Nutritional characterization of Mucuna pruriens

Effects of Dietary Protein Levels on Sheep Gut Metabolite Profiles during the Lactating Stage

Diet-associated characteristics such as dietary protein levels can modulate the gut's primary or secondary metabolites, leading to effects on the productive performance and overall health of animals. Whereas fecal metabolite changes are closely associated with gut metabolome, this study aimed to see changes in the rumen metabolite profile of lactating ewes fed different dietary protein levels. For this, eighteen lactating ewes (approximately 2 years old, averaging 38.52 ± 1.57 kg in their initial body weight) were divided into three groups (n = 6 ewes/group) by following the complete randomized design, and each group was assigned to one of three low-protein (D_I), medium-protein (D_m), and high-protein (D_h) diets containing 8.58%, 10.34%, and 13.93% crude protein contents on a dry basis, respectively. The fecal samples were subjected to untargeted metabolomics using ultra-performance liquid chromatography (UPLC). The metabolomes of the sheep fed to the high-protein-diet group were distinguished as per principal-component analysis from the medium- and low-protein diets. Fecal metabolite concentrations as well as their patterns were changed by feeding different dietary protein levels. The discriminating metabolites between groups of nursing sheep fed different protein levels were identified using partial least-squares discriminant analysis. The pathway enrichment revealed that dietary protein levels mainly influenced the metabolism-associated pathways (n = 63 and 39 in positive as well as negative ionic modes, respectively) followed by protein (n = 15 and 8 in positive as well as negative ionic modes, respectively) and amino-acid (n = 14 and 7 in positive as well as negative ionic modes, respectively) synthesis. Multivariate and univariate analyses showed comparative changes in the fecal concentrations of metabolites in both positive and negative ionic modes. Major changes were observed in protein metabolism, organic-acid biosynthesis, and fatty-acid oxidation. Pairwise analysis and PCA reveal a higher degree of aggregation within the D-h group than all other pairs. In both the PCA and PLS-DA plots, the comparative separation among the D_h/D_m, D_h/D_I, and D_m/D_I groups was superior in positive as well as negative ionic modes, which indicated that sheep fed higher protein levels had alterations in the levels of the metabolites. These metabolic findings provide insights into potentiated biomarker changes in the metabolism influenced by dietary protein levels. The target identification may further increase our knowledge of sheep gut metabolome, particularly regarding how dietary protein levels influence the molecular mechanisms of nutritional metabolism, growth performance, and milk synthesis of sheep.

L-DOPA synthesis in Mucuna pruriens (L.) DC. is regulated by polyphenol oxidase and not CYP 450/tyrosine hydroxylase: An analysis of metabolic pathway using biochemical and molecular markers

Mucuna pruriens L., commonly known as velvetbean or cow-itch, is a self-pollinated tropical legume of the family Fabaceae, known for its medicinal properties. The active principle L-DOPA extracted from the plant is a potent drug used in the treatment of Parkinson's disease. Although, it is hypothesized that a single step reaction can produce L-DOPA, the presence of optional routes makes the pathway more intricate. For instance, the catecholamine biosynthetic pathway, which leads to L-DOPA production, could occur by hydroxylation of tyrosine to L-DOPA either by polyphenol oxidase (PPO) or tyrosine hydroxylase (TH). Furthermore, Cytochrome P450 (CYP) enzymes can also cause hydroxylation of tyrosine, resulting in L-DOPA synthesis. Therefore, the present investigation was focused on validating the step, which catalyzes the synthesis of L-DOPA, at the biochemical and molecular levels. Enzyme inhibitor studies showed significant inhibition of PPO enzyme with corresponding decrease in L-DOPA synthesis while TH and CYP inhibition had no effect on L-DOPA synthesis. Activity staining of non-denaturing PAGE gel for PPO and TH showed activity only to PPO enzyme. Following in-gel assay and tryptic digestion of the excised stained gel portion, peptide recovery and LC-MS/MS analysis were performed. Degenerate primers based on peptide sequence resulted in an 800bp amplicon. The subsequent sub-cloning, RACE analysis and BLAST search resulted in the isolation of full-length PPO coding sequence of 1800 bp. Structure prediction and phylogenetic analysis of the obtained sequence revealed strong similarity to other plant PPO's like Glycine max, Vigna radiata and Vicia faba of the same family.

