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.

The toxicity of extracts of lavender (Lavandula officinalis) leaves and flowers was evaluated. Aqueous ethanolic and acetone extracts had higher tannin content than that in the aqueous solution. Polyphenol and flavonoid contents were measured in aqueous extracts of leaves and flowers. Polyphenol concentration in aqueous leaf and flower extracts was 61.31 and 84.43 mg tannic acid/g, respectively, whereas flavonoid concentration was 194.1 and 109.9 mg quercetin/g, respectively. Saponins content were 7.85 and 6.22% in leaves and flowers extract, respectively, and alkaloids content were 0.2651 and 0.2132% for leaves and flowers extract, respectively. The EC₅₀ (36 h) of hatching success of A. salina cysts was 0.301 and 0.915 mg/mL for aqueous extracts of leaves and flowers, respectively, whereas that for aqueous ethanolic extracts of leaves and flowers it was 0.111 and 0.586 mg/mL, respectively. The EC₅₀ (36 h) was 0.011 mg/mL for tannic acid. Additionally, the LC₅₀ (24 h) for aqueous extracts of leaves and flowers was 0.467 and 0.724 mg/mL, respectively, whereas that of the aqueous ethanolic extracts of leaves and flowers was 0.074 and 0.126 mg/mL, respectively. The LC₅₀ was 0.015 mg/mL for tannic acid. Although aromatherapy using lavender oils or extracts is beneficial to human health, particularly owing to its anxiolytic, analgesic, and antihyperlipidemic effects, we demonstrated that these extracts might exhibit toxicity. Hence, lavender should be used carefully by health practitioners, and lavender therapies should be closely monitored by medical staff to avoid its toxic effects.

The rapid iterative negative geotaxis (RING) assay is a commonly used behavioral test in Drosophila based on digital imaging of flies and requires minimal equipment and space. Larval mobility can be used to reliably determine the effect of drugs on locomotion in Drosophila larvae. The effects of Valeriana officinalis extract (VoE) and melatonin (ME) were tested in Drosophila melanogaster flies and larvae. In the RING assay, the locomotor activity of flies was reduced to 30.6, 72 and 70.4% when exposed to 10 mg/ml VoE, 8 mM ME, and a combination of 8 mM ME + 10 mg/ml VoE, respectively. The performance index (PI) was reduced to 68.9% (P = 0.0058), 33.3% (P = 0.0001), and 70% (P = 0.0013) when flies were exposed to 8 mM ME, 10 mg/ml VoE, and a combination of 8 mM ME + 10 mg/ml VoE, respectively. The number of body wall contractions of Drosophila larvae (nBWC) was reduced to 47.8, 37.7 and 38.5% when larvae were exposed to 8 mM ME, 10 mg/ml VoE, and a combination of 8 mM ME + 10 mg/ml VoE, respectively. The displacement velocity (V0) of larvae decreased significantly to 67.6, 60.1 and 55.6% when larvae were exposed to 8 mM ME, 10 mg/ml VoE, and a combination of 10 mg/ml VoE + 8 mM ME, respectively (P < 0.05). The effects of the VoE extract were not synergistic with ME as demonstrated by the RING assay, nBWC, and V0. Based on these results, valerian root extracts have demonstrated sedative effects that are better than those of melatonin in fruit flies, but did not show any increase in sedative effect when combined with melatonin. Key words: Valeriana officinalis roots, Melatonin, Drosophila melanogaster, negative geotaxis, sedative effect, antioxidant.