Cattleianal and Cattleianone: Two New Meroterpenoids from Psidium cattleianum Leaves and Their Selective Antiproliferative Action against Human Carcinoma Cells.

The Myrteacae family is known as a rich source of phloroglucinols, a group of secondary metabolites with notable biological activities. Leaves of Psidium cattleianum were extracted with chloroform: methanol 8:2 to target the isolation of phloroglucinol derivatives. Isolated compounds were characterized using different spectroscopic methods: nuclear magnetic resonance (NMR), ultra-violet (UV) and mass spectrometry (MS). Two new phloroglucinols were evaluated for cytotoxicity against a panel of six human cancer cell lines, namely colorectal adenocarcinoma cells (HT-29 and HCT-116); hepatocellular carcinoma cells (HepG-2); laryngeal carcinoma (Hep-2); breast adenocarcinoma cells (MCF7 and MDA-MB231), in addition to normal human melanocytes HFB-4. Additionally, cell cycle analysis and annexin-V/FITC-staining were used to gain insights into the mechanism of action of the isolated compounds. The new phloroglucinol meroterpenoids, designated cattleianal and cattleianone, showed selective antiproliferative action against HT-29 cells with IC50's of 35.2 and 32.1 µM, respectively. Results obtained using cell cycle analysis and annexin-V/FITC-staining implicated both necrosis and apoptosis pathways in the selective cytotoxicity of cattleianal and cattleianone. Our findings suggest that both compounds are selective antiproliferative agents and support further mechanistic studies for phloroglucinol meroterpenoids as scaffolds for developing new selective chemotherapeutic agents.

UPLC/QTOF/MS profiling of two Psidium species and the in-vivo hepatoprotective activity of their nano-formulated liposomes.

Liver diseases are major health problem in Egypt influencing lifestyle and economy. The demand for nutraceutical hepatoprotective agents is crucial to ameliorate the side effects of synthetic drugs. The present study aims to evaluate antioxidant and hepatoprotective activities of extracts of Psidium guajava L. and Psidium cattleianum Sabine leaves and their nano-formulated liposomes against paracetamol-induced liver damage in rats. Secondary metabolites profile of P. guajava and P. cattleianum leaves was investigated using UPLC-PDA-ESI-qTOF-MSn. The nano-liposomes containing Psidium extracts were prepared using thin film hydration method. Biochemical analysis was based on monitoring serum levels of AST, ALT, ALP and total bilirubin. The liver homogenate was used for determination of GSH and MDA. Histopathological alterations were also studied. Metabolic profiling revealed qualitative differences between the two investigated species providing a comprehensive map for the metabolites present in P. guajava and P. cattleianum leaves cultivated in Egypt. The identified metabolites belong to different phytochemical classes; polyphenolics, flavonoids, triterpenes and meroterpenoids. Significant hepatoprotective effects were observed as evident from the decreased levels of AST, ALT, ALP, MDA and total bilirubin as well as restoration of decreased GSH level in the two studied Psidium extracts (250, 500mg/kg b. wt) and their respective nano-liposomes (500mg/kg b. wt), when compared to the diseased group. Nano-liposomes of Psidium guajava leaves (500mg/kg b. wt) greatly restored the normal architecture of the liver in the histopathological study, as regards to standard silymarin. The present study verified the effectiveness of Psidium guajava and Psidium cattleianum leaves extracts and their nano-liposomes in ameliorating the paracetamol-induced hepatotoxicity in rats.

Chemical composition and bioactivity of the volatile oil from leaves and stems of Eucalyptus cinerea.

CONTEXT: Eucalyptus cinerea F. Muell. ex Benth. (Myrtaceae) is a medium-sized tree cultivated in Egypt. OBJECTIVE: First, to determine the chemical composition of the volatile oil of the juvenile leaves and stems of E. cinerea to identify its chemotype. Second, to study the in vivo antioxidant activity and in vitro antimicrobial activity of the studied volatile oils against selected Gram-positive, Gram-negative bacteria, yeast, and mycelia fungi. MATERIALS AND METHODS: The volatile oil was prepared by hydrodistillation and then identified by GC/MS analysis. Broth microdilution and agar dilution methods were applied for determining the MIC. The antioxidant activity was studied by determination of glutathione level in blood of alloxan-induced diabetic rats. RESULTS: The yield of the volatile oil hydrodistilled from the juvenile leaves and stems of E. cinerea was 4.5 and 0.5%, respectively. 1,8-Cineole was the major identified oxygenated monoterpenoid (84.55% and 60.15% in the juvenile leaves and stems, respectively). The antibacterial activity of the oil of the juvenile leaves was more potent against all the tested organisms than that of the stems. The (MIC) of volatile oil of the juvenile leaves against Escherichia coli, Pseudomonas aeruginosa, Streptococcus faecalis, Candida albicans, and Aspergillus flavus were 5.2, 5.6, 4, 4.8, and 12.8 µg/ml, respectively. Also, the juvenile leaves' oil was more active as an antioxidant than that of the stems. They restored glutathione level by 33.7 ± 1.1 and 29.6 ± 0.7 mg/dl, respectively, compared with vitamin E (35.9 ± 1.2 mg/dl) which was used as a reference. DISCUSSION AND CONCLUSION: RESULTS suggest that the volatile oil is 1,8-cineole chemotype. Moreover, the oil of the juvenile leaves of E. cinerea might find usefulness as a therapeutic agent following further development.

