Bioactive Peptides from Algae: Traditional and Novel Generation Strategies,Structure-Function Relationships,and Bioinformatics as Predictive Tools for Bioactivity

Over the last decade, algae have been explored as alternative and sustainable protein sources for a balanced diet and more recently, as a potential source of algal-derived bioactive peptides with potential health benefits. This review will focus on the emerging processes for the generation and isolation of bioactive peptides or cryptides from algae, including: (1) pre-treatments of algae for the extraction of protein by physical and biochemical methods; and (2) methods for the generation of bioactive including enzymatic hydrolysis and other emerging methods. To date, the main biological properties of the peptides identified from algae, including anti-hypertensive, antioxidant and anti-proliferative/cytotoxic effects (for this review, anti-proliferative/cytotoxic will be referred to by the term anti-cancer), assayed in vitro and/or in vivo, will also be summarized emphasizing the structure–function relationship and mechanism of action of these peptides. Moreover, the use of in silico methods, such as quantitative structural activity relationships (QSAR) and molecular docking for the identification of specific peptides of bioactive interest from hydrolysates will be described in detail together with the main challenges and opportunities to exploit algae as a source of bioactive peptides.     

Identification of bovine viral diarrhea virus type 1 in yaks (Bos poephagus grunniens) in the Himalayan region

Since cattle are widely infected by bovine viral diarrhea virus (BVDV) in India, we searched for pestivirus infection in yaks. Of 71 pure and crossbred yaks from Himalayan region, pestivirus antigen was detected by Ag-ELISA in three animals. Pestivirus in leukocyte and cell culture isolated virus samples originating from positive yaks was also confirmed by RT-PCR using panpestivirus specific primers selected from 5'-untranslated region (5' UTR). The 5' UTR, N(pro) and E2 regions were sequenced and used for genetic typing. Phylogenetic analysis revealed that pestiviruses detected in three Himalayan yaks were similar genetically, belonging to BVDV-1. Antigenic characterisation of yak pestivirus also confirmed the typing as BVDV-1. This is the first report on the identification of BVDV type 1 in yaks.     

Modulation of nicotinamide adenine dinucleotide phosphate oxidase activity through sequential posttranslational modifications of p22 phagocytic oxidase during capacitation and acrosome reaction in goat spermatozoa

Superoxide anion radical, produced in low quantities, plays a positive role in sperm function. Spermatozoa produce superoxide anion radical during posttesticular development, which shows an abrupt increase during capacitation. The NAD phosphate oxidase (NOX) family members NOX2 and NOX5 are the 2 enzymes implicated in superoxide production in spermatozoa. We examined the organization of NOX2 in goat spermatozoa during epididymal maturation, capacitation, and acrosome reaction. Spermatozoa from testis, caput epididymidis, corpus epididymidis, and cauda epididymidis possessed components of the phagocytic oxidase (PHOX; i.e., gp91phox, p22phox, p67phox, p47phox, p40phox), and ras-related C3 botulinum toxin substrate 1/2 (Rac1/2) on spermatozoa, and their concentrations did not show significant alterations during epididymal maturation. During capacitation in vitro, p22phox underwent Thr-phosphorylation, which resulted in a mobility shift of the corresponding band toward greater molecular mass. The Rac1/2 also showed a mobility shift from 32 to 23 kDa during capacitation. During progesterone-induced acrosome reaction, the spermatozoa experienced a total loss of p22phox and p47phox. The p47phox, but not p22phox, was detected in the exocytic vesicles of the acrosome. The Thr-phosphorylated form of p22phox was ubiquitinated and degraded through proteasome-mediated pathways in goat sperm cell lysates. Thus, Thr phosphorylation of p22phox acts as a regulatory switch in goat spermatozoa that transiently activates the NOX2 system during capacitation and subsequently directs it for degradation through the ubiiquitin-proteasomal pathway during progesterone-induced acrosome reaction.     

