Abstract:
This study aimed to determine the antioxidant activities and protective effect of some
tropical plant pigments on cyclophosphamide induced oxidative stress in rat's brain. The
pigments were extracted from four tropical plants namely: Zanthoxylum zanthoxyloides
(stem), Parkia filicoidea (fruit husk), Pterocarpus erinaceus (heartwood) and Harungana
madagascariensis (bark) with ethanol. Subsequently, phytochemical screening and
antioxidant activities (total phenol content, free radical scavenging ability, reducing
power, Fe2
+ chelating ability and in vitro inhibition of lipid peroxidation in rat's brain) of
the plant pigments were determined. Then the protective effect of dietary inclusion of the
pigments (0.5 & 1.0%) on cyclophosphamide (75 mg/kg of body weight) induced
oxidative stress in rat's brain was assessed. The results of the study revealed that the plant
pigments contained alkaloids, phleobatannin, anthraquinone, sapomn (except
P.erinaceus), tannin (except P.erinaceus) and flavonoids (except P.erinaceus); however,
H madagascariensis had the highest total phenol content (64.9%), free radical
scavenging ability (97.6%), reducing power, Fe2
+ chelating ability. Z. zanthoxyloides
had the highest inhibition of Fe (II) induced lipid peroxidation on rat's brain tissue (in
vitro). Furthermore, intraperitoneal administration of cyclophosphamide resulted in a
significant (P<0.05) increase in rat's brain malondialdehyde (MDA) content (147.2%)
and serum activities of aspartate aminotransferase (AST) (20.1 UIIL), alanine aminotransferase
(ALT) (28.0 UIIL), alkaline phosphatase (40.0UIIL) and total bilirubin (1.5
mg/dl). However, the dietary inclusion of the plant pigments caused a dose dependent
significant (p<0.05) decrease in rat's brain MDA content; and serum activity of AST.
ALT, ALP, and total bilirubin content. . Therefore dietary inclusion of these plant
pigments could prevent cyclophosphamide induced oxidative administration. However,
,
1.0% dietary inclusion of Zanthoxylum zanthoxyloides was a better protectant of the
brain.
