Guruprasad Kalthur

Vitamin E Supplementation in Semen-Freezing Medium Improves the Motility and Protects Sperm from Freeze-Thaw–Induced DNA Damage

This study evaluated the effect of vitamin E supplementation to cryoprotective media on post-thaw motility and DNA integrity of normozoospermic and asthenozoospermic semen samples. The results of this study indicate that supplementation of vitamin E (5 mM) significantly improves the post-thaw motility and DNA integrity in normozoospermic and asthenozoospermic semen samples.

Poor sperm quality and advancing age are associated with increased sperm DNA damage in infertile men

With increasing evidence for faulty paternal contribution to reproduction, there has been a steady increase in studies highlighting an association between sperm DNA damage, failed/delayed fertilisation and aberrant embryo development. Owing to prevailing ambiguity, the aims of the study were to analyse the genetic integrity of the male gamete and then to understand its association with age, standard semen parameters, lifestyle and occupational factors. The study included 504 subjects, attending university infertility clinic for fertility evaluation and treatment. Semen characteristics were analysed by standard criteria; terminal deoxynucelotidyl transferase–mediated nick end‐labelling assay was employed for DNA damage assessment. The average incidence of sperm DNA damage in patients with normozoospermic semen parameters was <10%. Patients with oligozoospermia, severe oligozoospermia, oligoasthenoteratospermia, asthenoteratozoospermia and necrozoospermia had significantly higher level of sperm DNA damage (P < 0.001). Patients above 40 years of age had significantly high levels of DNA damage (P < 0.001) compared with their counterparts. Patients with varicocele and a history of alcohol consumption had higher incidence of spermatozoa with DNA damage (P < 0.01). Poor sperm characteristics in the ejaculate are associated with increased sperm DNA damage. Age‐related increase in sperm DNA damage and association of the same with varicocele and alcohol consumption are also demonstrated.

Transgenerational changes in somatic and germ line genetic integrity of first-generation offspring derived from the DNA damaged sperm.

OBJECTIVE To report a more quantitative approach to study the influence of varying levels of sperm DNA damage on transgenerational changes in genomic instability in a mouse model. DESIGN Experimental prospective study. SETTING Embryology research laboratory. ANIMAL(S) Swiss albino mice. INTERVENTION(S) The sperm DNA damage was induced by different doses of gamma-irradiation to male mice followed by mating with healthy female mice. MAIN OUTCOME MEASURE(S) Genomic integrity in embryos, fetus, and spermatozoa of F1 mice derived from the DNA-damaged sperm. RESULT(S) The transgenerational changes in genetic integrity were attributed by a dose-dependent increase in the frequency of micronuclei in preimplantation embryos and a concomitant increase in genomic instability in fetal liver cells and sperm chromatin modifications in F1 males. A strong positive correlation was observed between the extent of sperm DNA damage and somatic and germ-line genomic instability. CONCLUSION(S) Sperm-mediated transgenerational genomic instability is dependent on the amount of DNA damage present in the sires sperm at the time of fertilization.

NMR studies of preimplantation embryo metabolism in human assisted reproductive techniques: a new biomarker for assessment of embryo implantation potential.

There has been growing interest in understanding energy metabolism in human embryos generated using assisted reproductive techniques (ART) for improving the overall success rate of the method. Using NMR spectroscopy as a noninvasive tool, we studied human embryo metabolism to identify specific biomarkers to assess the quality of embryos for their implantation potential. The study was based on estimation of pyruvate, lactate and alanine levels in the growth medium, ISM1, used in the culture of embryos. An NMR study involving 127 embryos from 48 couples revealed that embryos transferred on Day 3 (after 72 h in vitro culture) with successful implantation (pregnancy) exhibited significantly (p < 10‐5) lower pyruvate/alanine ratios compared to those that failed to implant. Lactate levels in media were similar for all embryos. This implies that in addition to lactate production, successfully implanted embryos use pyruvate to produce alanine and other cellular functions. While pyruvate and alanine individually have been used as biomarkers, the present study highlights the potential of combining them to provide a single parameter that correlates strongly with implantation potential. Copyright

Semen abnormalities, sperm DNA damage and global hypermethylation in health workers occupationally exposed to ionizing radiation.

