Antimicrobial, antioxidant, anti-inflammatory activities and phytoconstituents of extracts from the roots of Dissotis thollonii Cogn. (Melastomataceae)

Abstract Background Dissotis thollonii Cogn. belonging to the Malastomataceae family is used in the West Region of Cameroon for the treatment of inflammation, kidney diseases, pregnancy control and sinusitis. Despite the traditional use of this plant, no scientific report or information was found in the literature regarding neither its biological activity nor its chemical constituents. Aim of the study The present work was designed to determine the antimicrobial, antioxidant and anti-inflammatory activities of different extracts of the roots of D. thollonii Cogn. as well as the isolation and identification of the chemical constituents of this plant. Materials and methods The tests for antimicrobial, antioxidant and anti-inflammatory activities were performed over the MeOH, EtOAc, n-BuOH and aqueous extracts. Compounds were isolated from EtOAc and n-BuOH extracts of the roots of D. thollonii Cogn. through column chromatography and their structures were determined by means of NMR and MS analysis, and published data. Results According to the antimicrobial and antioxidant assays, the EtOAc and n-BuOH extracts were submitted to further separation and purification. This led to the isolation of twelve compounds identified as 3,3′-di- O -methylellagic acid 4′- O-β -D-xylopyranoside 1 , 3- O -methylellagic acid 4′- O-β -D-arabinopyranoside 2 , casuarinin 3 , betulinic acid 4 , β -sitosterol-3- O -D-glucopyranosyl-6′-mirystate 5 , cellobiosylsterol 6 , β -sitosterol 7 , β -sitosterol-3- O-β -D-glucopyranoside 8, arjunolic acid 9 , 3,3′-di- O -methylellagic acid 10 , ellagic acid 11 , and 3,3′-di- O -methylellagic acid 4′- O - β -D-glucopyranoside 12 . The EtOAc extract was the only antimicrobial active sample [diameter of the zone of inhibition (DZI) of 10 mm against Staphyloccocus aureus ] among all the tested extracts. The analysis of fractions of this extract revealed the presence of bioactive compounds with a described antimicrobial activity such as β -sitosterol, β -sitosterol-3- O-β -D-glucopyranoside and arjunolic acid. By using Trolox as the standard drug, all extracts showed antioxidant activity against DPPH in the following order of scavenging ability: Trolox > nBuOH > EtOAc > MeOH > WE (water extract). The ABTS •+ scavenging ability was similar to that found for the DPPH assay, being Trolox > n-BuOH > MeOH > EtOAc > WE. Along with the DPPH and ABTS assays, the FRAP assay showed the scale n-BuOH > MeOH > WE > EtOAc. The phytochemical study of the EtOAc and n-BuOH extracts revealed the presence of important known antioxidant compounds such as ellagic acid derivatives, arjunolic acid, betulinic acid and β -sitosterol. The anti-inflammatory properties of D. thollonii extracts were investigated using RAW 264.7 murine macrophage cells. The MeOH extract reduced the stimulated NO production in a concentration-dependent manner. 86% reduction was observed at the highest tested concentration of 100 μg/ml (IC 50 = 5.9 μg/ml). The n-BuOH extract showed higher dose dependent reduction of NO formation (IC 50 = 6.5 μg/ml) than the EtOAc extract (IC 50 = 18.1 μg/ml), whereas the water extract had no significant influence on the NO production. All the extracts did not have any influence on the macrophage viability. The phytochemical investigation of the EtOAc and n-BuOH extracts revealed that the main compounds identified do have potent anti-inflammatory properties. Conclusion The biological and phytochemical characterization of the root extracts of D. thollonii validates the use of this plant for the treatment of inflammation and sinusitis, thus providing evidence that this plant extracts, as well as some of the isolated compounds, might be potential sources of antioxidant and anti-inflammatory drugs

Hairy garlic (Allium subhirsutum) from Sicily (Italy): LC-DAD-MSn analysis of secondary metabolites and in vitro biological properties

