Introduction

“Garcinia cambogia (G.kola; bitter kola) is a popular plant in southern Nigeria and extensively used as food and herbal medicine”. It is found in the tropical rain forest of West-Africa₁. “The height of the plant is approximately 14m and it produces reddish, yellowish or orange colour fruits containing 2 to 4 seeds. The seeds when chewed have a bitter astringent taste. Several works done on G. Kola have confirmed its hypolipidermic₂,₃,₄ antifungal₅, anti-histaminic₆, spermatogenic₇; aphrodisiac and anti-microbial₈,₉, erythropoietic₄, antiviral₈,₁₀; anti-bacteria against Neisseria gonorrhoeae ₁₁and anti-ulcerogenic effects₁₂. Chewing sticks produced from G. Kola tree is very effective and reliable for cleaning teeth when used without toothpaste₁₃,₁₄. The seeds as well as chewing sticks are important products often seen in West African markets₃. The chewing stick is used to cure halitosis among the Yorubas of Nigeria.

The presence of biflavonoids and xanthone in G. kola seeds have been confirmed₁₅. These compounds are potent antioxidants₃,₇,₁₆. Administration of G. kola seed extracts caused an increase in testosterone production in Sprague-Dawley rats₁₇,₁₈ due to the anti-oxidant properties of its constituents.

The use of quantitative methods of light and electron microscope levels has increased remarkably over the last few years. These methods collectively called “morphometry” or “stereology” allow the number, volume, surface area and lineal extent of structures in three dimensions to be assessed from two dimensional images of light and electron microscopy₁₉,₂₀.

The aims of this study were to investigate the effects of methanolic extract of G. Kola seeds on testes and epididymides using morphometric and stereologic methods.

Materials And Methods

Animals

Plant Materials

Experimental Design

Statistical Analysis

Results

Morphometric analysis of Garcinia kola treated Testis: The diameter of seminiferous tubules showed an increment in the treated group as compared with the control (Table 1). This observation was pronounced in group C which received 200mg/kg B.W of the extract (Table 1). The germinative cell thickness and germinative cell thickness/ radius, showed a gradual reduction in the treated group as compared with the control. This observation is dose dependent.

Semen Analysis: The sperm concentration presents a dose dependent significant increment (P<0.05) as shown in Table 2 in contrast to dose dependent significant decrement observed in sperm motility.

Volume Density of Seminiferous Tubules: The volume density of seminiferous tubules was observed to present a non significant increment in the epithelium and lumen of the treated group as shown in Table 3. a dose dependent reduction was observed in the treated group (Table 3)

Volume Density of Epididymis: Table 4 presents the volume density of the epididymis. It shows a significantly higher volume of epithelium in a dose dependent manner when compared with the control. The luminal volume of Group B is not significantly different from that of the control while the volume of the Group C is significantly lower than that of the Group A and Group B. The connective tissue volume shows a dose dependent increase in both treatment groups compared to the control.

Figure 1

Table 1: Morphometric analysis of Garcinia kola treated Testis

Figure 2

Table 2: Semen Analysis

Figure 3

Table 3: Volume Density of Seminiferous Tubules (ST) (mm/mm)

Figure 4

Table 4: Volume Density of Epididymis (mm/mm)

Discussion

The morphometric analysis of the seminiferous tubules (Tables 1) of the present work justifies the increment in sperm counts as found in the epididymal lumen (Table 2). The increase in the diameter of the seminiferous tubules and the decrease in the germinative cell thickness could be as a result of rapid spermiogenesis resulting in the depopulation of the peripherally placed spermatids and increase in luminal sperm concentration. Spermatids develop into mature spermatozoa through the process of spermiogenesis₂₂. Rapid spermiogenesis is facilitated by antioxidants and increase in the peripheral testosterone level. These two factors are properties of G.kola's biflavonoids and xanthones₇,₂₃. The decrease in the motility of the spermatozoa could be due to the rapidity of development. The spermatozoa may need a moderate but progressive development for them to have excellent motility. This may also be due to the presence of some toxic component like benzophenone in the ethanolic extracts of G. kola. Cotterih et al₂₄, has reported the antioxidant potency of Kolaviron- an antioxidant extract of G.kola. Other antioxidant like carotenoid has been found to protect spermatogenesis in animals exposed to toxicant₂₅. Anti-oxidants such as carotenoids are well known as highly efficient scavengers of singlet oxygen and other excited species (oxidants). Apigenin-based flavonoids represent 60% of the total flavonoids present in the diethyl-ether fraction of G. kola₂₆. Other studies in man, have shown that lycopene helps men with idiopathic infertility, with an improvement in male fertility especially sperm characteristics₂₅.

However, the diameter of the ST is largest in the group receiving the 200mg/kg B.W of ethanolic extracts of G. kola. The diameter of the group receiving 200mg/kg B.W of ethanolic extracts of G. kola was significantly higher than that of 100mg/kg B.W extracts and the control. The volume density of the epithelium and lumen of the seminiferous tubules (Table 3) as assessed by the Weibel counting grids (point counting method) increase non-significantly as compared with the control (P>0.05). The volume density of C.T of the seminiferous tubules shows a dose dependent increase when compared with the control (Table 3). In relation to a report by Oluyemi et al₇ ,there is a need for the development of more connective tissues to support the contractile mechanism involved in the migration of immotile spermatozoa, formed in the seminiferous tubule, into the epididymis where they acquire motility. This mechanical contraction is brought about by the fibroblasts in the connective tissue walls of the seminiferous tubules. Young and Heath₂₇ affirmed that the contractile activity of fibroblasts increases in response to the testosterone level in the testis. This androgen (testosterone) is produced in the testis by the interstitial cells of Leydig in response to follicle stimulating hormone (FSH) produced by the anterior pituitary₂₇. Akpantah et al₂₃ found out that G. Kola extract increases the peripheral testosterone levels in wistar rats treated with 100mg/Kg B.W of the extract. Increased spermatogenic activity in seminiferous tubules associated with the administration of G. kola extract is hence due to the ability of the antioxidant compounds in the latter to increase peripheral testosterone levels₇,₂₃.

The significant decrease in the volume density of the lumen of the epididymis (Table 4) is most likely due to the significant increase in the epithelium (pseudostratified) of the epididymis with the corresponding increase in the volume density of the connective tissue of the epididymal wall. This is a very strong indication that G.Kola extract influences the epididymis in a positive direction. The ciliated epithelium is also important in the movement of the spermatozoa from the proximal to the distal portion of the tube prior to ejaculation which under the influence of sympathetic innervations. “The proximal portion of the muscular wall of epididymis exhibits slows rhythmic contractility which gently moves spermatozoa towards the ductus deferens. Distally the smooth muscle is richly innervated by the sympathetic nervous system which produces intense contractions of the lower part of the epididymis during ejaculation₂₇.

In conclusion, this work further confirmed the spermatogenic and tissue enhancing effects of G. Kola extract in male Wistar rats.

Aknowledgement