ABSTRACT

The proximate composition; nutritional potential; bioactive phytochemical components; antioxidant capacity; antimicrobial properties and toxic potential of different parts of grape plant Cissus multistnata were investigated using chemical, biochemical and toxicological methods, and water .methanol ,and chloroform as the extraction solvents. Phytochemical screening and proximate analysis revealed the presence of carbohydrate, protein, vitamins , fats , tannins and flavonoids at mean concentrations of 0.71+0.08 to 1.2+0.06%, 18.77+0.05 to 21.30+0.60%,27.53+1.10 to 32.6311.95%,18.00+1.73 to 34.3310.58%,0.24+0.00 to 0.34+0.01%, 0.35+0.01 to 6.2010.56%, respectively. Saponins, steroids, cardiac glycosides, minerals as well as g'yeonutrients such as xylose, galactose, fucose, mannose and glucose were also detected. Assessment of the nutritional potential of the plant leaf by administering doses of 100, 200, 300, 400. 500 and 600 mg/kg body weight to albino rats for 21 days resulted in statistically significant (P<0.05) increase in body weight .The lipoprotein profiles decreased with increase in the dosage> of the extract, except for high-density lipoprotein -cholesterol (HDL-cholesterol) which increased with increasing dosage of the extract. The protein profiles and glucose level were also increased when compared with the control. Determination of the phenols and the polyphenolic contents of the extracts showed varied concentrations of these compounds. 0.3810.01 to 0.564+0.00%, 0.2410.00 to 0.3810.013%, 0.3510.01 to 6.200 10.557% and 0.0510.01 to 0.8910.02 for phenols, tannins, flavonoids and anthocyanins respectively. The determination of the antioxidant capacity of the methanol extract using 2,2-diphenyl-l-picrylhydrazyl (DPPH) as well as nitric oxide radical scavenging activities and activities of antioxidant enzymes (Glutathione peroxidase and ^peroxide dtsmutase) showed the unripe fruit as exhibiting the highest DPPH scavenging effect with IC^o O.fe^nR/ml in comparison with the standard quercetin used (lCso= 166.50 pg/ml) .The anti lipid per oxidative properties and nitric oxide radical scavenging activities of the plant extracts were also positive . In addition, the unripe fruit showed the highest nitric oxide radical scavenging activity (ICso =0.77pg/ml) when vitamin C was used as the standard. Administration of the plant extract together with carbon tetrachloride toxicant resulted in an increase in activities of the antioxidant enzymes glutathione peroxidase and superoxide dismutase from 113.56 ±11.840 to 588.84+47.59 (U/L) and 18+16.97 to 88+16.97 (U/ml), respectively. Antimicrobial growth activity of each of the methanol, chloroform and aqueous leaf extract on eight clinical bacterial and two fungal isolates as determined by the tube dilution and agar ditch diffusion methods, showed that the minimum inhibitory concentration (MIC) of both methanol and chloroform extracts ranged between 25mg/ml and lOOmg/ml, depending on the clinical isolate and the extracting solvent. The chloroform extract showed the greater antibacterial activity while methanol extract exhibited a higher antifungal activity. Toxicity evaluation of the plant extracts was also investigated using different animal models. Cytotoxicity to brine shrimps (Artemia salina ) of the aqueous and chloroform extracts of the leaf, stem, ripe and unripe fruit caused low toxic effect on brine shrimps(Artem/o salina) and in rats as indicated in the standard assays, liver and kidney function test, LDSO measurement and hematological profiles. Study on the membrane stabilizing capacity of the plant extract also showed that methanol extracts exhibited minimum and maximum percentage of membrane stability of 43.43+0.69 and 66.52±0.99% on human erythrocyte. The highest membrane stabilizing activity was observed in the unripe fruit extract with percentage stability of 66.52±0.995. The human erythrocyte membrane stabilizing activity of the methanol extract was found to be comparable to the standard anti-inflammatory drug (Indomethacin) and most effective using the unripe fruit extract. The results suggest that C/ssus multistriota is a valuable source of antimicrobial agents and potentially rich source of important bioactive compounds. The study also indicates that Cissus multistr/ata can be a safe dietary source of natural antioxidant and nutrients. These results are discussed from the nutritional and toxicological view points