Influence of a highly purified senna extract on colonic epithelium.

BACKGROUND: Chronic use of sennoside laxatives often causes pseudomelanosis coli. A recent study suggested that pseudomelanosis coli is associated with an increased colorectal cancer risk. A single high dose of highly purified senna extract increased proliferation rate and reduced crypt length in the sigmoid colon compared to historical controls. AIMS: To evaluate in a controlled study the effects of highly purified senna extract on cell proliferation and crypt length in the entire colon and on p53 and bcl-2 expression. METHODS: Addition of a senna extract to colonic lavage was studied in 184 consecutive outpatients. From 32 randomised patients, 15 with sennosides (Sen), 17 without (NSen), biopsies were taken. Proliferative activity was studied in 4 areas of the colon, using 5-bromo-2'-deoxyuridine labelling and immunohistochemistry (labelling index, LI). Expression of p53 and bcl-2 in the sigmoid colon was determined immunohistochemically. RESULTS: Crypts were shorter in Sen than in NSen in the transverse and sigmoid colon. LI was higher in Sen than in NSen in the entire colon. No difference in p53 expression was seen. Bcl-2 expression was higher in both groups when crypts were shorter and/or proliferation was increased. CONCLUSION: Sennosides induce acute massive cell loss probably by apoptosis, causing shorter crypts, and increased cell proliferation and inhibition of apoptosis to restore cellularity. These effects may reflect the mechanism for the suggested cancer-promoting effect of chronic sennoside use.

Hyperthermic isolated limb perfusion with tumor necrosis factor-alpha and melphalan in patients with locally advanced soft tissue sarcomas: treatment response and clinical outcome related to changes in proliferation and apoptosis.

Hyperthermic isolated limb perfusion with tumor necrosis factor-alpha and melphalan (HILP-TM) with or without IFN-gamma is a promising local treatment in patients with locally advanced extremity soft tissue sarcomas (STSs), with response rates of up to 84%. The mechanisms of the treatment response are poorly understood. Here, we determined the HILP-TM-induced changes in mitotic activity, proliferation, and apoptosis in 37 STSs; the additional effect of IFN-gamma; and the association of HILP-TM with treatment response and clinical outcome. On archival material, obtained before and 6-8 weeks after HILP-TM with (n = 15) or without (n = 22) IFN-gamma, the number of mitoses was counted, and the proliferation fraction was determined by immunohistological staining for the proliferation associated Ki-67 antigen (MIB1). Apoptosis was visualized by enzymatic detection of DNA fragmentation (terminal deoxynucleotidyl transferase-mediated nick end labeling method). Clinical and histological response, follow-up status, and survival were recorded. The number of mitoses dropped 57% and proliferation rate decreased with 40% after HILP-TM, whereas the amount of apoptosis after HILP-TM more than doubled as before HILP-TM. The addition of IFN-gamma to HILP-TM did not influence the changes in tumor parameters and did not affect treatment response. A better clinical response to HILP-TM was correlated with high mitotic activity and low amount of apoptosis in tumor samples before HILP-TM. Patients with highly proliferative STS before and after HILP-TM had a relatively poor prognosis. Furthermore, patients who developed distant metastases after HILP-TM had a relatively high number of dividing cells in the tumor remnants after treatment.