Antioxidant Effects of Coenzyme Q10 in Naturally Aging Rats

 Coenzyme Q10, also known as ubiquinone 10, is a quinone cyclohexane compound, named after the polymerization degree of the polyisopentenyl group on the six-position side chain of the parent nucleus, which is 10. Coenzyme Q10 is found in the heart, liver, kidney and pancreas, and its physiological role is to act as a coenzyme in the oxidative phosphorylation reaction in the mitochondria. Its physiological role is to act as a coenzyme in the oxidative phosphorylation reaction in the mitochondria. Recent studies have found that in addition to its physiological function in the cellular respiratory chain, coenzyme Q10 also has a powerful scavenging effect on free radicals, and that exogenous intake of coenzyme Q10 into the organism can play a role in antioxidizing and delaying aging in vivo. In the present study, the in vivo antioxidant effect of coenzyme Q10 was investigated in aged rats to provide an experimental basis for its development and utilization.

 

1 Materials and methods

1.1  test subject

 The coenzyme Q10 solution provided by a domestic biological company using wheat germ oil as solvent was identified by the Physical and Chemical Inspection Institute of Guangxi Zhuang Autonomous Region Disease Prevention and Control Center, and the content of coenzyme Q10 in the solution was 4.5g/100g. The recommended human dosage of this solution is 1g per day for adults (equivalent to 45mg of coenzyme Q10), and the weight of adults is 60kg, which is equivalent to 0.75 mg/kg. （The recommended human dose of this solution is 1g per day for adults (equivalent to 45mg of Coenzyme Q10), or 0.75 mg/kg.BW for 60kg.

 

1.2 Laboratory animals  

48 18-month-old SPF male SD rats, purchased from Guangdong Medical Laboratory Animal Center, Laboratory Animal Production License No. SCXK 粤 2008-0002, Laboratory Animal Use License No. SYXK 桂 2007-0003, Laboratory Animal Room Temperature:

22～25℃, relative humidity: 55%～70%.

 

1.3 Main reagents and instruments  

Malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) kits were purchased from Nanjing Jianjian Bioengineering Institute. Methanol, ethanol, trichloromethane, sulfuric acid, quinine sulfate, etc., were all analytically pure in China. Hitachi KY2000 semi-automatic biochemistry instrument, fluorescence spectrophotometer, electronic analytical balance, low-temperature centrifuge, constant-temperature water bath, etc.

 

1.4 Experimental Methods  

The serum MDA levels of all rats were determined by the method of blood sampling from the inner canthus of the eye, and the rats were stratified according to the MDA levels and then randomly divided into 4 groups of 12 rats each. According to the recommended human dose of coenzyme Q10, three dose groups of 15.00, 7.50, and 3.75 mg/kg BW (equivalent to 20, 10, and 5 times the recommended human dose, respectively) and one negative control group were set up, and wheat germ oil was used as the solvent to prepare solutions with concentrations of 1.50, 0.75, and 0.375 mg/mL (in terms of the concentration of coenzyme Q10) as the test material of the dose groups, and the negative control group consisted of wheat germ oil as the solvent, and the test material of the negative control group consisted of wheat germ oil as the solvent. The negative control group was wheat germ oil. Wheat germ oil was used in the negative control group. 1.0mL/100g BW was administered orally to rats once daily for 90 days. At the end of the test, MDA, SOD and GSH-Px activities were measured in serum, brain and liver tissues of all rats, and lipofuscin (Lip) content was measured in brain and liver tissues.

 

1.5 Statistics  

One-way ANOVA and two-way comparisons between groups were performed using SPSS 13.0 statistical software.

 

2 Results

2.1 Effect of Coenzyme Q10 on body weight of rats There was no significant difference in the body weights of rats in each group before the test, and the differences in the body weights and weight gain of rats in each dosage group during the test were not significant when compared with those of the negative control group (P>0.05), which indicated that the sample did not have any significant effect on the body weights of old rats.

 

2.2 Effect of Coenzyme Q10 on malondialdehyde (MDA) in rats

At the end of the experiment, the MDA levels in serum, brain and liver tissues of rats in all dose groups were lower than those in the negative control group, and the differences between at least two dose groups and the negative control group were statistically significant (P < 0.05 or P < 0.01), as shown in Table 1, indicating that coenzyme Q10 can reduce the production of MDA in aged rats.

