The effects were studied of the total triterpenic fraction of Centella asiatica on serum levels of the uronic acids and lysosomal enzymes involved in mucopolysaccharide metabolism (beta-glycuronidase, beta-N-acetylglucosaminidase, arylsulfatase) in patients with varicose veins. The basal levels of uronic acids (467.7 +/- 69.3 micrograms/ml) and of lysosomal enzymes (beta-glycuronidase 1.8 +/- 0.4 microM/min/l, beta-N-acetylglucosaminidase 23.1 +/- 0.4 microM/min/l, arysulfatase 0.078 +/- 0.003 microM/min/l) were elevated, indicating an increased mucopolysaccharide turnover in subjects with varicose veins. During treatment with Centella asiatica extract (60 mg/day for three months), these levels fell progressively. At the end of treatment the serum uronic acid (231.8 +/- 51.5 micrograms/ml), beta-glycuronidase (1.2 +/- 0.05 microM/min/l), beta-N-acetylglucosaminidase (17.7 +/- 0.7 microM/min/l) and arysulfatase (0.042 +/- 0.003 microM/min/l) levels were highly significantly lower than the basal levels (p less than 0.01). The results of this trial provide an indirect confirmation of regulatory effects of the extract of Centella asiatica on metabolism in the connective tissue of the vascular wall.