Molecular Size of the Bio-active Components from Haruan Channa striatus Extract

Extracts of an indigenous tropical carnivorous and air breathing fish haruan Channa striatus was shown to have antinociceptive activity in mice and the aim was to study tinvestigateto, at the molecular size of the bioactive compound(s), for isolation and identification. The aqueous portion of crude extract in chloroform-methanol 2: v/v was subjected to filtration by Millipore Ultrafree-CL low binding cellulose filter 5,000; 10,000 and 30,000 Dalton (Nominal Molecules Weight Limit or NMWL) and centrifuged for 10 min at 5,000 rpm. Series of 0, 25, 50 and 100% dilutions of the filtered solutions in distilled water were purified through preparative HPLC. The fraction collected between 1-3 min was dried under vacuum yielding 30 mg to be reconstituted in distilled water to a concentration of 0.0005, 0.005, 0.05 and 0.5 mg mL-1 in distilled water which were then used for abdominal constriction tests in mice according to method described by Mat Jais. The non-filtered, the 5,000 and 10,000 NMWL samples produced similar HPLC traces. The results indicated that the bioactive compound is less than 5,000 NMWL and finally, the fraction 1 at retention times 1 to 3 min, of the HPLC purified sample was also produced inhibition in the constriction test.