The toxicity and efficacy evaluation of different fractions of Kansui fry-baked with vinegar on Walker-256 tumor-bearing malignant ascites effusion rats and normal rats

Ethnopharmacological relevance: Kansui, the root of Euphorbia kansui S.L.Liou ex S.B.Ho (E.kansui), is a classical traditional Chinese medicine (TCM) with certain toxicity. According to the theory of TCM, kansui fry-baked wtith vinegar (VEK) possesses low toxicity and mild diuretic and purgative efficacy. In clinical practice, it is commonly used for the treatmtablent of ascites and oliguria. The present study aimed to evaluate the toxicity and efficacy of different fractions of VEK and reveal the underlying material basis by employing an animal model of malignant ascites effusion (MAE) in rats. Materials and methodsta. The MAE rats as the model were constructed in SPF male wistar rats by intraperitoneal injection of Walker-256 tumor cells. The MAE rats were used and randomly divided into the control group (normal rats), control groups with different fractions (VEKA, VEKB, VEKC and VEKD), model group (MAE rats), positive control group (model group with furosemide), model groups with different fractions (VEKA, VEKB, VEKC and VEKD). Histopathological observation was used to confirm Walker-256 tumor-bearing organ injuries in rats. For the efficacy evaluation, the ascites and urine volumes, the urinary electrolyte concentrations (Na+, K+ and Cl-) and pH, the ascites levels of pro-inflammatory cytokines (IL-2, IL-6, TNF-alpha, IFN-gamma and VEGF), PRA, the serum levels of Ang II, ALD and ADH, as well as AQP8 protein expression in the gastrointestinal tract were detected. Furthermore, different levels of indicators were measured in the toxicity evaluation of different fractions both on normal and model rats, including serum liver enzymes (AST and ALT), serum oxidative damage parameters (GSH, MDA, LDH and SOD), expressions of inflammatory parameters (NF-kappa B, ICAM-1 and E-cadherin) and apoptosis signals (caspase-3, -8, -9, Bc1-2 and Bax) in the liver and gastrointestinal tract. Results: Walker-256 tumor-bearing malignant ascites effusion rats showed obvious hepatic and gastrointestinal injuries by histopathological observation. In the efficacy evaluation, model rats treated with VEKB and VEKC showed significant urine increase (VEKB, P < 0.01; VEKC, P < 0.01) and ascites reduction (VEKB, P < 0.01; VEKC, P < 0.01). These two fractions also balanced the concentrations of Na+ K+ and Cl- in urine (VEKB, all P < 0.05; VEKC, all P < 0.05), remarkably decreased urinary pH (VEKB, P < 0.01; VEKC, P < 0.01), and reduced the ascites levels of IL-2, IL-6, TNF-alpha, IFN-gamma and VEGF (VEKB, all P < 0.01; VEKC, all P < 0.01) in the model rats. Moreover, levels of PRA, the serum Ang II, ALD and ADH of model rats were decreased after treated by VEKB and VEKC (VEKB, all P < 0.05; VEKC, all P < 0.05). Meanwhile, the expression of gastrointestinal AQP8 of the model rats was also enhanced after treated by VEKB and VEKC (VEKB, P < 0.01; VEKC, P < 0.01). In the toxicity evaluation, although VEKB and VEKC caused toxic indexes moved to the worse aspects in normal rats, nearly all of these indicators notably improved in the model rats. Additionally, VEKA showed no effect on the indicators, either in the efficacy evaluation or in the toxicity evaluation. And VEKD could significantly improve some indicators (urine volume, concentration of IC+ in urine, serum MDA, AI and caspase-9) in MAE rats. Conclusions: VEKB and VEKC were demonstrated a significant efficacy in treating malignant ascites effusion,which could reduce hepatic and gastrointestinal damage on the model rats but cause the same damage to the normal. These data embody the traditional Chinese medicine application principle: You Gu Wu Yun. And these results will provide reference for the safer and better clinical utilization of kansui.