Abstract Book - 3rd International Symposium on Medicinal Plants ...

3.45 Chemical Composition of The Extracts and Anti-Oxydant Activity of
Chromatoraphic Fractions of Pistacia lentiscus
SALIMA SEBAIHI, DINA A., MERIEM B., KARIMA A., NASSIMA C. and D.
ATMANI
Laboratory of Applied Biochemistry, Department of Physico-Chemical Biology Faculty of Life and
Nature Sciences, University Abderrahmane Mira.
<strong>Abstract</strong>: Medicinal plants constitute an important source of active substances as they have a
remarkable role in traditional medicine. Our study was carried out on the anti-radical activity of the
leaf extracts of Pistacia lentiscus on DPPH and OH (DPPH test was evaluated by Massuda et al.
1999and OH test was evaluated by Halliwell and Gutteridget 1987). The extracts that gave high
antiradical activities were then fractionated by thin layer and column chromatographies, in order to
characterize and determine the active fractions. The best scavenging activity against DPPH was
obtained by the aqueous of chloroform extract at 100µg/ml with an IC 50 of 3,84µg/ml, the aqueous
of ethyl acetate being more potent against the OH radical, with an IC 50 of 20,6µg/ml. Fractions F 2
and F 3 obtained by column chromatography on silica gel from both extracts have exhibited an
important anti-radical activity against the two radicals. On the other hand, thin layer
chromatography has allowed us to detect the probable presence of gallic acid, quercetin and
catechic tannins in these fractions. Quantification of total phenol (the determination of total phenols
was estimated by Kähkönen et al. 1999) has demonstrated a high amount of these compounds in
the aqueous of chloroform and ethanolic extracts (491,7mg and 388,2 mg Eq cat/g extract)
respectively which confirms the richness of Pistacia lentiscus in phenolic compounds.
Key words: Anti- radicalaire, fractions chromatographiques, Pistacia lentiscus, polyphénols
3.46 Kava (Piper methysticum): Phytochemistry, Traditional Cultivars and
Toxicity
Schmidt Mathias 1 , Lebot Vincent 2 , and Vergano Paolo 3
1 Herbresearch Germany, Wartbergweg 15, 86874 Mattsies, Germany. 2 CIRAD, Port Vila, Efate,
Vanuatu. 3 FratiniVergano, 42 Rue de Haerne, 1040 Brussels, Belgium.
<strong>Abstract</strong>: Kava, the root of Piper methysticum, is an important endemic cultural plant in the South
Pacific Islands. More than 120 cultivars have been bred and selected for medicinal or social use.
Some of these cultivars are known to be suitable for daily consumption of kava as a social
beverage facilitating communication without having intoxicating effects. These cultivars are called
„noble“, whereas others, the „two-day“ varieties, are known to produce long lasting effects and
hang-over, and are therefore not used for traditional kava drinking. The use of peelings and
rhizomes of two-day varieties have been suspected to have been involved in the sudden
occurrence of cases of liver toxicity in Europe in 1999 and 2000, however, no clear correlation
could be made between the composition of kavalactones – the fraction assumed to be responsible
for the psychorelaxing effects – and toxicity. Albeit the distribution of the six major kavalactones
and especially the relative quantities of kavain and of methysticin/dihydromethyticin vary distinctly
between noble and non-noble cultivars (the latter containing less kavain and more M/DHM). The
kavalactones as such are obviously not liver-toxic. Recent research pointed to the fraction of
flavokavins, especially flavokavin B, which has been found toxic in rodents. In a pilot screening
study we sampled typical varieties of the major types of cultivars: two noble kavas, two two-day
varieties and one wild-type kava, each of them representative for a group of cultivars with similar
kavalactone composition. The material was separated by roots, peeled rhizomes, peeled stems
and the peelings. All samples were subjected to HPLC quantification of the six major kavalactones
and the flavokavins A to C. Non-noble kava varieties were found to contain 10 times more
flavokavins and especially flavokavin B than noble kava. There was an association between the
kavalactones M and DHM and the content of flavokavin B. This association may be used to
identify kava unsuitable for consumption (and potentially toxic) even in exported kava raw
materials. It may also serve for establishing international quality standards for kava.
Key words: flavokavin, kava, liver toxicity, medicinal, Piper methysti
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