Antioxidant activity of Egyptian Eucalyptus camaldulensisvar. brevirostrisleaf extracts

Abstract

Leaves from Eucalvptus camaldulensis var. brevirostris trees, planted in the Nile delta in Egypt, were examined for the antioxidant activity of their nonvolatile compounds. The extracts obtained by ethanol digestion and by supercritical fluid extraction (SFE; CO2 with 15% ethanol) showed the most promising antioxidative activities. In order to identify the most active compounds, both extracts were subjected to a semipreparative reversed-phase HPLC separation, the main fractions were collected, tested for antioxidative activity and analysed by different chromatographical and spectroscopical methods for identification of the most relevant compounds. Gallic and ellagic acid were found to be the prevailing antioxidants in the ethanolic extract. The main two compounds of the SFE extract with antioxidative activity revealed to be flavones. To a high degree of probability they were identified as 5-hydroxy-7,4'-dimethoxy flavone and 5-hydroxy-7,4'-dimethoxy-8-methyl flavone, respectively. The extracts obtained by ethanoldigestion were dried and administered to rats for toxicity evaluation (up to 3 g/kg body weight). No mortality was observed which indicates a very low lethality of the tested extract.

Chemical composition and antifungal potential of medicinal plants against seedborne mycoflora of eggplant (Solanum melongena L.)

“…The present results are in harmony with previous researchers who also extracted higher contents of fl avonoids from leaves of E. camaldulensis in ethanol solvent (El-Ghorab et al 2003, Gharekhani et al 2012). According to Takahashi et al (2004) three fl avonoids (2',6'-dihydroxy-3'-methyl-4'-methoxy-dihydro chalcone,8-desmethyl-eucalyptin and eucalyptin) isolated from Eucalyptus maculata leaf extracts commonly exhibited potent antimicrobial activities against seven micro-organisms causing food poisoning.…”

The pharmacological and therapeutic importance of Eucalyptus species grown in Iraq

“…In order to identify the most active compounds, the contents of both extracts were separated by reversed-phase HPLC. Gallic and ellagic acid were found to be the prevailing antioxidants in the ethanolic extract [126]. The antioxidant activity of the essential oils of Eucalyptus camaldulensis, was assessed by DPPH-test and expressed as Trolox equivalent antioxidant capacity, they showed values ranging between 0.5 and 5.8 mmol/l [98].The antioxidant activities of Eucalyptus camaldulensis, Eucalyptus camaldulensis var.…”

Rubus croceacanthus Leveille Inhibits Mast Cell-Mediated Anaphylactic-Like Reaction and Tumor Necrosis Factor-.ALPHA. Secretion

“…However, ellagic acid has very strong anti-oxidant properties, anti-carcinogenic activity and the ability to inhibit mutations within a cell's DNA. 3,30) Ellagic acid is also considered to be a cancer inhibitor which has the ability to cause apoptosis or normal cell death in cancer cells. 31) Therefore, further investigation is necessary to confirm the effect of ellagic acid on mast cell-mediated immediate-type allergic reactions.…”

“…1) More recently, some studies have shown that ellagic acid has a fatty acid synthase (FAS) inhibitory activity and an anti-oxidant activity. 2,3) Rubus croceacanthus Leveille (Fig. 1) also contains ellagic acid that has various effects previously described.…”