|Year : 2023 | Volume
| Issue : 2 | Page : 114-118
Sex hormones, antioxidants and lipid profile of aqueous Cucumis sativus L. (cucumber) treated male rats
Olawale O Obembe1, Taiwo A Abayomi2, Olorunfemi S Tokunbo2, Joseph B Dare2, Taofeek O Usman1
1 Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Osun State University, Osogbo, Osun State, Nigeria
2 Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Osun State University, Osogbo, Osun State, Nigeria
|Date of Submission||31-May-2022|
|Date of Decision||06-Aug-2022|
|Date of Acceptance||28-Oct-2022|
|Date of Web Publication||21-Mar-2023|
Olorunfemi S Tokunbo
Neuroscience Unit, Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Osun State University, Osogbo, Osun State
Source of Support: None, Conflict of Interest: None
Background: Cucumis sativus (cucumber) is regarded as a healthy fruit because of the beneficial effects of its phytochemical constituents. However, there is a deficit of information about its effect on male reproductive physiology. Objective: This study was conducted to investigate the effect of aqueous extract of C. sativus (AECS) on male reproductive hormones, oxidative stress biomarkers, and lipid profile. Materials and Methods: Ten male rats were randomly assigned into two (control and treated) groups (n = 5). In the treated group, a single dose of AECS (500 mg/kg) was administered daily for 6 weeks and thereafter sacrificed under sodium pentobarbital anesthesia. Blood was collected and analyzed for sex hormones, antioxidants, and lipid profile markers. The testicular homogenate was also analyzed for antioxidants. Results: The AECS increased (P < 0.05) serum testosterone and luteinizing hormone levels (4.43 ± 0.34 and 7.50 ± 1.31, respectively) when compared with the control. Also, testicular catalase and serum level of high-density lipoprotein were increased (27.45 ± 0.19 and 30.08 ± 5.22, respectively) (P < 0.05), whereas serum low-density lipoprotein decreased (72.79 ± 9.56) (P < 0.05) in the extract treated rats. However, serum antioxidant levels were not affected. Conclusions: AECS is beneficial to male reproductive physiology evidenced by improved lipid profile and hormonal indices. Also, the integrity of the testicular redox profile was well maintained.
Keywords: Antioxidants, cucumber, Cucumis sativus, lipid profile, sex hormones
|How to cite this article:|
Obembe OO, Abayomi TA, Tokunbo OS, Dare JB, Usman TO. Sex hormones, antioxidants and lipid profile of aqueous Cucumis sativus L. (cucumber) treated male rats. Int J Med Health Dev 2023;28:114-8
|How to cite this URL:|
Obembe OO, Abayomi TA, Tokunbo OS, Dare JB, Usman TO. Sex hormones, antioxidants and lipid profile of aqueous Cucumis sativus L. (cucumber) treated male rats. Int J Med Health Dev [serial online] 2023 [cited 2023 May 28];28:114-8. Available from: https://www.ijmhdev.com/text.asp?2023/28/2/114/372148
| Introduction|| |
Infertility is a highly prevalent global condition. Approximately 50% of infertility cases are due to male physiological factors, with at least 30 million infertile men worldwide especially in Africa and Eastern Europe. Research findings indicated that modifying lifestyle factors, such as diet, can greatly influence sexual behavior and fertility. Healthy diet that includes fruits and vegetables has been postulated to increase libido and fertility. Investigating the association between specific food and fertility may provide insight into the mechanisms by which specific diet influences reproductive physiology.
Cucumis sativus, popularly known as cucumber, is an edible fruit that belongs to the Cucurbitaceae family. It is ranked as the fourth most important vegetable in terms of economic importance. It was originally grown in South Asia but now grown in other continents including Africa. Its fruit contains more than 90% water. It is roughly cylindrical and elongated with a length of 24 inches and breadth of 3.9 inches. Phytochemical analysis of the aqueous and methanolic extracts of cucumber revealed that it contains various bioactive phenolic compounds such as flavonoids, alkaloids, terpenoids, tannins, saponins, steroids, reducing sugars, minerals, phenols, and glycosides.
Saponins and flavonoids have been reported to increase the bioavailability of male sex hormones. Saponins play a regulatory role in androgen biosynthesis by stimulating the release of luteinizing hormone (LH) from the anterior pituitary. Similarly, flavonoids sustain androgen biosynthesis by inhibiting the enzymatic activity of 17β-estradiol aromatase, an enzyme involved in the aromatization of testosterone to estrogen. Steroid such as cholesterol is the precursor molecule for androgens, and its availability promotes androgen production. In an in vitro study, aqueous C. sativus extract was shown to have antioxidant and analgesic effects. The presence of flavonoids and tannins in the extract as evidenced by preliminary phytochemical screening was suggested to be responsible for the free radical scavenging and analgesic effects. Reports from the literature suggest that its beneficial properties may be attributed to its phytochemical constituents.,,,,C. sativus extract exhibits antimicrobial, antidiabetic, anti-inflammatory, tissue repair, and antiulcer properties. It was also reported to contain a bioactive agent Cucurbitacin B that possibly reduces cancer growth.