 

Table 1 MDA levels in serum, brain and liver tissues of rats (n=12, ± s)

 

groups	Dose group (m gLkgBW )	Pre-test serum (nmoLLm L)	Final test serum (nmoLLm L)	Test end brain tissue (nmoLLg)	Test end liver tissue (nmoLLg)
high dose group	15.00	4.94±0.69	5.01±0.71**	287.00±29.80**	247.80±35.90**
middle-dose group	7.50	5.07±0.60	5.22±0.62*	284.00 ± 30.10**	272.40±36.90
low dose group	3.75	4.98±0.71	5.64±0.81	297.70±40.00*	263. 10±46.20*
negative control	0.00	4.97±0.72	5.97±0.65	334.40±40.20	302.50±41.20

Note : *P<0.05, **P<0.01 compared with the negative control group , below.

2.3 Effect of coenzyme Q10 on superoxide dismutase (SOD) activity in rats  

At the end of the experiment, the SOD activity in serum, liver and brain tissues of rats in each dose group was higher than that in the negative control group, and the differences between at least two dose groups and the negative control group were statistically significant (P<0.05 or P<0.01), as shown in Table 2, indicating that coenzyme Q10 could improve the activity of SOD in serum and tissues of aged rats.

 

Table 2 SOD activity in serum, brain and liver tissues of rats (n=12, ± s)

groups	dosages (m gLkgB W )	Serum SOD (kULm L)	brain tissue SOD (kULg)	Liver tissue SOD (kULg)
high dose group	N5.00	N74.30±OO.U0**	N 09U.00±N73.U0**	N SNS.50±O05.40**
middle-dose group	7.50	N4O.00±N3.40	n 0n9.90±n79.s0*	N 453.30±NUU.50**
low dose group	3.75	N5U.40±O5.40*	97O.40±N49.90	n 3n9.40±onn. n0
negative control	0.00	N37.00±N9.00	U4U.70±N47. N0	N O3N.O0±NUO. N0

 

2.4 Effect of coenzyme Q10 on glutathione peroxidase (GSH-Px) activity in rats  

At the end of the experiment, the GSH-Px activity in serum, liver and brain tissues of rats in all dose groups was higher than that in the negative control group, and the differences between at least one dose group and the negative control group were statistically significant (P<0.05 or P<0.01), as shown in Table 3, indicating that Coenzyme Q10 could increase the GSH-Px activity in serum and tissues of aged rats.

Table 3 GSH-Px activity in serum, brain and liver tissues of rats (n=12, ± s)

 

groups	dosages (m gLkgB W )	Serum G SH -mx (kULm L)	Brain tissue G SH-mx (kULg)	Liver tissue G SH -mx (kULg)
high dose group	N5.00	477.P0±P4.40GG	2 995.90±4S7. N0GG	2 9S2. N0±424.50GG
middle-dose group	7.50	472.00±2P.S0GG	2 702.70±PS9.50	2 94S.90±P74.90G
low dose group	P.75	4sp. n0±24. n0g	2 s7s.00±ppn. n0	2 759.P0±404.20
negative control	0.00	4P5.P0±P0.50	2 4N9.20±44P.U0	2 455.S0±50P.90

 

2.5 Effect of coenzyme Q10 on lipofuscin (Lip) content in rats  

At the end of the experiment, the lipofuscin content of liver and brain tissues of rats in all dose groups was lower than that of the negative control group, and the differences between at least one dose group and the control group were significant (P<0.05 or P<0.01), as shown in Table 4, indicating that CoQ10 could reduce the Lip content of tissues in aged rats.

