GC/MS profiling of essential oils from Bontia daphnoides L., chemometric discrimination, isolation of dehydroepingaione and evaluation of antiviral activity.

Bontia daphnoides L. has been utilized in traditional medicine for treatment of herpes, cough and colds. The aim of this study was to analyze the volatile constituents of this plant by GC/MS (Gas Chromatography coupled to Mass Spectrometry) and to assess their antiviral activity. A total of 64 compounds were identified where dehydroepingaione represented 83.60, 72.36, 58.78 and 34.18% in the leaves, stems, flowers and fruits, respectively. Principal component and hierarchical cluster analysis revealed the discrimination of the organs as the leaves and stems were distributed in the same cluster in contrast to the flowers and fruits. Furthermore, the antiviral activity was assessed where the oils of leaves and stems exhibited potent antiviral activity displaying IC50 of 11.98, 12.62 µg/ml against HSV-1 and 13.34, 14.50 µg/ml against CoxB4, respectively. Dehydroepingaione was isolated from the n-hexane fraction of the leaves and showed activity against HSV-1 and CoxB with IC50 of 24.46 and 25.32 µg/ml, respectively. Molecular modelling studies illustrated that the major compounds showed good affinity towards HSV type-1 thymidine kinase. Therefore, it can be concluded that the oils from B. daphnoides have promising antiviral activity that may be attributed to the major oxygenated sesquiterpenes.

Essential oils from the leaves and flowers of Leucophyllum frutescens (Scrophulariaceae): phytochemical analysis and inhibitory effects against elastase and collagenase in vitro.

Leucophyllum frutescens (Scrophulariaceae) is a medicinal plant of Mexican traditional medicine. The aim of this study was to analyse the volatile components from the leaves and flowers by GC/MS and to assess their anti-aging activity for the first time. A total of 30 compounds were identified where 1-octen-3-ol (73.56%) and D-limonene (11.12%) represented the major ingredients in the leaves, while n-heneicosane (32.30%) and dehydroepingaione (15.15%) were the major components in the flowers. In vitro anti-aging activity was measured via assessing collagenase and elastase inhibition. Essential oils from the leaves and flowers showed potential collagenase inhibitory activity with IC50 of 55.7 and 47.4 µg/mL. However, the oils from the leaves and flowers showed moderate anti-elastase activity with IC50 of 60.8 and 97.7 µg/mL. Therefore, the oil of Leucophyllum frutescens could afford a promising natural anti-aging drug.

GC-MS and GC-FID analyses of the volatile constituents of Brachychiton rupestris and Brachychiton discolor, their biological activities and their differentiation using multivariate data analysis.

The volatile constituents of the leaves and flowers of Brachychiton rupestris and Brachychiton discolor (Malvaceae) were characterized by GC-FID and GC-MS. A total of 92 compounds were identified. The major component of B. rupestris leaves was α-farnesene (34.57%) while in the flowers it was n-heptacosane (29.5%). (8Z, 11Z, 14Z)-heptadecatrienal (21.2%) in the leaves and palmitic acid (83.49%) in the flowers represent the abundant ingredients of B. discolor. Unsupervised pattern recognition techniques of multivariate data analysis exemplified by hierarchical cluster analysis (HCA) and principle component analysis (PCA) relying upon chromatographic results effectively discriminate the two related species. Also, both investigated species were assessed for their cytotoxic and antimicrobial efficacy. Results revealed that B. discolor flowers showed the highest cytotoxicity against human lung carcinoma (A-549) cell lines with IC50 equals 7.98 µg/mL, whereas B. discolor leaves exhibited the highest antimicrobial potency against all tested microorganisms namely Streptococcus pneumonia, Bacillus subtilis, Escherichia coli as well as Aspergillus fumigatus and Geotrichum candidum (MICs between 0.98 and 15.63 µg/mL) except for Salmonella typhi.

Study of the anti-allergic and anti-inflammatory activity of Brachychiton rupestris and Brachychiton discolor leaves (Malvaceae) using in vitro models.