Pharmacokinetics of cefpodoxime in plasma and subcutaneous fluid following oral administration of cefpodoxime proxetil in male beagle dogs

Kumar, V., Madabushi, R., Lucchesi, M. B. B., Derendorf, H. Pharmacokinetics of cefpodoxime in plasma and subcutaneous fluid following oral administration of cefpodoxime proxetil in male beagle dogs. J. vet. Pharmacol. Therap. 34 , 130–135. Pharmacokinetics of cefpodoxime in plasma (total concentration) and subcutaneous fluid (free concentration using microdialysis) was investigated in dogs following single oral administration of prodrug cefpodoxime proxetil (equivalent to 5 and 10 mg/kg of cefpodoxime). In a cross over study design, six dogs per dose were utilized after a 1 week washout period. Plasma, microdialysate, and urine samples were collected upto 24 h and analyzed using high performance liquid chromatography. The average maximum concentration (C_max) of cefpodoxime in plasma was 13.66 (±6.30) and 27.14 (±4.56) μg/mL with elimination half‐life (t_1/2) of 3.01 (±0.49) and 4.72 (±1.46) h following 5 and 10 mg/kg dose, respectively. The respective average area under the curve (AUC_0–∞) was 82.94 (±30.17) and 107.71 (±30.79) μg·h/mL. Cefpodoxime was readily distributed to skin and average free C_max in subcutaneous fluid was 1.70 (±0.55) and 3.06 (±0.93) μg/mL at the two doses. Urinary excretion (unchanged cefpodoxime) was the major elimination route. Comparison of subcutaneous fluid concentrations using pharmacokinetic/pharmacodynamic indices of fT_>MIC indicated that at 10 mg/kg dose; cefpodoxime would yield good therapeutic outcome in skin infections for bacteria with MIC₅₀ upto 0.5 μg/mL while higher doses (or more frequent dosing) may be needed for bacteria with higher MICs. High urine concentrations suggested cefpodoxime use for urinary infections in dogs.     

Anti-idiotype antibodies to Marek''s disease-associated tumour surface antigen in protection against Marek''s disease

Marek's disease-associated tumour surface antigen (MATSA) removed by enzymatic (papain) digestion of Marek's disease tumour cells was fractionated by gel filtration chromatography. The first peak (F1) was used to raise antibody in rabbits. Monoclonal antibody (RPH-6) directed against MATSA and the anti-F1 IgG were used as idiotypic antibodies to raise polyclonal anti-idiotype serum in heterologous hosts; rabbit and goat, respectively. The anti-idiotypes (anti-Id) were purified by affinity chromatography and characterized by competitive binding assay using immunofluorescent (IF) tests.

Day-old white Leghorn chicks were immunized with anti-Id to MATSA (Group 1) or anti-Id to F1 (Group 3) and challenged with virulent Marek's disease virus (MDV) on the tenth day post immunization. In positive control groups, the day-old chicks were inoculated with anti-BALB/c mouse globulin (Group 2) and anti-rabbit globulin (Group 4) and challenged with virulent MDV on the tenth day post inoculation. As compared with positive control groups, the vaccinated groups (1 and 3) had considerably lower level of MATSA positive cells during the post challenge observation period. The protection level against MD in the immunized groups was 66.6% (Group 1) and 86.6% (Group 3).     

Psoroptes cuniculi induced oxidative imbalance in rabbits and its alleviation by using vitamins A, D3, E, and H as adjunctive remedial

The oxidant/antioxidant balance of rabbits naturally infected with Psoroptes cuniculi and treated with ivermectin +/− vitamins A, D₃, E, and H supplementation was investigated. Two groups of seven mixed ♂ and ♀, 6-to-8 month-old New Zealand White rabbits, diagnosed Psoroptes mites-positive by skin scraping examination and seven clinically healthy control rabbits were examined. Blood samples were obtained on day 0 and at 28 days post-therapy to determine oxidative stress indices. On day 0, the levels of lipid peroxides were significantly higher (P ≤ 0.01) in the Psoroptes-infected rabbits compared with the healthy controls while those of reduced glutathione and the activities of the antioxidant enzymes glutathione peroxidase, glutathione-S-transferase, catalase, and superoxide dismutase were significantly lower (P ≤ 0.01). Vitamin supplementation of the ivermectin-treated rabbits revealed both faster clinical (14 days) and parasitological (10 days) recovery. It was concluded that significant alteration of oxidant/antioxidant balance is a factor in the pathogenesis of P. cuniculi infestation of rabbits, and recovery can be enhanced by combining ivermectin treatment with vitamin A, D_3, E, and H supplementation.     

