Abstract:
Plant resins are reported to have high medicinal values due to their content of bioactive
metabolites. Few reports were found in the last two decades concerning the chemistry and anti-
inflammatory activity of the resins belonging to Eucalyptus and Araucaria genera. Therefore,
the exudate resins of Eucalyptus maculata, Araucaria excelsa and Araucaria bidwillii were
evaluated for their phenolic and flavonoid content, together with their possible anti-
inflammatory potential via carrageenan-induced paw edema in rats at the doses of 100, 200, and
400 mg/kg. The methanol extract of E. maculata (MEME) kino resin was the richest in
phenolics (572.82 ± 1.75 µg GAE/mg extract), and flavonoids (11.60 ± 0.01 µg QE/mg extract).
The MEME (400 mg/kg) showed the most significant percentage inhibition of paw oedema
(50.91%), compared to indomethacin (66.11%). The extract also decreased serum
malondialdehyde (MDA) (42%), nuclear factor kappa B (NF-κB) (42.7%), tumor necrosis
factor-alpha (TNF-α) (40.5%), cyclooxygenase-2 (COX-2) (42%) and nitric oxide (NO) (23%).
In addition, it increased antioxidant enzymes; reduced glutathione (GSH) (2.6-fold) and
superoxide dismutase (SOD) (1.3-fold), compared to control group. Moreover, it displayed a
profound antioxidant property with IC50 of 6.83 ± 0.77μg/mL compared to trolox (IC50 21.18 ±
0.59 μg/mL) using DPPH assay. The methanol extract of E. maculata resin was standardized by
HPLC to contain 68.21 mg of 7-O-methyl aromadendrin (MA)/g extract. These findings suggest
that E. maculata kino resin is a potent antioxidant with potential therapeutic efficacy for treating
inflammation.
