The objective of this study
As L-Cysteine and Cystamine have been characterized analytically earlier, the same has been reported here for Indomethacin. Indomethacin in 0.2 M sodium phosphate and 0.9% Sodium chloride showed A203nm > A267nm > A320nm. Linearity in both the solvents at the absorption maxima were established up to 175 μg/ml for Indomethacin. A203nm, A267nm and A320nm values of Indomethacin (140 μg/ml) were constant with dose up to 120 Gy at a dose rate of 1.2 Gy/s in 0.2 M sodium phosphate but in 0.9% sodium chloride these values decreased with dose exponentially.
Survival studies indicate that when used singly Cystamine (100 mM), L-Cysteine (0.1 M) and Indomethacin (35 mg/ml) treated mice showed 100% survival in the unirradiated state. But upon mixing (i.e. Cystamine + Indomethacin and L-Cysteine + Indomethacin), these produced amide bonds as evidenced by IR spectroscopy. Both these addition compounds showed less percentage survival. Survival studies against a dose of 10 Gy have shown that percentage survival is in the following decreasing order:-
Indomethacin 35 µg/ml + Cystamine 100 mM > Cystamine 100 mM > L-Cysteine 0.1 M
Moreover, CFU studies for endogenous colony formation for different radiation doses of 5, 7.5 and 10 Gy with different radioprotectors either singly or in combination have also indicated the same pattern as above. So, Cystamine 100 mM + Indomethacin 35 µg/ml is the best radioprotector combination.
The present study shows that this combination can be used as a chemotherapeutic adjuvant for stem cell renewal and repopulation when administered before radiation exposure.
