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Antioxidant effect of burdock (Arctium lappa L.) on cadmium-induced damage in rat testis, epididymis and liver: biochemistry, morphology, morphometry and ultrastructure

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Author(s):
Fabricia de Souza Predes
Total Authors: 1
Document type: Doctoral Thesis
Press: Campinas, SP.
Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
Defense date:
Examining board members:
Mary Anne Heidi Dolder; Rejane Maira Góes; Fabiana Cristina Silveira Alves de Melo; Juliana Silva Rocha; Sergio Luis Pinto da Matta
Advisor: Mary Ann Foglio; Mary Anne Heidi Dolder
Abstract

Cadmium (Cd) is a heavy metal associated with severe damage in various organs, including male reproductive organs and liver. Arctium lappa is widely used in popular medicine for treating hypertension, gout, hepatitis and other inflammatory disorders. Pharmacological studies indicated that A. lappa roots have hepatoprotective, free radical scavenging and antiproliferative activities. The objectives of this work were evaluate: (1) histomorphometrically the threshold modifications of seminiferous tubules caused by single acute low doses of Cd, (2) antioxidant properties of different A. lappa extracts to choose the best one for "in vivo" study, (3) the ability of A. lappa to attenuate cadmium-induced damage to the testis, epididymis and liver of male rats. Dichloromethanic, ethanolic, aqueous extracts, hydroethanolic and total aqueous extract of A. lappa roots were investigated regarding radical scavenging activity and the total phenolic content. The extracts were tested for their antiproliferative activity in vitro using human cancer cell lines. The higher radical scavenging activity and yield were found in the hydroethanolic extract. Higher phenolic contents were found in the dichloromethanic and hydroethanolic extracts. Only the dichloromethanic extracts exhibited activity against cancer cell lines. Highresolution electrospray ionization mass spectroscopy for the hydroethanolic extract demonstrated the presence of: arctigenin, quercetin, chlorogenic acid and caffeic acid. The hydroalcoholic lyophilized extract was chosen for the experiments in vivo. To study the association of Cd and A. lappa, adult Wistar rats were assigned to four groups: control (C), A.lappa extract (Al), cadmium (Cd) and cadmium plus A. lappa (CdAl). The animals received water or A. lappa hydroethanolic extract (300 mg/Kg BW) by gavage and i.p. injections of saline or 1.2 mg/Kg BW of cadmium chloride. The animals were sacrificed after 7 and 56 days of treatment. The Cd caused reduction in testis, epididymis and seminal vesicle weights, seminiferous tubule (ST) proportion, total length of ST and ST diameter. Degenerated germ cells and multinucleated aggregates were observed in ST and progressive damage resulted in tubules lined only with Sertoli cells. There was a decreased in tubular proportion and increased epithelial height in epididymis after 56 days. Cd caused an increase in plasma GOT and GPT levels after 56 days, but A. lappa extract improved these levels. No relevant alteration was observed in liver transaminase levels. After 7 days, the Cd group showed decrease in hepatocyte proportion and increase sinusoid capillary proportion, also the nuclear density decrease. However, after 56 days, only the hepatocyte nuclear density decreased. In Al and CdAl groups, after 7 days, the hepatocyte nuclear proportion increased and the cytoplasmic decreased, with no alteration in capillary sinusoid proportion. In Al and CdAl groups, after 56 days, hepatocyte nuclear proportion increased and the sinusoid capillary proportion decreased. Also, an increase of hepatocyte nuclear density was observed in Al and CdAl groups. This study revealed that low doses of Cd cause progressive morphological and morphometrical alterations on rat testis and that Cd has a subtle toxic threshold. The dichloromethanic extracts showed antiproliferative activity against K562, MCF-7 and 786-0 human cancer cell lines. The hydroethanolic extract showed higher free radical scavenger activity and higher phenolic content, and was chosen as the best extract for the "in vivo" studies. A. lappa hydroethanolic extract was ineffective in protecting the testis and epididymis against Cd-induced damage, however effectively protected liver tissue. (AU)