Devaraj SankarGanesh

Spermidine may decrease ER stress in pancreatic beta cells and may reduce apoptosis via activating AMPK dependent autophagy pathway

The risk for diabetes increases with increasing BMI<25. Insulin resistance is the key factor for type 2 diabetes; studies revealed that endoplasmic reticulum stress is the main factor behind this disease. With increase in ER stress, pancreatic beta cells start to undergo apoptosis, leading to a decline in the pancreatic beta cell population. The ER stress arises due to unfolded protein response. Recently, spermidine get importance for increasing the longevity in most of the eukaryotes including yeast, Caenorhabditis elegans, Drosophila and human peripheral blood mononuclear cells via induction of autophagy pathway. Autophagy is also involved in regulation of scavenging of proteins. One of the major cellular pathways for scavenging the aggregated intracellular protein is autophagy. Hence spermidine can be a candidate for the treatment type 2 diabetes. Autophagy genes are regulated by mTOR (mammalian Target Of Rapamycin) dependent or independent pathway via AMPK. Hence either inhibition of mTOR or activation of AMPK by spermidine will play two crucial roles, first being the activation of autophagy and secondly the reduction of endoplasmic reticulum stress which will reduce beta cell death by apoptosis and thus can be a novel therapeutic candidate in the treatment of insulin resistance in type 2 diabetes and preserving pancreatic beta cell mass.

Faecal chemical cues in water buffalo that facilitate estrus detection

Chemo-signals are among the reliable non-invasive methods for estrus detection in mammals. Water buffalo is a silent heat animal and, hence, there is search for chemo-signals which would be effective non-invasive indicators of estrus state. We analyzed the faecal chemical cues during the estrous cycle in buffalo and to find the estrus-specific faecal volatile compounds adopting bull behavior assay. The faecal samples were collected at three phases of the estrous cycle (i.e., proestrus, estrus and postestrus) and subjected to gas chromatography-mass spectrometry analyses. We found 27 volatile compounds in the faeces of buffaloes, of which 4-methyl phenol (4mp) and trans-verbenol (tv) were found only in estrus faeces. The faecal samples of estrus buffaloes and the estrus-specific compound(s) (4mp+tv) at three different concentrations were tested for behavioral responses (flehmen and mounting behavior) in the bull. The bulls exhibited repeated flehmen when exposed to a combination of the two compounds (i.e., 4mp+tv) as compared to the individual compounds or raw faecal sample collected from buffalo when in estrus (P<0.05). However, higher number of mounting behavior was recorded when bulls were exposed to 4mp followed by a combination of the two compounds (4mp+tv) and trans-verbenol (P<0.05), in that order. By contrast, less number of mounting behavior was exhibited by bulls when exposed to the control sample (i.e., Hexadecanoic acid) (P<0.05). As inferred from the bull behavior assay, the present study suggests that the two compounds, 4 methyl phenol and trans-verbenol would be reliable indicators of estrus in buffaloes.

Increased squalene concentrations in the clitoral gland during the estrous cycle in rats: an estrus-indicating scent mark?

Squalene in the rat clitoral gland is reported to be semi-volatile and may serve as a chemo-signal. The objective was to determine squalene concentrations in the clitoral gland throughout the reproductive cycle. Clitoral glands were extracted with dichloromethane; 23 compounds were identified with Gas Chromatography linked Mass Spectrometry (GC-MS). Since squalene concentrations were significantly higher during proestrus and estrus, and remarkably reduced during metestrus and diestrus, we inferred that it could be an ovulation-indicating chemosignal in the female rat, acting as a scent mark for the male. This hypothesis was tested by investigating its efficacy to attract males, including studying the role of the olfactory-vomeronasal system of the male in perceiving squalene. For detection of squalene, males used their conventional olfactory system when at a distance from the female, whereas the vomeronasal organ was used when they were in close proximity to the female. We concluded that squalene was a female-specific chemosignal that attracted males, and furthermore, that the olfactory-vomeronasal system had an important role in the perception of squalene.