However, reports abound in the literature of medicinal plants with a nutritive value, but which are detrimental to fertility. Examples of these include the antifertility effects of Curcuma longa (turmeric),Piper nigrum (black pepper),Syzygium aromaticum (clove),Momordica charantia (bitter gourd), and Buchholzia coriacea (wonderful kola). There is a dearth of knowledge on the effects of C. sativus on the male reproductive system. Consequently, this study was undertaken to investigate the effects of aqueous extract of C. sativus (AECS) on male sex hormones, oxidative stress biomarkers, and lipid profile of male albino rats.
| Materials and Methods|| |
Fresh C. sativus fruits were procured from Oke-Baale Market, Osogbo, Osun State, Nigeria, and authenticated at the herbarium of the Department of Botany, Obafemi Awolowo University, and voucher number 16978 was assigned. The fruits were washed thoroughly with distilled water to remove adhering particles, after which they were sliced, properly shade dried, and pulverized. The seeds were picked and separated from the dried fruits.
Ten male Wistar rats were procured and kept in well-aerated cages with solid floors covered with wood shavings in the animal house of the College of Health Sciences, Osun State University, Osogbo. They were exposed to 12 h light 12 h dark cycle. The rats were fed with standard pellets (21% protein, 35% fat, 30% carbohydrate, 0.8% phosphorus, and 0.8% calcium) purchased from Ladokun livestock feeds, Ibadan, and had access to water ad libitum. All procedures in this study conformed to the guiding principles for research involving animals as recommended by the Declaration of Helsinki and the guiding principles in the care and use of animals (2002) as amended. The rats were acclimatized for 2 weeks before the onset of experiment.
Extraction of C. sativus
Pulverized C. sativus fruit (171 g) was soaked in distilled water for 24 h. It was thereafter filtered through Whatman filter paper, and the filtrate was concentrated on a rotary evaporator (45°C). It was further concentrated on a vacuum oven (40°C and 700 mmHg). The percentage yield of crude AECS obtained was calculated and thereafter refrigerated at 10°C for preservation.
Rats were randomly assigned into two groups of five rats each. Group 1 served as the control and received the distilled water (vehicle) only, whereas group 2 was treated with AECS (500 mg/kg). The treatments were administered once daily for 6 weeks. The rats were then anesthetized using sodium pentobarbital (30 mg/kg) and sacrificed by cervical dislocation. Before sacrifice, blood was obtained from each rat by cardiac puncture and centrifuged at 3000 rpm for 5 min. The serum was obtained and stored at −20°C. Also, testis was excised from the rats immediately after sacrifice and homogenized. Sex hormones, lipid profile markers, and oxidative stress biomarkers were assayed from the serum obtained.
The left testis of the rats were excised, washed in 1.15% KCl solution, blotted with filter paper, and weighed. Afterward, they were homogenized on ice pack in four volumes of homogenizing fluid (phosphate buffered saline, pH 7.4) using Teflon homogenizer. The resulting homogenate was centrifuged at 10,000 rpm for 10 min in a cold centrifuge (4°C) to obtain post mitochondria fraction. Biomarkers of oxidative stress were estimated from the supernatant obtained.
Serum levels of testosterone, LH, and follicle-stimulating hormone (FSH) were assayed via enzyme-linked immunoassay technique using appropriate commercially available kits. The kits were obtained from Calbiotech Inc. (California, USA) and contained the respective enzyme label, substrate reagent, and quality control sample. The quality control was carried out at the beginning and end of the assay in order to ascertain acceptability with respect to bias and within variations. Testosterone kit used had a sensitivity of 0.075 ng/mL with intra- and interassay variations of 3.9% and 4.3%, respectively. LH kit had a sensitivity of 0.12 mIU/mL with intra- and intervariation of 7.6% and 10.83%, whereas FSH kit had a sensitivity of 0.353 mIU/mL with intra- and interassay variation of 5.6% and 6.4%, respectively.
Biomarkers of oxidative stress were assayed spectrophotometrically from the serum and testicular homogenate. Malondialdehyde (MDA) was determined as described by Uchiyama and Mihara, superoxide dismutase (SOD) according to Alici and Arabaci, and catalase as described by Aebi.
