Effect of various levels of dietary Jatropha curcas seed meal on rabbits infested by the adult ticks of Hyalomma marginatum marginatum I. Animal performance, anti-tick feeding and haemogram

Benefits and Challenges of Jatropha Meal as Novel Biofeed for Animal Production

Jatropha curcas L. has gained importance as a source of seed oil for biodiesel production. The meal contained about 60% protein with a good balance of essential amino acids, containing various bioactive compounds, including saponins, phytic acids, trypsin inhibitors, lectins, phenolics, and flavonoids, which render it as a potential biofeed for animal production. The Jatropha meal demonstrated various biological activities, including antioxidant, antibacterial, and anti-inflammatory effects which enhance its property as a bio-feed. The levels of these bioactive compounds in the seeds are dependent on the genotypes. The J. curcas possessed different varieties which are either toxic or non-toxic according to the presence of phorbol esters. The presence of phorbol esters in the meal confirmed the toxic variety of Jatropha resulting in the limited application of meal as a biofeed. The Jatropha meal devoid of phorbol esters could be applied as a biofeed in the animal production industry, and for the toxic varieties, various techniques such as physicochemical and biological treatments have been introduced to the industry to remove the phorbol esters from Jatropha meal. Several studies employing various cells and animals confirmed the toxicity of the phorbol esters. The molecular mechanism of action of phorbol esters is through up-regulation of PKC-β II gene, overexpression of down-stream proto-oncogenes resulted in inflammation and oxidative stress ending by apoptotic cell death. Despite the presence of valuable bioactive compounds in the Jatropha meal, its nutritional application is not recommended unless the phorbol esters are completely removed.

Hydroxy-octadecenoic acids instead of phorbol esters are responsible for the Jatropha curcas kernel cake's toxicity

The toxic kernel cake of Jatropha curcas (KCakeJ) is an emerging health and environmental concern. Although phorbol esters are widely recognized as the major toxin of KCakeJ, convincing evidence is absent. Here, we show that rather than phorbol esters an isomeric mixture of 11-hydroxy-9E-octadecenoic acid, 12-hydroxy-10E-octadecenoic acid and 12-hydroxy-10Z-octadecenoic acid (hydroxy-octadecenoic acids, molecular formula C₁₈H₃₄O₃) is the major toxic component. The toxicities of hydroxy-octadecenoic acids on experimental animals, e.g. acute lethality, causing inflammation, pulmonary hemorrhage and thrombi, allergies, diarrhea and abortion, are consistent with those on human/animals caused by Jatropha seed and/or KCakeJ. The hydroxyl group and the double bond are essential for hydroxy-octadecenoic acids’ toxicity. The main pathway of the toxicity mechanism includes down-regulating UCP3 gene expression, promoting ROS production, thus activating CD62P expression (platelet activation) and mast cell degranulation. The identification of the major toxin of KCakeJ lays a foundation for establishing an environmentally friendly Jatropha biofuel industry.

Wang et al. report that an isomeric mixture of 3 hydroxy-octadecenoic acids, instead of widely recognised phorbol esters, are the major toxic component of Jatropha curcas kernel cake. They test its effects on animal models and also attempt to elucidate the mechanism behind the toxicity, with a goal to help establish an environmentally friendly Jatropha biofuel industry.

Digestibility of solvent-treated Jatropha curcas kernel by broiler chickens in Senegal

Jatropha curcas is a drought-resistant shrub belonging to the Euphorbiaceae family. The kernel contains approximately 60 % lipid in dry matter, and the meal obtained after oil extraction could be an exceptional source of protein for family poultry farming, in the absence of curcin and, especially, some diterpene derivatives phorbol esters that are partially lipophilic. The nutrient digestibility of J. curcas kernel meal (JKM), obtained after partial physicochemical deoiling was thus evaluated in broiler chickens. Twenty broiler chickens, 6 weeks old, were maintained in individual metabolic cages and divided into four groups of five animals, according to a 4 × 4 Latin square design where deoiled JKM was incorporated into grinded corn at 0, 4, 8, and 12 % levels (diets 0, 4, 8, and 12 J), allowing measurement of nutrient digestibility by the differential method. The dry matter (DM) and organic matter (OM) digestibility of diets was affected to a low extent by JKM (85 and 86 % in 0 J and 81 % in 12 J, respectively) in such a way that DM and OM digestibility of JKM was estimated to be close to 50 %. The ether extract (EE) digestibility of JKM remained high, at about 90 %, while crude protein (CP) and crude fiber (CF) digestibility were largely impacted by JKM, with values closed to 40 % at the highest levels of incorporation. J. curcas kernel presents various nutrient digestibilities but has adverse effects on CP and CF digestibility of the diet. The effects of an additional heat or biological treatment on JKM remain to be assessed.