Spasmogenic effect of a Solanummelongena leaf extract on guinea pig tracheal chains and its possible mechanism(s)

Chemical Composition Analysis, Antioxidant, and Antibacterial Activities of Eggplant Leaves

Agricultural by-products represent one of the biggest pollutants for the environment, therefore, investigating new sources for the extraction of bioactive compounds is a topic of great interest for the entire scientific community. This work is aimed at studying the chemical composition (pigments, phenolics, volatile compounds) and biological activities (antioxidant and antimicrobial properties) of young and mature leaves of five eggplant cultivars (Solanum melongena L.) grown in Tunisia (Tizona, A1014, Nawel, A336, and Mirval). Pigment analysis showed no statistical variations between the two types of leaves, whereas higher levels of anthocyanins were recorded in young leaves of three out of five cultivars (24.7-52.8 mg 100 g^-1 ). Total phenolic compounds (966.5-2072.6 mg 100 g^-1 ) and o-diphenols (343.9-741.2 mg 100 g^-1 ) contents varied significantly according to leaf age and cultivar. However, no statistically significant variation between young and mature leaves was found in flavonols and tannins content. As for volatile profiles, 62 constituents were characterized with non-terpene derivatives (52.0-61.6 %) and apocarotenes (19.9-35.6 %) as major chemical classes. Regarding the antioxidant activity, methanol extracts of Tizona cultivar mature leaves displayed important antiradical properties using DPPH, ABTS, and phosphomolybdenum assays (IC₅₀ 0.1, 0.2 and 0.01 mg mL^-1 , respectively). With regards to reducing power determination, the most active extract was obtained from mature A1014 leaves. Further, young Mirval leaves proved to be significantly active from a bactericidal point of view against Candida albicans and Staphylococcus aureus of 3.1 mg mL^-1 and 0.2 mg mL^-1 MBC, respectively. In conclusion, eggplant leaves are a noteworthy source of antioxidant and antimicrobial compounds with potential use in the pharmaceutical, the cosmetics and the food industries.

Phytochemical and biological studies of Solanum schimperianum Hochst

Chemical reinvestigation of the aerial parts of Solanum schimperianum Hochst led to the isolation of ten compounds, lupeol (1), β-sitosterol (2), β-sitosterol glucoside (3), oleanolic acid (4), teferidin (5), teferin (6), ferutinin (7), 5-hydroxy-3,7,4'-trimethoxyflavone (8), retusin (9) and kaempferol-3-O-β-d-glucopyranoside (10). Compounds 5-7 were isolated for the first time from Solanaceae and compounds 1-4 and 8-9 for the first time from Solanum schimperianum. The structure elucidation of the isolated compounds was based on careful inspection of spectral data including 1D ((1)H and (13)C NMR), 2D ((1)H-H COSY, HMQC and HMBC, ROESY), UV, MS and IR, in addition to, comparison with literatures. The antimicrobial activity of the extracts as well as the isolated compounds was tested. Only hexane extract showed activity against Bacillus subtilus and Staphylococcus aureus.

Toxicological evaluation of acute and sub-chronic ingestion of hydroalcoholic extract of Solanum cernuum Vell. in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Solanum cernuum Vellozo is a Brazilian shrub or small tree, restricted to Southwest states of the country. It has been widely used for the treatment of many ailments. The pharmacological activity of the extract on gastric ulcer has been the major therapeutic target proposed by the population investigated.

MATERIALS AND METHODS

In the acute toxicity test was used increasing doses of the extract (2, 4, 8, 12, 16, 20 and 25 g of extract per kilogram of body weight). The animal behavior was observed from 5h after a single administration of the extract and subsequently monitored daily until the fourteenth day, beyond the calculation of the estimated LD50 of the extract. In the test sub-chronic toxicity was used two doses of the extract (0.1 and 1.4 g/kg) and the parameters analyzed over 31 days were: body weight, food intake, behavior, respiratory rate, movement and mortality of animals. After anesthesia, blood samples were collected for hematological and biochemical analysis. The animals were euthanized followed by macroscopic analysis of the stomach and intestine. Liver, lungs and kidneys were removed, weighed and analyzed histopathologically.

RESULTS

In the acute toxicity test was observed a dose-dependent mortality and the value of estimated LD50 was 14.50 g/kg. In the hematological and biochemical analyses there were significant increase in the activities of AST and ALT indicating liver toxicity, but the extract was not able to alter food intake, body weight and organ weights after 31 days of treatment and it did not produce significant histopathological changes.

CONCLUSION

Therefore we can consider the hydroalcoholic extract of Solanum cernuum Vell as practically non-toxic in acute administration and safe in the sub-chronic administration, as hepatotoxicity was observed only with the highest dose used, not with the dose routinely used by the native population.

Spasmolytic effect of constituents from Lepechinia caulescens on rat uterus

Lepechinia caulescens Ortega Epling (Lamiaceae) is a perennial herb used in Mexican folk medicine to treat diabetes, hypertension, gastrointestinal infections, dysmenorrhea and as abortifacient. In this study, a bioassay-guided fractionation of the hexanes extract of the leaves, evaluating the capacity to relax contraction of rat uterus rings induced by KCl (60mM), was made. The results indicated that, from the four isolated terpenes, spathulenol (1) was the most potent spasmolytic agent, followed by methyl 9alpha,13alpha-epidioxyabiet-8(14)-en-18-oate (2), 9alpha-hydroxydehydroabietyl alcohol (4) and dehydroabietic acid (3) studied at 10 and 30 microg/mL. The spasmolytic activity of 1 was totally reverted by addition of increasing extracellular Ca2+ concentrations ([Ca2+]o), while incubation of uterus rings with 1 in calcium free solutions reduced the contraction produced by [Ca2+]o in a concentration-dependent manner. Moreover, the presence of L-NAME (100 microM) or propranolol (10 microM) did not block the spasmolytic effect. These results suggest that 1 induces a greater blocking action on voltage-operated calcium channels. EtOAc and MeOH extracts of the leaves, which showed slight relaxing activity, led to 4 and rosmarinic acid (5).