Effects Of L-proline Research Articles

Effects of L-Proline on the Stability of Mulberry Anthocyanins and the Mechanism of Interaction between L-Proline and Cyanidin-3-O-Glycoside.

The protective effects of L-aspartic acid, L-valine, and L-proline on the stability of mulberry anthocyanins were investigated. Results showed that L-aspartic acid, L-valine, and L-proline significantly enhanced (p < 0.05) the stability of mulberry anthocyanins under constant light or ascorbic acid (AA). L-Proline had the best protective effect against anthocyanin degradation. The interaction between L-proline and cyanidin-3-O-glucoside (C3G) through hydrogen bonding and van der Waals forces, which improved the stability of C3G, was confirmed using FT-IR, 1H NMR, XRD, and molecular docking analyses, as well as molecular dynamics modes. In vitro digestion experiments yielded that both 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging capacities of the C3G/Pro group were increased in the intestinal fluid (p < 0.05). The above findings suggest that L-proline effectively slowed down the degradation of mulberry anthocyanins, and that it could be used as an auxiliary pigment and food additive to extend the optimal flavor period of products containing mulberry anthocyanins, and can improve the bioavailability of mulberry anthocyanins.

Effects of L-proline on swimming parameters of Daphnia magna subjected to heat stress.

L-proline (L-PROL) is an essential amino acid, a constituent of many proteins and the osmoprotective molecule produced and accumulated in higher plants and some freshwater microalgae in response to various environmental stressors. Knowledge on thermoprotective effects of this amino acid on freshwater invertebrates is very scarce. Therefore the aim of our study was to determine the effect of L-PROL at concentrations: 10 mg/L, 20 mg/L and 50 mg/L on swimming behavior (immobilization, swimming track density, swimming speed, turning ability) of Daphnia magna subjected to temperatures: 22 °C, 35 °C and 38 °C. We found that L-PROL elevated all the measured swimming parameters at 22 °C when compared to the untreated crustaceans. Furthermore, L-PROL alleviated heat-induced inhibition of these parameters in the experimental animals subjected to 35 °C. The results suggest that L-PROL stimulates swimming performance and alleviates alterations of swimming parameters induced by heat stress in D. magna. Moreover, these findings may support the hypothesis that in natural conditions, L-PROL may protect crustaceans against thermal stress.

Establishment of a Simple Plant Regeneration System Using Callus from Apomictic and Sexual Seeds of Guinea Grass (Panicum maximum)

Aims: For analysis of apomixis genes, as the first step, an efficient and simple plant regeneration system has been established using callus from apomictic and sexual seeds of guinea grass (Panicum maximum). Study Design: The best basic medium for callus formation from matured seeds of guinea grass was selected, and then, the best combinations of growth regulators on different media were selected for plant regeneration by indirect organogenesis. Methodology: Guinea grass accessions of sexual and apomict of seeds were used for culture. Seeds sterilized were cultured in Murashige and Skoog [10] medium (MS) and in that proposed by Chu et al. [12] (N6D) for callus formation. The best medium and, the effects of L-proline and growth Original Research Article Chen et al.; BBJ, 7(4): 183-190, 2015; Article no.BBJ.2015.059 184 regulators’ type and concentrations on callus formation and plant regeneration in 3 accessions were examined, respectively. After the plantlets rooting in MS hormone-free medium, the complete plants were planted in pots for hardening. Results: N6D medium has given better rates for callus formation, that is, 97.1% in sexual N68/968-o-5, and 91.7% and 84.6% in apomict N68/96-8-o-11 and ‘Natsukaze’, respectively. MS medium with 0.2 mg/l of Kinetin has given the best rate or plant regeneration among the used 4 kinds of the media. For each material, the best results were obtained on MS with 0.2 mg/l of Kinetin for N68/968-o-5, and MS with 2.0 mg/l of L-proline and 0.2 mg/l of Kinetin for ‘Natsukaze’. After hardening of the regenerated plants in soil, 100% of surviving rates were obtained, and showed normal growth comparing with the plants-derived from seeds. Conclusion: We have established, as the first case, an efficient and simple plant regeneration system by using callus from apomictic and sexual seeds of guinea grass for analysis of apomixis genes, consisting of analysis of the best media, L-proline usages and phytohormone combinations for callus formation, plant regeneration and hardening in different stages, respectively.

Improving Culture Conditions for Temporomandibular Joint Disc Tissue Engineering

Background: The temporomandibular joint (TMJ) is extremely important for activities like eating and talking, which can become painful and difficult for patients with TMJ dysfunction. Tissue engineering is a potential alternative to current surgical interventions through replacement of diseased or injured tissue with a functional construct. Since research with TMJ disc cells began relatively recently, optimal culturing conditions must be determined. Methods: Metabolic additives, L-glutamine, L-alanyl-L-glutamine, sodium pyruvate, and insulin, were examined for their effects on TMJ disc cells in monolayer. Effects of L-proline were examined in three-dimensional (3-D) culture at concentrations of 0, 25 and 100 mg/l. Results: The combination of L-glutamine, sodium pyruvate, and insulin improved cell proliferation rates without affecting collagen production or gene expression. No differences were observed in mechanical properties of the engineered constructs; however, collagen and glycosaminoglycan quantities normalized to cell number decreased at the highest concentration of L-proline. Conclusion: This work identified supplements for 2-D monolayer expansion. Other supplements or culture conditions still need to be investigated for 3-D tissue production. This work improves upon porcine TMJ disc cell culturing conditions, taking us closer to being able to engineer the TMJ disc.

