Evaluation of the preventive potential of graded dietary inclusion of Hyphaene thebaica (Linn) fruit in rat model of colon carcinogenesis.

The preventive effect of Hyphaene thebaica fruit in colon carcinogenesis was evaluated in Wistar rats at 0, 2.5, 5 and 10% inclusion rates for twelve weeks with concomitant 72-h intra-rectal N-methyl-N-nitrosourea (MNU) instillations. Indices of antioxidant status and carcinogenesis were analyzed using spectrophotometric, ELISA, histological and immunohistochemical techniques. The fruit protected against lipid peroxidation and level of early biomarkers of colon carcinogenesis, accompanied by decrease in some endogenous antioxidant enzymes functionality. It also prevented colon tissues against MNU-induced severe inflammations and damage to the mutL-homolog 1 (MLH1) gene. There was significant negative correlation between endogenous antioxidant enzyme activities and carcinoembryonic antigen (CEA) as well as lipid peroxidation, but relationship between total polyphenols and percentage expression of MLH1 proteins as well as endogenous antioxidant enzyme activities was positive. These results validate the folkloric use of H. thebaica fruit in the management of colorectal disorders. PRACTICAL APPLICATIONS: Hyphaene thebaica fruit which is widely consumed in northern Nigeria and other countries of sub-Saharan Africa is rich in fiber and antioxidant polyphenols. These two classes of compounds have demonstrated capacity to prevent colorectal cancer and cancer of other sites. Therefore, the validated protective Hyphaene thebaica fruit suggests that it can be processed for inclusion in beverages/diets as functional foods for prevention and management of colorectal disorders.

Crassocephalum rubens (Juss Ex Jacq) leaf diets ameliorate systemic oxidative stress and tissue damage in a Wistar rat model.

The capacity of Crassocephalum rubens (Juss Ex Jacq) leaf to protect against systemic oxidative stress was evaluated in N-methyl-N-nitrosourea (MNU) - intoxicated rats fed at various inclusion rates for a period of twelve (12) weeks. Major organs and tissues were then assessed for indices of lipid peroxidation and oxidative stress. Crassocephalum rubens leaf significantly (p < .05) sustained the activities of superoxide dismutase and catalase with significant decrease in lipid peroxidation in MNU-intoxicated animals, particularly at 5% and 10% inlusion rates. The dietary inclusion also prevented significant changes in hematological parameters such as neutrophil and lymphocyte counts. It also reduced the severity of histologic damages such as necrosis, epithelial degeneration, inflammatory cell infiltration and other pathological changes to major organs. These results indicate that regular consumption of C. rubens leaf, prevents the deleterious biologic effects of the damaging reactive oxidative species (ROS). PRACTICAL APPLICATIONS: Crassocephalum rubens leaf has potential for development into a nutraceutical or functional food for chemoprevention and management of neurodegenerative diseases and other diseases associated with systemic oxidative stress, This is because its inclusion in the diet has attenuated lipid peroxidation, sustained the activity of antioxidant enzymes and mitigated deleterious changes in blood composition and tissue architecture resulting from exposure to a chemical carcinogen.

Blood of African Hedgehog Atelerix albiventris Contains 115-kDa Trypanolytic Protein that Kills Trypanosoma congolense.