Biochemical Analysis of Female Mice Urine with Reference to Endocrine Function: A Key Tool for Estrus Detection

Species-specific chemical signals released through urine, sweat, saliva and feces are involved in communication between animals. Urinary biochemical constituents along with pheromones may contribute to variation across reproductive cycles and facilitate to estrus detection. Hence, the present study was designed to analyze such biochemical profiles, such as proteins, carbohydrates, lipids, fatty acids, in response with steroid hormones such as estradiol and progesterone. The experimental groups were normal, prepubertal, ovariectomized, and ovariectomized with estrogentreated female mice. In normal mice, the protein and lipid concentrations in urine were significantly higher in proestrus and estrus phases and the quantity of fatty acids was also comparatively higher in estrus. Furthermore, certain fatty acids, namely tridecanoic, palmitic and oleic acids, were present during proestrus and estrus phases, but were exclusively absent in ovariectomized mice. However, the carbohydrate level was equally maintained throughout the four phases of estrous cycle. For successful communication, higher concentrations of protein and specific fatty acids in estrus are directly involved. The significant increase in estradiol at estrus and progesterone at metestrus seems to be of greater importance in the expression pattern of biochemical constituents and may play a notable role in estrous cycle regulation. Thus, we conclude that the variations observed in the concentration of the biochemical constituents depend on the phase of the reproductive cycle as well as hormonal status of animals. The appearance of protein and specific fatty acids during estrus phase raises the possibility to use these as a urinary indicators for estrus detection.

Areca catechu Linn.–Derived Silver Nanoparticles: A Novel Antitumor Agent against Dalton's Ascites Lymphoma

ABSTRACT The present investigation emphasizes biomimetic synthesis of silver nanoparticles (AgNPs) using an aqueous extract of Areca catechu and its impact on a Daltons ascites lymphoma (DAL) mice model. The ultraviolet (UV) spectrum of AgNPs at 428 nm confirmed the spherical shape of the particles and average size of 80 nm was determined using electron microscopic analysis. Elemental silver and adhered biomolecules conferred a synergetic antitumor activity with a significant increase in life span of tumor-induced mice with decreased body weight and tumor volume. Acridine Orange staining and DNA fragmentation studies of harvested tumor cells showed higher level of cytotoxicity by AgNPs when compared to aqueous extract of Areca catechu.

A correlation of fecal volatiles and steroid hormone profiles with behavioral expression during estrous cycle of goat, Capra hircus

Chemical signals (both volatile and non-volatile) form the major communication channels in animals. These signals are transferred mainly through excretory sources to facilitate inter-individual communication. In particular, the reproductive cycle of female mammals, including goats, exhibits significant changes in the constituents of their excretory products, and female mammals also express different behavioral patterns. We propose that feces is one of the important sources of chemo-signals in goats. However, the behavioral patterns and analysis of excretory sources based on chemical communication have not yet been studied in the Indian goat, Capra hircus. To validate our hypothesis, we analyzed the behavioral patterns and the volatiles and steroid hormone profiles in the feces samples of female goats during the estrous cycle. Here, we synchronized the estrous cycle in six female goats and obtained feces samples. The samples were extracted with dichloromethane and analyzed using gas chromatography-mass spectrometry. A portion of the sample was used for hormone assay to confirm the phases in the estrous cycle. Induction of she-goats into estrus was detected from the vaginal swelling, mucus discharge, restlessness, reduced milk secretion, bellowing, bleating, frequent urination, standing heat, allowing the male to mount, mounting on other females and teasing of males. The repeated male behaviors viz., flehmen, mounting, penile protrusion, body rubbing, dominance over other males and finally coitus with estrus female by male goats were observed. Analysis of volatiles revealed a total of twenty-four compounds combining all the phases in the estrous cycle. Among those, some of the volatile compounds and two antioxidants (ascorbic acid and vitamin E) were estrus-specific. Based on the fecal steroid analysis, higher level of estradiol during estrus and higher level of progesterone during post-estrus were observed. The behavioral patterns of female and male goats combined with qualitative differences in the volatile compounds and the two antioxidants rendered the estrus identifiable. Furthermore, the fecal steroid analysis also supported the detection of hormonal status during the estrous cycle. To the best of our knowledge, this is the first report correlating the behavior with volatiles and hormones in the feces samples from female Indian goats. It is concluded that the volatile pattern and hormone profile in feces, supported by specific behavioral patterns, should be considered a better modality of non-invasive estrus detection in goats.

Adriamycin induced spermatogenesis defect is due to the reduction in epididymal adipose tissue mass: a possible hypothesis.