Nature of equilibrium shifts in racemic praseodymium(iii) tris(2,2′-oxydiacetate) induced by interaction with chiral probes

The effects of L-proline and its derivatives N-acetyl-L-proline, L-proline methyl ester, and L-proline benzyl ester on the equilibrium shift in the racemic Pr(ODA)33− complex, in which ODA is 2,2′-oxydiacetate, have been studied by means of circular dichroism (CD) and 1H NMR spectroscopy. While N-acetyl-L-proline did not induce any optical activity in Pr(ODA)33−, the addition of L-proline, L-proline methyl ester, and L-proline benzyl ester led to the appearance of the Pfeiffer effect in this lanthanide complex. The signs of the induced CD signals at 484 nm which correspond to the 3P0 ← 3H4 transition implied that L-proline interacts more favourably with the Λ-enantiomer of the Pr(ODA)33−, while L-proline methyl ester and L-proline benzyl ester preferably interact with the Δ-enantiomer of the same complex. The 1H NMR studies suggested that L-proline and its esters adopt different conformations upon interaction with Pr(ODA)33−. The dependence of the absorption dissymmetry factor, gabs, on the concentration of the L-proline indicated that the Pfeiffer effect in this lanthanide complex is best described by the associated model. Measurements in the solution of various pH, ionic strength, and dielectric constant suggested that the chiral discriminatory interaction is a combination of electrostatic and hydrophobic forces, while the hydrogen bonding effects are less important.

Effects of L-proline on phase I and phase II xenobiotic biotransformation capacities of rat and human hepatocytes in long-term collagen gel cultures.

L-Proline supplementation of the medium for collagen gel cultures of hepatocytes has been shown to improve albumin secretion. A study was made as to whether L-proline is also essential for the maintenance of xenobiotic biotransformation capacities in collagen gel sandwich and immobilisation cultures of rat and human hepatocytes. Key phase I (cytochrome P450-dependent monooxygenase [CYP)] and microsomal epoxide hydrase [mEH]) and phase II (glutathione S-transferase [GST]) biotransformation enzyme activities and the secretion of albumin in the culture medium were assessed in the absence and presence of L-proline. CYP and mEH activities were not affected by the addition of L-proline, whereas phase II alpha-Class GST activity of rat hepatocytes in collagen cultures was decreased. Species differences were demonstrated, as human hepatocytes showed a better maintenance of GST activities than their rat counterparts in the presence of L-proline. Albumin secretion, often considered to be a marker for differentiated cell function, does not parallel the biotransformation capacities of the hepatocytes in culture. Additional results demonstrated an L-proline-mediated enhancement of the proliferation rate of contaminating stellate cells in conventional monolayer culture. Transdifferentiation of stellate cells to proliferating myofibroblasts, along with an increased albumin secretion and collagen synthesis, are characteristic of fibrotic liver. Since the last two phenomena have been observed in L-proline-supplemented collagen gel cultures, it can be concluded that when stable collagen gel cultures of rat hepatocytes are needed for long-term pharmacotoxicological studies, it is preferable to use an L-proline-free culture medium. Further studies on medium optimisation are required for hepatocytes from species other than rat.

Proline-glutamate interactions in the CNS

1. 1. Crude synaptosomes (P 2) and synaptosomal membranes were prepared from normal C57/B110 mouse brains and Wistar rats respectively. 2. 2. [ 3H]Pro binding to mouse brain synaptic membranes was examined in the presence of competitive NMDA antagonist, MK-801, or HA-966. Conversely, the effects of l-proline on [ 3H]MK-801 binding were also probed. The effects of l-proline on glutamatemedicated [Ca +2], levels were tested. 3. 3. The authors could not detect any effect of proline on glutamate-mediated [CA +2] i levels using FURA-2 in synaptosomes or neuroblastoma cells. 4. 4. NMDA competitive antagonists, AP-7, CPP, and CGS 19755 inhibit [ 3H]Pro binding to mouse brain synaptic membranes. 5. 5. MK-801, a NMDA channel blocker, also inhibits [ 3]Pro binding, but 200 mM praline is incapable of inhibiting [ 3H] MK-801 binding. 6. 6. HA-966, a glycine site partial agonist inhibits [ 3]Pro binding. Praline has modest effects on [ 3H]glycine binding.

NaCl stress in rice seedlings: effects of L-proline, glycinebetaine, L-and D-asparagine on seedling growth

The effect of L-proline, glycinebetaine, L-and D-asparagine on rice seedling growth under NaCl stress was investigated. Glycinebetaine and L-asparagine were not effective in reducing NaCl inhibition in shoot growth of rice seedlings. L-Proline and D-asparagine were found to be able to reduce shoot growth inhibition under NaCl stress. However, L-proline, glycinebetaine, D- and L-asparagine further enhanced NaCl inhibition of root growth.

Effects of L-proline and post-plating temperature treatment on Maize (Zea mays L.) anther culture

Comparison of different post-plating temperature regimes with a control treatment (27° C) revealed that a short-term cold (8/14°C:2/2 days or 14°C:4 days) as well as a heat treatment (30°C:14 days) increased the production of embryro-like-structures (ELS) from cultured maize anthers. The beneficial effects of short-term cold treatments were magnified 2-3 times when L-proline (PROL) was added to the induction medium (125-500 mg/L). In the best treatment (14°C:4 days, 125 mg/L L-proline) one genotype produced 143.5 ELS/100 anthers. Anthers subjected to high temperature (30°C:4 days, 30°C:7 days, 30°C:14 days) generally showed a lower response than did cold treated anthers, although genotypic differences were observed. Regeneration frequency did not appear to be affected by the presence of L-proline in the induction medium.