New prenylflavonoids from Artocarpus communis

Two New Geranylated Biphenyl Esters From Artocarpus altilis

Two new geranylated biphenyl esters, 2,3′,4,4′-tetrahydroxy-3-geranyl-5-carboxyethyl-biphenyl methyl ester (1), 2,3′,4,4′-tetrahydroxy-3-geranyl-5-carboxymethyl-biphenyl methyl ester (2), together with 4 known compounds were isolated from the methanol extract of the leaves of Artocarpus altilis. Their structures were established by spectroscopic means and by comparison with literature data. Compound 1 possessed moderate cytotoxicity toward MDA-MB-231 (a breast carcinoma cell line) with a half-maximal inhibitory concentration value of 30 µM and inhibited the growth of 8 bacteria, including gram-negative and gram-positive organisms, but was inactive against fungi.

Bioactive chemical constituents from the root bark of Morus australis

Two new pyranoflavonoids, morustralins A (1) and B (2), a new natural benzene derivative, one benzenoid (Z)-1-hydroxy-4-(2-nitroethenyl)benzene (3), and thirty known compounds were isolated and characterized from the root bark of Morus australis. The structures of the new compounds were established from spectroscopic and spectrometric analyses. Ten isolates (1-10) were examined for inhibitory effects on adenosine diphosphate (ADP)-, arachidonic acid (AA)-, and platelet-aggregating factor (PAF)-induced platelet aggregation. Among the tested compounds, compound 3 displayed the most significant inhibition of ADP- and AA-induced platelet aggregation with IC₅₀ values of 9.76±5.54 and 9.81±2.7μM, respectively. In addition, eight purified compounds (3-10) were examined for inhibition of nitric oxide (NO) production in RAW 264.7 cells and six compounds (3-8) displayed significant inhibitory effects with IC₅₀ values ranging from 2.1±0.3 to 6.3±0.6μM.

Prenylated flavonoids from Artocarpus altilis: antioxidant activities and inhibitory effects on melanin production

Flavonoids, 10-oxoartogomezianone (1), 8-geranyl-3-(hydroxyprenyl)isoetin (2), hydroxyartoflavone A (3), isocycloartobiloxanthone (4), and furanocyclocommunin (5), together with 12 known compounds, were isolated from heartwood and cortex of Artocarpus altilis, and their structures were identified by comparing their spectra with those of similar compounds. To identify natural antioxidants and whitening agents, the ability of these prenylated flavonoids was assessed to scavenge the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+·)) radical cation, and the superoxide anion (O2(-·)), and their abilities to inhibit tyrosinase and melanin production. It was found that compounds 3, 4, and artoflavone A (15) had moderate DPPH(·)-scavenging activity, whereas compound 4 exhibited significant ABTS(+·)-scavenging activity, and that norartocarpetin (7) and artogomezianone (8) exhibited moderate ABTS(+·)-scavenging activity, with compounds 2, 7, and artocarpin (6) displaying good superoxide anion-scavenging activity. In addition, compounds 7, 8, cudraflavone A (14), and artonin M (17), inhibited melanin production by strongly suppressing tyrosinase activity. Compound 6 reduced the melanin content without inhibiting tyrosinase activity. These results suggest that flavonoids isolated from A. altilis may be candidate antioxidants and/or skin-whitening agents. However, further investigations are required to determine their mechanisms of action.

Cytotoxic effects of new geranyl chalcone derivatives isolated from the leaves of Artocarpus communis in SW 872 human liposarcoma cells

Breadfruit (Artocarpus communis Moraceae) is cultivated in tropical and subtropical regions as a traditional starch crop and also has potential medicinal properties. The aim of this work was to study the in vitro anticancer activity of compounds isolated from the leaves of Artocarpus communis. Three new geranyl chalcone derivatives including isolespeol (1), 5'-geranyl-2',4',4-trihydroxychalcone (2), and 3,4,2',4'-tetrahydroxy-3'-geranyldihydrochalcone (3), together with two known compounds lespeol (4) and xanthoangelol (5), were isolated from the leaves of Artocarpus communis. The structures of 1- 5 were elucidated by spectroscopy and through comparison with data reported in the literature. The effects of geranyl chalcone derivatives (1- 5) on the viability of human cancer cells (including SW 872, HT-29, COLO 205, Hep3B, PLC5, Huh7, and HepG2 cells) were investigated. The results indicate that isolespeol (1) showed the highest inhibitory activity with an IC 50 value of 3.8 muM in SW 872 human liposarcoma cells. Treatment of SW 872 human liposarcoma cells with isolespeol (1) caused the loss of mitochondrial membrane potential (DeltaPsim). Western blotting revealed that isolespeol (1) stimulated increased protein expression of Fas, FasL, and p53. The expression ratios of pro- and antiapoptotic Bcl-2 family members were also changed by isolespeol (1) treatment to subsequently induce the activation of caspase-9 and caspase-3, which was followed by cleavage of poly (ADP-ribose) polymerase (PARP). These results demonstrate that isolespeol (1) induces apoptosis in SW 872 cells through Fas- and mitochondria-mediated pathways.

Cytotoxic and apoptotic effects of prenylflavonoid artonin B in human acute lymphoblastic leukemia cells

AIM

To investigate the anticancer effects and molecular mechanism of artonin B on the human acute lymphoblastic leukemia CCRF-CEM cells compared with other prenylflavonoid compounds.

METHODS

The effects of four prenylflavonoids on the growth of CCRF-CEM and HaCa cells were studied by 3-(4,5)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Apoptosis were detected through Hoechst 33258 staining. The effect of artonin B on the cell cycle of CCRF-CEM cells were studied by propidium iodide method. The change in mitochondrial membrane potential was detected by rohdamine 123 staining. The cytochrome c release and caspase 3 activity were checked by immunoassay kits, respectively. The expression of Bcl-2 family proteins was detected by Western blot.

RESULTS

Our data revealed that artonin B strongly induced human CCRF-CEM leukemia cell death in a dose- and time-dependent manner by MTT assay, but not on normal epithelia cells (HaCa cells). Artonin B-induced cell death was considered to be apoptotic by observing the typical apoptotic morphological change by Hoechst 33258 staining. The induction of human CCRF-CEM leukemia cancer cell death was caused by an induction of apoptosis through mitochondrial membrane potential change, cytochrome c release, sub-G1 proportion increase, downregulation of Bcl-2 expression, upregulation of Bax and Bak expression and activation of caspase 3 pathways.

CONCLUSION

These results clearly demonstrated that artonin B is able to inhibit proliferation by induction of hypoploid cells and cell apoptosis. Moreover, the anticancer effects of artonin B were related to mitochondrial pathway and caspase 3 activation in human CCRF-CEM leukemia cells.