BACKGROUND: Brachychiton rupestris and Brachychiton discolor (Malvaceae) are ornamental trees native to Australia. Some members of Brachychiton and its highly related genus, Sterculia, are employed in traditional medicine for itching, dermatitis and other skin diseases. However, scientific studies on these two genera are scarce. Aiming to reveal the scientific basis of the folk medicinal use of these plants, the cytotoxicity, anti-inflammatory and anti-allergic activities of Brachychiton rupestris and Brachychiton discolor leaves extracts and fractions were evaluated. Also, phytochemical investigation of B. rupestris was performed to identify the compounds exerting the biological effect. METHODS: Extracts as well as fractions of Brachychiton rupestris and Brachychiton discolor were tested for their cytotoxicity versus hepatoma HepG2, lung A549, and breast MDA-MB-231 cancer cell lines. Assessment of the anti-allergic activity was done using degranulation assay in RBL-2H3 mast cells. Anti-inflammatory effect was tested by measuring the suppression of superoxide anion production as well as elastase release in fMLF/CB-induced human neutrophils. Phytochemical investigation of the n-hexane, dichloromethane and ethyl acetate fractions of B. rupestris was done using different chromatographic and spectroscopic techniques. RESULTS: The tested samples showed no cytotoxicity towards the tested cell lines. The nonpolar fractions of both B. rupestris and B. discolor showed potent anti-allergic potency by inhibiting the release of ß-hexosaminidase. The dichloromethane fraction of both species exhibited the highest anti-inflammatory activity by suppressing superoxide anion generation and elastase release with IC50 values of 2.99 and 1.98 µg/mL, respectively for B. rupestris, and 0.78 and 1.57 µg/mL, respectively for B. discolor. Phytochemical investigation of various fractions of B. rupestris resulted in the isolation of ß-amyrin acetate (1), ß-sitosterol (2) and stigmasterol (3) from the n-hexane fraction. Scopoletin (4) and ß-sitosterol-3-O-ß-D-glucoside (5) were obtained from the dichloromethane fraction. Dihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucoside (6) and dihydrodehydrodiconiferyl alcohol 9-O-ß-D-glucoside (7) were separated from the ethyl acetate fraction. Scopoletin (4) showed anti-allergic and anti-inflammatory activity. CONCLUSIONS: It was concluded that the nonpolar fractions of both Brachychiton species exhibited anti-allergic and anti-inflammatory activities.

Validation of the antihyperglycaemic and hepatoprotective activity of the flavonoid rich fraction of Brachychiton rupestris using in vivo experimental models and molecular modelling.

Oxidative stress leads to many disorders as diabetes mellitus and liver diseases. This study evaluates the antihyperglycemic and hepatoprotective activities of Brachychiton rupestris (Malvaceae). The antihyperglycemic activity of the total methanol extract of B. rupestris leaves (BRT) and its ethyl acetate fraction (BRE) was evaluated using streptozotocin induced diabetic rats. The hepatoprotective activity was assessed using carbon-tetrachloride induced hepatotoxicity. Oral administration of 50 mg/kg b.wt (body weight) of BRT and BRE to Streptozotocin -diabetic rats caused a notable decrease in serum glucose by 39.38 and 42.09% with 35.62 and 15.44% increase in serum insulin, respectively, compared with Streptozotocin-diabetic rats. Oral administration of BRT and BRE to carbon-tetrachloride -treated rats (50 mg/kg b.wt) resulted in reduction in serum aspartate transaminase (AST) (28.88 and 27.2%, respectively) and alanine transaminase (ALT) (8 and 13.56%) levels, respectively. They also ameliorated oxidative stress in both models as evidenced from oxidative stress markers. Liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) analysis of the most active fraction (BRE) identified nine compounds including flavonoids and phenolic acids. Molecular modelling of the identified compounds was performed on human pancreatic α-amylase (HPA) and human α-glucosidase (HAG) using Discovery Studio 2.5. Quercetin-3-O-(6″-O-α-l-rhamnopyranosyl)-ß-D-glucoside showed the greatest affinity towards both HPA and HAG. Thus, this study provided scientific evidence on the antihyperglycemic and hepatoprotective activities of Brachychiton rupestris.

Sterculia and Brachychiton: a comprehensive overview on their ethnopharmacology, biological activities, phytochemistry and the role of their gummy exudates in drug delivery.

OBJECTIVES: Sterculia and Brachychiton are two related genera (Malvaceae) containing more than 300 species. Most of these species are ornamental trees that are native to Australia and widely cultivated in many countries. Different members of the two genera were used by various cultures for medicinal and economical purposes. This review sheds light on the medicinal values and chemical composition of various species of these two genera. KEY FINDINGS: Sterculia and Brachychiton species were used traditionally for the treatment of gastrointestinal disorders, microbial infection, skin diseases, inflammation and many other conditions. The seeds of various species were roasted and eaten by many traditional tribes. Plants from the two genera revealed their anti-inflammatory, antioxidant, antimicrobial, antidiabetic, antiulcer, insecticidal and analgesic activity. These activities may be attributed to the presence of a wide range of secondary metabolites as flavonoids, phenolic acids, coumarins, terpenoids particularly sesquiterpenes and triterpenes in addition to sterols and fatty acids. Moreover, the gummy exudates obtained from some members of these genera played an important role in different pharmaceutical dosage forms and drug-delivery systems. CONCLUSIONS: More research is recommended on other species of Sterculia and Brachychiton to discover new molecular entities with potential biological and economic values.