Comparative Study to Characterise the Pharmaceutical Potential of Synthesised Snake Venom Bradykinin-Potentiating Peptides In Vivo.

BACKGROUND: Bradykinin-potentiating peptides (BPPs) are snake venom peptides inhibiting the angiotensin-converting enzyme (ACE). ACE plays an important role in the regulation of blood pressure. BPPs lead to the development of ACE inhibitors for the treatment of hypertension. OBJECTIVE: The objective of the present work was to carry out a comprehensive comparative study of four synthesised snake venom BPPs in vivo. METHODS: Four synthesised snake venom BPPs were administered to rats via the intraperitoneal route for 15 days at a fixed dose. Lisinopril was used as a comparative standard. Thirty male albino rats were divided into six groups: A, B, C, D, E (lisinopril), and F (control). Group F was maintained as the control group and given only saline. After 15 days, blood samples and tissues were removed for the study of selective biochemical parameters and histomorphometric analysis. Statistical evaluation of all results was also performed. RESULTS: The results indicated that peptide I, with the sequence ZSAPGNEAIPP, was highly toxic and adversely affected all the biochemical and histological parameters studied in this work. Peptide II (ZNWPHPQIPP) and peptide IV (ZQWAQGRAPHPP) showed lower toxicity. None of the BPPs raised the serum creatinine level and exhibited nephroprotective effects. Although lisinopril raised the creatinine level, it showed a protective role towards the pancreas and lungs in parallel. CONCLUSION: The present work shows that although there is a high sequence similarity between the four BPPs, their in vivo activity varies. The sequences of peptide II and peptide IV can be used to improve the design of current ACE inhibitors used for hypertension treatment.

Season influence on serum kisspeptin level and its association with hormonal levels and semen kinematics of buffalo bulls (Bubalus bubalis).

Kisspeptin has an important role in the stimulation of hypothalamic-pituitary-gonadal axis in term of pubertal development, release of reproductive and metabolic hormones and ultimately affecting the fertility. The aim of the present study was to evaluate the serum kisspeptin level and its correlation with semen quality and selected hormones in buffalo bulls during the summer and spring seasons. Semen and blood samples from eight Nili-Ravi buffalo bulls (age: 9.21 ± 1.02 years) were collected. Semen was analysed using computer-assisted semen analysis. Serum concentrations of kisspeptin, gonadotropin releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, cortisol, triiodothyronine (T3), thyroxin (T4) and insulin like growth factor (IGF-1) were estimated using enzyme-linked immunosorbent assay kits. Kisspeptin was neither affected by seasons and nor correlated with semen parameters and hormones. Higher levels of GnRH, LH, cortisol, IGF-1, total motility (TM), average path velocity (VAP), straight-line velocity (VSL), curvilinear velocity (VCL) and linearity (LIN) were recorded in summer compared to spring. Correlations of GnRH versusIGF-1 and LH, LH versus IGF-1 and cortisol, FSH versus T4 and testosterone, testosterone versus T3 and T4 and T3 versus T4 were observed. The GnRH and IGF-1 were positively associated with TM, VAP, VSL, VCL and LIN. The LH was correlated with VSL, straightness and LIN. In conclusion, GnRH, LH, and IGF-1 correlations with semen parameters can be used to indicate semen quality. The buffalo bulls are well-adapted and can give quality semen in the summer season.