthy volunteers (nine male, nine female), who consumed either OLE (51 mg oleuropein; 10 mg HT), or a matched control (separated by a 4-week wash out) on a single occasion. Vascular function was measured by digital volume pulse (DVP), while blood collected at baseline, 1, 3 and 6 h was cultured for 24 h in the presence of lipopolysaccharide in order to investigate effects on cytokine production. Urine was analysed for phenolic metabolites by HPLC. DVP-stiffness index and ex vivo IL-8 production were significantly reduced ( P < 0·05) after consumption of OLE compared to the control. These effects were accompanied by the excretion of several phenolic metabolites, namely HT and oleuropein derivatives, which peaked in urine after 8–24 h. The present study provides the first evidence that OLE positively modulates vascular function and IL-8 production in vivo , adding to growing evidence that olive phenolics could be beneficial for health.

The Mediterranean diet (MD) is a combination of foods mainly rich in antioxidants and anti-inflammatory nutrients that have been shown to have many health-enhancing effects. Extra-virgin olive oil (EVOO) is an important component of the MD. The importance of EVOO can be attributed to phenolic compounds, represented by phenolic alcohols, hydroxytyrosol, and tyrosol, and to secoiridoids, which include oleocanthal, oleacein, oleuropein, and ligstroside (along with the aglycone and glycosidic derivatives of the latter two). Each secoiridoid has been studied and characterized, and their effects on human health have been documented by several studies. Secoiridoids have antioxidant, anti-inflammatory, and anti-proliferative properties and, therefore, exhibit anti-cancer activity. This review summarizes the most recent findings regarding the pharmacological properties, molecular targets, and action mechanisms of secoiridoids, focusing attention on their preventive and anti-cancer activities. It provides a critical analysis of preclinical, in vitro and in vivo, studies of these natural bioactive compounds used as agents against various human cancers. The prospects for their possible use in human cancer prevention and treatment is also discussed.

Purpose Dietary polyphenols have been demonstrated to favourably modify a number of cardiovascular risk markers such as blood pressure (BP), endothelial function and plasma lipids. We conducted a randomised, double-blind, controlled, crossover trial to investigate the effects of a phenolic-rich olive leaf extract (OLE) on BP and a number of associated vascular and metabolic measures. Methods A total of 60 pre-hypertensive [systolic blood pressure (SBP): 121–140 mmHg; diastolic blood pressure (DBP): 81–90 mmHg] males [mean age 45 (±SD 12.7 years, BMI 26.7 (±3.21) kg/m 2 ] consumed either OLE (136 mg oleuropein; 6 mg hydroxytyrosol) or a polyphenol-free control daily for 6 weeks before switching to the alternate arm after a 4-week washout. Results Daytime [−3.95 (±SD 11.48) mmHg, p  = 0.027] and 24-h SBP [−3.33 (±SD 10.81) mmHg, p  = 0.045] and daytime and 24-h DBP [−3.00 (±SD 8.54) mmHg, p  = 0.025; −2.42 (±SD 7.61) mmHg, p  = 0.039] were all significantly lower following OLE intake, relative to the control. Reductions in plasma total cholesterol [−0.32 (±SD 0.70) mmol/L, p  = 0.002], LDL cholesterol [−0.19 (±SD 0.56) mmol/L, p  = 0.017] and triglycerides [−0.18 (±SD 0.48), p  = 0.008] were also induced by OLE compared to control, whilst a reduction in interleukin-8 [−0.63 (±SD 1.13) pg/ml; p  = 0.026] was also detected. Other markers of inflammation, vascular function and glucose metabolism were not affected. Conclusion Our data support previous research, suggesting that OLE intake engenders hypotensive and lipid-lowering effects in vivo.

Lonicera caerulea L., also known as haskap or honeysuckle berry, is a fruit commonly planted in eastern Europe, Canada and Asia. The fruit was registered as a traditional food from a third country under European Union regulations only on December 2018. It is resistant to cold, pests, various soil acidities and diseases. However, its attractiveness is associated mostly with its health properties. The fruit shows anticancer, anti-inflammatory, and antioxidant activity—important factors in improving health. These features result from the diverse content of phytochemicals in honeysuckle berries with high concentrations of phytocompounds, mainly hydroxycinnamic acids, hydroxybenzoic acids, flavanols, flavones, isoflavones, flavonols, flavanones and anthocyanins but also iridoids, present in the fruit in exceptional amounts. The content and health properties of the fruit were identified to be dependent on cultivar, genotype and the place of harvesting. Great potential benefits of this nutritious food are its ability to minimize the negative effects of UV radiation, diabetes mellitus and neurodegenerative diseases, and to exert hepato- and cardioprotective activity.

