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IN VIVO SUBCRONIC TREATMENT EFFECTS OF THE FLAVONOIDS QUERCETIN AND MORIN ON PLASMA ACID PHOSPHATASE ACTIVITIES
Camargo, C.A.1; Araujo, D.R.1; da Silva, M.E.F.1,2, Palombino, D.D.1; Sousa,R.R.R1; Miranda, M.A.1; de Paula, E.1; Aoyama, H.1
1 Departamento de Bioquímica, Instituto de Biologia, UNICAMP – Campinas – SP; 2 Instituto de Ciências da Saúde, Universidade Paulista, UNIP – Campus Swift; Campinas - SP
Protein tyrosine phosphatases (PTPs), enzymes largely distributed in the organisms, participate in protein signaling controlling a variety of fundamental cellular processes. Therefore, abnormal activities of PTPs can be responsible for some human pathologies, such as cancer, diabetes, rheumatoid arthritis, hypertension and inflammations. Flavonoids, plant phenolic compounds with medicinal properties, can inhibit several important enzymes in cellular systems, including ATPase, phospholipase, cyclooxygenase, lipoxygenase, aldose reductase, hexokinase and protein kinase. We have previously observed that depending on their structures, the flavonoids could differently affect the in vitro activities of phosphatases. In this work we described the in vivo subcronic treatment effects of quercetin and morin on mouse plasma acid phosphatases activities.
The enzyme activities were determined at pH 5.0 using p-nitrophenylphosphate (pNPP) as substrate, at 37° C for 10 minutes, in the absence (total acid phosphatase, TAP) or in the presence of 10mM fluoride and tartrate (low molecular weight phosphotyrosine protein phosphatase, LMW-PTP), or 10mM tartrate and 1mM p-hydroxymercuribenzoate (tartrate-resistant acid phosphatase, TRAP), or at pH 9.4 (alkaline fosfatase, FAL). Thirty days after diary subcutaneous administrations of 100mM quercetin or morin on male mouse, plasma was collected, homogenized in 0.1M acetate buffer (pH5.0), centrifuged, and the clear extracts were used for enzyme activities and protein determinations.
Acid phosphatases were distinctly affected by quercetin and morin. Morin decreased the TAP and LMW-PTP activities 1.35-, and 1.3-fold (p < 0.05), respectively, when compared with the control, and quercetin increased the LMW-PTP activity 1.7-fold (p < 0.05). These in vivo results correlate well with previous in vitro finding with morin acting as inhibitor and quercetin as activator of LMW-PTP purified from bovine kidney.
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