Chronic wounds and wounds that are difficult to heal are a major
concern for Australian healthcare expenditure and a source of
misery for those who suffer from them. For example, in Australia
in 2012, there were an estimated 433,000 people suffering from
these, costing an estimated AUD2.6 billion dollars for the year
to July. Novel ways of healing wounds are continually being
sought. Two strategies used to accelerate wound healing are
augmenting angiogenesis and through manipulation of wound healing
growth factors. The method of stimulating angiogenesis proposed
in this research was through the use of a topically applied
flavonoid or lignan molecule. Two compounds in particular, the
lignan erythro-guaiacylglycerol-8-O-4’-coniferyl alcohol (T1)
and the flavonoid naringenin, have demonstrated pro-angiogenic
activity based on in vitro testing but they had not been trialled
previously in vivo.
C57BL/6J mice were used in techniques building on previous
studies. Wounds were created with a control, positive control,
and T1 and naringenin topically applied at varying
concentrations. The compounds tested were applied at 3-day
intervals, aiming for wound healing within 12 days. A second
group was used to analyse the wounds and compounds trialled at
day 3 after wounding, the day of maximal angiogenesis. The
wounds were recorded and measured using pictorial and
digital-image analysis. Results showed that both the flavonoid
(naringenin) and the lignan (T1) when applied to wounds actually
increased the size of the wounds and the length of time required
for the wounds to heal. Subsequent histological analysis
revealed that wounds treated with both T1 and naringenin,
although not healing faster, produced higher amounts of
granulation tissue and collagen deposition. Based on these data
it is hypothesised that the above compounds caused an excessive
deposition of granulation tissue, preventing effective wound
healing. Although the wounds did not heal effectively, the
results obtained from this study may be useful when applied to
wounds that are difficult and slow to heal, such as diabetic
ulcers.
In conclusion, further studies are required to confirm that these
novel compounds increase angiogenesis, granulation tissue and
collagen deposition within wounds. If so, new studies to find
optimal dosage and application regimes may provide useful
approaches to accelerating wound healing in the future
