Project description:It is well known that the intake of antioxidants with increased consumption of fruits and vegetables and medicinal herbs contributes towards reduced risk of certain diseases including cancers. This study aims to evaluate the broad-spectrum antioxidant and antimutagenic activities as well as to elucidate phytochemical profile of an Indian medicinal plant Murraya koenigii (curry) leaves. Leaves of the plant were successively fractionated in various organic solvents. Benzene fraction demonstrated the highest phenolic content followed by petroleum ether. The benzene fraction showed maximum antioxidant activity in all tested assays, namely, phosphomolybdenum, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, ferric reducing antioxidant power (FRAP) and cupric reducing antioxidant capacity (CUPRAC) assays. Based on the promising broad-spectrum antioxidant activity, benzene fraction was further evaluated for antimutagenic activity and showed a dose-dependent antimutagenic response in Ames Salmonella mutagenicity assay. It inhibited 72-86% mutagenicity induced by sodium azide, methyl methanesulfonate, benzo(a)pyrene, and 2-aminoflourene at the maximum tested concentration (100 ?g/mL) in Salmonella typhimurium tester strains. At least 21 compounds were detected by GC/MS. The findings clearly demonstrated that phenolic-rich benzene fraction has promising broad-spectrum antioxidant and antimutagenic property and needs further evaluation to exploit its therapeutic potential.
Project description:Therapy that directly targets apoptosis and/or inflammation could be highly effective for the treatment of cancer. Murraya koenigii is an edible herb that has been traditionally used for cancer treatment as well as inflammation. Here, we describe that girinimbine, a carbazole alkaloid isolated from M. koenigii, induced apoptosis and inhibited inflammation in vitro as well as in vivo. Induction of apoptosis in human colon cancer cells (HT-29) by girinimbine revealed decreased cell viability in HT-29, whereas there was no cytotoxic effect on normal colon cells. Changes in mitochondrial membrane potential, nuclear condensation, cell permeability, and cytochrome c translocation in girinimbine-treated HT-29 cells demonstrated involvement of mitochondria in apoptosis. Early-phase apoptosis was shown in both acridine orange/propidium iodide and annexin V results. Girinimbine treatment also resulted in an induction of G0/G1 phase arrest which was further corroborated with the upregulation of two cyclin-dependent kinase proteins, p21 and p27. Girinimbine treatment activated apoptosis through the intrinsic pathway by activation of caspases 3 and 9 as well as cleaved caspases 3 and 9 which ended by triggering the execution pathway. Moreover, apoptosis was confirmed by downregulation of Bcl-2 and upregulation of Bax in girinimbine-treated cells. In addition, the key tumor suppressor protein, p53, was seen to be considerably upregulated upon girinimbine treatment. Induction of apoptosis by girinimbine was also evidenced in vivo in zebrafish embryos, with results demonstrating significant distribution of apoptotic cells in embryos after a 24-hour treatment period. Meanwhile, anti-inflammatory action was evidenced by the significant dose-dependent girinimbine inhibition of nitric oxide production in lipopolysaccharide/interferon-gamma-induced cells along with significant inhibition of nuclear factor-kappa B translocation from the cytoplasm to nucleus in stimulated RAW 264.7 cells. Girinimbine was also shown to have considerable antioxidant activity whereby 20 ?g/mL of girinimbine was equivalent to 82.17±1.88 ?M of Trolox. In mice with carrageenan-induced peritonitis, oral pretreatment with girinimbine helped limit total leukocyte migration (mainly of neutrophils), and reduced pro-inflammatory cytokine levels (interleukin-1beta and tumor necrosis factor-alpha) in the peritoneal fluid. These findings strongly suggest that girinimbine could act as a chemopreventive and/or chemotherapeutic agent by inducing apoptosis while suppressing inflammation. There is a potential for girinimbine to be further investigated for its applicability in treating early stages of cancer.