Identification of TRPV1 Ion Channels Agonists of Tropaeolum tuberosum in Human Skin Keratinocytes

Tropaeolum tuberosum, commonly known as Mashua, is an herbal remedy used in traditional Andean medicine for the relief of kidney and bladder pain, as well as contusions. This study aimed to evaluate the fractions and isolated compounds from T. tuberosum with analgesic activity mediated by the transient receptor potential vanilloid-1 receptor. A bioguided phytochemical analysis based on NMR/MS was performed to identify the compounds of the n-heptane fractions from samples of purple tubers of T. tuberosum. The transient receptor potential vanilloid-1 agonist and antagonist activity were assessed through the measurement of intracellular Ca²⁺ in HEK001 cells. The chemical structure determination led to the identification of two alkamides: N-(2-hydroxyethyl)-7Z,10Z,13Z,16Z-docosatetraenamide (1: ) and N-oleoyldopamine (2: ). Both compounds induced increased intracellular calcium flow with IC₅₀ values of 3.2 nM and 7.9 nM, respectively, thus activating the transient receptor potential vanilloid-1 receptor. Our research is the first report to show that these two compounds isolated from T. tuberosum can act as agonists of the transient receptor potential vanilloid-1 receptor, providing scientific evidence for the traditional use of this species in pain relief.

Cocoa Flavanols Protect Human Endothelial Cells from Oxidative Stress

Oxidative stress may cause functional disorders of vascular endothelia which can lead to endothelial apoptosis and thus alter the function and structure of the vascular tissues. Plant antioxidants protect the endothelium against oxidative stress and then become an effective option to treat vascular diseases. Cocoa flavanols have been proven to protect against oxidative stress in cell culture and animal models. In addition, epidemiological and interventional studies strongly suggest that cocoa consumption has numerous beneficial effects on cardiovascular health. The objective of this study was to test the chemo-protective effect of realistic concentrations of a cocoa phenolic extract and its main monomeric flavanol epicatechin on cultured human endothelial cells submitted to an oxidative challenge. Both products efficiently restrained stress-induced reactive oxygen species and biomarkers of oxidative stress such as carbonyl groups and malondialdehyde, and recovered depleted glutathione, antioxidant defences and cell viability. Our results demonstrate for the first time that a polyphenolic extract from cocoa and its main flavonoid protect human endothelial cells against an oxidative insult by modulating oxygen radical generation and antioxidant enzyme and non-enzyme defences.

Paronychia argentea Lam. protects renal endothelial cells against oxidative injury

ETHNOPHARMACOLOGICAL RELEVANCE

Paronychia argentea Lam. (Arabic tea), a species spontaneously growing in the Mediterranean area, has been used in folk medicine for renal diseases.

AIM OF THE STUDY

To assess the antioxidant and protective potentials of different extracts from P. argentea in the renal endothelial NRK-52E cell line by several in vitro models, including a H₂O₂-induced oxidative stress model.

MATERIAL AND METHODS

Aerial parts of P. argentea were collected in Algeria and ethanolic, chloroform and aqueous-chloroform extracts were obtained from dried plant. The antioxidant capacity was first evaluated by the Oxygen Radical Absorbance Capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Cellular viability was assessed by MTT method assay after 24 h pretreatment with each extract concentration in order to measure protection from H₂O₂ in NRK-52E cells. Furthermore, the intracellular ROS formation (DCFH-DA method), was determined.

RESULTS

P. argentea showed in vitro antioxidant activity as evidenced by the ORAC and DPPH assays. No cell toxicity was observed for concentrations ranging from 0.1 to 100 μg/mL of each extract. These extracts also exerted a protective effect on renal endothelial cells simultaneously treated with 1 mM H₂O₂. Chemical composition for the aqueous-chloroform extract was assessed by HPLC, as it showed the strongest antioxidant ability, revealing three quercetin derivatives as the main phenolic compounds.

CONCLUSION

P. argentea is endorsed with antioxidant activity and protects renal endothelial cells against oxidative damage which indicate this plant constitutes a potential treatment for renal diseases.

Molecular Targets Involved in the Neuroprotection Mediated by Terpenoids

Natural products and their derivatives represent the most consistently successful source of drug leads. Terpenoids, a structurally diverse group, are secondary metabolites widely distributed in nature, endowed with a wide range of biological activities such as antibacterial, anti-inflammatory, antitumoral, or neuroprotective effects, which consolidate their therapeutic value. During the last decades, and taking into consideration the prevalence of aging-related diseases, research activity into the neuroprotective effects of these types of compounds has increased enormously. Several signaling pathways involved in neuroprotection are targets of their mechanism of action and mediate their pleiotropic protective activity in neuronal cell damage. In the present review, molecular basis of the neuroprotection exerted by terpenoids is presented, focusing on preclinical evidence of the therapeutic potential of diterpenoids and triterpenoids on neurodegenerative disorders. By acting on diverse mechanisms simultaneously, terpenoids have been emphasized as promising multitarget agents.

