Antioxidative Constituents of the Aerial Parts of Galium spurium

Secondary metabolites from Rubiaceae species

This study describes some characteristics of the Rubiaceae family pertaining to the occurrence and distribution of secondary metabolites in the main genera of this family. It reports the review of phytochemical studies addressing all species of Rubiaceae, published between 1990 and 2014. Iridoids, anthraquinones, triterpenes, indole alkaloids as well as other varying alkaloid subclasses, have shown to be the most common. These compounds have been mostly isolated from the genera Uncaria, Psychotria, Hedyotis, Ophiorrhiza and Morinda. The occurrence and distribution of iridoids, alkaloids and anthraquinones point out their chemotaxonomic correlation among tribes and subfamilies. From an evolutionary point of view, Rubioideae is the most ancient subfamily, followed by Ixoroideae and finally Cinchonoideae. The chemical biosynthetic pathway, which is not so specific in Rubioideae, can explain this and large amounts of both iridoids and indole alkaloids are produced. In Ixoroideae, the most active biosysthetic pathway is the one that produces iridoids; while in Cinchonoideae, it produces indole alkaloids together with other alkaloids. The chemical biosynthetic pathway now supports this botanical conclusion.

Eckol inhibits ultraviolet B-induced cell damage in human keratinocytes via a decrease in oxidative stress

In previous reports, the antioxidant effects of eckol were shown to protect cells against hydrogen peroxide- and gamma ray-induced oxidative stress. In this study, the role of eckol in protecting human skin keratinocytes (HaCaT) against UVB-induced oxidative cell damage was investigated. Also, triphlorethol-A, one of the chemical components in Ecklonia cava, and quercetin a well known antioxidant, were compared with eckol in terms of antioxidant activity based on chemical structure. Eckol decreased UVB-induced intracellular reactive oxygen species (ROS), decreased injury to cellular components resulting from UVB-induced oxidative stress, and restored cell viability. In addition, eckol reduced UVB-induced apoptosis by inhibiting the disruption of mitochondrial membranes. These results suggest that eckol protects human keratinocytes against UVB-induced oxidative stress by scavenging ROS, thereby lessening injury to cellular components.

UPLC-TOF-MS analysis of Galium spurium towards its neuroprotective and anticonvulsant activities

ETHNOPHARMACOLOGICAL RELEVANCE

Galium species have been reported to be used against epilepsy in traditional Turkish folk medicine.

AIM OF STUDY

The present work was undertaken to evaluate the in vivo anticonvulsant and in vitro neuroprotective effects of Galium spurium L. and to determine the major constituents by UPLC-TOF-MS.

MATERIALS AND METHODS

Anticonvulsant activity of the aerial parts of Galium spurium was investigated using pentylenetetrazole, picrotoxin, and maximal electroshock-induced seizure animal models. In order to evaluate the safety, neurotoxicity (Rota rod test) of the ethanol extract was also determined. In vitro neuroprotective effect of the ethanol extract of Galium spurium was assessed by acetylcholinesterase and butrylcholinesterase inhibitions. Ultra Performance Liquid Chromatography-Time of Flight Mass Spectrometer (UPLC-TOF-MS) was used to identify the major compounds in the extract.

RESULTS

In pentylenetetrazole-induced seizure, the ethanol extract at doses of 250 and 1000mg/kg prolonged the onset of seizures. Similarly, Galium spurium (250 and 500mg/kg) significantly delayed the onset of picrotoxin-induced seizures in mice and these doses also exhibited 12.5% and 17% protection, respectively, against picrotoxin-induced seizures. Furthermore, Galium spurium extract showed a significant protective effect against maximal electroshock-induced seizures at doses of 250 and 1000mg/kg (50% and 37.5%, respectively) and also all tested doses prolonged the onset of seizures. No motor co-ordination was observed with intraperitoneal injection of Galium spurium extract at doses of 500 and 1000mg/kg. The extract exhibited 16.2% inhibition against butrylcholinesterase at 200μg/mL concentration, whereas it did not inhibit acetylcholinesterase. Phytochemical analysis of the extract based on the MS data by UPLC-TOF-MS, ten major compounds (phenolic and triterpenic acids, flavonoids and iridoids) were determined.

CONCLUSIONS

The results indicate that Galium spurium may have anticonvulsant activity against picrotoxin and maximal electroshock-induced seizures in mice. Phenolic acids, flavonoids and iridoids might be responsible for anticonvulsant activity. The results offer possible beneficial effects by the plant's aerial parts and may suggest a realistic explanation for its traditonal usage in epilepsy.