PHYTOTHERAPY RESEARCH, VOL. 7,213-215 (1993) zyxwvu SHORT COMMUNICATION zyxwv Antiarthritic Effect of Lupeol Acetate? G. Kweifio-Okai* Anthony R. Carroll Department of Anatomy and Physiology, Royal Melbourne Institute of Technology, Bundoora, 3083, Australia Department of Chemistry and Biochemistry, James Cook University of North Queensland, Townsville, 4810, Australia Lupeol acetate isolated from the petroleum ether fraction of zyxwvu Alshnia boonei root barks was tested for its antiarthritic effect in CFA-induced arthritic rats. Administered orally every 48 h (66 mgkg body weight) from days 32 to zyxwvutsr 40 postadjuvant and assessed on day 60, lupeol acetate returned the increase in spleen weight and the reduction in serum alkaline phosphatase to nonarthritic control values. Keywords: adjuvant arthritis; lupeol acetate; triterpenes; Alstonia boonei; alkaline phosphatase. INTRODUCTION Water or alcoholic extracts of Alstoniu boonez root barks are used in antiarthritic therapy in traditional herbal medicine in Ghana (Kweifio-Okai, 1991a, 1991b). Previous studies showed that the triterpene contents of the petroleum ether fraction-a-amyrin acetate, b-amyrin acetate, P-amyrin and lupeol acetate were antiarthritic in the adjuvant model of arthritis in rats but were associated with varying degrees of toxicity as shown by the swellings of liver, kidney or spleen and increases in SGOT (Kweifio-Okai and Carroll, 1992). In the present experiment lupeol acetate, the least toxic of the triterpenes, was tested on CFA-induced arthritic rats at a more advanced stage of the disease and in a way that was thought would demonstrate antiarthritic effect without toxic manifestations. Even though the local and histopathological changes are normally tar- geted for screening potential antiarthritic effects, it was decided to assess the effects on a wider range of clinical manifestations in adjuvant disease. Hence this paper reports the effects on local physical changes as well as on biochemical changes in bone metabolism and organ dysfunction. Joint and organ histopathological effects are yet to be reported. MATERIALS AND METHODS Outbred male Wistar rats 8-9 weeks old weighing between 154189 g (Monash University Animal House, Clayton, Australia) were used. Animals were kept in groups of five at 23 "C on a 12:12 h lighddark cycle and had free access to food and water throughout the experiment. Rats were inoculated with complete Freund's adjuvant (CFA) (Difco Laboratories, Detroit, MI) as reported previously (Kweifio-Okai and Carroll, 1992). From the population of inoculated rats, 10 were selected for satisfactory arthritis on the basis of the following criteria-a minimum of 3.4 mm increase t Patent pending. Author to whom correspondence should be addressed. in ipsilateral (injected) paw diameter by day 11 of adjuvant maintained up to day 32 postadjuvant, severe restriction of movement in affected limbs and pain responses on handling. These criteria for the successful induction of arthritis are similar to those used by Jacka and others (1983). On days 32, 34, 36, 38 and 40 postadjuvant, five arthritic rats were orally adminis- tered with 66 mg/kg body weight of lupeol acetate isolated from the petroleum ether fraction of zy Alstoniu boonei root barks as described previously (Kweifio- Okai and Carroll, 1992). Anteroposterior diameters of ankle and dorsoventral heights of hindfoot pads were measured with a sliding vernier scale on selected days up to day 60. On day 60, the rats were anaesthetized, and blood was removed by cardiac puncture, allowed to clot and centrifuged. The serum was extracted for biochemical measurements with a Kodak Ektachrom DT Analyser System (Eastman Kodak Company, N.Y.) using the appropriate slides. Liver, kidney and spleen were removed for weighing. RESULTS Limb diameter and body weight changes Ipsilateral (right) and contralateral (left) ankle and paw diameters remained unchanged in control rats through- out the experiment. Ipsilateral ankle and paw dia- meters increased significantly and peaked by day 11 of adjuvant (+37% and 112% respectively) and were maintained up to day 60. Lupeol acetate had no effect on the increases during and after drug administration. In both treated and untreated arthritic rats, contrala- teral ankle and paw diameters remained unchanged up to day 60. Body weights of rats increased to virtually the same extent in all three rat groups. Biochemical and organ weight changes Neither adjuvant nor lupeol acetate affected serum Ca++ and inorganic PO; but adjuvant significantly reduced serum alkaline phosphatase by 17% (Table 1). 095 1 -4 18X/93/0202 13-03 $06.50 zyxwvutsrq 0 1993 by John Wiley zyxwvutsrqpo & Sons, Ltd. Accepted (revised) I September 1992