DNA methylation patterns associated with cyanogenic cassava exposure and konzo in Sub-Saharan Africa

Konzo, a disease characterized by sudden, irreversible spastic paraparesis, affecting up to 10% of the population in some regions of Sub-Saharan Africa during outbreaks and is strongly associated with dietary exposure to cyanogenic bitter cassava. The molecular mechanisms underlying the development of konzo, remain largely unknown. Here, through an analysis of 16 individuals with konzo and matched healthy controls from the same outbreak zones, we identified 117 differentially methylated loci involved in numerous biological processes that may identify cyanogenic- sensitive regions of the genome, providing the first study of epigenomic alterations associated with sub-lethal cyanide exposure and a clinical phenotype.

Integrasi Kearifan Lokal dalam Evaluasi Lahan bagi Budidaya Enbal (Manihot esculenta Crantz) pada Kaki Gunung Ar, Pulau Yut, Maluku Tenggara

Cassava is a food and trade commodity in the Kei Islands, Maluku Province. Various aspects of the cultivation of this crop are determined by traditional knowledge held by farmers from generation to generation. This study aimed to: 1) describe the potential of local wisdom (traditional knowledge) about the land owned by the Ohoi Wasar community in the Kei Islands regarding the suitability of the coastal land management for ‘enbal’ (bitter cassava) cultivation; 2) integrate local knowledge about land belonging to the Ohoi Wasar indigenous people with FAO land evaluation (modern soil knowledge in land suitability evaluation) for sustainable cultivation of ‘enbal’ cassava. This research was carried out using a transect-based survey method that was participatory and goal-oriented, which focused on farmers who cultivate ‘enbal’ cassava and their fields on the coastal land in the footslope of Mount Ar. The results of the study were: 1) there was local-traditional wisdom of the Wasar community that was directly related to ‘enbal’ cultivation (ethnopedological system); firstly, the wisdom of determining land suitability for ‘enbal’ cassava cultivation (ie. hadoichr ngametan or black soil = Renzina, and hadoichr vuil or red soil = Cambisol Dystrict); secondly was the wisdom of determining the time/day of land clearing for ‘enbal’ gardens (slash-and-burn) and the planting time which was started in early May; in addition, there was a supporting wisdom in the diversity or reliance of local foods, namely the habit of harvesting and consuming "boo" with " es­­`u/laor " at the end of March; 2) when the potential of local knowledge about soils (ethnopedology system) was integrated with the FAO FAO system of land evaluation, it appeared that there was an overlap in the studies of soil fertility, namely both categorizing “black soil” as more fertile (very suitable), and “red soil” as a less fertile" (slightly suitable) soil. Keywords: Ar-Wasar, bitter cassava, ‘enbal’, land evaluation, local wisdom ABSTRAK Ubi kayu merupakan komoditas pangan dan perdagangan di Kepulauan Kei, Provinsi Maluku. Berbagai aspek budidaya tanaman ini ditentukan oleh pengetahuan tradisional yang dipegang oleh petani secara turun temurun. Penelitian ini bertujuan: 1) menginventarisasi potensi kearifan lokal (pengetahuan tradisional) tentang tanah yang dimiliki masyarakat Ohoi Wasar di Kepulauan Kei terkait kesesuaian pengelolaan lahan pesisir bagi budidaya tanaman enbal (ubi kayu pahit); 2) mengintegrasikan kearifan pengetahuan lokal tentang tanah yang dimiliki masyarakat adat Ohoi Wasar dengan evaluasi lahan FAO (pengetahuan tanah moderen dalam evaluasi kesesuaian lahan) bagi budidaya tanaman enbal yang berkelanjutan. Penelitian dilaksankan dengan metode survey berbasis transek secara partisipatif berorientasi tujuan, yang difokuskan pada petani yang bercocok tanam enbal dan kebunnya pada lahan pesisir kaki Gunung Ar. Hasil penelitian adalah: 1) Ada kearifan lokal-tradisonal dari masyarakat Wasar yang terkait langsung dengan budidaya enbal (sistem etnopedologi); pertama, kearifan penentuan tanah/lahan yang cocok atau sesuai bagi usaha kebun enbal (yakni hadoichr ngametan atau tanah hitam = Renzina, dan hadoichr vuil atau tanah merah =Kambisol Distrik); kedua, kearifan penentuan waktu/hari buka kebun enbal (tebas-bakar) dan waktu tanam di awal Mei; selain itu, terdapat kearifan pendukung dalam keragaman/kemandirian pangan lokal, yakni kebiasaan panen dan konsumsi “boo” bersama “es­­`u/laor” pada akhir Maret. 2) Jika potensi kearifan pengetahuan tanah lokal (sistem etnopedologi) diintegrasikan dengan evaluasi lahan sistem FAO, nampak titik temunya (overlap) pada telaahan kesuburan tanah, yakni keduanya mengkategorikan “tanah hitam” sebagai yang lebih subur (sangat sesuai), dan “tanah merah” kurang subur (cukup sesuai). Kata kunci: Ar-Wasar , enbal, evaluasi lahan, kearifan lokal, ubi kayu pahit

