Phytochemicals from Phyllanthus niruri Linn. and their pharmacological properties: a review

Englerin A, a selective inhibitor of renal cancer cell growth, from Phyllanthus engleri

An extract from Phyllanthus engleri was identified in a bioinformatic analysis of NCI 60-cell natural product extract screening data that selectively inhibited the growth of renal cancer cell lines. Bioassay-guided fractionation yielded two new guaiane sesquiterpenes, englerins A (1) and B (2). Englerin A showed 1000-fold selectivity against six of eight renal cancer cell lines with GI(50) values ranging from 1-87 nM. The structures of 1 and 2 and their relative stereochemistry were established by spectroscopic methods.

Protocols for in vitro culture and phytochemical analysis of Phyllanthus species (euphorbiaceae)

We developed reproducible protocols for micropropagation, callus culture, and root culture of the medicinal plant Phyllanthus urinaria, P. niruri, P. tenellus, P. corcovadensis, P. caroliniensis, P. stipulatus, and P. fraternus by using single node explants. Genotype-linked differences are visible among the Phyllanthus species concerning shoot culture, callus culture, and root culture growth. The protocols developed for phytochemical screening of callus and root extracts of P. urinaria, P. caroliniensis, P. stipulatus, and P. fraternus have shown the production of sterols and triterpenes. Both compounds are known to account for the antinociceptive activity of the methanolic extracts as glochidone and stigmasterol have strong activity against neurogenic and inflammatory pain. Similarly, methanolic callus extracts of P. tenellus, P. niruri and P. corcovadensis have potent analgesic properties, however phenolics are major compounds isolated from these species. The optimized micropropagation, callus culture, and root culture protocols offer the possibility to use cell/root culture techniques for vegetative propagation and secondary metabolite studies.

Antitumoral and antiangiogenic activity of Synadenium umbellatum Pax

AIM OF THE STUDY

Synadenium umbellatum Pax (SU), a plant used in the Midwestern region of Brazil, was tested for its antitumor and antiangiogenic activities in vitro, using K-562 and Ehrlich ascites tumor (EAT) cells, and in vivo, using the EAT-bearing model.

MATERIALS AND METHODS

The viability of tumor cells was evaluated by MTT and trypan blue exclusion assays, after incubation with the ethanolic extract of SU (EESU) (0.15-20mg/mL) or equivalent concentrations of its partitioned fractions (chloroformic, hexanic, and methanolic). In vivo studies were performed in EAT-bearing mice treated intraperitoneally with 5, 10, and 25mg/kg of the EESU or equivalent doses of the fractions for 10 days. The methotrexate (1.5mg/kg), for 10 days, was used as control.

RESULTS

SU and fractions, except the methanolic, decreased the viability of the cells in a concentration-dependent manner. In vivo results showed a significant dose-dependent antitumoral efficacy of SU against EAT growth. The best results in prolonging life span were produced by 25mg/kg of EESU. In these animals, the levels of vascular endothelial growth factor were markedly decreased after the treatment.

CONCLUSIONS

The data presented herein could open interesting perspectives for further research of SU as a candidate anticancer agent.

In vitro anti-influenza screening of several Euphorbiaceae species: structure of a bioactive Cyanoglucoside from Codiaeum variegatum

A bio-guided screening against influenza A virus (FLUAV) was carried out with seven Euphorbiaceae species. The results showed that chromatographic fractions from Phyllantus niruri, Euphorbia pulcherrima and Codiaeum variegatum had relevant anti-FLUAV activity, although only chromatographical subfractions from C. variegatum kept the activity. From this plant, the active compound against FLUAV was isolated. Its structure was assigned as 2-(3,4,5)-trihydroxy-6-hydroxymethyltetrahydropyran-2-yloxymethyl)acrylonitrile (1) on the basis of NMR, mass spectrometry and X-ray diffraction analysis. The compound displayed virucidal activity without impairment of haemagglutination properties of the used virus strain. This is the first report indicating antiviral activity of a cyanoglucoside.

Pharmacokinetics and tissue distribution of 8,9-epoxy brevifolin in rats, a hepatoprotective constituent isolated from Phyllanthus simplex Retz by liquid chromatography coupled with mass spectrometry method

8,9-Epoxy brevifolin (EBF) is a novel compound isolated from Phyllanthus simplex Retz (P. simplex) and has been demonstrated to possess a hepatoprotective effect. The purposes of the present study were to examine the in vivo pharmacokinetics and tissue distribution of EBF in rats using a liquid chromatography coupled with mass spectrometry quantitative detection method (LC-MS/MS), with luteolin-7-O-glucoside being employed as an internal standard (IS). The method was validated within the concentration range 20-15 000 ng/ml, and the calibration curves were linear with correlation coefficients of >0.999. The limit of quantitation (LOQ) for EBF was 20 ng/ml. The intra-assay accuracy and precision ranged from 98.7% to 100.2% and 2.19% to 6.25%, respectively, while the inter-assay accuracy and precision ranged from 97.5% to 100.3% and 3.35% to 7.28%, respectively. The method was further applied to assess the pharmacokinetics and oral bioavailability of EBF after intravenous and oral administration in rats. The oral bioavailability of EBF was 12.46 +/- 2.31%. In the tissue distribution assay, its concentration was higher in the heart (13.2 +/- 0.24 microg/g) and liver (14.5 +/- 0.19 microg/g) than in other tissues.

