Inhibitory effects of palm tocotrienol-rich fraction supplementation on bilirubin-metabolizing enzymes in hyperbilirubinemic adult rats.

Phenylhydrazine, a hemolytic agent, is widely used as a model of experimental hyperbilirubinemia. Palm tocotrienol-rich fraction (TRF) was shown to exert beneficial effects in hyperbilirubinemic rat neonates.To investigate the effects of palm TRF supplementation on hepatic bilirubin-metabolizing enzymes and oxidative stress status in rats administered phenylhydrazine.Twenty-four male Wistar rats were divided into two groups; one group was intraperitoneally injected with palm TRF at the dose of 30 mg/kg/day, while another group was only given vehicle (control) (vitamin E-free palm oil) for 14 days. Twenty-four hours after the last dose, each group was further subdivided into another two groups. One group was administered phenylhydrazine (100 mg/kg, intraperitoneally) and another group was administered normal saline. Twenty-four hours later, blood and liver were collected for biochemical parameter measurements.Phenylhydrazine increased plasma total bilirubin level and oxidative stress in the erythrocytes as well as in the liver, which were reduced by the pretreatment of palm TRF. Palm TRF also prevented the increases in hepatic heme oxygenase, biliverdin reductase and UDP-glucuronyltransferase activities induced by phenylhydrazine.Palm tocotrienol-rich fraction was able to afford protection against phenylhydrazine-induced hyperbilirubinemia, possibly by reducing oxidative stress and inhibiting bilirubin-metabolizing enzymes in the liver

Reversal of Myoblast Aging by Tocotrienol Rich Fraction Posttreatment

Skeletal muscle satellite cells are heavily involved in the regeneration of skeletal muscle in response to the aging-related deterioration of the skeletal muscle mass, strength, and regenerative capacity, termed as sarcopenia. This study focused on the effect of tocotrienol rich fraction (TRF) on regenerative capacity of myoblasts in stress-induced premature senescence (SIPS). The myoblasts was grouped as young control, SIPS-induced, TRF control, TRF pretreatment, and TRF posttreatment. Optimum dose of TRF, morphological observation, activity of senescence-associated β-galactosidase (SA-β-galactosidase), and cell proliferation were determined. 50 μg/mL TRF treatment exhibited the highest cell proliferation capacity. SIPS-induced myoblasts exhibit large flattened cells and prominent intermediate filaments (senescent-like morphology). The activity of SA-β-galactosidase was significantly increased, but the proliferation capacity was significantly reduced as compared to young control. The activity of SA-β-galactosidase was significantly reduced and cell proliferation was significantly increased in the posttreatment group whereas there was no significant difference in SA-β-galactosidase activity and proliferation capacity of pretreatment group as compared to SIPS-induced myoblasts. Based on the data, we hypothesized that TRF may reverse the myoblasts aging through replenishing the regenerative capacity of the cells. However, further investigation on the mechanism of TRF in reversing the myoblast aging is needed

Oxidative stress markers in liver.

<p>Values are mean ± standard error (n = 6).</p><p>*Different from the saline-treated control (P<0.001),</p>#<p>different from the control+PHZ (P<0.001). [TRF: tocotrienol-rich fraction; PHZ: phenylhydrazine].</p

Hepatic aminolevulinic acid (ALA) synthase activity.

<p>Bars represent mean ± standard error (n = 6). *Different from the control+saline group (p<0.05). [TRF: tocotrienol-rich fraction; PHZ: phenylhydrazine].</p

UDP-glucuronyltransferase activity in rat liver.

<p>Bars represent mean ± standard error (n = 6). *Different from the control+saline group; #different from the control+PHZ (p<0.05). [TRF: tocotrienol-rich fraction; PHZ: phenylhydrazine].</p

Oxidative stress markers in red blood cells.

<p>Values are mean ± standard error (n = 6).</p><p>*Different from the saline-treated control (P<0.05),</p>#<p>different from the control+PHZ (P<0.05). [TRF: tocotrienol-rich fraction; PHZ: phenylhydrazine].</p

Hepatic biliverdin reductase activity.

<p>Bars represent mean ± standard error (n = 6). *Different from the control+saline group (p<0.05). [TRF: tocotrienol-rich fraction; PHZ: phenylhydrazine].</p