Limonin, a citrus plant-derived bio-active compound believed to play a role in cancer chemotherapy. In this study, we found that the treatment of limonin (50 mg/kg/bw; p.o) for 28 successive days to Aflatoxin B 1 (2 mg/kg bodyweight; ip)... more
Limonin, a citrus plant-derived bio-active compound believed to play a role in cancer chemotherapy. In this study, we found that the treatment of limonin (50 mg/kg/bw; p.o) for 28 successive days to Aflatoxin B 1 (2 mg/kg bodyweight; ip) induced liver cancer bearing rats provides protection against the oxidative stress caused by the carcinogen and thereby prevents hepatocellular carcinogenesis. On administration of the carcinogen, the levels of marker enzymes increased markedly, but were found to be significantly lowered by limonin treatment. On the contrary, the antioxidant levels were decreased in carcinogen-administered animals, which were improved to normalcy upon limonin administration. In conclusion, these findings indicate that limonin prevents oxidative stress induced by Aflatoxin B1 and protects the antioxidant system. INTRODUCTION: Hepatocellular carcinoma (HCC) is defined as a malignant tumor composed of cells resembling hepatocytes but normal in appearance and a plate-like organisation around sinusoids is common and is nearly always present somewhere in the tumor (1). In the developing countries, 80% of the burden of HCC is manifest is due to the occurrence of HCC is coincident with regions where aflatoxin exposure is high. The human diet contains a wide variety of natural carcinogens that are present in foods as the result of contaminated raw materials that are produced during the processing and/or cooking of foods. Aflatoxins, a group of potent mycotoxins with mutagenic, carcinogenic , teratogenic, hepatotoxic and immunosuppressive properties are of particular importance because of their adverse effects on animal and human health (2). Aflatoxin B 1 (AFB 1) has the highest potency as a toxin and is classified as group I carcinogen by the International Agency for Research on Cancer (IARC) (3) since it cause of human primary hepatocellular carcinoma (4). Among laboratory animals, rat is most susceptible to AFB 1 carcinogenic-ity (5) hence they have been employed as a model system in understanding AFB 1 hepatocarcinogenicity and response of HCC to anticancer drug therapy (6). Once ingested, AFB 1 is metabolized by Cytochromes P 450 (CYP) to an active intermediate and ultimate carcinogen AFB 1-exo-8, 9-epoxide (AFBO) (7; 8), which is later detoxified through a variety of metabolic processes. The intermediate epoxide has been shown to bind and damage DNA, primarily at the N 7 position of guanine (9).
A method has been developed for the quantitation of the bitter component limonin in grapefruit juice and other citrus juices. The sample clean-up consisted of centrifugation, filtration and a selective, rapid and reproducible purification... more
A method has been developed for the quantitation of the bitter component limonin in grapefruit juice and other citrus juices. The sample clean-up consisted of centrifugation, filtration and a selective, rapid and reproducible purification with a C2 solid-phase extraction column. The limonin concentration was determined by high-performance liquid chromatography on a C18 column with UV detection at 210 nm. A linear response was obtained from 0.0 to 45 ppm limonin. The minimum detectable amount was 2 ng. The minimum concentration which was detected without concentration with good precision was 0.1 ppm. The method was also used for the determination of limonin in different types of oranges, including navel oranges, mandarins, lemons, limes, pomelos and uglis.
