FERTILISER CREDIT AND AGROECOLOGICAL USE OF ORGANIC SOIL AMENDMENTS IN NORTHERN GHANA

Contemporary African agricultural policy embodies the African Green Revolution’s drive towards modernisation and commercialisation. Agroecologists have criticised this movement on ecological, social and political grounds. Northern Ghanaian fertiliser credit schemes provide a good example through which these critiques can be examined in a context where agricultural policy reflects the African Green Revolution’s ideals. This study aimed to determine the relationship of such credit schemes to farmers’ use of organic amendments, elucidate other factors related to organic amendment use, and comment on the relevance of this modernisation policy and its relationship to agroecology. A first research phase employed semi-structured key informant interviews. Qualitative data from these informed construction of a semi-structured questionnaire that was used in a survey of 205 farmers. Multistage sampling purposively identified five villages and selected farmers within who had joined government and donor-funded fertiliser credit schemes. The use of organic and inorganic amendments was compared to that of peers who had not taken part in such schemes. Quantitative data were used in binomial logistic regression, inferential and descriptive statistics. Qualitative data were content analysed. Credit group membership was associated with higher fertiliser application and yield, but had little influence on the extent of commercialisation. Farmers who applied organic amendments were 40% less likely to belong to a fertiliser credit scheme than not, indicating substitution between organic and inorganic fertilisers. Organic amendments were 40% more likely to be applied to compound farms than outfields and six times more likely to be applied by household heads than other household members. However, household heads also preferentially joined credit groups. This was part of an agroecological soil fertility management strategy. Household heads appreciated the soil moisture retention properties of organic amendments, and applied them to compound farms to reduce risk to their household food supply in a semi-arid environment. They simultaneously accessed fertiliser to enhance this household provisioning strategy. They appreciated the increased yields this achieved, yet complained that the repayment terms of credit schemes were unfair, fertiliser did not enhance yields in dry conditions and fertilisers were supplied late. Farmers’ use of credited fertiliser alongside their existing agroecological strategy is helpful to the extent that it raises yields, yet is problematic in that it conflicts with risk-reduction strategies based on organics. There is some potential for modernised and agroecological management paradigms to coexist. For fertiliser credit to play a role in this, schemes must use fairer repayment terms and involve a focus on simultaneous use of organic amendments.

Impaired reverse cholesterol transport and hepatic steatosis contribute to pathogenesis of high fat dietinduced hyperlipidemia in murine models

Purpose: To investigate the pathogenesis of high fat diet (HFD)-induced hyperlipidemia (HLP) in mice, rats and hamsters and to comparatively evaluate their sensitivity to HFD. Methods: Mice, rats and hamsters were fed with high-fat diet formulation (HFD, n = 8) or a control diet (control, n = 8) for 4 weeks. Changes in body weight, relative liver weight, serum lipid profile, expressions of hepatic marker gene of lipid metabolism and liver morphology were observed in three hyperlipidemic models. Results: Elevated total cholesterol (TC), triglyceride, low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) levels and body weight were observed in all hyperlipidemic animals (p < 0.05), while hepatic steatosis was manifested in rat and hamster HLP models, and increased hepatic TC level was only seen (p < 0.05) in hamster HLP model. Suppression of HMG-CoA reductase and up-regulation of lipoproteinlipase were observed in all HFD groups. Hepatic gene expression of LDLR, CYP7A1, LCAT, SR-B1, and ApoA I, which are a response to reverse cholesterol transport (RCT), were inhibited by HFD in the three models. Among these models, simultaneous suppression of HMG-CR, LCAT, LDLR and SR-BI and elevated LPL were features of the hamster model. Conclusion: As the results show, impaired RCT and excessive fat accumulation are major contributors to pathogenesis of HFD-induced murine HLP. Thus, the hamster model is more appropriate for hyperlipidemia research.

Licochalcone A exerts antitumor activity in bladder cancer cell lines and mice models

Purpose: To investigate the effect of licochalcone A (LA) on the inhibition of cell proliferation and ERK1/2 phosphorylation in bladder carcinoma cell lines. Methods: Cell viability was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. Dye-binding method was used to examine the concentration of proteins. Lymphocytes were extracted from mice and after surface staining were subjected to BD fixation and permeabilization for intracellular staining. Flow cytometry was used to measure cellular fluorescence. Results: MTT results revealed a significant decrease in the proliferation of UM-UC-3, J82 and HT-1197 cell lines on treatment with LA. LA also induced reduction in phosphorylation of ERK1/2 in all three carcinoma cell lines. In the mouse model, licochalcone A treatment via intraperitoneal (ip) administration induced a significant decrease in the level of regulatory T cells (Tregs). Comparison of the mouse interferon-α (IFN-α)-treated and LA-treated groups revealed that LA treatment caused enhancement of cytotoxic T lymphocyte (CTL) activity similar to that of IFN-α. Administration of UM-UC-3 cells in C3H/HeN mice resulted in marked reduction in the counts for splenocytes and CD4+ CD25+ Foxp3+ T (regulatory T cells) cell proportion in LA-treated mice compared to untreated control group. Conclusion: Licochalcone A may be of therapeutic importance for the prevention of bladder carcinoma. However, studies are required to ascertain the compound’s usefulness in this regard.