Utilization of Mucuna pruriens whole pods to feed lactating hair ewes

Twenty nine Pelibuey × Katahdin hair ewes rearing single lamb were used during 42 days of lactation to evaluate the effect of including the Mucuna pruriens whole pods in the diets of lactating ewes on milk production and offspring performance. Animals were distributed at random into three experimental diets: a control diet without Mucuna (M0), and two more diets with the inclusion of 13 (M13) and 26% (M26), of milled pods of Mucuna pruriens, respectively. Dry matter intake, was not significantly different (P > 0.05) among diets. Milk yield (P > 0.05) was 734, 786, and 694 g/day for diets M0, M13, and M26, respectively. Milk fat (P > 0.05), milk protein (P > 0.05), and milk lactose (P > 0.05) did not differ between treatments. Lambs had similar daily weight gain (P > 0.05) among diets (180, 174, and 171 g/day for diets M0, M13, and M26, respectively). Diets with Mucuna whole pods were 5.6 and 12.9% more profitable (M13 and M26, respectively) than control diet. Under the conditions of this work, Mucuna pruriens whole pods can be included up to 26% in the diets of lactating crossbred hair ewes without negatively affecting their productive performance during the first 6 weeks of lactation.

Nutrient Digestibility and Metabolizable Energy Content of Mucuna pruriens Whole Pods Fed to Growing Pelibuey Lambs

The nutrient digestibility, nitrogen balance and in vivo metabolizable energy supply of Mucuna pruriens whole pods fed to growing Pelibuey lambs was investigated. Eight Pelibuey sheep housed in metabolic crates were fed increasing levels of Mucuna pruriens pods: 0 (control), 100 (Mucuna100), 200 (Mucuna200) and 300 (Mucuna300) g/kg dry matter. A quadratic (p<0.002) effect was observed for dry matter (DM), neutral detergent fibre (aNDF), nitrogen (N) and gross energy (GE) intakes with higher intakes in the Mucuna100 and Mucuna200 treatments. Increasing M. pruriens in the diets had no effect (p>0.05) on DM and GE apparent digestibility (p<0.05). A linear reduction in N digestibility and N retention was observed with increasing mucuna pod level. This effect was accompanied by a quadratic effect (p<0.05) on fecal-N and N-balance which were higher in the Mucuna100 and Mucuna200 treatments. Urine-N excretion, GE retention and dietary estimated nutrient supply (metabolizable protein and metabolizable energy) were not affected (p>0.05). DM, N and GE apparent digestibility coefficient of M. pruriens whole pods obtained through multiple regression equations were 0.692, 0.457, 0.654 respectively. In vivo DE and ME content of mucuna whole pod were estimated in 11.0 and 9.7 MJ/kg DM. It was concluded that whole pods from M. pruriens did not affect nutrient utilization when included in an mixed diet up to 200 g/kg DM. This is the first in vivo estimation of mucuna whole pod ME value for ruminants.

Evaluation of the metabolizable energy value for growing lambs of the Mucuna pruriens seed and the whole pod

Whole pod and seeds of velvet bean (Mucuna pruriens) were included in diets for growing sheep used to validate previously estimated ME values of 9.7 MJ and 12.6 MJ for whole pod and seed respectively. Twenty-four lambs, 15 females and nine males of 18.7 ± 2.4 kg average weight, were allocated in three treatments using a completely randomized block design with eight replicates per treatment. Each group was given a diet with a ratio of 60% of Napier grass (Pennisetum purpureum) and 40% of a supplement with the addition of 0%, 50% whole pod or 66% of M. pruriens seeds, for TI, TII and TIII respectively. Diets were formulated to meet the requirements for 100-g daily live weight gain (LWG). The total dry matter intake (836 g a(-1) d(-1), forage + supplement), LWG (90 g a(-1) d(-1)) and feed conversion (9.66 kg DM/kg LWG) of lambs from TIII were lower (P < 0.05) compared to 941 g, 121 g, and 7.78 kg DM/kg LWG from TII and 976 g, 132 g and 7.50 kg DM/kg LWG from TI respectively. No difference was found (P > 0.05) between TI and TII in the three evaluated variables. The ME values of whole pod and seeds of M. pruriens used in this work were validated. It was concluded that M. pruriens can be included as a component in diets for growing sheep, as a partial replacement of conventional feedstuffs.