The main objectives of this study were to develop an optimized green extraction process to obtain high contents of oleuropein and flavonoids from olive leaves. A deep eutectic solvent (DES) combined with wall-breaking extraction (WBE) was employed. A DES composed of choline chloride and ethylene glycol in a 1:2 molar ratio with 30% moisture content outperformed lactic acid and methanol as extraction solvents. The optimal conditions, determined by response surface methodology, were 30% moisture content, 140 s of wall-breaking time, and a 230 mL/g liquid–solid ratio. Under these conditions, 88.87 mg/g DM oleuropein, 4.57 mg/g DM luteolin-7-O-glucoside, and 114.31 mg RE/g total flavonoids were obtained. Among three olive varieties (Arbosana, Arbequina, and Picholine) cultivated in China, young Picholine leaves exhibited the highest contents. The Picholine-enriched extract demonstrated higher antioxidant activity (ABTS•+ 155.10 mg/mL, DPPH• 44.58 mg/mL) compared to other DES-based extracts, although it was lower than that of purified compounds. Furthermore, the CCK-8 assay revealed significant inhibition of Eca-109 human esophageal cells by the Picholine-enriched extract at 25 µg/mL for 24 h, compared to Het-1A cells. This process effectively recovers bioactive compounds from olive by-product, and shows potential for applications in nutritional supplements, cosmetics, and the food industry.

Osteoporosis is a skeletal disorder characterized by impaired bone turnover and compromised bone strength, thereby predisposing to increased risk of fracture. Preclinical research has shown that compounds produced by the olive tree (Olea europaea), may protect from bone loss, by increasing osteoblast activity at the expense of adipocyte formation. The aim of this exploratory study was to obtain a first insight on the effect of intake of an olive extract on bone turnover in postmenopausal women with decreased bone mass (osteopenia). For that, a double blind, placebo-controlled study was performed in which participants were randomly allocated to either treatment or placebo groups. 64 osteopenic patients, with a mean bone mineral density (BMD) T-score between −1.5 and −2.5 in the lumbar spine (L2–L4) were included in the study. Participants received for 12 months daily either 250 mg/day of olive extract and 1000 mg Ca (treatment) or 1000 mg Ca alone (placebo). Primary endpoints consisted of evaluation of bone turnover markers. Secondary endpoints included BMD measurements and blood lipid profiles. After 12 months, the levels of the pro-osteoblastic marker osteocalcin were found to significantly increase in the treatment group as compared to placebo. Simultaneously, BMD decreased in the placebo group, while remaining stable in the treatment group. In addition, improved lipid profiles were observed, with significant decrease in total- and LDL-cholesterol in the treatment group. This exploratory study supports preclinical observations and warrants further research by showing that a specific olive polyphenol extract (Bonolive®) affects serum osteocalcin levels and may stabilize lumbar spine BMD. Moreover, the improved blood lipid profiles suggest additional health benefits associated to the intake of the olive polyphenol extract.

The study focused on the distribution of polyphenolic compounds, iridoids, organic acids, and sugars, as well as in vitro antioxidant, anti-inflammatory, antidiabetic, antiproliferation, and antibacterial potential, and physicochemical properties between the skin and flesh of 10 haskap berry (Lonicera caerulea var. kamtschatica Sevast.) cultivars. It was found that the content of individual bioactive compounds significantly depended on the fruit cultivar and the analyzed morphological part. Anthocyanins, kaempferol derivatives and iridoids dominated in the skin, which significantly correlated with most of the analyzed health-promoting properties. In turn, the flesh showed a higher content of quercetin derivatives, sugars and organic acids. No differences were found in the content of phenolic acids, flavan-3-ols and antibacterial activity. The most beneficial properties were shown for the cultivar (cv.) ‘Honeybee’. The study suggests that haskap fruit skin is a valuable raw material for use in the pharmaceutical and food industries.

Geniposide, an iridoid glucoside, is a major component in the fruit of Gardenia jasminoides Ellis (Gardenia fruits). Geniposide has been experimentally proved to possess multiple pharmacological actions involving antioxidative stress, anti-inflammatory, antiapoptosis, antiangiogenesis, antiendoplasmic reticulum stress (ERS), etc. In vitro and in vivo studies have further identified the value of geniposide in a spectrum of preclinical models of diabetes mellitus (DM) and cardiovascular disorders. The antioxidative property of geniposide should be attributed to the result of either the inhibition of numerous pathological processes or the activation of various proteins associated with cell survival or a combination of both. In this review, we will summarize the available knowledge on the antioxidative property and protective effects of geniposide in DM and cardiovascular disease in the literature and discuss antioxidant mechanisms as well as its potential applications in clinic.