Allium subhirsutum, known as hairy garlic, is a bulbous plant widespread in the Mediterranean area and locally used as a food and spice. In the present study, the chemical profile of the ethanolic extracts from bulbs (BE) and aerial parts (APE) were analyzed by HPLC-ESI-MSn, and antioxidant properties were evaluated by DPPH, ABTS and TEAC assays. The traditional use in the diet, and the well documented biological activity of Allium species suggest a potential as a new nutraceutical. For this reason, the potential usefulness of this food can be considered in the treatment and prevention of degenerative Alzheimer disease. For this reason, acetylcholinesterase inhibitory property was investigated. Furthermore, due to the observed presence of sulfur-containing and phenolic constituents, the cytotoxicity on tumor cells line was investigated. Results revealed significant AChE inhibitory activity for BE and APE. Both extracts exhibited also moderate antioxidant properties in the in vitro assays. Finally, limited cytotoxic activity was observed towards Human colon carcinoma and adenocarcinoma cell line, with differences between the individual parts tested. HPLC-ESI-MSn analysis showed that hairy garlic is a good source of sulphur compounds, flavonoids and phenylpropanoids derivatives, thus being a valid alternative to the common garlic (A. sativum). This work opens new opportunities for the application of A. subhirsutum as a health-promoting food

DNA and BSA binding, anticancer and antimicrobial properties of Co(II), Co(II/III), Cu(II) and Ag(I) complexes of arylhydrazones of barbituric acid

Two new cocrystalline compounds, (Hen)(H2L2)$2/3H2O (2) and (Him)(H3L3)$2H2O (8), were prepared by the reaction of 5-(2-(4-chlorophenyl)hydrazono)pyrimidine-2,4,6(1H,3H,5H)-trione (H3L2) and the sodium salt of 2-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazinyl)benzenesulfonic acid (H4L3), [Na(H3L3)(m-H2O)(H2O)2]2 (1) with protonated ethylenediamine (Hen) and imidazole (Him), respectively. By using 5-(2-(2-hydroxyphenyl)hydrazono)pyrimidine-2,4,6(1H,3H,5H)-trione (H4L1) and 1, several known CuII, CoII, CoII/III and new AgI complexes, [Cu(H2L1)(H2O)(im)]$3H2O (3), [Co(H2O)6]- [Co(H2L1)2]2$8H2O (4), [Co(H2L3)(im)3] (5), [Cu(H2L3)(im)2]$H2O (6), [Ag(H2O)(m-H3L3)]n (7) and [Co(H2O)6]- [H3L3]2$8H2O (9), were also prepared in order to study their DNA and BSA binding, anticancer and antimicrobial properties. The complexes are able to interact with DNA and BSA with high binding constant values. In particular, complex 4 strongly intercalates DNA and binds BSA. The antimicrobial activity of all compounds, determined against a panel of reference bacterial and fungal strains, indicates that only 2 and 7 possess antimicrobial activity. The same compounds 2 and 7 show a pronounced antiproliferative activity against the human tumor cell lines A375, MDA-MB 231 and HCT116

Comparison of ACE activity in amphibian tissues: Rana esculenta and Xenopus laevis

Angiotensin converting enzyme (ACE) is the dipeptidyl-carboxypeptidase of the renin–angiotensin system involved in the control of blood pressure and hydromineral metabolism. It converts angiotensin I to angiotensin II, the biologically active octapeptide. Angiotensin converting enzyme-like activity has been demonstrated in a wide range of vertebrates. The presence of ACE was investigated in tissues of two amphibian species, the frog Rana esculenta and the toad Xenopus laevis. ACE activities were determined by specific substrate hydrolysis in gut, gonads, lung, kidney, heart, liver, skin, erythrocytes, and muscle homogenates and plasma by means of high performance liquid chromatography. Significant ACE activity was found in gut, gonads, lung and kidney, while that in heart, liver, skin, erythrocytes, muscle, and plasma was very low. Testis of toad contained the highest ACE activity, while that in erythrocytes of male and female frogs was notable

Effects of paraquat and glyphosate on steroidogenesis in gonads of the frog Rana esculenta in vitro.

Herbicides are toxic for amphibians, influencing various developmental stages. In particular, paraquat and glyphosate have teratogenic effects on tadpole development, though little information is available on how they affect reproduction in amphibians. In the present work, ovarian tissue and testis of the water frog Rana esculenta were incubated in vitro in presence of different concentrations of the two herbicides. 17-estradiol and testosterone levels were measured in the incubation medium by radioimmunoassay. The data showed that paraquat inhibited testosterone and 17-estradiol production, with the lowest observed effect concentration (LOEC) of 10-4 M, while paraquat inhibition of steroidogenesis in amphibian gonads was reversed by the presence of epigallocatechin gallate in the culture medium. These result indicates that paraquat acts on gonadal steridogenesis through a mechanism involving reactive oxygen species. Glyphosate showed no effect on gonadal steroidogenesis. These results suggest that paracqua may interfere in amphibian reproductive processes

