|Year : 2021 | Volume
| Issue : 3 | Page : 182-185
Aqueous extract of Nicotiana tabacum impaired serum testosterone and testicular weight in male wistar rats
Azubuike Raphael Nwaji1, Iniobong Ating Ante2, Favour-Ann Kyrian Nwoke3
1 Department of Physiology, Faculty of Basic Medical Sciences, Alex Ekwueme Federal University, Ndufu-Alike, Ebonyi State; Department of Physiology, Faculty of Basic Medical Sciences, University of Calabar, Calabar, Cross River, Nigeria
2 Department of Physiology, Faculty of Basic Medical Sciences, University of Calabar, Calabar, Cross River, Nigeria, India
3 Department of Physiology, Faculty of Basic Medical Sciences, Alex Ekwueme Federal University, Ndufu-Alike, Ebonyi State, Nigeria
|Date of Submission||31-Jul-2021|
|Date of Decision||06-Aug-2021|
|Date of Acceptance||07-Aug-2021|
|Date of Web Publication||30-Nov-2021|
Mr. Azubuike Raphael Nwaji
Department of Physiology, Faculty of Basic Medical Sciences, Alex Ekwueme Federal University, Ndufu Alike, Ebonyi State
Source of Support: None, Conflict of Interest: None
Background: Tobacco which is a product of Nicotiana tabacum (N. tabacum) has nicotine as its primary phytochemical. Nicotine has been reported to be an addictive drug and the leading cause of tobacco addiction worldwide. The male reproductive system is known to be highly sensitive to many chemicals and drugs which have been found to pose adverse effects on male reproductive capacity. Aim: The aim of this study is to investigate the effect of the aqueous extract of N. tabacum on serum testosterone and testicular weight in male Wistar rats. Materials and Methods: A total of 18 male rats weighing (140–230 g) were used for this study. The animals were randomly divided into three groups (A, B, and C), containing six rats each. Group A served as control, whereas Group B and C were orally administered sublethal doses of 20 and 30 mg/kg body weight of the N. tabacum extract, respectively, once per day for 21 days. At the end of the experimental period, all the animals were sacrificed. Blood samples were collected for hormonal assay and both testes were excised and weighed immediately. Results: There was a significant decrease (P < 0.05) in the serum testosterone levels of rats treated with the extract in a dose-dependent manner when compared with the control, there was also a significant reduction in the testicular weight of the treated groups when compared to the control group (P < 0.05). Conclusion: The results suggest that aqueous extract of N. tabacum at doses of 20 mg/kg and 30 mg/kg when administered for a period of 3-week impaired serum testosterone level, testicular weight, and bodyweight of male Wistar rats.
Keywords: Nicotiana tabacum, testicular weight, testosterone, Wistar rats
|How to cite this article:|
Nwaji AR, Ante IA, Nwoke FAK. Aqueous extract of Nicotiana tabacum impaired serum testosterone and testicular weight in male wistar rats. Niger J Exp Clin Biosci 2021;9:182-5
|How to cite this URL:|
Nwaji AR, Ante IA, Nwoke FAK. Aqueous extract of Nicotiana tabacum impaired serum testosterone and testicular weight in male wistar rats. Niger J Exp Clin Biosci [serial online] 2021 [cited 2022 Aug 14];9:182-5. Available from: https://www.njecbonline.org/text.asp?2021/9/3/182/331557
| Introduction|| |
Cigarette smoking is a widely recognized health hazard, yet despite worldwide antismoking campaigns, some people continue to consume cigarettes on regular basis, and according to Langgassner (1999), the highest prevalence of smoking is observed in young adult males during their reproductive age.
Tobacco is derived from any plant of the genus Nicotiana of the Solanaceae family. The products manufactured from its leaf include cigars, cigarettes, snuff, and chewing tobacco. Nicotine is considered the primary chemical in tobacco that is responsible for engendering tobacco use and dependence.,
Smokeless tobacco comes in two different forms, namely, “Tobacco snuff” and “Chewing tobacco.” Tobacco snuff is the powdered form blended with potash as the main additive in Nigeria, and has been recommended as a substitute for a cigarette since it is devoid of hazardous elements such as tar and carbon monoxide. For this reason, many people believe that using smokeless tobacco is safer than smoking it. However, this is not true because smokeless tobacco can induce addiction to nicotine and leukoplakia.
The male reproductive system is known to be highly sensitive to many chemicals and drugs which have been found to pose adverse effects on male reproductive capacity under certain conditions. Some effects of nicotine on reproduction have been reported., In spite of the growing knowledge of adverse reproductive effects of smoking on reproduction, it is relatively unclear whether or not; smokeless tobacco has the same effects on male reproductive activities. Nevertheless, studies that comprehensively associated nicotine with decreased serum testosterone, did not account for smokeless tobacco effects on serum testosterone and testicular weight. The present study was, therefore, designed to evaluate the effect of aqueous extract of Nicotiana tabacum on serum testosterone level and testicular weight in male Wistar rats.
| Materials and Methods|| |
Plant collection and identification
Leaves of N. tabacum were collected, identified, and authenticated by a botanist at the Department of Botany, Ebonyi state University Abakaliki, Ebonyi State.