Background Cytogenetic studies have demonstrated that low levels of chronic radiation exposure can potentially increase the frequency of chromosomal aberrations and aneuploidy in somatic cells. Epidemiological studies have shown that health workers occupationally exposed to ionizing radiation bear an increased risk of hematological malignancies. Objectives To find the influence of occupational radiation exposure on semen characteristics, including genetic and epigenetic integrity of spermatozoa in a chronically exposed population. Methods This cross sectional study included 134 male volunteers of which 83 were occupationally exposed to ionizing radiation and 51 were non-exposed control subjects. Semen characteristics, sperm DNA fragmentation, aneuploidy and incidence of global hypermethylation in the spermatozoa were determined and compared between the non-exposed and the exposed group. Results Direct comparison of the semen characteristics between the non-exposed and the exposed population revealed significant differences in motility characteristics, viability, and morphological abnormalities (P<0.05–0.0001). Although, the level of sperm DNA fragmentation was significantly higher in the exposed group as compared to the non-exposed group (P<0.05–0.0001), the incidence of sperm aneuploidy was not statistically different between the two groups. However, a significant number of hypermethylated spermatozoa were observed in the exposed group in comparison to non-exposed group (P<0.05). Conclusions We provide the first evidence on the detrimental effects of occupational radiation exposure on functional, genetic and epigenetic integrity of sperm in health workers. However, further studies are required to confirm the potential detrimental effects of ionizing radiation in these subjects.

Effect of Withaferin A on the development and decay of thermotolerance in B16F1 melanoma: a preliminary study.

Protein synthesis inhibitors can suppress the development of thermotolerance in tumor tissues on repeated heating. Withaferin A (WA), isolated from Withania somnifera has cytotoxic and inhibitory action on protein synthesis. In the present investigation, effect of WA on development and decay of thermotolerance in B16F1 melanoma was studied in C57BL mice. Tumors of 10010 mm3 size were subjected to repeated hyperthermia (HT) at 43°C for 30 minutes. WA was injected after first hyperthermia treatment. The tumor response was assessed by calculating the tumor growth delay (GD). The GD increased with increase in time gap between two hyperthermia treatments and was significantly higher (p < 0.05 to p < 0.001) in WA treated groups at all the respective time gaps (except at 0h and 120h) compared to hyperthermia alone group. WA increases the tumor response during repeated hyperthermia by reducing the magnitude of thermotolerance developed and by decreasing the recovery time from thermotolerance.

Development and evaluation of sunscreen creams containing morin-encapsulated nanoparticles for enhanced UV radiation protection and antioxidant activity

The objective of present work was to develop novel sunscreen creams containing polymeric nanoparticles (NPs) of morin. Polymeric NPs containing morin were prepared and optimized. The creams containing morin NPs were also prepared and evaluated. Optimized NPs exhibited particle size of 90.6 nm and zeta potential of −31 mV. The entrapment efficiency of morin, within the polymeric NPs, was found to be low (12.27%). Fourier transformed infrared spectroscopy and differential scanning calorimetry studies revealed no interaction between morin and excipients. Transmission electron microscopy and atomic force microscopy revealed that the NPs were spherical in shape with approximately 100 nm diameter. Optimized NPs showed excellent in vitro free radical scavenging activity. Skin permeation and deposition of morin from its NPs was higher than its plain form. Different sunscreen creams (SC1–SC8) were formulated by incorporating morin NPs along with nano zinc oxide and nano titanium dioxide. SC5 and SC8 creams showed excellent sun protection factor values (≈40). In vitro and in vivo skin permeation studies of sunscreen creams containing morin NPs indicated excellent deposition of morin within the skin. Morin NPs and optimized cream formulations (SC5 and SC8) did not exhibit cytotoxicity in Vero and HaCaT cells. Optimized sunscreen creams showed excellent dermal safety. SC5 and SC8 creams demonstrated exceptional in vivo antioxidant effect (estimation of catalase, superoxide dismutase, and glutathione) in UV radiation-exposed rats. The optimized sunscreen creams confirmed outstanding UV radiation protection as well as antioxidant properties.