The Nonvolatile and Volatile Metabolites of Prangos ferulacea and Their Biological Properties

Prangos ferulacea (L.) Lindl. (Fam. Apiaceae), an orophilous species of eastern Mediterranean and western Asia, possesses a number of biological properties that are worthy of exploitation in different fields. Phytochemical investigations revealed the presence of coumarins, prenyl-coumarins, and furano-coumarins as the main constituents of this species, as well as several flavonoids. Among prenyl-coumarins, osthol is a promising apoptotic agent quite selective toward cancer cells. In addition, the essential oils have been extensively investigated, and several chemotypes have been identified. This work reviews the literature on this species published between 1965 and 2018, describes its volatile and nonvolatile metabolites, and outlines its pharmacological effects

Inhibition of steroidogenesis in frog testis "in vitro" by synthetic seminal plasma peptide

Seminal plasma peptide (pGlu-Val-Ala-Asp-Ser-Asp-Gln-Asn), synthesized following data obtained from biochemical and mass spectrometry analysis of a highly purified fraction from bovine seminal plasma, was characterized at paracrine level as an “in vitro” modulator of testosterone production in rat Leydig cells. 10-8 M synthetic peptide exerted the highest testosterone inhibition in rat Leydig cells stimulated with 50 mU of LH. The basal testosterone production (without LH stimulation) was not influenced by synthetic seminal plasma peptide. In Rana esculenta, spermatogenesis is well characterized at morphological, endocrine and paracrine levels. Spermatogonial multiplication occurs in late winter-early spring, while spermatocytes (I and II) and spermatids are rare or totally absent. Progression of spermatogenesis lasts until autumn with spermatids and appearance of spermatozoa. After the winter stasis, in the germinal compartment of the testis, only spermatogonia and spermatozoa are observed, due to the degeneration of the other stages. The aim of our research was to study the influence of synthetic seminal plasma peptide in amphibian testicular steroidogenesis during the annual reproductive cycle of the male frog, Rana esculenta. Male frogs were captured at different times throughout the year and testes were removed, placed in DMEM in presence of 10 mM Hepes, 0.1 U/ml penicillin G and 0.1 mg/ml streptomycin and incubated for 6 h at 25 °C with increasing doses of synthetic peptide. Testosterone levels in the incubation medium were measured by radioimmunoassay. Preliminary results showed inhibition of testosterone production by frog testis with the highest value (42%) in summer at a peptide concentration of 10-6 M, suggesting the influence of synthetic seminal plasma peptide in spermatocyte differentiation

Is bradykinin involved in angiotensin converting enzyme modulation of ovarian steroidogenesis and prostaglandin production in amphibians?

Angiotensin converting enzyme (ACE) is a glycosilated integral membrane protein present on the luminal surface of the cell membrane and responsible for the conversion of angiotensin I to octapeptide angiotensin II, the biologically active product. Angiotensin II is involved in the regulation of blood pressure and in the hydromineral metabolism. The role of ACE in the mammary ovary is not clear and we used an amphibian model to study the influence of ACE on ovarian steroidogenesis and prostaglandin production. ACE was demonstrated to modulate the production of 17β-estradiol, progesterone and prostaglandin E2 in frog ovary of Rana esculenta. The activity was not mediated by Ang II. In an attempt to identify the peptide involved in the pathway modulated by ACE , another physiological substrate of ACE, bradykinin, was chosen. It was incubated in presence of the membrane suspension purified from homogenate of frog ovary. The hydrolytic products were analyzed by reverse-phase HPLC analysis, and the results show that bradykinin was metabolized by membrane suspension. The presence of the protease inhibitors in the incubation mixture showed that ACE and neutral endopeptidase were responsible for the bradykinin hydrolysis. Frog ovary was incubated "in vitro" in the presence of bradykinin (10 µM), bradykinin plus protease inhibitors (captopril and lisinopril, 0.1 mM) and the antagonist of bradykinin (NPC567, 1 mg/ml). Production of 17β-estradiol an prostaglandin E2 was determined by radioimmunoassay. The results showed no modulating activity by bradykinin on ovarian 17β-estradiol and prostaglandin E2 production, also in presence of protease inhibitors, thus excluding the bradykinin as mediator in the ACE-modulated pathway