title: Anti-tumour promoting activity and antioxidant properties of girinimbine isolated from the stem bark of Murraya koenigii S.
abstract: Girinimbine, a carbazole alkaloid isolated from the stem bark of Murraya koenigii was tested for the in vitro anti-tumour promoting and antioxidant activities. Anti-tumour promoting activity was determined by assaying the capability of this compound to inhibit the expression of early antigen of Epstein-Barr virus (EA-EBV) in Raji cells that was induced by the tumour promoter, phorbol 12-myristate 13-acetate. The concentration of this compound that gave an inhibition rate at fifty percent was 6.0 µg/mL and was not cytotoxic to the cells. Immunoblotting analysis of the expression of EA-EBV showed that girinimbine was able to suppress restricted early antigen (EA-R). However, diffused early antigen (EA-D) was partially suppressed when used at 32.0 µg/mL. Girinimbine exhibited a very strong antioxidant activity as compared to a-tocopherol and was able to inhibit superoxide generation in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiated premyelocytic HL-60 cells more than 95%, when treated with the compound at 5.3 and 26.3 µg/mL, respectively. However girinimbine failed to scavenge the stable diphenyl picryl hydrazyl (DPPH)-free radical.
authors.affiliation: Department of Cell and Molecular Biology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. yihyih_kok@imu.edu.my
authors.forename: Yih Yih
authors.initials: YY
authors.lastname: Kok
authors.forename: Lim Yang
authors.initials: LY
authors.lastname: Mooi
authors.forename: Kartini
authors.initials: K
authors.lastname: Ahmad
authors.forename: Mohd Aspollah
authors.initials: MA
authors.lastname: Sukari
authors.forename: Nashriyah
authors.initials: N
authors.lastname: Mat
authors.forename: Mawardi
authors.initials: M
authors.lastname: Rahmani
authors.forename: Abdul Manaf
authors.initials: AM
authors.lastname: Ali
mesh_terms: D000470:Alkaloids / Q000302:isolation & purification / Q000494:pharmacology*; D000956:Antigens, Viral / Q000235:genetics; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D032101:Murraya / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D013481:Superoxides / Q000378:metabolism
chemical_list: D000470:Alkaloids; D000956:Antigens, Viral; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; C033305:Epstein-Barr virus early antigen; D013481:Superoxides; C034052:girinimbine