INTRODUCTION: Protozoan parasites of the Order Trypanosomatida infect a wide range of multicellular plants and animals, causing devastating and potentially fatal diseases. Trypanosomes are the most relevant members of the order in sub-Saharan Africa because of mortalities and morbidities caused to humans and livestock. PURPOSE: There are growing concerns that trypanosomes are expanding their reservoirs among wild animals, which habours the parasites, withstand the infection, and from which tsetse flies transmit the parasites back to humans and livestock. This study was designed to investigate the potentials of the African hedgehog serving as reservoir for African animal trypanosomes. METHODS: Five adult hedgehogs alongside five laboratory mice were intraperitoneally inoculated with 106 and 104 of Trypanosoma congolense cells, respectively, and monitored for parasitemia and survival. Serum from twenty hedgehogs was subjected to trypanocidal activity-guided fractionation by successive ion-exchange and gel-filtration chromatographies, followed by characterization with Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE). RESULTS: Hedgehogs were resistant to the infection as no parasite was detected and none died even after 60 days, while all the mice died within 12 days. Both the serum and plasma prepared from hedgehogs demonstrated trypanocidal activity- rapidly killed trypanosomes even when diluted 1000 times. The trypanolytic factor was identified to be proteinaceous with an estimated molecular weight of 115-kDa. CONCLUSION: For the first time, it is here demonstrated that hedgehog blood has significant trypanolytic activity against T. congolense. The potential application of the hedgehog protein for the breeding of trypanosomosis-resistant livestock in tsetse fly belt is discussed.

Preventive potential of dietary inclusion of Brachystegia eurycoma (Harms) seeds on N-methyl-N-nitrosourea-induced colon carcinogenesis in Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Brachystegia eurycoma seed is used as dietary condiment and as part of recipes for treating colorectal disorders, while laboratory studies have established that it contains crude fiber and polyphenols which are important in cancer prevention. AIM OF THE STUDY: To establish the efficacy of a Nigerian diet in colon cancer prevention, a study was conducted to evaluate dietary inclusion of Brachystegia eurycoma seed in experimental colon carcinogenesis. METHODS: Rats undergoing intra-rectal instillations of N-Methyl-N-nitrosourea (MNU) were fed B. eurycoma included diets at 0%, 2.5%, 5% and 10% for a period of ten (10) weeks following which they were sacrificed; blood and tissues were monitored for biochemical, histological and immunohistochemical parameters. RESULTS: Brachystegia eurycoma significantly (P < 0.05) prevented MNU-induced elevation of malondialdehyde and carcinoembryonic antigen (CEA) as well as reduced activities of catalase and superoxide dismutase. The colon showed deep mucosal ulceration with moderate inter-glandular inflammation in the MNU control group, but only mild or no inflammation was observed in the colon of the MNU groups fed experimental diets. Similarly, colon immunohistochemistry assay showed that the dietary inclusion significantly prevented MNU-induced damage to mismatch repair gene (MutL homolog1). Positive relationship existed between fiber content of B. eurycoma seeds and MutL homolog1 protein expression while that between polyphenol/flavonoids contents of diets and CEA was negative. CONCLUSION: These data suggest that both dietary fiber and polyphenol/flavonoids contribute synergistically or additively to the potential preventive effect of B. eurycoma seeds in colon carcinogenesis, presumably through mechanisms that involve limiting the extent of oxidative stress and preventing or delaying the onset of pro-carcinogenic inflammatory processes.

Effect of methanolic extract of Tetrapleura tetraptera (Schum and Thonn) Taub leaves on hyperglycemia and indices of diabetic complications in alloxan-induced diabetic rats.

OBJECTIVE: To investigate the ameliorative role of Tetrapleura tetraptera (Schum and Thonn) Taub (T. tetraptera) leaf in hyperglycemia with associated conditions like oxidative stress, kidney damage and disorders in lipid metabolism. METHODS: Five groups of five rats each intraperitoneally received the following treatment schedules for 7 d: untreated normal control, untreated alloxan-diabetic control, diabetic treated with glibenclamide, normal rats treated with extract (50 mg/kg) and diabetic rats treated with the extract. Evaluations were made for fasting blood sugar, body weight changes, malondialdehyde, aspartate aminotransferase, alanine aminotransferase, bilirubin, superoxide dismutase, catalase, lipid profile, packed cell volume, hemoglobin, urea and creatinine in all the rats. RESULTS: Whereas the untreated diabetic rats showed a significant decrease (P<0.05) in packed cell volume, superoxide dismutase, catalase and high-density lipoprotein-cholesterol with a concomitant increase in the levels of malondialdehyde, fasting blood sugar, aspartate aminotransferase, alanine aminotransferase, bilirubin, urea and creatinine, administration of methanolic extract of T. tetraptera leaf or glibenclamide alleviated these altered parameters in the treated rats. CONCLUSIONS: Methanolic extract of T. tetraptera leaves possesses a potent capacity for treatment of diabetes and the accompanying complications, including oxidative stress and hyperlipidemia.

