A review of the herbal phosphodiesterase inhibitors; Future perspective of new drugs

Phosphodiesterase inhibitors (PDEIs) are a class of drugs that are widely used because of their various pharmacological properties including cardiotonic, vasodilator, smooth muscle relaxant, antidepressant, antithrombotic, bronchodilator, antiinflammatory and enhancer of cognitive function. In the recent years, interest in drugs of plant origin has been progressively increased. Some pharmacologically active substances that come from plants demonstrate PDEI activity. They mainly belong to alkaloids, flavonoids, and saponins. In this review, studies on herbal PDEI were reviewed and their possible therapeutic applications were discussed. Screening plants for PDE inhibitory activity may help to develop standardized phytotherapeutic products or find new sources for new lead structures with PDEI pharmacological activity. The studies discussed in this paper are mainly in vitro and for more reasonable and conclusive results, it is required to conduct in vivo and finally human and clinical tests.     

Performance,rumen fermentation,blood minerals,leukocyte and antioxidant capacity of young Holstein calves receiving high-surface ZnO instead of common ZnO

ABSTRACT

This study was conducted to assess the effect of feeding high-surface ZnO instead of common ZnO on the performance, rumen fermentation, blood minerals, leukocytes and antioxidant capacity of pre- and post-weaning calves. Thirty male suckling Holstein calves were allotted to one of three experimental groups (10 replicates) in a completely randomised design. Calves received: (1) a low Zn diet without Zn supplementation (control diet), (2) a high Zn diet containing 50 mg supplementary Zn/kg dry matter (DM) as common ZnO or (3) a high Zn diet containing 50 mg supplementary Zn/kg DM as high-surface ZnO (nano-ZnO). The control diet contained a native Zn content of 35.5, 34.7 or 33.7 mg/kg DM for the age periods of 7 to 30, 31 to 70 and 71 to 100 d, respectively. Supplementation of the diet with Zn did not change the dry matter intake (DMI) of calves during d 7 to 30 but increased the ADG in this period (p < 0.05). During age periods of 31 to 70 and 71 to 100 d, DMI and ADG of the Zn supplemented calves were higher (p < 0.05) than the control animals. The nutrient digestibility and the concentration of rumen volatile fatty acids were positively affected (p < 0.05) and the rumen ammonia-N concentration decreased (p < 0.05) by dietary Zn supplementation. Furthermore, the incidence of diarrhoea and pneumonia was lower in calves receiving the Zn supplemented diets. Irrespective of ZnO source, the blood total antioxidant capacity, leukocyte and haematocrit levels significantly increased (p < 0.05) with the ZnO supplemented diets. The post-weaning DMI, nutrient digestibility and blood haematocrit levels were higher in calves receiving high-surface ZnO, compared to those supplemented with common ZnO. With inclusion of the Zn sources in pre- and post-weaning diets, the blood Zn concentration increased (p < 0.05), but the blood Cu, Fe, Ca, P and Mg levels remained unchanged. Regardless of source, dietary supplementation of young calves with ZnO improved the performance and decreased rumen ammonia-N and the incidence of diseases. Moreover, high-surface ZnO had advantages over common ZnO in increasing the post-weaning feed intake, digestibility and blood Zn concentration.     

Comparison of PCR-RFLP with 21-plex PCR and rDNA Sequencing for Identification of Clinical Yeast Isolates

Non-albicans Candida species and other rare yeasts have emerged as major opportunistic pathogens in fungal infections. Identification of opportunistic yeasts in developing countries is mainly performed by phenotypic assay, which are time-consuming and prone to errors. The aim of the present study was to evaluate PCR-RFLP as a routinely used identification technique for the most clinically important Candida species in Iran and make a comparison with a novel multiplex PCR, called 21-plex PCR. One hundred and seventy-three yeast isolates from clinical sources were selected and identified with sequence analysis of the D1/D2 domains of rDNA (LSU rDNA) sequencing as the gold standard method. The results were compared with those obtained by PCR-RFLP using MspI restriction enzyme and the 21-plex PCR. PCR-RFLP correctly identified 93.4% of common pathogenic Candida species (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and P. kudriavsevii (=?C. krusei)) and was able to identify 45.5% of isolates of the uncommon yeast species compared to the D1/D2 rDNA sequencing. Compared with PCR-RFLP, all common Candida species and 72.7% of uncommon yeast species were correctly identified by the 21-plex PCR. The application of the 21-plex PCR assay as a non-sequence-based molecular method for the identification of common and rare yeasts can reduce turnaround time and costs for the identification of clinically important yeasts and can be applied in resource-limited settings.

