Olea europaea (Oleaceae) leaves of 14 different cultivars have been studied by a new isocratic HPLC method. Qualitative and quantitative determinations of principal compounds were established for each cultivar. Oleuropein concentration was determined for each sampled tree, using coumarin as internal standard. Bid el Haman, Chemlali, Meski, Cailletier, Tanche, a Verdale-Picholine hybrid, and Lucques, in particular, had high oleuropein concentrations and could be useful sources for industrial extractions.

The iridoids of Harpagophytum procumbens and Harpagophytum zeyheri were studied by CLHP. Harpagoside is the main iridoid for both drugs whereas 8-p-coumaroylharpagide is a representative iridoid of Harpagophytum zeyheri only. The ratio harpagoside/8-p-coumaroylharpagide can be used to distinguish chemically both species. For commercial dried aqueous extracts this ratio is intermediate because they are probably prepared from a mixture of H. procumbens and H. zeyheri drugs. The aqueous extracts of both drugs show similar analgesic and anti-inflammatory properties. Harpagophytum procumbens and Harpagophytum zeyheri should be accepted as sources for the drug Harpagophyti radix.

This study was carried out to evaluate the phytochemical constituents and antioxidant potential of the leaves and flowers extracts of Halimium halimifolium in order to validate the medicinal potential of this herb. The antioxidant activity of alcoholic and aqueous extracts was evaluated using 2, 2-diphenyl-l-picrylhydrazyl (DPPH), 2, 2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. The total polyphenol, flavonoid and tannin content were determined according respectively to Folin-Ciocalteu method, Zhishen method and Broadhurst method. The leaves of H. halimifolium had greater antioxidant activity than flowers by DPPH and ABTS assays. The ethanol extract of the leaves exhibited the better antioxidant activity by DPPH assay (IC50 = 1.19 µg.mL-1), the n-butanol by ABTS assays (IC50 = 1.73µg.mL-1). As opposed to FRAP method the flowers had greater antioxidant activity as leaves. Ethyl acetate extract exhibited better antioxidant activity (IC50 = 15.5 mmol Fe 2+ .g-1). The obtained results showed that the extracting solvent significantly influenced the antioxidant property estimations of Halimium halimifolium. The ethanol is a recommended solvent for extracting antioxidants from this plant. The antioxidant activity determined by DPPH, ABTS and FRAP demonstrated a linear relationship with their polyphenols, flavonoids and tannins content.

No abstract

No abstract