Objective: The aim of the study was evaluate the tannin content, antioxidant activity and the lethality of unripe fruits extract of Solanum viarum Dunal (Solanaceae) against brine shrimps. Methods: The tested samples for tannins content were water, ethanol:water (1:3) and acetone:water (1:3) extract. The unripe fruits powder of S. viarum was used to extraction in a Soxhlet apparatus for 2 hr. Cytotoxicity was screened using Brine Shrimp Lethality Test and aqueous extract. Results: The results demonstrated that the yield of tannins for the acetone:water extraction was substantially higher than that typical yields obtained by ethanol:water or water extraction [31.10% for Total Solids (%), 14.99% for Stiasny’s Index (%), 3.99% for Condensed Tannins in the Extract (%) and 1.09% for Condensed Tannins in the Unripe Fruits (%). The antioxidant activity was 61.12±12.42 % compared to ascorbic acid (100%) and polyphenol concentration was 39.33±4.45 mg of tannic acid/g of extract obtained from the tannic acid calibration curve y = 0.0128x - 0.0015 (R2 = 0.9988). Flavonoid concentration was 89.36 ± 11.6 mg of quercetin/g of extract obtained by quercetin calibration curve y=0.0153x+0.0109, R2=0.9827. The results demonstrated that the positive control (potassium dichromate) hatching success was significantly higher than the S. viarum extract (P<0.05). LC50 was 66.01 μg/ml for the water extract of unripe fruit of S. viarum and in accord to Clarkson’s toxicity criterion, LC50< 100 μg/mL are considered highly toxic for aqueous extract. Conclusion: The unripe fruit extract of S. viarum demonstrated low percentage in phenolic content, but significant antioxidant activity and phenolic and flavonoid concentrations. S. viarum unripe fruits extract is toxic to Artemia salina.
Key words: Solanum viarum, Toxicity, Antioxidant, Flavonoid, Phenolic, LC50, Artemia salina.