Garcinia kola seed ameliorates renal, hepatic, and testicular oxidative damage in streptozotocin-induced diabetic rats

Figures & data

Figure 1. The unpeeled (A) and peeled (B) ethnomedicinal seeds of Garcinia kola. Chemical structures of garcinoic acid (C) and kolaviron (D).

Figure 2. Effect of Garcinia kola seed on body weight (A) and blood glucose levels (B) in control and STZ-induced diabetic rats. Each bar represents mean ± SD of 10 rats. (a) Values differ significantly from control (p < 0.05). (b) Values differ significantly from the diabetic control group (p < 0.05).

Table 1. Effect of Garcinia kola seed on relative organ weights (g/100 g bw) in STZ-induced diabetic rats.

	Control	Diabetic control	Diabetic + GK	GK alone
Kidney	0.64 ± 0.01	0.87 ± 0.02^a	0.61 ± 0.04^b	0.66 ± 0.03
Liver	3.35 ± 0.06	4.15 ± 0.26^a	3.62 ± 0.05^b	3.38 ± 0.07
Testes	1.07 ± 0.02	0.85 ± 0.09^a	1.03 ± 0.03^b	1.12 ± 0.08
Epididymis	0.13 ± 0.06	0.07 ± 0.02^a	0.09 ± 0.02^b	0.11 ± 0.04
Seminal vesicle	0.36 ± 0.08	0.31 ± 0.02	0.34 ± 0.07	0.38 ± 0.03
Prostate gland	0.19 ± 0.04	0.18 ± 0.05	0.17 ± 0.02	0.18 ± 0.06

GK, Garcinia kola. The data are expressed as mean ± SD for 10 rats per group after 14 d treatment period.

^ap < 0.05 against control.

^bp < 0.05 against diabetic control.

Table 2. Effect of Garcinia kola seed on liver and kidney function parameters in STZ-induced diabetic rats.

	Control	Diabetic control	Diabetic + GK	GK alone
ALT (IU/L)	51.25 ± 6.29	72.5 ± 9.5^a	57.5 ± 11.9^b	53.2 ± 5.78
AST (IU/L)	76.03 ± 5.16	102.54 ± 9.57^a	81.13 ± 8.94^b	72.84 ± 7.32
ALP (IU/L)	95.18 ± 7	166.98 ± 11.56^a	101.2 ± 11.64^b	86.48 ± 9.63
Bilirubin (mg/dL)	1.16 ± 0.17	3.02 ± 0.93^a	1.16 ± 0.24^b	1.13 ± 0.33
Urea (mg/dL)	17.81 ± 2.81	26.27 ± 2.94^a	18.27 ± 1.96^b	16.48 ± 1.92
Creatinine (mg/dL)	3.55 ± 0.12	6.85 ± 0.11^a	4.17 ± 0.04^b	3.81 ± 0.11

ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; GK, Garcinia kola. The data are expressed as mean ± SD for 10 rats per group after 14 d treatment period.

^ap < 0.05 against control.

^bp < 0.05 against diabetic control.

Table 3. Effect of Garcinia kola seed on hormonal profile in STZ-induced diabetic rats.

Endpoints	Control	Diabetic control	Diabetic + GK	GK alone
LH (ng/mL)	6.53 ± 1.05	5.13 ± 1.02^a	6.01 ± 0.85^b	6.67 ± 1.03
FSH (ng/mL)	5.61 ± 0.57	3.67 ± 0.47^a	4.95 ± 0.71^b	5.82 ± 0.58
Testosterone (ng/mL)	4.31 ± 0.11	2.55 ± 0.07^a	3.86 ± 0.13^b	4.63 ± 0.14
T3 (ng/dL)	0.83 ± 0.07	0.51 ± 0.04^a	0.77 ± 0.05^b	0.85 ± 0.08
T4 (ug/dL)	5.03 ± 0.17	3.71 ± 0.91^a	4.84 ± 0.55^b	5.11 ± 0.43
T3/T4 ratio	0.17 ± 0.02	0.14 ± 0.01^a	0.16 ± 0.02^b	0.17 ± 0.01

LH, luteinizing hormone; FSH, follicle stimulating hormone; T₃, triiodothyronine; T₄, tetraiodothyronine; GK, Garcinia kola. The data are expressed as mean ± SD for 10 rats per group after 14 d treatment period.

^ap < 0.05 against control.

^bp < 0.05 against diabetic control.

Figure 3. Effects of Garcinia kola seed on the GSH level and activities of SOD and CAT in control and STZ-induced diabetic rats. Each bar represents mean ± SD of 10 rats. (a) Values differ significantly from control (p < 0.05). (b) Values differ significantly from the diabetic control group (p < 0.05).

Figure 4. Effects of Garcinia kola seed on H₂O₂ (A) and MDA (B) levels and spermiogram (C and D) in control and STZ-induced diabetic rats. Each bar represents mean ± SD of ten rats. (a) Values differ significantly from control (p < 0.05). (b) Values differ significantly from the diabetic control group (p < 0.05).

Figure 5. Histopathology guide of kidney, liver, and testes of control and STZ-induced diabetic rats treated with Garcinia kola seed. The upper panel (AK, AL, and AT) shows representative photomicrographs of kidney, liver, and testes from control rats, respectively. STZ-induced diabetic control rats showed severe histopathologic alterations in kidney, liver, and testes of rats (BK, BL, and BT). Tubular necrosis (black arrow), interstitial, and periglomerular cellular infiltration by mononuclear cells (line arrow), periportal fatty infiltration (notched arrow), hydropic degeneration of hepatocytes (chevron), interstitial congestion and edema (white arrow), and decreased germinal epithelium (white notched arrow). The investigated organs from STZ-induced diabetic rats administered with Garcinia kola seed appeared structurally and functionally normal but with a very mild renal interstial congestion and a few periportal cellular infiltration in the liver (CK, CL, and CT). Normal rats administered with Garcinia kola seed alone showed regular architecture (DK, DL, and DT). Original magnification: 160×.