Faculty of Applied Sciences
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Item Improving the survival of probiotic in simulated conditions and azoxymethane-induced colon tumour bearing mice using modified citrus pectin-alginate microencapsulation(PKP Publishing Services Network, 2016) Odun-Ayo, Frederick Oluwasheyi; Mellem, John Jason; Reddy, LaliniBackground: For a probiotic to be viable it needs to be preserved at a recommended minimum level of 6–7 log10cfu/g in the product being consumed, as suggested by the International Dairy Federation. Different biopolymer matrices have been used for encapsulation of probiotic; however, loss of viability is still a challenge. Materials and Methods: Modified citrus pectin-alginate microbeads containing Lactobacillus acidophilus ATCC 4356 was developed. Efficiency of the microbeads was evaluated in simulated conditions of the gastrointestinal tract and in Balb/c mice induced with colon tumor. Genomic identification of faecal lactobacilli samples from treated mice was also performed. Results: The Modified citrus pectin-alginate probiotic microbeads significantly enhanced the viability of Lactobacillus acidophilus ATCC 4356 compared to the control (p< 0.05) both in vitro and in vivo. Exposure of the modified citrus pectin-alginate microbeads to 3 hours of simulated gastric juice resulted in 82.7% survival of L. acidophilus ATCC 4356. Also, the number of faecal lactobacilli in the modified citrus pectin-alginate probiotic treated mice increased by 10.2% after 28 days. Conclusion: Modified citrus pectin-alginate is a novel effective means of oral delivery of bacterial cells and bioactive compounds. Modified citrus pectin-alginate can be used in probiotic therapy which may improve the prevention of colon cancer.Item Molecular immunogenetics of apoptosis : experimental dilemas(International Journal of Biological & Pharmaceutical Research, 2012) Singh, Rishan; Reddy, LaliniThere have been several research articles published on the biological and biochemical nature of apoptosis. These have included studies on the molecular genetics of apoptosis. Apart from the genes that are involved in the apoptotic cascade, there are several other genes that are either activated or inhibited when cell lines are exposed to apoptotic stimuli. This article addresses the simplicity and complexity of the genetic nature of apoptosis in a variety of cell lines.Item Apoptosis in the human laryngeal carcinoma (HEp-2) cell line by Bulbine natalensis and B. Frutescens fractions(IJBPR, 2012) Singh, Rishan; Reddy, LaliniMany plants that belong to the genus Bulbine have compounds in their roots and leaves which are considered important for traditional treatments. The stems and roots of Bulbine species are believed to contain anticancer compounds such as anthraquinones, including chrysophanol and knipholone. However, in general, people utilise plants of the Bulbine genus for the treatment of rashes, itches, wounds, burns, cracked lips and cracked skin. This study assessed the effect of aqueous and organic fractions of Bulbine natalensis and Bulbine frutescens on the human laryngeal carcinoma cell line (HEp-2) for apoptosis. The MTT assay was used to determine the cytotoxicity of the fractions administered and to select fractions for analysis of bax and caspase-3 gene expression, which are induced during programmed cell death type 1, known as apoptosis. All of the B. natalensis fractions induced expression of caspase-3, while the tested B. frutescens aqueous root fractions failed to induce expression of caspase-3. The variation in bax gene expression indicated that HEp-2 cell death was due to apoptosis and other unknown forms of cell death that may or may not activate caspase-3 gene expression.Item Ochratoxins--food contaminants : impact on human health(MDPI, 2010-04-20) Reddy, Lalini; Bhoola, KantiOchratoxins are secondary metabolites of Aspergillus and Penicillium, that are hazardous to health through contamination of dietary foods. Ochratoxin A (OTA) remains the single most potent member of this group of mycotoxins. OTA has a long half-life in humans and is thus easily detected in serum. Dietary intake studies have confirmed link between endemic nephrotoxicity in humans to their daily household intake of OTA. OTA has been reported to contribute to endemic nephrotoxicity and carcinogenicity in humans and animals. OTA produces renal tumours, DNA adducts and chromosomal aberrations in kidneys. OTA may be embryotoxic, teratogenic, and immunotoxic only at doses higher than those causing nephrotoxicity. The incidence of endemic nephrotoxicity has been mostly reported in northeast Europe since the early fifties. Recent studies however have warned that OTA and other toxins, such as aristolochic acid, show very similar renal pathology. There is thus the need for thorough co-occurrence studies on toxin incidence.Item Chemoprotective action of natural products on cultured human epithelial cells exposed to aflatoxin B1(2005) Reddy, Lalini; Odhav, BhartiPrevious studies indicate that a mutation in the non-oncogenic p53 gene is epidemiologically linked to human HCC (Ozturk, 1991; Chan et al., 2003). Hsu et al. (1991) found this link in Chinese, South African and Asian patients and Hollstein et al. (1993) found the same gene mutation in Taiwanese patients. The incidence of these aberrations is reported to be about 20- 50% in HCC’s (Kishimoto et al., 1997). There is sufficient evidence to indicate that carotenoids in addition to their well known antioxidant properties (Paiva and Russel, 1999), also affect intercellular communication, immune responses, neoplastic transformations and growth control, and cellular levels of enzymes that detoxify carcinogens (Zhang et al., 1991; Brockman et al., 1992; Pryor et al., 2000). To date studies carried out have used the rat (Foote et al., 1970; Gradelet et al., 1998) and the mule duckling model (Cheng et al., 2001) to show the protective effect of these carotenoids against AFB1 exposure. Of the well known carotenoids, lycopene and beta- carotene occur in abundance in fruits and vegetables and are safe for human consumption. Aflatoxin B1 frequently induces mutations of the p53 gene which is linked to HCC. Although there is much evidence from epidemiological studies linking the beneficial aspects of carotenoids to the prevention of cancer, the cellular and molecular mechanisms need to be understood in order to implement large scale intervention strategies to prevent AFB1 induced carcinoma. The use of chemical or dietary interventions to alter the susceptibility of humans to the actions of carcinogens and to block, retard or reverse carcinogenesis is an emerging chemoprotective strategy for disease prevention (Abdulla and Gruber, 2000; Kensler et al., 2003; Bingham and Riboli, 2004). Chemoprotection by natural products involves maintaining cellular integrity, preventing DNA alterations, activation of p53 suppressor protein and apoptosis. The aim of this study was thus to investigate the cellular and molecular mechanisms by which beta-carotene and lycopene may prevent the AFB1-induced toxic changes in human hepatocytes. In order to achieve this aim, the following objectives were set out: i. To optimise an in vitro system for the evaluation of AFB1 damage to cultured hepatocytes. ii. To determine the biochemical protection offered by beta-carotene and lycopene to AFB1-exposed hepatocytes, by measuring the mitochondrial activity, cell viability and ROS levels using appropriate enzyme assays and flow cytometry. iii. To determine the cellular protection offered by beta-carotene and lycopene to AFB1-exposed hepatocytes, by studying the morphological changes at the structural and ultrastructural levels using phase contrast light and electron microscopy respectively. iv. To determine the molecular protection offered by beta-carotene and lycopene to AFB1-exposed hepatocytes, by detecting apoptotic bodies as genomic markers and measuring the levels of p53 protein and AFB1-N7-guanine adducts produced.