Seroprevalence of brucellosis in yaks (Poephagus grunniens) in India and evaluation of protective immunity to S19 vaccine

The present study was carried out to explore the seroprevalence of brucellosis in yaks of North-Eastern hilly yak tracts of Arunachal Pradesh, India. Of 374 animals tested, 23.79, 21.11 and 18.98% were found positive for brucellosis using avidin-biotin ELISA (AB-ELISA), Rose-Bengal plate test (RBPT) and standard tube-agglutination test (STAT), respectively. The relative sensitivity and specificity for STAT were 79.77 and 100%, respectively and the same for RBPT were 88.76 and 100%, respectively in comparison to AB-ELISA. The alarming prevalence as recorded was highest among the yak cows (31.42%) followed by heifers (23.85%) and bulls (8.88%). The immune response in yaks following standard dose of calfhood vaccination with Brucella abortus strain 19 vaccine showed that protective antibody level persisted up to 210 days. This is the first report from India on prevalence of brucellosis and immunization with B abortus strain 19 vaccine in yaks. The present investigation would be a valuable guideline for future control measure and eradication programme of brucellosis in yaks.     

Cytokine profiles, apoptosis and pathology of experimental Pasteurella multocida serotype A1 infection in mice

Mice were experimentally infected with Pasteurella multocida serotype A1 to study the cytokine profiles, host cell apoptosis and sequential pathology at different hours of post-infection. Infected mice were dull, anorectic and depressed. A transient leukocytopenia followed by progressive leukocytosis was observed in the course of infection. Serum cytokine profiles showed significantly (P < 0.01) higher amount of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6 and mouse KC) in the infected mice when compared to control mice. The circulating lymphocytes were apoptotic on annexin V staining. Apoptotic nuclei were detected in splenocytes, hepatocytes and infiltrating leukocytes of the lungs on TUNEL staining. The lungs were grossly congested and hemorrhagic, and showed infiltration with polymorphonuclear cells at early and mononuclear cells in the late hours of infection. Alveolar epithelia, inter-alveolar septa and capillary endothelium of the lungs showed ultrastructural changes. Liver had degenerative changes in histological and ultrathin sections.     

Sonographic characteristics of goat testis on water bath based ultrasonography

Assessing the health of the testes in domestic animals is an important aspect of the breeding soundness examination and selection. The aim of the present study was to develop a simple method for scanning and to establish ultrasonographically the gross anatomic structures of the goat testes. Six adult male goats were examined to study the sonographic appearance of normal testes and epididymides using a water bath based ultrasound scanning technique. The ultrasonographic examinations were done using a 5–9 MHz/60 mm (7.5 MHz) linear-array transducer and a B-mode scanner. The ultrasonographic examination was performed in goats after standardizing the procedure on six testes collected from slaughter house. Results showed that in live goats when the probe was placed directly over the scrotum it gave distorted and unclear image. In water bath method the entire scrotum was dipped into a container filled with water and linear probe was used to observe the sonographic features of the testis. Each testis was viewed vertically, resulting in longitudinal image which was frozen, measured and printed through a thermal printer. The results of the ultrasonogram revealed that the testicular parenchyma was homogenous and moderately echogenic throughout. The diameter (mean±se) of the right and left testes was 4.47±0.14 and 4.42±0.07 cm respectively and no significant difference was observed between the testes. The mediastinum testis was a 1.50±0.22 cm wide linear structure of greater echogenicity than the testicular parenchyma when viewed in the transverse plane and nearly circular echogenic “spot” in the midline of the testis when viewed horizontally. The head and tail of the epididymides were easily identified on all the testes, but the epididymal body and ductus deferens were difficult to identify consistently. The tail of the epididymis was easily identified on the distal end of the testis with sonolucent tubules and appeared sonographically as a ‘peaked cap’ upon the testicular parenchyma. The diameter (mean±se) of the tail of right and left epididymis was 2.11±0.18 and 1.92±0.06 cm and no significant difference was observed between epididymides. The vascular pampiniform plexus (1.42±0.18 cm) was easily identified on the proximal end of the testes. The tunics of the testes appeared as a bright echogenic line. Inter-testicular septum appeared between testes as a hyperechoic line. It is concluded that ultrasonography permits a noninvasive evaluation of the internal structure of the scrotum and testes and water bath based sonographic examination may prove to be a valuable simple diagnostic methodology for evaluating physiopathologic conditions of goat testes and can be employed as a routine investigative method during breeding soundness and clinical examination.