Autism Studies and Related Medical Conditions, January 2009 - TACA

Reddi K, Henderson B, Meghji S, Wilson M, Poole S, Hopper C, Harris M, Hodges SJ.
Interleukin 6 production by lipopolysaccharide-stimulated human fibroblasts is potently
inhibited by naphthoquinone (vitamin K) compounds. Cytokine. 1995 Apr;7(3):287-90.
Department of Oral and Maxillofacial Surgery, Eastman Dental Institute for Oral
Healthcare Sciences, London.
Naphthoquinone vitamins (vitamins K) are widely recognized for their role in the
gamma-carboxylation of specific glutamyl residues in coagulation, anticoagulation
and extra-hepatic proteins. Recently, however, there have been
reports that these compounds can exert actions other than those normally
associated with protein gamma-carboxylation. These observations suggest that
naphthoquinones may have effects on the production of inflammatory mediators
including cytokines. Fibroblasts are now recognized as a rich source of cytokines
and we have examined the effect of various naphthoquinones on the production
of interleukin 6 (IL-6) by lipopolysaccharide-stimulated human gingival
fibroblasts. Compounds examined in this study include: phylloquinone (K1),
menaquinone-4 (K2), menadione (K3), 2,3-dimethoxy-1,4-naphthoquinone
(DMK) and a synthetic product of vitamin K catabolism, 2-methyl, 3-(2'methyl)-
hexanoic acid-1,4-naphthoquinone (KCAT). All of these compounds are capable
of inhibiting IL-6 production with a rank order of potency: KCAT > K3 > DMK >
K2 > K1. The most potent compound, KCAT, inhibited IL-6 production with an
IC50 of 3 x 10(-7)M. The mechanism of action of these naphthoquinones on
fibroblast IL-6 production is unknown. Given that K3 and KCAT are inactive in the
gamma-carboxylation reaction, we suggest that this activity is not essential for
the inhibition of IL-6 production and that activity may be related to the redox
capacity of these naphthoquinones.
PMID: 7640347 [PubMed - indexed for MEDLINE]
Richardson AJ. Omega-3 fatty acids in ADHD and related neurodevelopmental disorders.
Int Rev Psychiatry. 2006 Apr;18(2):155-72.
Department of Physiology, Human Anatomy and Genetics, University of Oxford, UK.
alex.richardson@physiol.ox.ac.uk
Omega-3 fatty acids are dietary essentials, and are critical to brain development
and function. Increasing evidence suggests that a relative lack of omega-3 may
contribute to many psychiatric and neurodevelopmental disorders. This review
focuses on the possible role of omega-3 in attention-deficit/hyperactivity disorder
(ADHD) and related childhood developmental disorders, evaluating the existing
evidence from both research and clinical perspectives. Theory and experimental
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