Total cholesterol, triglyceride, high-density lipoproteins (HDL), and low-density lipoprotein (LDL) in serum obtained were determined by enzymatic colorimetric method as described by Rifai et al. The determination was based on the formation of color after enzymatic hydrolysis and oxidation. The indicator quinoneimine used was formed from H202 and 4-amino-antipyrine in the presence of phenol. All the biochemical parameters were assayed using the respective commercial diagnostic kits obtained from Diasys Diagnostic systems (Istanbul, Turkey) on a Statfax Diasys 1904 plus Biochemical Analyzer.
Data obtained were expressed as mean ± standard error of mean. The means of the two groups were compared by Student t-test using SPSS version 16 (SPSS Inc., Chicago USA). P < 0.05 was considered significant.
| Results|| |
C. sativus extract
AECS obtained after the extraction was dark brown in color, highly soluble in water, and weighed 23.427 g. Percentage yield was 13.7%.
The administration of AECS significantly (P < 0.05) increased serum testosterone (4.43 ± 0.34) and LH (7.50 ± 1.31) when compared with the control (1.96 ± 0.39 and 1.69 ± 0.68, respectively). However, the extract had no effect on FSH [Table 1].
AECS caused a significant (P < 0.05) increase in HDLs (30.08 ± 5.22) and a significant (P < 0.05) decline in LDLs (72.79 ± 9.56) when compared with the control (15.35 ± 1.67 and 108.22 ± 1.82, respectively). There was no significant effect on cholesterol and triglycerides [Table 2].
Testicular oxidative stress
The administration of AECS significantly (P < 0.05) increased testicular catalase (27.45 ± 0.19) when compared with the control group (23.61 ± 1.05). However, no significant effect was observed on testicular SOD and MDA. Also, all serum oxidative stress biomarkers assayed were not affected by C. sativus [Table 3].
| Discussion|| |
C. sativus is generally considered a healthy fruit because it is highly nutritive and rich in bioactive compounds such as saponins and flavonoids, which have been proved to be beneficial. Saponins and flavonoids increases androgen synthesis and increases the bioavailability of male sex hormones., Reproductive functions are dependent on the interactions between sex hormones and reproductive organs and may be greatly influenced by diet. This study revealed that C. sativus significantly increased serum levels of testosterone and LH. The increase in testosterone and LH suggests that C. sativus has a stimulatory effect on either the pituitary gonadotropes or Leydig cells of the testes or both. LH stimulates the testicular interstitial Leydig cells to secrete testosterone. Therefore, the observed increase in the testosterone of C. sativus treated rats may be a result of direct stimulatory effect on the testicular Leydig cells or indirectly by increasing LH secretion from the gonadotropic cells on the anterior pituitary gland. It is also not impossible that both mechanisms work synergistically and probably responsible for the marked increase in testosterone. Saponins are steroids or triterpenoid glycosides common in a large number of plants and plant products. Saponin-rich plant products have been reported to suppress FSH secretion.C. sativus is rich in saponins, and this may account for the transient decline of FSH level of the treated rats when compared with the control.
Hyperlipidemia occurs when there is an abnormal increase in blood LDL or cholesterol (>5.2 mmol/L) level, and this increases the risk of developing cardiovascular diseases. C. sativus may reduce the risk of developing atherosclerosis and other cardiovascular diseases as a serum level of LDL was lower and HDL increased in C. sativus treated rats. This is consistent with an earlier report, where hypolipidemic effect of cucumber was reported. It is well documented that HDL levels share an inverse relationship with the risk of cardiovascular diseases. Also, high level of HDL has been reported to be beneficial to male reproductive physiology by promoting sperm capacitation and acrosome reaction.
Though serum antioxidants and testicular SOD and MDA levels were not affected in this study, a significantly higher testicular catalase was observed. This corroborates the work of Zhou et al. who reported that C. sativus contains a catalase gene (CsCAT3) and has an intrinsic catalase activity. Catalase is a preventive antioxidant that scavenges hydrogen peroxide and defends the body against stress and illnesses.C. sativus therefore promotes the removal of hydrogen peroxide and other oxidants from the rat testis, defending the testis against oxidative stress. The antioxidants present in C. sativus might be involved in the elevation of the HDL and lowering of the LDL, as many of the phytochemicals present in C. sativus have been proved to be effective in lowering lipids. Also, phytosterols, plant steroid present in C. sativus, are known to be effective in lowering LDL by inhibiting the absorption of cholesterol from the small intestine. Hence, C. sativus offer the protection against the development of cardiovascular diseases, and the outcome of this study therefore further corroborates the benefits of incorporating cucumber into diet.
| Conclusion|| |
AECS mediates a beneficial effect on male reproductive physiology by its stimulatory effect on testicular androgen and catalase activity coupled with its hypolipidemic potentials.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]