Table 4 Lip content in rat brain and liver tissues (n=12, ±s)

 

groups	Dose group (m gLkgB W )	Brain tissue iip (μgLg )	Liver tissue iip (μgLg )
high dose group	15.00	21.66±6.01**	8.75±2.26*
middle-dose group	7.50	23.54±4.64*	9.32±2. 19
low dose group	3.75	22.77±5.30*	10.75±2.51
negative control	0.00	28. 18±4.28	11.35±2.84

 

3 Discussion

Since oxidative stress has become the classic theory of cellular aging, the search for safe, efficient and multi-functional antioxidants has been a hot topic in medical research. Many antioxidants are unable to enter the cell due to permeability or cellular rejection, and they can only scavenge extracellular free radicals and protect the cell membrane, but they are unable to deal with oxidative damage to the mitochondrial membrane, which is the key to cellular aging. In recent years, it has been found that coenzyme Q10, as a component of the mitochondrial respiratory chain, is embedded in the lipid bilayer of the inner mitochondrial membrane, which not only acts as a coenzyme in the cellular energy production process, but also protects the mitochondrial membrane from the attack of free radicals by the six unstable double bonds contained in its own structure[1] , which aroused a great deal of interest from the researchers, and caused a great deal of research on the antioxidant effects and mechanisms of coenzyme Q10. This has aroused great interest among researchers and triggered a wave of research on the antioxidant effects and mechanisms of coenzyme Q10.

 

In the present study, we used naturally aged rats, which can more accurately reflect the antioxidant effect of coenzyme Q10 than the galactose-constructed aging model. The results showed that coenzyme Q10 effectively reduced the contents of MDA and lipofuscin, the products of lipid peroxidation, and increased the activities of the two major antioxidant enzymes, SOD and GSH-Px, which indicate that coenzyme Q10 has an antioxidant effect on rats. Coenzyme Q10 has antioxidant effects in rats. Coenzyme Q10 reduces MDA by scavenging free radicals and indirectly increases the activities of SOD and GSH-Px, but whether it has a direct effect on these two antioxidant enzymes is not known.

 

Coenzyme Q10 has a significant advantage as an antioxidant in that it also reduces physical fatigue. With the increase of age, the content of coenzyme Q10 in the human body gradually decreases, and the cellular energy production is also affected. Supplementation of exogenous coenzyme Q10 not only ensures the smoothness of the cellular respiratory chain, but also increases the body's reserve of hepatic glycogen[2] , which shows that coenzyme Q10 can be used as an anti-aging agent through both antioxidant and physical strength improvement. "This is an unparalleled advantage of any other antioxidant. Another significant advantage of coenzyme Q10 is that it is an endogenous enzyme in the human body, so it has a very high safety profile.

 

No significant side effects have been reported with 200 mg daily for 6-12 months or 100 mg daily for 6 years [3]. Coenzyme Q10 has been included as one of the health food ingredients licensed by the Ministry of Health, and can be used as a health food for long-term use. The human body needs at least 30 mg of coenzyme Q10 per day, and the older the person is, the higher the need is. Inadequate intake of coenzyme Q10 increases the risk of cardiovascular diseases, infections, and tumors. The human body can only synthesize trace amounts of coenzyme Q10, and the source of coenzyme Q10 in food is very limited, so the human body is very vulnerable to deficiency of coenzyme Q10. Foreign studies have shown that supplementation of exogenous coenzyme Q10 has a good effect on the treatment of Alzheimer's disease, obesity, ulcerative diseases, psoriasis, cystic fibrosis, acoustic trauma, and other diseases, and it can alleviate fatigue, anxiety, and improve the immunity of the human body and sexual function, etc. [4]. From the results of this study and other research literature, we believe that the use of coenzyme Q10 as an antioxidant for middle-aged and elderly people is safe and has multiple effects, and is worth further research and application.

 

References:

[1] Shoal RS, Forster MJ. Coenzyme Q, oxidative stress and aging[J]. Mitochondrion, 2007, 7(suppl): 103-111.

[2] SONG Yi, LIAO Yuan, XU Jiayu. An experimental study of coenzyme Q10 to alleviate locomotor fatigue in mice [J]. Modern Preventive Medicine, 2010, 37(3): 449-450.

[3] ZHANG J-Z, CHI L-L, SHEN Y-L. Production of coenzyme Q10 and its application in medicine[J]. Production of coenzyme Q10 and its application in medicine[J]. Journal of Shanghai Institute of Applied Technology, 2004, 4(4): 301-305.

[4] PENG Liang, HAN Yanbin, WANG Yanwu. Experimental study on the effect of coenzyme Q10 on immune function in mice[J]. Chinese Journal of Hygiene and Inspection, 2010, 20(12): 3125-3127.