Abstract Purpose: To evaluate the effect of aqueous extract of Baccharis trimera leaves on the proliferative capacity of the liver after partial hepatectomy (PH) in rats. Methods: Twenty Wistar rats weighing between 300 and 450g were divided into two groups: control (HP) and test (HP100-rats that received the aqueous extract of Baccharis trimera for four days at a dose of 100 mg / kg / day). On the fifth day, animals from both groups underwent resection of 70% of the liver. Twenty-four hours later, they were sacrificed and the remnant liver was removed and prepared for studied through PCNA immunohistochemistry. Data analysis for comparison between the two groups was made through the non-parametric statistical test Mann-Whitney test. Results: In all the animals studied was found most abundant nuclear immunostaining positive hepatocytes interlobular located in regions of the liver. Quantitative analysis of PCNA-positive cells revealed positivity rate significantly higher mean (p = 0.02) in HP100 group (77.1 ± 13.6) compared to the HP group (45.8 ± 12.9). Conclusion: DAdministration of aqueous extract of the leaves of Baccharis trimera 100 mg/kg of animal has a significant positive effect on liver regeneration in rats, 24 hours after hepatectomy (70%).

ABSTRACT PURPOSE: To assess the effect of aqueous extract of Peumus Boldus (AEPB) on the liver proliferative response after parcial hepatectomy of 70% (PH) in rodents. METHODS: Twenty Wistar rats were divided in two groups: AEPB100 (whose rats received 100mg/Kg of AEPB, once a day, orally, in 4 days prior to the first surgical procedure) and Vehicle (whose rats were treated similarly with distilled water). Both groups underwent PH. After 24 hours the remaining livers were removed for studying the proliferation of hepatocytes by Ki-67 and 2mL of blood were collected for serological assessment: cholesterol, glucose, triglycerides, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and total, direct and indirect bilirubin. All data were analyzed by Gaussian distribution. Statistically significant differences between mean values were analyzed using T Student's test. Non-Gaussian data were analyzed using Mann-Whitney's test. RESULTS: The liver of all these rats presented positive staining of Ki-67, indicating liver proliferation. Laboratory results showed no significant difference in serum values between the analyzed groups. The analysis of Ki-67 was significantly more positive in AEPB100 group than in Vehicle group. CONCLUSION: Aqueous extract of Peumus Boldus acute administration exerts significant positive effect on liver regeneration after 24h in rats that underwent parcial hepatectomy, while maintaining unchanged hepatic function.