Protective Effect of Silybum marianum and Silibinin on Endothelial Cells Submitted to High Glucose Concentration

Silybum marianum Gaertn. (Milk thistle) has been used since ancient times for the relief of liver diseases characterized by intense oxidative stress such as inflammatory liver disease and cirrhosis. As oxidative stress by hyperglycemia is involved in micro- and macrovascular complications of type 2 diabetes, our aim was to assess the protective effect of milk thistle seed extract against oxidative stress induced by a high glucose concentration on endothelial cells (EA.hy926 cells). High-performance liquid chromatographic analysis shows flavonolignans silychristin and silibinin A and B as major components. No cell toxicity was observed for concentrations up to 100 µg/mL of milk thistle extract for 24 h. Concentrations of 5-25 µg/mL of the extract were used to assess the protective effect on EA.hy926 cells treated with 30 mM glucose for 24 h. Oxidative damage by 30 mM glucose was shown as a significant decrease in reduced glutathione and a significant increase in protein carbonyls and antioxidant enzyme activities. S. marianum extract recovered reduced glutathione and balanced the elevated carbonyls and enzyme activity. Silibinin alone also recovered reduced glutathione and antioxidant enzymes. S. marianum protects endothelial cell against oxidative damage by modulating antioxidant enzyme activity, reduced glutathione, and protein carbonyl levels.

Geographic origin influences the phenolic composition and antioxidant potential of wild Crataegus monogyna from Spain

CONTEXT

Crataegus monogyna Jacq L. (Lind.) (Rosaceae) is used in folk medicine as a sedative, aerial parts being rich in polyphenols with antioxidant ability.

OBJECTIVES

To study the variation in polyphenolic composition and antioxidant ability of spontaneous samples of C. monogyna in order to assess the relationship among these variables.

MATERIALS AND METHODS

Aerial parts of C. monogyna were collected from nine different locations in central Spain and extracted with methanol after drying. Total polyphenols were determined by the Folin-Ciocalteu method using gallic acid (GA) as standard. Sixteen polyphenolic compounds (11 flavonoids and 5 phenolic acids) were identified and quantified by reversed-phase HPLC in one single analysis. The antioxidant ability was evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Linear correlation analysis was used to explore the relationships between the studied variables.

RESULTS

Total polyphenol content ranged between 117.729 ± 0.011 and 204.286 ± 0.015 mg GAE/g extract, depending on the geographic origin. No relationship was found between total polyphenols and antioxidant ability by the ORAC or DPPH methods. Chromatographic analysis yielded lower amounts of polyphenols (23.3-143.26 mg/kg), as only flavonoids and phenolic acids were quantified. All the samples exhibited antioxidant activity between 1.32 ± 0.08 and 2.76 ± 0.007 μmol Trolox equivalents/mg and IC₅₀ from 0.82 ± 0.10 to 3.76 ± 0.67 μg/mL.

CONCLUSION

A statistically significant relationship between flavonoids and phenolic acids content and the antioxidant potential obtained by the ORAC method for C. monogyna samples was proven.

Effectiveness of Rosmarinus officinalis essential oil as antihypotensive agent in primary hypotensive patients and its influence on health-related quality of life

ETHNOPHARMACOLOGICAL RELEVANCE

To study Rosmarinus officinalis (Rosemary) essential oil effect on primary hypotension and its influence on both physical and psychological aspects responsible for health-related quality of life (HRQOL) of patients.

METHODOLOGY

Thirty-two patients with diagnosed hypotension were recruited between March 2007 and September 2008 for a prospective study for 72 weeks in a Spanish pharmacy. Clinical evaluation was carried out through the control of systolic and diastolic blood pressure levels (SBP and DBP, respectively) according to the International Standards from the American Society of Hypertension. HRQOL data were recorded within the SF-36 Health Survey(®) questionnaire throughout the study. Statistical methods were used as the essential tools to evaluate the effectiveness of Rosemary essential oil and to assess the relationship between the two quantitative variables (SBP and DBP) and scores from physical and mental summary components (PSC and MSC) obtained from the SF-36 Health Survey.

RESULTS

Both blood pressure variables of SBP and DBP reflect the clinically significant antihypotensive effect of Rosemary essential oil that was maintained throughout the treatment period. After validation of the use of the questionnaire (Cronbach's alpha coefficient>0.82), statistically significant differences have been found between pre-treatment and post-treatment values of PSC and MSC, which indicate an improvement in these parameters that is directly related to the variation in blood pressure values.