Cytotoxic activity of acyl phloroglucinols isolated from the leaves of Eucalyptus cinerea F. Muell. ex Benth. cultivated in Egypt.

Two acyl phloroglucinol compounds namely; Sideroxylonal B (1) and Macrocarpal A (2) were isolated from the Sideroxylonal-Rich Extract (SRE) of the juvenile leaves of Eucalyptus cinerea; F. Muell. ex Benth cultivated in Egypt. Identification of the isolated compounds was established on the basis of physico-chemical properties and spectral analysis (1D & 2D NMR). The two compounds were isolated for the first time from this species. The SRE alongside with the isolated compounds were tested against three human cancer cell lines; MCF7 (breast carcinoma cell line), HEP2 (laryngeal carcinoma), CaCo (colonic adenocarcinoma) and one type of normal human cell line;10 FS (fibroblast cells). The SRE, (1), and (2) showed cytotoxic activity with IC50 13.6 ± 0.62, 7.2 ± 0.5, 14.8 ± 0.55 µg mL-1 against HEP2 respectively, 11.6 ± 0.47, 4 ± 0.36, 11.4 ± 0.45 µg mL-1 against CaCo, respectively, and 8.6 ± 0.29, 4.4 ± 0.25, and 7.8 ± 0.3 µg mL-1 against MCF7, respectively. Meanwhile, the (SRE) together with (1) and (2) exhibited low cytotoxicity against normal cell line 10 FS, with IC50 55.4 ± 1.4, 43 ± 0.8 and 50.1 ± 1.12 µg mL-1, respectively. The antiprofilerative activity of the tested compounds was evaluated. The cell cycle profile of cells treated with Sideroxylonal-B and Macrocarpal-A indicates possible S-phase specific effects.

Simultaneous determination of saponins and a flavonoid from aerial parts of Zygophyllum coccineum L.

Triterpenoid saponins are a class of glycosides with a wide range of bioactivities, which make them interesting research candidates. Zygophyllum coccineum is an Egyptian desert plant rich in triterpenoid saponins. Reviewing the relevant literature, no data concerning the HPLC or ultra-performance LC (UPLC) analysis of Zygophyllum content were found. This paper presents two methods, HPLC-UV and UPLC-UV-evaporative light scattering detector (ELSD)/MS, for the simultaneous determination of 10 compounds in the alcohol extract of Z. coccineum. The HPLC method uses a C18 column and water-acetonitrile (both containing 0.1% trifluoroacetic acid) gradient system. The separation was achieved within 32 min. The developed UPLC method simultaneously detects and quantifies the 10 compounds using an Acquity UPLC BEH Shield RP18 column and reagent alcohol-acetonitrile (80/20, v/v) and water (both containing 0.5% formic acid) gradient system within 14 min with UV, ELS, and MS detectors. The methods were used to analyze another species, Z. simplex, and results revealed a great variation between the secondary metabolite pattern of both species.

Triterpenoidal saponins: bioactive secondary metabolites from Zygophyllum coccineum.

Phytochemical investigation of the aerial parts of Zygophyllum coccineum L. led to the isolation of nine ursane-type triterpene saponins (1- 9), including the new one; zygophylloside S (1), together with a known flavonoid glycoside (10) and a sterol glycoside (11). The isolated compounds were tested for antifungal activity against several important plant pathogens and for insecticidal activity against two important mosquito species. Among the isolated compounds 1, 3, 5, 6, and 9 showed 32-77 % fungal growth inhibition at a concentration of 30 µM against Phomopsis viticola. Compound 9 showed 90 % and 80 % mosquitocidal activity at 3.1 µg/0.5 µL against Aedes aegypti and Culex quinquefasciatus, respectively.