The Effect of Vitamin C on Ischemia Reperfusion Injury Because of Prolonged Tourniquet Application With Reperfusion Intervals

Ascorbic Acid Attenuates Multifidus Muscles Injury and Atrophy After Posterior Lumbar Spine Surgery by Suppressing Inflammation and Oxidative Stress in a Rat Model

STUDY DESIGN

A rat model of multifidus muscles injury and atrophy after posterior lumbar spine surgery.

OBJECTIVE

We determined the effect of ascorbic acid (AA) on the postoperative multifidus muscles in rat model.

SUMMARY OF BACKGROUND DATA

Previous studies show oxidative stress and inflammation are two main molecular mechanisms in multifidus muscle injury and atrophy after posterior lumbar surgery. AA may have a protective effect in postoperative multifidus muscles.

METHODS

Rats were divided into sham surgery, control surgery, and surgery plus AA groups. Multifidus muscles of the control and AA groups were excised from the osseous structures. The muscles were retracted continuously for 2 hours. In the sham and AA groups, AA was administered via oral gavage daily in the first week. In each group, the oxidative stress was evaluated by measuring malondialdehyde (MDA) and Total superoxide dismutase (T-SOD). The inflammation, fat degeneration, or fibrosis of multifidus muscle were evaluated by quantitative real-time polymerase chain reaction (q-PCR), histology, or immunohistochemical analysis.

RESULTS

T-SOD activity was significantly lower in the control group than that in the AA group in the first week. MDA levels were significantly higher in the AA group. Interleukin-6 and tumor necrosis factor-α in multifidus muscles also showed significant differences when treated with AA. The inflammation score on histology was significantly lower in the AA group postoperatively in the first week. In the long run, marker genes for fibrosis and fat degeneration, and fibrosis and fat degeneration scores, were significantly lower in the AA than the control group on days 14 and 28 postoperatively.

CONCLUSION

In conclusion, AA attenuated the oxidative stress and inflammation response in the postoperative multifidus muscles, and remarkable differences were observed from the histological assessment and related marker genes expression. Our results provided important insight into the anti-inflammatory and anti-oxidative effects of AA in the postoperative multifidus muscles.

LEVEL OF EVIDENCE

N/A.

Vitamin C revisited

This narrative review summarizes the role of vitamin C in mitigating oxidative injury-induced microcirculatory impairment and associated organ failure in ischemia/reperfusion or sepsis. Preclinical studies show that high-dose vitamin C can prevent or restore microcirculatory flow impairment by inhibiting activation of nicotinamide adenine dinucleotide phosphate-oxidase and inducible nitric oxide synthase, augmenting tetrahydrobiopterin, preventing uncoupling of oxidative phosphorylation, and decreasing the formation of superoxide and peroxynitrite, and by directly scavenging superoxide. Vitamin C can additionally restore vascular responsiveness to vasoconstrictors, preserve endothelial barrier by maintaining cyclic guanylate phosphatase and occludin phosphorylation and preventing apoptosis. Finally, high-dose vitamin C can augment antibacterial defense. These protective effects against overwhelming oxidative stress due to ischemia/reperfusion, sepsis or burn seems to mitigate organ injury and dysfunction, and promote recovery after cardiac revascularization and in critically ill patients, in the latter partially in combination with other antioxidants. Of note, several questions remain to be solved, including optimal dose, timing and combination of vitamin C with other antioxidants. The combination obviously offers a synergistic effect and seems reasonable during sustained critical illness. High-dose vitamin C, however, provides a cheap, strong and multifaceted antioxidant, especially robust for resuscitation of the circulation. Vitamin C given as early as possible after the injurious event, or before if feasible, seems most effective. The latter could be considered at the start of cardiac surgery, organ transplant or major gastrointestinal surgery. Preoperative supplementation should consider the inhibiting effect of vitamin C on ischemic preconditioning. In critically ill patients, future research should focus on the use of short-term high-dose intravenous vitamin C as a resuscitation drug, to intervene as early as possible in the oxidant cascade in order to optimize macrocirculation and microcirculation and limit cellular injury.

Antioxidant support in composite musculo-adipose-fasciocutaneous flap applications: an experimental study

Free radicals are chemicals that play roles in the etio-pathogenesis of ischaemia-reperfusion injury. Various antioxidants have been used in an attempt to mitigate the damage induced by these chemicals. In the present study, the antioxidative effects of grape seed extract (proanthocyanidin), tomato extract (lycopene), and vitamin C (ascorbic acid) on a composite re-established-flow inferior epigastric artery based rectus abdominis muscle-skin flap model on which experimental ischaemia was induced were investigated. The rats have been administered antioxidants for 2 weeks prior to the surgery and for 2 more weeks thereafter. Macroscopic, histopathological, and biochemical analyses were carried out at the decision of the experiment. It was found that flap skin island necrosis was significantly reduced in the proanthocyanidin, lycopene, vitamin C groups (p < 0.001). Statistical analyses showed significant decreases in inflammation, oedema, congestion, and granulation tissue in the proanthocyanidin and lycopene groups compared to the vitamin C and control groups (p < 0.001). When the viability rates of fat and muscle tissues were examined, significant improvements were found in the proanthocyanidin and lycopene groups in comparison to the other groups (p < 0.001). Serum antioxidant capacity measurements revealed significant differences in the lycopene group compared to all other groups (p < 0.001). It is concluded that lycopene and proanthocyanidin are protective antioxidants in rat composite muscle-skin flap ischaemia-reperfusion models.