editorial


71

Antagonism of vitamin C and vitamin E
on action of quinolones

Julius E. Surjawidjaja
Department of Microbiology, Faculty of Medicine, Trisakti University

Univ Med - Vol. 31 No.2

The quinolone antibiotics are potent drugs for combating infections caused by various
bacterial species with satisfactory results and relatively minimal adverse effects. Antioxidant
dietary supplements, such as vitamin C (ascorbic acid) and vitamin E (α -tocopherol), are
occasionally prescribed along with quinolone antibiotics during the course of treatment of an
infection. Therefore it is important to understand the effects of these antioxidants on the
antibacterial action of quinolone antibiotics.

Pfister et al.(1) conducted  a study using 4 groups of 12 young Wistar rats. Group I was given
normal feed, group II was given vitamin E-enriched feed and group III magnesium-enriched feed,
while group IV was given feed enriched with magnesium and vitamin E, all for 10 days. All
groups received ciprofloxacin (CPFX) at a dosage of 600 mg. Vitamin E was shown to reduce the
number of abnormalities in the pelvic and femoral bones.

Gurbay et al.(2) studied the cytotoxic effects of CPFX in fibroblasts given pretreatment with
vitamin E, in comparison with those given no vitamin E pretreatment. Vitamin E pretreatment of
the cells provided significant protection against CPFX-induced cytotoxicity; lowered the level of
lipid peroxidation significantly. It was concluded that CPFX cytotoxicity was due to oxidative
stress in the fibroblasts and that pretreatment with vitamin E was capable of protecting the cells.
A subsequent study conducted by Gurbay et al.(3) on CPFX cytotoxicity in rat astrocytes also
concluded that CPFX-induced cytotoxicity is related to oxidative stress.

Masadeh et al.(4) conducted a study on the effects of CPFX-induced oxidative stress on a
number of reference bacterial strains and the protective effects of vitamin C and vitamin E on
these bacteria. The bacteria used were P. aeruginosa ATCC 27853, E. coli ATCC 25922, S.
aureus ATCC 29213, and clinical isolates of MRSA (methicillin resistant S. aureus). The inhibitory
activity of CPFX on the test bacteria was determined by calculating the minimal inhibitory
concentration (MIC), while oxidative stress was assessed through measurement  of H

2
O

2
 production

by means of FACScan flow cytometry. The bacteria pretreated with vitamin C and vitamin E
were found to be protected from CPFX-induced cytotoxicity. This study demonstrates the
antagonistic effect of vitamin E and vitamin C administration on the bactericidal effects of CPFX,
when given concurrently during treatment of infections. More recently, the antioxidant ubiquinone
(coenzyme Q10) demonstrated protective effects on human Achilles tendon cells exposed to
ciprofloxacin and moxifloxacin.(5) Oxidative stress frequently occurs in the mitochondria, and
fluroquinolone-induced oxidative damage to mitochondria in tenocytes and chondrocytes has
been reported. Fluoroquinolones are important antibiotics with immense therapeutic value, and



72 Univ Med - Vol. 31 No.2

the effectiveness of treatment by these drugs may be affected by dietary intake and cellular levels
of these antioxidants. Overall, these antibacterial agents can be considered safe and well tolerated
drugs. Patients should always be counseled regarding the risk associated with fluoroquinolones,
even when they are prescribed according to standard recommendations.

REFERENCES

1. Pfister K, Mazur D, Vormann J, Stahlmann R. Diminished ciprofloxacin-induced chondrocytotoxicity by
supplementation with magnesium and vitamin E in immature rats. Antimicrob Agents Chemother 2007;51:
1022-7.

2. Gurbay A, Garrell C, Osman M, Richard MJ, Favier A, Hincal F. Cytotoxicity in ciprofloxacin-treated
human fibroblast cells and protection by vitamin E. Hum Exper Toxicol 2002;12:635-41.

3. Gurbay  A, Gonthier B, Barret L, Favier A, Hincal F. Cytotoxic effect of ciprofloxacin in primary culture
of rat astrocytes and protection by vitamin E. Toxicol 2007;229:54-61.

4. Masadeh MM, Mhaidat NM, Alzoubi KH, Al-azzam SI, Shaweesh AI. Ciprofloxacin-induced antibacterial
activity is reversed by vitamin E and vitamin C. Curr Microbiol 2012;64:457-62.

5. Hall MM, Finnoff JT, Smith J. Musculoskeletal complications of fluroquinolones: guidelines and
precautions for usage in the athletic population. PMR 2011;3:132-42.