Pharmacokinetics and antiangiogenic studies of potassium koetjapate in rats

Purpose: Koetjapic acid is an active compound of a traditional medicinal plant, Sandoricum koetjape. Although koetjapic acid has a promising anticancer potential, yet it is highly insoluble in aqueous solutions. To increase aqueous solubility of koetjapic acid, we have previously reported a chemical modification of koetjapic acid to potassium koetjapate (KKA). However, pharmacokinetics of KKA has not been studied. In this study, pharmacokinetics and antiangiogenic efficacy of KKA are investigated.

Methods: Pharmacokinetics of KKA was studied after intravenous and oral administration in SD rats using HPLC. Anti-angiogenic efficacy of KKA was investigated in rat aorta, human endothelial cells (EA.hy926) and nude mice implanted with matrigel.

Results: Pharmacokinetic study revealed that KKA was readily absorbed into blood and stayed for a long time in the body with T_max 2.89 ± 0.12 h, C_max 7.24 ± 0.36 μg/mL and T_1/2 1.46 ± 0.03 h. The pharmacological results showed that KKA significantly suppressed sprouting of microvessels in rat aorta with IC₅₀ 18.4 ± 4.2 μM and demonstrated remarkable inhibition of major endothelial functions such as migration, differentiation and VEGF expression in endothelial cells. Further, KKA significantly inhibited vascularization in matrigel plugs implanted in nude mice.

Conclusions: The results indicate that bioabsorption of KKA from oral route was considerably efficient with longer retention in body than compared to that of the intravenous route. Further, improved antiangiogenic activity of KKA was recorded which could probably be due to its increased solubility and bioavailability. The results revealed that KKA inhibits angiogenesis by suppressing endothelial functions and expression of VEGF.

Keywords: Angiogenesis; Bioavailability; HPLC; Koetjapic acid; Potassium koetjapate; Sandoricum koetjape.