Short communication TOXICITY STUDY IN MICE OF RESINS OF THREE COMMIPHORA SPECIES

Acute toxicity studies of crude extracts of resins of Commiphora myrrha, C. guidottii and C. erlangeriana, and pure compounds isolated from C. erlangeriana were conducted on Swiss albino mice. The extract from C. erlangeriana had a mean LD50 of 410 mg/kg body weight. However the extracts from C. myrrha and C. guidotti were not toxic at the doses tested. The pure compound isolated from C. erlangeriana, erlangerin D (1) demonstrated a mean LD50 of 140 mg/kg body weight. On the other hand erlangerin A (2) was not toxic to the mice at even four times the LD50 value of erlangerin D (1). Key words/phrases: Commiphora erlangeriana, C. guidotti, C. myrrha, myrrh, opopanax * Author to whom correspondence should be addressed. INTRODUCTION Several species belonging to the genus Commiphora (Burseraceae) are distinguished by their ability to produce aromatic and medicinal resins which have been used since ancient times in Africa and many middle eastern countries. Ethiopia is endowed with several Commiphora species (Vollesen, 1989). C. myrrha (Nees) Engl. and C. guidottii Chiov. produce resins commonly known as myrrh and opopanax, respectively. Myrrh is known in Amharic as Kerbe and in Somali as Dhidin. Opopanax also known as scented myrrh is called in Amharic as Abeked, in Somali as Habak Hadi and in Oromifa as Hanketa. Both myrrh and opopanax are well known traditional medicines not only for human use but also to treat maladies of cattle and camels. Myrrh is smoked to repel snakes while opopanax is used as a cure for diarrhea. Claeson (1990) observed that in Somali traditional medicine ca. 5 g of crushed opopanax resin is stirred in about one litre of water and the whole preparation is taken orally. Myrrh and opopanax are important items of commerce because their essential oils are used for fragrance purposes and in aromatherapy. We have recently reported the result of the analysis of the essential oils of myrrh, opopanax and frankincense (Baser et al., 2003). During a field study in the Ogaden region of Ethiopia we came across a unique resin called locally as Dhunkal that is produced by Commiphora erlangeriana Engl. It is common knowledge that the resin is used to poison and kill some omnivorous wild animals such as hyena. However, we do not know the amount given to poison the animals. The structures of the main compounds present in Dhunkal resin were reported recently by our group (Aman Dekebo et al., 2002). Subsequently Solomon Habtemariam (2003) reported the cytostatic and cytotoxic properties of these compounds. We report here results of comparative toxicity studies on mice carried out using crude extracts of the three resins namely C. myrrha (myrrh), C. guidotti (opopanax) and C. erlangeriana (Dhunkal). The toxicity of two pure compounds of C. erlageriana namely erlangerin A and D were also studied in the course of this work. Yalemtsehay Mekonnen et al. 152 MATERIALS AND METHODS