About 100 g of the plant material was extracted by maceration in 1000 ml of distilled water with intermittent agitation (8 h day) for 3 days using mechanical shake. Afterward, the mixture was filtered using Whatman filter paper and the filtrate concentrate by rotary evaporation to dryness and yield 23.5 g (23.5) of solid residue was obtained. The residue in form of paste dark brown product was transferred to an airtight bottle and stored in the refrigerator until use. The concentration of the extract was determined using this formula:
And the actual dose administered was obtained using this formula:
A total of 18 male Wistar rats weighing 140–230 g were used for this study. The animals were acclimatized for 2 weeks at the Animal House of the Department of Physiology, Alex-Ekwueme Federal University, Ndufu-Alike. The animals were randomly divided into three groups, containing six male rats each. The experimental design consisted of three groups designated Group A (control), B, and C. Group B and C were orally administered sublethal doses of 20 and 30 mg/kg body weight, of the N. tabacum extract, respectively.
The experiment was conducted in accordance with the Guidelines of the U.S. National Institute of Health (NIH) on the care and the use of laboratory animals.
The animals were kept under good laboratory conditions with 12 h light-dark cycle. The animals were fed with normal rat chow and water ad libitum for 3 weeks.
Sample collection and analysis
All administrations were done orally using oropharyngeal cannula once per day for 21 days. On the last day of the experimental study, all the animals were sacrificed. Blood samples were collected by cardiac puncture into plain tubes, centrifuged at 3000 rpm for 10 min, and the serum was separated and used to analyze the level of testosterone. The animals were dissected and both testes were excised, trimmed of adherent tissues, and weighed immediately with an electronic weighing balance, model DT 1000 England with a capacity of 0.1–1000 g. The body weights of the animals were measured on the first and the last day of the experimental period.
Testosterone assay procedure
An enzyme-linked immunosorbent assay system was used to measure testosterone level in serum samples collected. The EIA kit was obtained from immunometric (London, UK) and contained a testosterone EIA enzyme label, testosterone EIA substrate reagent, and EIA quality control sample. This was carried out at Alex-Ekwueme Federal University Teaching Hospital, Abakaliki (AE-FUTHA), Ebonyi State.
Data were expressed as mean ± standard error of mean. Data were analyzed using Graphpad prism version 7.0 for windows (Graphpad ® software, San Diego, CA, USA). Differences in means were compared using ANOVA and Student's t-test. P ≤0.05 was considered statistically significant.
| Results|| |
The effect of N. tabacum on bodyweight, serum testosterone level, and testicular weight is shown in [Table 1] and [Figure 1], [Figure 2], [Figure 3] below.
|Table 1: Effect of aqueous extract of Nicotiana tabacum on serum testosterone and testicular weight. Values are expressed as mean±standard error of mean (n=6)|
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|Figure 1: Effect of Nicotiana tabacum extract on percentage bodyweight of rats (n = 6)|
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|Figure 2: Effect of Nicotiana tabacum extract on serum testosterone levels of rats (n = 6)|
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|Figure 3: Effect of Nicotiana tabacum extract on testicular weight of rats (n = 6)|
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Effect of Nicotiana tabacum on body weight
There was a significant decrease in the percentage body weight of the treated groups in a dose-dependent manner when compared to the control group as shown in [Table 1] and [Figure 1].
Effect of Nicotiana tabacum on serum level of testosterone and testicular weight
[Figure 2] shows the mean serum testosterone levels in rats that received low (20 mg/kg b.w) and high (30 mg/kg b.w) doses of N. tabacum. There was a significant decrease in the serum testosterone levels of rats treated with the extract in a dose-dependent manner when compared with the control. As indicated in [Figure 3], there was also a significant reduction in the testicular weight of the treated groups when compared to the control group (P < 0.05).
| Discussion|| |
Nicotine is a primary phytochemical in Tobacco which is a product of N. tabacum. Nicotine is reported to be an addictive drug and the leading cause of tobacco addiction worldwide. In addition to its addictive effects, other adverse health effects have been and are still being investigated, one of which areas is the adverse effects of Tobacco (Nicotine) smoking on reproductive health. However, several of these studies related tobacco smoking with the reduction in male reproductive parameters,,, with less report on whether the smokeless tobacco presents the same result.
The result of this study shows that aqueous leaf extract of N. tabacum causes a decrease in serum testosterone levels as well as decreases testicular weight in a dose-dependent manner.
The result of this study is in consonance with the findings of,,,, which all reported a reduction in male reproductive parameters with Tobacco smoking and nicotine use.
Testosterone is necessary for the development, growth, and normal functioning of the testis and the male accessory reproductive gland. The decrease in serum testosterone concentration of rats treated with N. tabacum observed in this present study may be attributed to its possible role in causing a reduction in luteinizing hormone (LH) concentration and disruption of testicular cytoarchitecture. Consequently, this might have adversely affected Leydig cell number and functioning leading to decrease in serum testosterone level since Leydig cells secrete testosterone. The circulating LH is responsible for maintaining the normal plasma testosterone concentration in the male rats. Testosterone is secreted by the interstitial cells of Leydig in the testes, but only when they are stimulated by LH from the anterior pituitary gland.
Furthermore, low serum testosterone levels have been reported to adversely affect the structure, weight, and functioning of the testis and epididymis. Hence, the reduction in testicular weight observed in this study, could be associated with the decrease in the serum level of testosterone in the treated rats.
Hence, in concurrence with several reports on the adverse effects of tobacco smoking on the male reproductive parameters, this study also suggests a reduction in male reproductive parameters with smokeless consumption.
| Conclusion|| |
The aqueous extract of N. tabacum at doses of 20 mg/kg and 30 mg/kg, when administered for a period of 3 weeks showed a significant decrease in serum testosterone level, testicular weight, and bodyweight of male Wistar rats.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]