CONCLUSIONS

The increase achieved in blood pressure values after administration of Rosemary essential oil is clinically significant. The results obtained from this prospective clinical trial prove the effectiveness of statistical methodology as a new approach to explain the antihypotensive effect of rosemary essential oil and its relationship with the improvement in patients' quality of life.

Ethnopharmacological study of medicinal plants used in the treatment of CNS disorders in Sinai Peninsula, Egypt

ETHNOPHARMACOLOGICAL RELEVANCE

To provide ethnopharmacological information on the use of medicinal plants for central nervous system (CNS) disorders in the Sinai Peninsula region (Egypt). To collect, analyze and evaluate the ethnobotanical knowledge about these medicinal plants in the Sinai Peninsula region with 61,000 km (2) and 379,000 inhabitants.

METHODOLOGY

Field work was concluded between March 2006 and May 2011, using semi-structured questionnaire with 700 informants (mean age: 59; 100% men) from 117 settlements of 17 Bedouin tribes. Transects walks in wild herbal plant collection areas and bibliographical review on the collected plants were also conducted. The Interview/ Inhabitant index (I/P), relative importance value of the species and informant consensus factor (FIC) were calculated.

RESULTS

More than 300 species were traditionally used in folk medicine in the Sinai Peninsula; 101 of these species belonging to 40 families were reported as useful in different CNS disorders. Only 5 species are endemic of the studied area. All different part plants were used, leaves and aerial parts being the most frequent. Most of the remedies were prepared as infusion or decoction, while oral administration was the most common way to be used. Gastrointestinal (67.3%) and respiratory disorders (42.57%) were also reported as frequently treated by Bedouins with herbal remedies.

CONCLUSIONS

Only a few species were found where the traditional use is supported by pharmacological studies (Acacia nilotica, Achillea fragrantissima, Ajuga iva or Mentha longifolia). No bibliographical references in the scientific literature were found for 22 species (21.78%); finally, several studies were published with different pharmacological activities than those provided by Bedouins.

HPLC isolation of antioxidant constituents from Xanthoparmelia spp

A chromatographic method is described for the purification and characterization of secondary lichen substances with biological activity. A simple reversed-phase high-performance liquid chromatography method with gradient elution has been developed that allows the determination and isolation of salazinic, usnic and stictic acids from lichen samples in a single run and the quantification of every acid in the tested extracts. The antioxidant activity of both the isolated compounds and the respective lichen belonging to Xanthoparmelia genus was determined by the Oxygen Radical Absorbance Capacity (ORAC) assay; their effect as free radical scavengers, effect on cell survival by the 3(4,5-dimethyltiazol-2-yl)-2,5-diphenyltetrazolium reduction assay and 2',7'-dichlorofluorescin diacetate method were tested on U373 MG human astrocytome cell line. Both lichens extracts and all isolated compounds protected U373 MG cells from hydrogen peroxide-induced damage, suggesting that they could act as antioxidant agents in those neurodegenerative disorders associated with oxidative damage, such as Alzheimer's disease and Parkinson's disease.

Study of red wine neuroprotection on astrocytes

Phenolic composition of wine depends not only on the grape variety from which it is made, but on some external factors such as winemaking technology. Red wine possesses the most antioxidant effect because of its high polyphenolic content. The aim of this work is to study for the first time, the neuroprotective activity of four monovarietal Spanish red wines (Merlot (ME), Tempranillo (T), Garnacha (G) and Cabernet-Sauvignon (CS)) through its antioxidant ability, and to relate this neuroprotection to its polyphenolic composition, if possible. The wine effect on neuroprotection was studied through its effect as free radical scavenger against FeSO4, H2O2 and FeSO4 + H2O2. Effect on cell survival was determined by 3(4,5-dimethyltiazol-2-il)-2,5-diphenyltetrazolium reduction assay (MTT) and lactate dehydrogenase (LDH) release assay on astrocytes cultures. Results showed that most of the studied wine varieties induced neuroprotection through their antioxidant ability in astrocytes, Merlot being the most active; this variety is especially rich in phenolic compounds, mainly catechins and oligomeric proanthocyanidins. Our results show that red wine exerts a protection against oxidative stress generated by different toxic agents and that the observed neuroprotective activity is related to their polyphenolic content.

Isoscutellarein 7-glucosyl(1-->2)xyloside from sixteen species of Sideritis

A new flavone diglycoside isolated from the aerial parts of Sideritis lutoela was characterized as isoscutellarein 7-O-beta-D-glucopyranosyl(1-->2) beta-D-xylopyranoside by means of spectral analyses, applying 2D NMR techniques and NOE experiments. Its presence in 15 other species of Sideritis is described.