Rodent Experimental Model of Konzo: Characterization of Motor Impairment and Neurodegeneration after Cassava Neurotoxicity in the Rat

Konzo is a motor neuron neurodegenerative disease caused by bitter cassava toxicity that presents as a non-progressive spastic paraparesis. The ability of bitter cassava to produce behavioural and structural changes in adult rat nervous system was examined. Twenty five rats were used for this study, and pruned to 20 after consistent baseline performance was achieved (n=20; control=5, cassava chow=15). The rats were switched to a cassava diet for another 5 weeks (n=15). After the cassava consumption period, 5 rats underwent rehabilitation training three times a week and their performance tested once in a week for 5 weeks. Quantitative and qualitative assessments using a reaching movement scale and reach-to-grasp success rate were respectively carried out. Animals subjected to cassava toxicity performed significantly worse than the controls when determining the success rate in a reach-to-grasp experiment (baseline=69.8%, cassava diet=21.4%, post-cassava diet =48.9%). The various movement of the rat was analysed using ANOVA and there was significant difference (p < 0.05) in the performance. The rats couldn’t pronate, grasp, withdraw or open the digits properly when fed with cassava diet. Histology showed neuropathological damages on the motor cortex, less neurons in the motor neuron pool of the spinal cord and disruption of pyramidal layer of the hippocampus when rats were given bitter cassava. Immunofluorescence stain shows motor neurons and numerous choline acetyltransferase (ChAT+) processes and some C-boutons. There are behavioural evidence and neuropathological changes in the motor cortex and ventral horn of the spinal cord that may underlie movement impairments in rats fed with bitter cassava.

Reaction kinetics of lactic acid fermentation from bitter cassava (Manihot glaziovii) starch by Lactobacillus casei

One of the utilizations of bitter cassava is modified cassava flour (Mocaf) production using the fermentation process by Lactobacillus casei. The Mocaf has potential as the future of food security products. It has a characteristic property similar to wheat flour. Lactic acid was also produced as a by‐product during fermentation. After 40 h of fermentation, the proximate composition content of Mocaf was lactic acid content of 0.000928 g/L, hydrogen cyanide levels of 0.02 ppm, starch content of 59.13%, amylose content of 12.98% and amylopectin content of 46.15%. In the scaling‐up process from a laboratory scale to a pilot and industrial scale, modeling is needed. There are five equation models used to describe the kinetic reactions of lactic acid from bitter cassava starch: Monod, Moser, Powell, Blackman, and Product Inhibitor. Each parameter was being searched by a fitting curve using sigmaplot 12.0. The best result in terms of the highest R2 (0.65913) was obtained in the Powell equation with the value of µmax of 1.668/h, Ks of 123.4 g/L, and maintenance rate (m) of 4.672. The kinetic data obtained can be used to design biochemical reactors for industrial scale Mocaf flour production.

Composition of Two Local Cassava Varieties and the Effect of Processing on their Hydrocyanic Acid Content and Nutrient Digestibility by the Rat

Two common Nigerian cassava varieties Were subjected to proximate analysis with a view to assessing the relative potential nutrient composition of the roots, stems, leaves and seeds. The results obtained showed that the leaves, seeds and stems in that order are much richer than the roots in protein but higher in crude fibre. There was a relationship between the crude protein contents of the roots and stem and the hydrocyanic acid (HCN) content of the plant while that of the leaves and seeds did not appear to follow the same trend. HCN of the bitter cassava variety was considerably higher in the whole tuber, pulp and peel than in the sweet strain, sundrying and ensiling resulted in appreciable losses of HCN. Grated root lost about half its HCN content within six hours while stored whole roots showed a rapid decline in HCN from the fifth day after harvest. Apparent digestibility coefficients (A.D.C.) of the major nutrients of cassava roots were not significantly (P <0.05) affected by the processes of boiling or sundrying.

Effects of Postharvest Storage on Cyanide Content and Activity of Partially Purified Rhodanese from Bitter Cassava (Manihot Utilissima) Tubers

This research investigated the effects of postharvest storage on cyanide content and rhodanese isolated from bitter cassava (Manihot Utilissima) tubers. Cyanide content of freshly harvested sample, samples stored for 4 days and samples stored for 8 days were estimated by silver nitrate titration method. Rhodanese was purified using 80% ammonium sulphate precipitate and ion-exchange chromatography on CM-Sephadex C-25.Cyanide content from freshly harvested sample was 345.6 mg HCN/kg while 237.6 mg HCN/kg and 108 mg HCN/kg were obtained for samples stored for 4 days and samples stored for 8 days respectively. Specific activity of rhodanese from freshly harvested sample was 3.411 RU/mg while 5.92 RU/mg and 5.35 RU/mg were obtained for samples stored for 4 days and samples stored for 8 days respectively. The Km values of rhodanese for KCN were 3.18 mM, 2.40 mM, 0.25 mM for freshly harvested sample, samples stored for 4 days and samples stored for 8 days respectively. The optimum temperature from freshly harvested sample and sample stored for 4 days was 70 0C while samples stored for 8 days was 50 0C. An optimum pH of 4.0 was obtained from the 3 samples.Rhodanese play plausible role in cyanide reduction during the postharvest storage.