Date of Award

5-2017

Culminating Project Type

Thesis

Degree Name

Biological Sciences - Cell and Molecular: M.S.

Department

Biology

College

College of Science and Engineering

First Advisor

Oladele Gazal

Second Advisor

Heiko Schoenfuss

Third Advisor

Susan Parault-Dowds

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Keywords and Subject Headings

Lepidium sativum, Garden cress, Supplementation, Inclusion, Perifusion, Reproduction

Abstract

Plants have been utilized as herbicides, insecticides, antimicrobials, antifungals, antivirals, cosmetics and therapeutic agents. Traditional medicine plays a pivotal role in health care around the globe. Lepidium sativum (LS) has been utilized in cooking for its peppery, tangy flavor and aroma and in traditional medicine. LS has been used to treat inflammation, bone fractures, hypertension, microbial infections, diabetes, bronchial asthma, osteoarthritis, constipation and other diseases. There have been no studies investigating the effects of LS seed extracts on preovulatory surge secretion of gonadotropin releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The highest level of inclusion of LS seeds at 50% has shown lethal effects. At 10% LS seed inclusion has shown ambiguous toxic and non-toxic effects. There is a paucity of information on LS effects on female and male reproductive function. To date, LS has been shown in females to act as a galactagogue, abortifacient and contraceptive. There are ambiguous results of LS having anti-ovulatory properties. In males, LS has been shown to increase testicular and epididymal sperm concentration and act as an aphrodisiac. The objectives of the study were to determine the effect of aqueous LS seed extract on the development and magnitude of surge releases of GnRH, LH and FSH and secondly, to determine the acute and chronic effects of 15% LS seed supplementation on gross organ morphology and histomorphometric indices, testosterone secretion and spermatogenesis in the Sprague-Dawley rat.

Thirty-two female Sprague-Dawley rats were ovariectomized using standard procedures for Experiment 1. Ten days post-ovariectomy, all rats were injected with estradiol-17β (10 μg/0.2 mL/rat, s.c. in corn oil) for three days. On the fourth day at 0800 h, sixteen rats were treated with LSE (40 mg/Kg BW, i.p.) while the remaining sixteen received normal saline diluent at the same rate. At 1000 h, eight rats that received LSE and eight rats that received normal saline were treated with corn oil (0.2 mL/rat, s.c.). The remaining sixteen rats were treated with progesterone (2.5 mg/0.2 mL/rat, s.c. in corn oil). At 1300 h, the rats were euthanized using an overdose of 6 mL 2.5% tribromoethanol. The hypothalamus and pituitary glands were extracted and perifused in artificial cerebrospinal fluid for seven hours at a constant temperature of 37°C. Hypothalamic GnRH and pituitary LH and FSH concentrations were determined utilizing radioimmunoassays. There were no significant differences in GnRH, LH or FSH secretions. There was an observed GnRH surge in rats receiving saline and progesterone. Rats that received LSE and progesterone observed an earlier and diminished secretion of GnRH, but was not significant. Progesterone administration had a suppressive effect on LH average secretion. GnRH administration had no effect on LH or FSH secretion. Total hormonal secretions for GnRH, LH and FSH had no significant changes.

Forty-eight male Sprague-Dawley rats were utilized for Experiment 2. Upon arrival, rats were given feed and water ad libitum for two weeks for acclimation. The rats were weighed and assigned to either a control group (0% LS seed inclusion; n=24) or a treatment group (15% LS seed inclusion; n=24). At 0800 h rats were offered either normal rat chow or the 15% LS seed included rat chow for 8 weeks. At 2, 4, 6 and 8 weeks, six rats from each the Control or the Treatment groups were euthanized with carbon dioxide asphyxiation for a minimum of 10-minutes. All rats were weighed on the first day of the experiment, every other day and immediately after euthanization. Every day feed intake and refusal was measured. Immediately post euthanization, trunk blood was collected for hormone assays. Further, the paired testicles, epididymides, prostate gland, seminal vesicles, kidneys, adrenal glands, heart, liver, spleen, lungs, brain and pancreas were harvested and weighed. The relative organ weights were normalized to weight per 100 g BW. One kidney and one testis was collected and used for histological analysis. The other testes were utilized for in vitro testosterone production. One cauda epididymis per rat was isolated and used for epididymal sperm count. Our results indicated a decrease in Treatment group’s body weight during the first few days of the experiment. This occurred concurrent with a strong feed aversion for the Treatment group during the first few days. This effect is explained by the novel food source being offered to the rats. There was no effect of LS seed inclusion on adrenal gland, heart, liver, and spleen or lung weight. There was a significant increase in brain weight possibly due to hydrocephalus. There was also a significant increase in pancreatic weight possibly due to pancreatitis. There were no effects of LS supplementation on paired testicular, epididymides or seminal vesicle weights. The prostate gland did show a significant decrease in weight. The mechanism for this significant weight decrease is unknown. The testis histological analysis had no significant results except for an increase in week two Leydig cell diameter. There was no significant changes for in vitro testosterone production or plasma testosterone. Therefore, our results suggest no conclusive data for the aphrodisiac claims. The epididymal sperm density did not have significant changes, although they did increase concurrent between the groups through the experiment. Interestingly, there was an increase in renal weight through the experiment for the Treatment group. Histological analysis showed a significant change in the diameter of the Bowman’s capsule, glomerulus and Bowman’s space for the Treatment group. There was also an increase in glomerulosclerosis, metaplasia and hyperplasia in rats fed 15% LS seed inclusion. In the proximal and distal tubules there was a significant increase in tubular degeneration throughout the experiment. These results paired together show a significant toxic effect for rats fed 15% LS seed. Overall, LS seed consumption for medicinal purposes should be consumed with caution because of the possible narrow therapeutic index.

Comments/Acknowledgements

My deep appreciation goes to Dr. Oladele Gazal, my major Professor, for his excellent advice, direction and support. I would also like to thank Dr. Heiko Schoenfuss and Dr. Susan Parault-Dowds for serving on my committee and for sharing their invaluable wealth of knowledge with me. I appreciate the help and guidance of Brian Lorenz and his staff of the Vivarium at SCSU.

Thanks goes to graduate students: Erum Khan and Benjamin Westerhoff. Thanks also goes to undergraduate students: Kirsti Kallinen, Mariam Afolabi, Melissa Ferguson and Valerie Ponce. Special thanks to Olubunmi Sodipe and Tosin Imade. Finally, thanks to my father John Westphal, my mother Janell Schoonover and girlfriend Kassandra Kavanaugh for their love and support.

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