Chemoprofiling and Analgesic Effect of Methanol Leaves Extract and Fractions of Carica papaya

Omotoso Abayomi E1* and Igbinaduwa Patrick2

The present study was carried out to identify the chemical compounds present in the partitioned extracts of C. papaya dried leaves using GC-MS technique and also to evaluate the analgesic activity of the methanol crude extract of the dried leaves obtained via hot method in mice using two laboratory models namely: hotplate latency assays and acetic acid induced writhing. The extract given orally (50-200 mg/Kg), increased the reaction time from 2.5 ± 0.6 to 5.3 ± 1.2 seconds in the hot plate model which showed a significant, dose dependent analgesic activity when compared with the control (p<0.05 and p<0.01). Likewise, the extract at the same doses demonstrated analgesic activity by reducing the writhing numbers from 119.6 ± 26 to 68.8 ± 62. From the GC-MS analysis, the majority of the compounds identified are fatty acids and the major chemical constituents of the four partitioned extracts (methanol, petroleum ether, chloroform and ethyl acetate partitioned extract) were n-Hexadecanoic acid, 9-Octadecenoic acid (E)-, Octadecanoic acid Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethyl ester. Other chemical constituents identified were Hexadecane, Tritetracontane, Pentadecane2,6,10,14-tetramethyl, Dodecane, 2,6,10-trimethyl, Octacosane, Palmitoleic acid, 2-methylhexacosane, l-(+)-Ascorbic acid 2,6 dihexadecanoate, Tetrapentacontane, Oleic Acid, Dichloroacetic acid, tridec-2-ynyl ester, erythro-9,10-Dibromopentacosane, Cholestan-7-one, cyclic 1,2 ethanediylacetal, Oleoylchloride, Methyl 9-methyltetradecanoate, 15-Hydroxypentadecanoic acid, Eicosanoic acid, Cyclononasiloxane, octadecamethyl,9,12,15-Octadecatrienoic acid, 2,3-dihydroxypropyl, 2,3-Dihydroxypropyl elaidate, Pentadecanoic acid, 14-methyl-, methyl ester and Tetradecanoic acid. Many of the compounds identified have antioxidant, hypocholesterolemic, nematicidal, pesticide, antiandrogenic, haemolytic, anti-inflammatory/analgesic, cancer preventive, dermatitigenic, hypotensive, anemiagenic and insectifuge activity which justify the folklore use of the leaves in traditional system to cure various ailments. The results suggest that the methanol leaves extract of C. papaya has significant analgesic activity.