ABSTRACT

The chemical constituents ofthe tubers ofIcacina trichantha were studied. The study revealed the presence of some active and useful phytochemicals of medicinal values such as flavonoids, alkaloids, saponins and phenols of which flavonoids were the most abundant. The proximate analysis showed carbohydrate as the most abundant (89.0%) indicating high energy level, followed by the moisture content (43.20%) and fat (kal) to be 41.12%. the crude fiber was the least giving 0.93%. Also, the nutritive content ofthe tuber was found to be sufficient enough for an almost a whole meal. The antioxidant assay indicated that the extracts showed significant DPPH, FRAP and NO scavenging effects which compared favourably with those of vitamin C used as standard. The observed effects was attributed to its phytochemical contents as well as dose dependency. Toxicity study at doses 10 mg/kg, 100 mg/kg, and 1000 mg/kg for the first phase showed no toxicity, also at 1600 mg/kg, 2900 mg/kg in the second phase even at and 5000 mg/kg showed no mortality. The tuber was extracted by percolation using methanol and chloroform as solvents and concentrated using rotary evaporator. The chloroform and the methanol crude were subjected to GC-MS and some bioactive components such as phorbol derivatives, hermatoporphyrin, molybdenum derivatives, lycoxanthin among others were identified which are antioxidants, antimicrobial, insecticidal, antitumor, antidepressant, antipsychotic, anthelminthic, antibacterial among others. The compounds were eluted from the column chromatography packed with silica gel and celite using solvent mixtures of hexane, ethyl acetate, chloroform and methanol. Using NMR spectroscopy (*H-NMR, 13C-NMR, COSY) and FT-IR, a steroidal compound (OAU 4) and two other compounds (OAU 2 and OAU 3) were isolated from the chloroform extract using extensive TLC which gave Rfvalues of0.51, 0.57 and 0.69 respectively. The antimicrobial activity on the crude and pure isolates using the agar well diffusion test showed inhibition against the two test organisms {streptococcus pnemoniae and klebsiella pnemoniae) using ciprofloxacin as standard. The MIC carried out indicated inhibition within 9.67±3.17b to 25.17±0.29d and 12.67±0.29b to 25.17±0.29c which showed effective inhibition for the test organisms while the MBC indicated total eradication at concentrations 12.17±0.68a,b to 35.20±13.12c and 16.67±7.22a,b to 33.33±14.43b for the test organisms. Antimycobactaerial activity using two strains (MDT-TB and H37RV) showed appreciable inhibition power as compared to the two controls (moxifloxacin and isoniazid) respectively proving its ability for the treatment oftuberculosis and related upper respiratory ailments. These results are indications that the tubers of I.trichantha may be used against tuberculosis. Although some ofthe plants used in ethno-medicine have no scientific basis to justify their use, I. trichantha tuber has proven otherwise. The need for extensive Fractionation, isolation ofmore active constituents for expanding and development ofTB drugs as well as more toxicity studies should be carried out on different fractions ofthis and other plant parts to ascertain more effective fractions are highly recommended.