     

Pelleting of broiler diets: An overview with emphasis on pellet quality and nutritional value

Pelleting is the most prevalent heat treatment in the production of poultry feed. The objective of pelleting is to agglomerate smaller feed particles into larger particles as pellets to enhance the economics of production by increasing the feed intake, and thus growth performance and feed efficiency. However, due to the heat, moisture and mechanical pressure applied during conditioning and pelleting, some chemical and physical alterations occur that may have beneficial or detrimental effects on feed components, gastrointestinal development and subsequent bird performance. Pelleting process has been shown to gelatinise starch, but only to a small extent, and thus may be of modest relevance in starch digestion. Pelleting process may also result in partial denaturation of proteins; a process which can potentially improve protein and to some extent starch digestibility due to inactivation of proteinaceous enzyme inhibitors. Cell wall breakage, as a result of the physical stress of pelleting, may also provide greater accessibility of nutrient contents, previously encapsulated within endosperm sub-aleurone, to digestive enzymes. In diets based on viscous cereals, nutrient availability may be negatively affected through increased digesta viscosity as a result of either an increase in soluble carbohydrate concentration or changes in the molecular weight of soluble fibres or both, due to pelleting. Pelleting process also remains a potentially aggressive process on the stability of exogenous feed enzymes and vitamins, a major concern of feed manufacturers. Particle size-reducing property of the pelleting process may result in a suboptimal gizzard development and thus reduced nutrient digestibility of diets for poultry. While physical pellet quality is a critical factor to optimise feed efficiency and growth response of broilers, the present review highlights that it is the balance between nutrient availability and physical quality of pellets which is critical in determining the actual performance of broilers. Under the conventional pelleting process, good pellet quality is usually obtained at the expense of nutritional quality. Research is warranted to identify and evaluate possible strategies to manufacture highly digestible high quality pellets. Such strategies will require novel approaches of improving feed hygiene which are not detrimental to feed nutrients.     

Effects of alpha lipoic acid and its derivative “andrographolid-lipoic acid-1” on ulcerative colitis: A systematic review with meta-analysis of animal studies

We aimed to review and meta-analyze the inflammatory and oxidative factors following alpha lipoic acid (ALA) and its derivative “andrographolid-lipoic acid-1” (AL-1) in ulcerative colitis (UC). ALA plays an important role in scavenging intracellular radicals and inflammatory elements. AL-1 is found in herbal medicines with potent anti-inflammatory properties. Data were collected from the Google Scholar, PubMed, Scopus, Evidence-based medicine/clinical trials, and Cochrane library database until 2017, which finally resulted in 22 animal studies (70 rats and 162 mice). The beneficial effects of ALA or AL-1 on the most important parameters of UC were reviewed; also, studies were considered separately in mice and rats. Administration of ALA and AL-1 significantly reduced the tumor necrosis factor-α level compared with the controls, while data were not noteworthy in the meta-analysis (mean differences = −18.57 [95% CI = −42.65 to 5.51], P = 0.13). In spite of insignificant decrease in meta-analysis outcomes (differences = 6.92 [95% CI = −39.33 to 53.16], P = 0.77), a significant reduction in myeloperoxidase activity was shown following ALA or AL-1 treatment compared with the controls. Despite significant differences in each study, we had to exclude some studies to homogenize data for meta-analyzing as they showed insignificant results. Interleukin 6, cyclooxygenase-2, glutathione, malondialdehyde, superoxide dismutase, histopathological score, macroscopic and microscopic scores, disease activity index, body weight change, and colon length were also reviewed. Most studies have emphasized on significant positive effects of ALA and AL-1. Comprehensive clinical trials are obligatory to determine the precious position of ALA or AL-1 in the management of UC.     

Steric restrictions on the binding of large metal ions to serum transferrin

Apotransferrin in 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid at 25 degrees C and pH 7.4 was titrated with acidic solutions of Lu3+, Tb3+, and Eu3+. Metal binding at the two specific metal-binding sites of transferrin was followed from changes in the difference UV spectra at 245 nm. The binding of Tb3+ was also followed from changes in the fluorescence emission spectrum at 549 nm. Apotransferrin was titrated with solutions containing varying ratios of the metal ion and the competitive chelating agent nitrilotriacetic acid, and metal-transferrin binding constants were calculated by nonlinear least-squares fits of the absorbance as a function of titrant added. The sequential carbonate-independent equilibrium constants for the binding of two metal ions are log KM1 = 11.08 and log KM2 = 7.93 for Lu3+, log KM1 = 11.20 and log KM2 = 7.61 for Tb3+, and log KM1 = 9.66 and log KM2 = 7.27 for Eu3+. Titrations of both C-terminal and N-terminal monoferric transferrins indicate that all of these metal ions bind more strongly to the C-terminal binding site. The trend in log K values as a function of the lanthanide ionic radius has been evaluated both by plots of log K versus the metal ion charge/radius ratio and by linear free-energy relationships in which binding constants for complexes of the larger lanthanides are plotted versus the binding constants for complexes with the smallest lanthanide, Lu3+. Both methods indicate that there is a sharp drop in the binding constants for the C-terminal binding site for metals larger than Tb3+. This decrease is attributed to a steric hindrance to the binding of the larger cations. The steric effect is not as strong for metal binding at the N-terminal site. As a result, the selectivity for binding to the C-terminal site, which is quite high for the smaller lanthanides, drops sharply on going from Tb3+ to Nd3+.