Chemical and immunological modifications of an arabinogalactan present in tea preparations of Phyllanthus niruri after treatment with gastric fluid

An arabinogalactan (AG) obtained from tea preparations of Phyllanthus niruri was previously investigated and presented immunological properties when tested with peritoneal mice macrophages. AG was now submitted to acidic and neutral gastric conditions using human gastric fluids and aq. HCl solution. Since the acidic procedures gave rise to the same free monosaccharidic composition, the acid hydrolyzate of AG at pH 2.00 was treated with ethanol to form insoluble (AG-P) and soluble fractions (AG-S). These were analyzed using (13)C NMR, HPSEC, and GC-MS for monosaccharide composition and methylation analyses. The results showed an intense partial degradation, including cleavages of the main chain. AG-S presented the monosaccharides released from the native polymer and some oligosaccharides as shown by methylation data. AG-P contained larger molecular fragments comprising the internal units from AG, which were not attacked by the hydrolysis condition. Both fractions were tested in peritoneal mice macrophages and remained active, promoting an increase of superoxide anion production of 2.0 and 2.3-fold, at 250 microg/mL, for AG-S and AG-P, respectively. When compared to AG, a slight diminished response was observed, revealing a structure-activity relation. The significance of the results is that most plant extracts are orally ingested and will reach the gastrointestinal tract before performing a biological function, so checking these changes is crucial to propose future clinical therapies based on the rational use of phytomedicine.

Nematicidal prenylated flavanones from Phyllanthus niruri

Two prenylated flavanones have been isolated from the hexane extract of Phyllanthus niruri plant. The structure of these flavanones were established as 8-(3-Methyl-but-2-enyl)-2-phenyl chroman-4-one (1) and 2-(4-hydroxyphenyl)-8-(3-methyl-but-2-enyl)-chroman-4-one (2) on the basis of spectral analysis. These were evaluated for nematicidal activity against root-knot, Meloidogyne incognita, and reniform, Rotylenchulus reniformis, nematodes. Compound 2 exhibited nematicidal activity at par with the standard carbofuran (LC50 3.3 and 3.1ppm, respectively) when tested against reniform nematode. The LC50 value against root-knot nematode was found to be 14.5ppm. Compound 1 however, showed moderate activity against both the test nematodes.

Volatile Constituents from the Leaves of Phyllanthus Salviaefolius H. B. K. from the Venezuelan Andes

The essential oil from the leaves of Phyllanthus salviaefolius H. B. K. (Euphorbiaceae) collected in February 2007 at Mucurubá (Mérida State) was analyzed by GC/MS. The yield of oil extracted by hydrodistillation was 0.005%. Sixteen components were identified, which represent 94.6% of the oil. Phytol (21.5%), β-citronellol (17.7%), trans-geraniol (13.5%), cis-3-hexenol (12.6%) and 1-hexanol (11.3%) were the most abundant components.

Phyllanthus urinaria ameliorates the severity of nutritional steatohepatitis both in vitro and in vivo

Hepatic oxidative stress plays a critical role in metabolic forms of steatohepatitis. Phyllanthus urinaria, an herbal medicine, has been reported to have potential antioxidant properties. We tested the effects of P. urinaria on nutritional steatohepatitis both in vitro and in vivo. Immortalized normal hepatocytes (AML-12) or primary hepatocytes were exposed to control, the methionine-and-choline-deficient (MCD) culture medium, in the presence or absence of P. urinaria for 24 hours. Hepatocyte triglyceride, release of alanine aminotransferase, lipoperoxides, and reactive oxygen species production were determined. Age-matched C57BL/6 and db/db mice were fed control or MCD diet for 10 days with or without P. urinaria. Hepatic steatosis, necroinflammation, triglycerides, and lipid peroxide levels were determined. Hepatic expression of inflammatory factors and lipid regulatory mediators were assayed. P. urinaria reduced steatosis and alanine aminotransferase (ALT) levels in culture of hepatocytes in a dose-dependent manner. Phyllanthus prevented MCD-induced hepatic fat accumulation and steatohepatitis in mice. This effect was associated with repressed levels of hepatic lipid peroxides, reduced expression of cytochrome P450-2E1, pro-inflammatory tumor necrosis factor alpha, interleukin-6, dampened activation of inflammatory c-Jun N-terminal kinase (JNK) and nuclear factor kappa B (NF-kappaB), increased expression of lipolytic cytochrome P450 (Cyp4a10), and suppressed transcriptional activity of lipogenic CCAAT/enhancer binding protein beta (C/EBPbeta). Hepatic acyl co-enzyme A oxidase that regulated hepatic beta-oxidation of fatty acid and other lipid regulators were not affected by P. urinaria. In conclusion, P. urinaria effectively alleviated the steatohepatitis induced by the MCD, probably through dampening oxidative stress, ameliorating inflammation, and decreasing lipid accumulation.