Chemical Profiles and Cytotoxic Activities of Essential Oils from Six Species of Baccharis Subgenus Coridifoliae (Asteraceae).

Several Baccharis species are popularly known in traditional medicine as "carquejas", "vassouras", "ervas-santas" and "mio-mios", and are used as anti-inflammatories, digestives, and diuretics. This study aimed to investigate the chemical compositions and cytotoxic activities of essential oils (EOs) of six Baccharis species belonging to subgenus Coridifoliae, namely B. albilanosa, B. coridifolia, B. erigeroides, B. napaea, B. ochracea, and B. pluricapitulata. GC/MS analyses of the EOs showed that the oxygenated sesquiterpenes spathulenol (7.32-38.22 %) and caryophyllene oxide (10.83-16.75 %) were the major components for all the species. The EOs of almost all species were cytotoxic against cancer (BT-549, KB, SK-MEL and SK-OV-3) and normal kidney (VERO and LLC-PK1) cell lines, whereas B. erigeroides EO showed cytotoxicity only against LLC-PK1. This article augments the current knowledge about the chemical-biological properties of Baccharis subgenus Coridifoliae and discusses the therapeutic potentials of these economically unexploited plants.

Pharmacological Evaluation of Secondary Metabolites and Their Simultaneous Determination in the Arabian Medicinal Plant Plicosepalus curviflorus Using HPTLC Validated Method.

Plicosepalus is an important genus of the Loranthaceae family, and it is a semiparasitic plant grown in Saudi Arabia, traditionally used as a cure for diabetes and cancer in human and for increasing lactation in cattle. A flavonoid quercetin (P1), (-)-catechin (P2), and a flavane gallate 2S,3R-3,3',4',5,7-pentahydroxyflavane-5-O-gallate (P3) were isolated from the methanol extract of the aerial parts of P. curviflorus (PCME). The PCME and the isolated compounds were subjected to pharmacological assays to estimate peroxisome proliferator-activated receptors PPARα and PPARγ agonistic, anti-inflammatory, cytotoxic, and antimicrobial activities. Results proved for the first time the dual PPAR activation effect of the PCME and catechin (P2), in addition to the promising anti-inflammatory activity of the flavonoid quercetin (P1). Interestingly, both PCME and isolated compounds showed potent antioxidant activities while no antimicrobial effect against certain microbial strains had been reported from the extract and the isolated compounds. Based on the pharmacological importance of these compounds, an HPTLC validated method was developed for the simultaneous estimation of these compounds in PCME. It was found to furnish a compact and sharp band of compounds P1, P2, and P3 at R f = 0.34, 0.47, and 0.65, respectively, using dichloromethane, methanol, and formic acid (90 : 9.5 : 0.5, (v/v/v)) as the mobile phase. Compounds P1, P2, and P3 were found to be 11.06, 10.9, 6.96 µg/mg, respectively, in PCME. The proposed HPTLC method offers a sensitive, precise, and specific analytical tool for the quantification of quercetin, catechin, and flavane gallates in P. curviflorus.

Biological Evaluation of Different Extracts of Aerial Parts of Nepeta deflersiana and Standardization of Active Extracts Using 8-Epi-7-Deoxyloganic Acid and Ursolic Acid by Validated HPTLC Method.

Nepeta deflersiana (Lamiaceae) is a well-known medicinal plant that grows in Saudi Arabia. This plant is used in Saudi and Yemeni folk medicine as an anti-inflammatory, carminative, and antirheumatic agent. In order to prove its use in folk medicine, four different extracts from the aerial parts of the plant: petroleum ether, chloroform, ethyl acetate, and n-butanol extracts were subjected to biological assays to screen PPARα and PPAR ϒ agnostic, antioxidant, anti-inflammatory, and cytotoxic activities. Ethyl acetate and n-butanol extracts of N. deflersiana NDEE and NDBE, respectively, showed a decrease in oxidative stress and inhibition of both NF-kB and iNOS activities with no cytotoxic effects on four human cancer cell lines. Both active extracts were standardized using two bioactive metabolites which were isolated from the aerial parts of the same plant [8-epi-7-deoxyloganic acid (compound 1) and Ursolic acid (compound 2)] by developing a validated HPTLC method. It was found to provide a sharp and compact band of compound 1 at Rf = 0.07 and Rf = 0.57 for compound 2, using chloroform, methanol, and formic acid (8.9:0.8:0.3, v/v/v) as mobile phase at 550 nm. Compounds 1 and 2 were found in NDEE by 9.59 %, w/w, and 84.63 %, w/w, respectively, and by 11.97 %, w/w, and 21.26 %, w/w, respectively, in NDBE.

Bioactivity and chemical characterization of Acalypha fruticosa Forssk. growing in Saudi Arabia.

