ABSTRACT
The anticholinesterase and acaricidal activities of two plants of family Aizoaceae; Trianthema portulacastrum L.and Aizoon canariensis L. against Rhipicephalus annulatus tick were performed. Acaricidal activity was evaluatedusing adult and larval immersion tests of different concentrations (12.5, 25, 50, 100, and 150 mg/ml). Antiacetylcholinesterase activity of plant extracts and isolated compounds were performed spectrophotometrically usingdifferent concentrations (0.25, 0.5, and 1 mg/ml). Trianthema portulacastrum crude hydroalcoholic (CH) extractshowed 100% adult and larval mortality, while A. canariensis L. showed only 20% and 25%, respectively (p ≥ 0.05).The bioassay-guided fractionation of T. portulacastrum hydroalcoholic extract was performed for the acaricidalactivity and both n-hexane fraction and the unsaponifiable matter (USM) retained a significant activity in immersiontests. Its column chromatography (CC) led to the isolation of a β-sitosterol (1)-stigmasterol (2) mixture (1:1). Ethylacetate (EA) fraction showed 70% adult mortality and the compound 20-hydroxyecdysone (3) was isolated as a majorcompound. The hydroalcoholic extract of T. portulacastrum, hexane fraction, and 20-hydroxyecdysone (3) producedthe most potent inhibitory effect on acetylcholinesterase (AChE). In conclusion, T. portulacastrum L. containssecondary metabolites with acaricidal activities that provide promising natural products for controlling bovine tick.These acaricidal effects may be mediated, at least in part, via AChE inhibitory activities.
ABSTRACT
Calligonum polygonoides L. subsp. comosum; locally known as “arta”, is tall woody shrub, perennial desert plant. TLC screening, estrogenic and antimicrobial activities of different fractions of hydroalcoholic extract of the leaves; n-hexane, CH2Cl2, EtOAc and n-BuOH, were studied in order to find the correlation between the phytoconstituents and the biological activity. Estrogenic activity was studied in immature ovariectomized female Wistar rats by oral administration of 75 and 150 mg extract/kg body weight for seven days using 1 μg estradiol/rat/day as positive control. The antimicrobial activity against Aspergillus fumigatus, Candida albicans, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumonia was carried out using agar diffusion method with determination of the minimum inhibitory concentration (MIC). The CH2Cl2 fraction showed significant estrogenic and antimicrobial activity by significantly increasing uterine weight and low MIC values for all tested microorganisms ranging from 0.03 and 3.9 mg/mL. The n-hexane fraction showed mainly the presence of sterols and/or triterpenoids. The EtOAc and n-BuOH fractions were the richest in flavonoids while that of methylene chloride was found to contain both classes of chemical compounds. In conclusion; flavonoids, sterols and/or triterpenes exhibit synergistic effect to the antimicrobial and estrogenic activity of Calligonum polygonoides leaves. Abbreviations: CH2Cl2: methylene chloride, EtOAc: ethyl acetate, n-BuOH: normal butanol, MIC: minimum inhibitory concentration, TLC: thin layer chromatography, b. wt. body weight, p. o.: oral administration, HE: n-hexane extracts of leaves, ME: methylene chloride extract of leaves, EE: ethyl acetate extract of leaves, BE: n-butanol extract of leaves, RCMB: Regional Center for Mycology and Biotechnology, NA: No activity.