Ginger extract (Zingiber officinale Roscoe) triggers apoptosis in hepatocarcinogenesis induced rats

Ginger extract has been reported previously by our group to exhibit anticancer and an-tioxidant effects by reducing tumour burden and lipid peroxidation respectively in he-patocarcinogenesis induced rats. The current study examined the expression of pro-apoptotic protein caspase-8 and anti-apoptotic protein Bcl-2 in hepatocarcinogenesis treated rats. Thirty normal male Wistar rats were divided into 5 groups based on the diet given: i) control (normal rat chow), ii) olive oil, iii) ginger extract (100mg/kg body weight), iv) choline deficient diet + ethionine, CDE (to induce liver cancer) and v) CDE+ ginger extract. Rats were killed at week 8, and liver tissues were excised for immuno-histochemical study to identify pro-apoptotic and anti-apoptotic proteins, caspase-8 and Bcl-2. The observation on H&E staining confirmed the CDE diet induced liver can-cer as indicated by the presence of numerous oval cells. Identification of Bcl-2 expres-sion showed that 91.6% (11/12) of the samples from the CDE group revealed positive staining while treatment with ginger extract however inhibited the expression with only 8.4% (1/12) samples showing positive staining for Bcl-2. As for caspase-8 protein, 41.7% (5/12) of the samples from CDE group showed positive staining, which in-creased to 100% (12/12) with ginger extract treatment. Our findings suggest that gin-ger extract has an anticancer effect by inducing apoptosis in liver cancer cells via up-regulation of the expression of pro-apoptotic protein, caspase-8 and down-regulation of the expression of anti-apoptotic protein Bcl-

Melanogenesis inhibition by palm tocotrienol rich fraction in cellular ageing

Melanin is the pigment that determines skin color. Melanin synthesis is catalysed by the enzyme tyrosinase and is controlled by TYR, TYRP1 and TYRP2 genes. In this study, tocotrienol rich fraction (TRF) was used to inhibit melanin synthesis. TRF contains 75% α-tocotrienol and 25% tocopherol. The objective of this study was to determine the effect of tocotrienol rich fraction (TRF) on melanin synthesis by determining melanin content and expression of genes involved in the regulation of melanin synthesis in skin melanocytes. Melanin synthesis was studied by determining melanin level and tyrosinase enzyme activity, while expression of TYR, TYRP1 and TYRP2 genes was determined by quantitative real time reverse transcriptase poly-merase chain reaction (real time RT-PCR). Primary culture of skin melanocytes were divided into two groups; control and cells that were treated with 500 μg/ml tocotrienol rich fraction for 24 hours. Our results showed that there was a reduction in melanin content and tyrosinase activity in skin melanocytes treated with tocotrienol rich fraction compared to the control (p<0.05). Expression of TYRP2 gene in melanocytes treated with tocotrienol rich fraction was also decreased (p<0.05) compared to the control. In conclusion, palm tocotrienol rich fraction has anti pigmentation property that inhibits melanin synthesis in cellular aging by inhibiting tyrosinase activity and down regulating TYRP2 gene expression