Acalypha is an important genus of the Euphorbiaceae family. The genus is represented by five species in Saudi Arabia. Acalypha fruticosa Forssk. Fl. Aeg is traditionally used as a cure for stomachache, dyspepsia, rheumatism, dermatitis, and swellings of the body. The present study endeavors to provide a phytochemical and biological evaluation of the plant, with the aim of relating activity to constituting secondary metabolites in the plant. Column chromatographic separation of the methanol extract led to the isolation of four compounds namely 2-methyl-5,7-dihydroxychromone 5-O-ß-d-glucopyranoside 1, acalyphin 2, apigenin 3 and kaempferol 3-O-rutinoside 4. The plant extracts and the isolated compounds were subjected to biological assays to screen peroxisome proliferator-activated receptor alpha (PPARα) and PPARγ agonistic, anti-inflammatory and cytotoxic activities. Results proved for the first time, the PPARγ activator effect of acalyphin, as well as its promising anti-inflammatory activity, in addition to the dual PPAR activator effect of the chromone glucoside. The plant extracts and isolated compounds were non-cytotoxic to the tested cell lines. Thus A. fruticosa could be a valuable source of important therapeutics that may hold clinical prospect.

New ellagic acid derivative from the fruits of heat-tolerant plant Conocarpus lancifolius Engl. and their anti-inflammatory, cytotoxic, PPAR agonistic activities.

Conocarpus lancifolius (Combretaceae), is distributed in Riyadh, Saudi Arabia. It is a heat-tolerant Saudi medicinal plant, demonstrates prominent antidiabetic potential and the fruit extract fruits showed cytotoxicity against MRC-5 cancer cell line, as well as prominent antiprotozoal and antibacterial activities. The objective of this study is to isolate the compounds and evaluate the anti-inflammatory, cytotoxic, PPAR agonistic and antioxidant activities of extracts and pure constituents from C. lancifolius. A new trimethoxyellagic acid derivative 1 and two compounds, kaempferol 3-O-rutinoside 2 and ß-sitosterol glucoside 3 were isolated from the fruits of Conocarpus lancifolius, a heat-tolerant plant. Compound 2 showed strong dual activation for PPARα and PPARγ with 2.6 fold increment in PPARα activity, while 2.2 fold increment in PPARγ at 25µ/ml. This is first report on isolation and screening of different biological activities of extract and pure constituents from fruits of C. lancifolius.

Microbial metabolism. Part 14. Isolation and bioactivity evaluation of microbial metabolites of resveratrol.

The fungi, Beauveria bassiana (ATCC 13144) and Penicillium chrysogenium (ATCC 9480) transformed resveratrol to resveratrol-3-O-sulphate. The former, in addition, gave 5-methoxyresveratrol-3-O-ß-glucoside with the latter yielding 5-methoxyresveratrol-3-O-sulphate. The structures were established by spectroscopic methods. Evaluation of biological activity of metabolites through a series of mammalian cell based assays indicated that resveratrol tends to lose its anti-inflammatory, cytotoxic and anti-oxidant activities with the substitution of its hydroxyl groups.

Transport of harman alkaloids across Caco-2 cell monolayers.

This study examined the intestinal transport of five harman alkaloids using the Caco-2 cell monolayer as a model of the human intestinal mucosa. Transport parameters, permeability coefficients and percent transports, were calculated and compared under identical conditions with atenolol. Permeability coefficients were also compared with the reported values for model compounds like mannitol, propranolol and glucose. Sodium fluorescein was used as the marker for paracellular leakage. These alkaloids, in the concentration range of 250-500 microM, demonstrated substantial transport across the monolayer with moderate to high efflux rates and permeability coefficients. The transport was linear with time and was concentration dependent.

Identification and biological activity of microbial metabolites of xanthohumol.

Microbial transformation of xanthohumol using the culture broth of Cunninghamella echinulata NRRL 3655 afforded (2S)-8-[4"-hydroxy-3"-methyl-(2"-Z)-butenyl]-4',7-dihydroxy-5-methoxyflavanone (5) and (2S)-8-[5"-hydroxy-3"-methyl-(2"-E)-butenyl]-4',7-dihydroxy-5-methoxyflavanone (6). Xanthohumol (1) and flavanone 6 as well as (E)-2"-(2"'-hydroxyisopropyl)-dihydrofurano[2",3":4',3']-2',4-dihydroxy-6'-methoxychalcone (2), (2S)-2"-(2"'-hydroxyisopropyl)-dihydrofurano[2",3":7,8]-4'-hydroxy-5-methoxyflavanone (3) obtained with Pichia membranifaciens showed antimalarial activity against Plasmodium falciparum.