Nigerian foodstuffs with prostate cancer chemopreventive polyphenols.

Dietary polyphenols are antioxidants that can scavenge biological free radicals, and chemoprevent diseases with biological oxidation as their main etiological factor. In this paper, we review our laboratory data vis-á½°-vis available literature on prostate cancer chemopreventive substances in Nigerian foodstuffs. Dacryodes edulis fruit, Moringa oleifera and Syzygium aromaticum contained prostate active polyphenols like ellagic acid, gallate, methylgallate, catechol, kaempferol quercetin and their derivatives. Also Canarium schweinfurthii Engl oil contained ten phenolic compounds and lignans, namely; catechol, p-hydroxybenzaldehyde, dihydroxyphenylacetic acid, tyrosol, p-hydroxybenzoic acid, dihydroxybenzoic acid, vanillic acid, phloretic acid, pinoresinol, secoisolariciresinol. In addition, tomatoes (Lycopersicon esculentum Mill) which contains the powerful antioxidant and anti-prostate cancer agent, lycopene; cabbage (Brassica oleracea) containing indole-3-carbinol; citrus fruits containing pectin; Soursop (Annona muricata) containing annonaceous acetogenins; soya beans (Glycine max) containing isoflavones; chilli pepper (Capsicum annuum) containing capsaicin, and green tea (Camellia sinensis) containing (-) epigallocatechin gallate (EGCG), (-) epicatechin, (-) epicatechin-3-gallate and (-) epigallocatechin -3-gallate which are widely reported to posses prostate cancer chemopreventive compounds are also grown in Nigeria and other African countries. Thus, the high incidence of prostate cancer among males of African extraction can be dramatically reduced, and the age of onset drastically increased, if the population at risk consumes the right kinds of foods in the right proportion, beginning early in life, especially as prostate cancer has a latency period of about 50 years.

Content of polyphenolic compounds in the Nigerian stimulants Cola nitida ssp. alba, Cola nitida ssp. rubra A. Chev, and Cola acuminata Schott & Endl and their antioxidant capacity.

Varieties of kola nuts (Cola nitida alba, Cola nitida rubra A. Chev, and Cola acuminata Schott & Endl), a group of popular Nigerian and West African stimulants, were analyzed for their content of secondary plant metabolites. The three varieties of the kola nuts contained appreciable levels of (+)-catechin (27-37 g/kg), caffeine (18-24 g/kg), (-)-epicatechin (20-21 g/kg), procyanidin B 1 [epicatechin-(4beta-->8)-catechin] (15-19 g/kg), and procyanidin B2 [epicatechin-(4beta-->8)-epicatechin] (7-10 g/kg). Antioxidant capacity of the extracts and purified metabolites was assessed by two HPLC-based and two colorimetric in vitro assays. Extracts of all varieties exhibited antioxidant capacity with IC 50 values in the range 1.70-2.83 and 2.74-4.08 mg/mL in the hypoxanthine/xanthine oxidase and 2-deoxyguanosine HPLC-based assays, respectively. Utilization of HPLC-based assays designed to reflect in situ generation of free radicals (e.g., HO(*)), as opposed to general assays (DPPH, FRAP) in common use which do not, indicate that, of the major secondary plant metabolites present in kola nut extracts, caffeine is potentially the more effective cancer chemopreventive metabolite in terms of its antioxidant capacity.