Protection of Chinese olive fruit extract and its fractions against advanced glycation endproduct-induced oxidative stress and pro-inflammatory factors in cultured vascular endothelial and human monocytic cells

Comparative metabolic profiling of olive leaf extracts from twelve different cultivars collected in both fruiting and flowering seasons

Olea europaea is an economically significant crop native to Mediterranean countries. Its leaves exhibit several biological properties associated to their chemical composition. The aqueous ethanolic extracts of olive leaves from twelve different cultivars were analyzed by high performance liquid chromatography coupled to photodiode array and electrospray ionization mass spectrometry (HPLC/PDA/ESI-MS/MS). A total of 49 phytochemicals were identified in both positive and negative ionization modes. The identified compounds belonged to four classes of secondary metabolites including secoiridoids, flavonoids, pentacyclic triterpenoids and various phenolic compounds. Seasonal variation in chemical composition among the studied cultivars was apparent in autumn and spring. Secologanoside, oleuropein, hydroxy-oleuropein, demethyl oleuropein, gallocatechin, luteolin-O-hexoside, diosmetin, oleanolic acid and maslinic acid were detected in all cultivars in both seasons. Oleuropein-O-deoxyhexoside was tentatively identified for the first time in olive leaf extracts; detected only in the Spanish cultivar Picual (PIC) collected in spring. Also, dihydroxy-oxooleanenoic acid and hydroxy-oxooleanenoic acid, two bioactive pentacyclic triterpenes, were identified. Principle component analysis (PCA) showed good discrimination among the studied cultivars in terms of their botanical origin. This study is considered the first study for non-targeted metabolic profiling of different olive leaf cultivars cultivated in Egypt.

Ethnopharmacology, biological activities and chemical compounds of Canarium strictum: An important resin-yielding medicinal tree in India

The resin of Canarium strictum Roxb. is used for rheumatism and asthma; the bark is used as a mosquito repellent. The major compounds in the resin are triterpenoids, but as no studies have been performed on the bark, this study investigated this economically important resource. Ten folk healers were interviewed about their medicinal uses of C. strictum. Resin and bark were extracted with dichloromethane followed by methanol using accelerated solvent extraction. The extracts were fractionated using different chromatographic methods, and isolated compounds were identified by NMR spectroscopy and GC-MS. Resin and bark extracts were investigated for DPPH radical scavenging, 15-lipoxygenase inhibition, effects on nitric oxide (NO) production in LPS-activated dendritic D2SC/I cells and toxicity against Artemia salina nauplii. Traditional healers used resin to treat colds, airway afflictions and rheumatoid arthritis. α-Amyrin and β-amyrin were identified as the major constituents in the dichloromethane resin extract. From the stem bark, procyanidins, gallic acid, methyl gallate, scopoletin, 3,3'-di-O-methylellagic acid 4-O-α-arabinofuranoside and elephantorrhizol (3,3',4',5,6,7,8-heptahydroxyflavan) were isolated and identified. By GC-MS, α-amyrin and β-amyrin and their acetates, lupeol, and taraxasterol were identified. Radical scavenging, 15-lipoxygenase inhibitory activity and inhibition of NO production was observed from resin and bark extracts, and no toxicity towards Artemia salina nauplii was found. Triterpenoids and procyanidins are the major compounds in C. strictum resin and stem bark, respectively. The high content of triterpenoids might contribute to anti-inflammatory effects and give a rationale for the widespread usage of the resin in India.

Macleaya cordata extract alleviated oxidative stress and altered innate immune response in mice challenged with enterotoxigenic Escherichia coli

This study examines the effects of dietary Macleaya cordata extract (MCE) on bacterial burden and resistance to enterotoxigenic Escherichia coli (ETEC) in ICR mice. ICR mice were randomly distributed into one of the following groups: (i) basal diet; (ii) basal diet with 200 mg kg^-1 MCE; (iii) basal diet challenged with ETEC; and (iv) basal diet with 200 mg kg^-1 MCE and challenged with ETEC. Following a 7-day period of pre-treatment, CTRL-ETEC and MCE-ETEC mice were subjected to oral infection using 5×10⁸E. coli SEC 470. The results showed dietary 200 mg kg^-1 MCE markedly reduced intestinal ETEC burden (P < 0.05) and the disease-associated mortality was significantly alleviated in the MCE treated group (P < 0.05). In addition, dietary MCE markedly alleviated ETEC-induced oxidative stress, evidenced by the lowered methane dicarboxylic aldehyde (MDA) abundance and enhanced activities of catalase and glutathione peroxidase (P < 0.05). Furthermore, MCE mice exhibited higher immune activity, which might have further mediated ETEC infection. These results indicate MCE plays a preventative role with respect to ETEC infection. Future research should aim to develop MCE as a therapeutic approach to the promotion of intestinal health and a safeguard against ETEC infection.