Methyl Parathion Inhibits the Nuclear Maturation, Decreases the Cytoplasmic Quality in Oocytes and Alters the Developmental Potential of Embryos of Swiss Albino Mice

Methyl parathion (MP) is one of the most commonly used and extremely toxic organophosphorous group of pesticide. A large number of studies in the literature suggest that it has adverse effects on the male reproductive system. However, there is limited information about its toxicity to the female reproductive system. In the present study we report the toxic effects of methyl parathion on the female reproductive system using Swiss albino mice as the experimental model. The female mice were administered orally with 5, 10 and 20mg/kg of MP. One week later, the mice were superovulated with pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to study the quality of the oocytes, spindle organization, developmental potential of early embryos and the DNA integrity in blastocysts. MP exposure resulted in a non-significant decrease in the number of primordial follicles and increased DNA damage in granulosa cells. Though MP did not have any effect on the ovulation it had a significant inhibitory effect on the nuclear maturity of oocytes which was associated with spindle deformity. In addition, the oocytes had higher cytoplasmic abnormalities with depleted glutathione level. Even though it did not have any effect on the fertilization and blastocyst rate at lower doses, at 20 mg/kg MP it resulted in a significant decrease in blastocyst hatching, decrease in cell number and high DNA damage. While low body weight gain was observed in F1 generation from 5mg/kg group, at higher dose, the body weight in F1 generation was marginally higher than control. Post-natal death in F1 generation was observed only in mice treated with 20mg/kg MP. In conclusion, we report that MP has adverse effects on the oocyte quality, developmental potential of the embryo and reproductive outcome.

Influence of peptide dendrimers and sonophoresis on the transdermal delivery of ketoprofen

The aim of this study was to determine the individual and combined effects of peptide dendrimers and low frequency ultrasound on the transdermal permeation of ketoprofen. Arginine terminated peptide dendrimers of varying charges (4+, 8+ and 16+, named as A4. A8 and A16 respectively) were synthesized and characterized. Ketoprofen was subjected to passive, peptide dendrimer-assisted and sonophoretic permeation studies (with and without dendrimer application) across Swiss albino mouse skin, both in vitro and in vivo. The studies revealed that the synthesized peptide dendrimers considerably increased the transdermal permeation of ketoprofen and displayed enhancement ratios of up to 3.25 (with A16 dendrimer), compared to passive diffusion of drug alone in vitro. Moreover, the combination of peptide dendrimer treatment and ultrasound application worked in synergy and gave enhancement ratios of up to 1369.15 (with ketoprofen-A16 dendrimer complex). In vivo studies demonstrated that dendrimer and ultrasound-assisted permeation of drug achieved much higher plasma concentration of drug, compared to passive diffusion. Comparison of transdermal and oral absorption studies revealed that transdermal administration of ketoprofen with A8 dendrimer showed comparable absorption and plasma drug levels with oral route. The excised mouse skin after in vivo permeation study with dendrimers and ultrasound did not show major toxic reactions. This study demonstrates that arginine terminated peptide dendrimers combined with sonophoresis can effectively improve the transdermal permeation of ketoprofen.

Skin delivery of epigallocatechin-3-gallate (EGCG) and hyaluronic acid loaded nano-transfersomes for antioxidant and anti-aging effects in UV radiation induced skin damage

Abstract The present work attempts to develop and statistically optimize transfersomes containing EGCG and hyaluronic acid to synergize the UV radiation-protective ability of both compounds, along with imparting antioxidant and anti-aging effects. Transfersomes were prepared by thin film hydration technique, using soy phosphatidylcholine and sodium cholate, combined with high-pressure homogenization. They were characterized with respect to size, polydispersity index, zeta potential, morphology, entrapment efficiency, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), in vitro antioxidant activity and ex vivo skin permeation studies. Cell viability, lipid peroxidation, intracellular ROS levels and expression of MMPs (2 and 9) were determined in human keratinocyte cell lines (HaCaT). The composition of the transfersomes was statistically optimized by Design of Experiments using Box–Behnken design with four factors at three levels. The optimized transfersome formulation showed vesicle size, polydispersity index and zeta potential of 101.2 ± 6.0 nm, 0.245 ± 0.069 and −44.8 ± 5.24 mV, respectively. FTIR and DSC showed no interaction between EGCG and the selected excipients. XRD results revealed no form conversion of EGCG in its transfersomal form. The optimized transfersomes were found to increase the cell viability and reduce the lipid peroxidation, intracellular ROS and expression of MMPs in HaCaT cells. The optimized transfersomal formulation of EGCG and HA exhibited considerably higher skin permeation and deposition of EGCG than that observed with plain EGCG. The results underline the potential application of the developed transfersomes in sunscreen cream/lotions for improvement of UV radiation-protection along with deriving antioxidant and anti-aging effects.