Evaluation of hepatoprotective effect of Pistacia lentiscus, Phillyrea latifolia and Nicotiana glauca

Abstract

The hepatoprotective effect of the boiled and non-boiled aqueous extracts of Pistacia lentiscus, Phillyrea latifolia, and Nicotiana glauca, that are alleged to be effective in the treatment of jaundice in Jordanian folk medicine, was evaluated in vivo using carbon tetrachloride (CCl₄) intoxicated rats as an experimental model. Plant extracts were administrated orally at a dose of 4 ml/kg body weight, containing various amounts of solid matter. Only total serum bilirubin level was reduced by treatment with non-boiled aqueous extract of N. glauca leaves, while the boiled and non-boiled aqueous extracts of the N. glauca flowers were non effective. Bilirubin level and the activity of alkaline phosphatase (ALP) were both reduced upon treatment with boiled aqueous extract of P. latifolia without reducing the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Aqueous extract of P. lentiscus (both boiled and non-boiled) showed marked antihepatotoxic activity against CCl₄ by reducing the activity of the three enzymes and the level of bilirubin. The effect of the non-boiled aqueous extract was more pronounced than that of the boiled extract.

Introduction

Decoctions of Pistacia lentiscus leaves, Phillyrea latifolia leaves, and Nicotiana glauca leaves and flowers, are being currently used in Jordanian folk medicine to ameliorate jaundice. The decoction is prepared by boiling leaves or flowers of the plants for few minutes. Although methods of preparation vary slightly from group to group, the efficiency of these decoctions is claimed high.

P. lentiscus and P. latifolia are evergreen shrubs, which are widely distributed in the Mediterranean region (Encyclopaedia Britannica, 1990). On the other hand, N. glauca is an annual shrub, which originated from South America (Zohary, 1972) but recently it has started infesting large areas in the valley of Jordan during summer.

In the Palestinian area P. lentiscus is also used as a folk medicine to ameliorate jaundice. In the Mediterranean region, the use of P. lentiscus as an antibacterial agent was reported by several research groups (Magiatis et al., 1999, Ali-Shtayeh et al., 1998, Iauk et al., 1996). It was also found as a potent antiulcer agent (Al-Said et al., 1986).

In Spain, Mediterranean Europe, and North Africa, people have used infusions prepared from the leaves and fruits of P. latifoliai as an astringent, diuretic and for the treatment of mouth ulcers and inflammations (Diaz et al., 2001). P. latifolia also has an anti-inflammatory activity (Diaz et al., 2000). The use of P. latifolia to ameliorate jaundice is unique to Jordanian folk medicine.

N. gluaca is known as a highly toxic and teratogenic plant (Panter et al., 1999), it is used to treat burns and inflammatory diseases in Italy (Morel et al., 1998). The use of N. glauca as an anti-jaundice plant is also unique to Jordanian folk medicine.

The present study was undertaken to evaluate the efficacy of the boiled and non-boiled aqueous extracts of these three plants against experimental liver damage inflicted by a reliable hepatotoxin, CCl₄. Boiled extracts were used to simulate the most used method by Jordanians to ameliorate jaundice. Whereas non-boiled extracts were used to detect whether boiling affects the activity of the decoctions or not.