Adriamycin is an anthracycline antibiotic used as anticancer drug since past few decades. Though effective against cancer, it is cardiotoxic, nephrotoxic, hepatotoxic and also toxic for reproductive system. Although a number of potential toxic mechanisms have been identified following exposure to adriamycin, the major pathogenic mechanism appears to be the generation of toxic reactive oxygen species (ROS). Animals treated with adriamycin have shown a decrease in total sperm count. This implies that adriamycin impairs the process of spermatogenesis. Epididymal white adipose tissue (EWAT) is necessary for normal spermatogenesis, and decrease in the EWAT causes disturbance in spermatogenesis. Factor X is an unknown molecule synthesized by EWAT that plays crucial role in spermatogenesis. Adriamycin inhibits Kruppel-like factor 4 (KLF-4) and thus downregulates the adipogenesis process needed to maintain the EWAT mass. Apart form adipocytes, KLF-4 and peroxisome proliferator-activated receptor gamma (PPAR-γ) are also found in spermatogonium and testis, implying its vital role in spermatogenesis. Adriamycin treatment inhibits KLF-4 and thus PPAR-γ in EWAT and spermatogonium. Reduction of EWAT might cause a decrease in Factor X level. Declining of Factor X level, KLF-4 and PPAR-γ together will lead to disturbance in spermatogenesis process.

Modulating role of pheromonal cues from oestrus-specific urine on 3-methylcholanthrene-induced male reproductive toxicity.

Polyaromatic hydrocarbons (PAHs) are persistent organic pollutants that contribute to endocrine/gonadal disruption. This study was designed to investigate the endocrine modulating role of pheromones in alleviating the reproductive toxic effects of 3‐MC (3‐methylcholanthrene), one of the common PAHs, in rat model. The rats were injected intraperitoneally with 3‐MC at a dose of 25 mg kg−1 BW. The serum levels of testosterone and other biochemical parameters were altered to significant levels in 3‐MC‐treated rats and oestrus‐specific urine exposure restored all these effects to near normal. Although testis weight did not indicate any significant change, sperm and spermatid counts were significantly reduced in 3‐MC‐treated rats, which became normal in oestrus‐urine‐exposed rats. Hence, this study suggests that oestrus‐specific urinary pheromones have the potential to modulate the endocrine system and alleviate the male reproductive toxic effects produced by 3‐MC.

Heat shock protein(s) may serve as estrus indicators in animals: A conceptual hypothesis

The estrous cycle consists of episodic phases that eventually regulate reproduction in non-primate mammals. Females are sexually receptive to males only during estrus phase, which lasts from few hours to 2 days. Estrus detection is crucial for reproductive management of animal herd; however, precise estrus detection method/tools are not available. The analysis of body fluids, e.g., facets of proteomics during recent years is promising in the progression of estrus markers. Specifically, heat shock proteins (HSPs) present in body fluids and reproductive organs could be possibly used as markers of estrus. We note the possible vital roles of hyperthermia, stress and steroid hormones during estrus that could positively regulate the expression of HSPs. To validate our hypothesis, we explained the possible mechanism of production of HSPs, specifically during estrus phase. We recommend intensive research on HSPs to develop credible estrus detection tools in animals.

Squalene is a potential endocrine modulator in rat: A proof-of-principle study with 3-methylcholanthrene-induced toxicity

Oestrus urine was proved as a potential endocrine modulator in alleviating the toxicity induced by 3‐methylcholanthrene (3‐MC) in male rats. We, in this study, aimed to prove the attributing potential of toxicity alleviation to squalene, an oestrus‐specific pheromone in rats. A single dose of 3‐methylcholanthrene (25 mg/kg BW, i.p.) was administered to male Wistar rats with concurrent exposure to squalene sprayed in bedding material (Group III). Group II rats did receive 3‐MC treatment but did not expose to squalene. Group I rats were intact control neither administered 3‐MC nor sprayed with squalene. In consequence of 3‐MC toxicity, liver and testes weights were increased and the components of blood cells (RBC and WBC count, Hb level) and testosterone concentration were significantly reduced in Group II rats. Moreover, sperm count was reduced and antioxidants (testes and epididymis) were significantly altered. Exposure to squalene in Group III rats comparatively normalised all the variable components towards baseline and reorganised the histological architecture of reproductive tissues that were exacerbated with 3‐MC toxicity. This study ultimately proved squalene as a potent molecule in alleviating the toxicity induced by 3‐methylcholanthrene.