Chemical constituents and bioactivities of Glinus oppositifolius.

OBJECTIVES: To isolate the secondary metabolites from the dichloromethane (DCM) extracts of Glinus oppositifolius; to test for the cytotoxicity of a new triterpene, oppositifolone (1); and to test for the hypoglycemic, analgesic, and antimicrobial potentials of 1, DCM and aqueous leaf extracts of G. oppositifolius. METHODS: The compounds were isolated by silica gel chromatography and identified by nuclear magnetic resonance spectroscopy. The cytotoxicity potential of 1 was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Triterpene 1, DCM, and aqueous leaf extracts were tested for hypoglycemic potential using the oral glucose tolerance test; analgesic potential using the tail-flick assay, and antimicrobial potential using the disc diffusion method. RESULTS: The DCM extracts of G. oppositifolius afforded 1, squalene, spinasterol, oleanolic acid, phytol, and lutein from the leaves; squalene and spergulagenin A from the stems; and spinasterol from the roots. Triterpene 1 was cytotoxic against human colon carcinoma 116 with an IC50 value of 28.7 but did not exhibit cytotoxicity against A549. The aqueous leaf extract at 200 mg/kg body weight (BW) exhibited hypoglycemic activity with a pronounced % blood glucose reduction of 70.76% ±17.4% within 0.5 h after introduction. The DCM leaf extract showed a lower % blood glucose reduction of 18.52% ±13.5% at 200 mg/kg BW within 1.5 h after introduction, while 1 did not exhibit hypoglycemic activity. The samples did not exhibit analgesic property and were inactive against multiple drug resistant bacterial pathogens. CONCLUSION: The compounds responsible for the hypoglycemic activity of G. oppositifolius which are fast acting (0.5 h) are found in the aqueous leaf extract.

Angio-suppressive triterpenoids from Ardisia cf. elliptica (subgenus Tinus) on duck (Anas platyrynchos L.) chorioallantoic membrane.

The dichloromethane extract of the air-dried leaves of Ardisia cf. elliptica (subgenus Tinus) afforded a mixture of bauerenol (1a), α-amyrin (1b) and ß-amyrin (1c). Their structures were identified by NMR spectroscopy. Mixtures of the triterpenes (1a-1c) at ratios of 2 : 2 : 1, 2 : 2 : 3 and 1 : 1 : 1 were tested for their angio-suppressive effects on duck chorioallantoic membrane (CAM). All three ratios were found to be effective in restricting inter-capillary length, while 1a-1c (2 : 2 : 1) was most effective in reducing branch point density with 100% CAM viability and embryo survivability, suggesting a high impact angio-suppressive potential of 1a-1c (2 : 2 : 1).

Bioactivities of triterpenes and a sterol from Syzygium samarangense.

Cycloartenyl stearate (1a), lupenyl stearate (1b), sitosteryl stearate (1c), and 24-methylenecycloartanyl stearate (1d) (sample 1) from the air-dried leaves of Syzygium samarangense exhibited potent analgesic and anti-inflammatory activities at effective doses of 6.25 mg/kg body weight and 12.5 mg/kg body weight, respectively. Sample 1 also exhibited negligible toxicity on zebrafish embryonic tissues. There were incidences of mortality upon direct exposure of sample 1 to dechorionated embryos, but higher mortality and aberration were observed during intact chorion treatment.

A bioactive sesquiterpene from Bixa orellana.

A dichloromethane extract of the air-dried leaves of Bixa orellana afforded ishwarane 1, phytol 2, polyprenol 3, and a mixture of stigmasterol 4a and sitosterol 4b by silica gel chromatography. The structure of 1 was elucidated by extensive 1D and 2D NMR spectroscopy. Compound 1 at three doses (25, 50, and 100 mg/kg BW) was tested for prophylactic, gastrointestinal motility, analgesic, hypoglycemic, and antimicrobial potentials. Results of the prophylactic assay demonstrated the anti-toxic property of 1 at 100 mg/kg BW. A 50 mg/kg BW dose of 1 resulted in a more propulsive movement of the gastrointestinal tract (88.38 ± 13.59%) compared to the negative control (78.47 ± 10.61%). Tail flick and acetic acid writhing tests indicated that 100 mg/kg BW 1 had minimal analgesic activity. Compound 1 demonstrated no hypoglycemic potential on the animals tested. Compound 1 exhibited moderate antifungal activity against C. albicans, low activity against T. mentagrophytes, and low antibacterial activity against E. coli, S. aureus, and P. aeruginosa. It was inactive against B. subtilis and A. niger.

Effects of the oral administration of nonpolar extract from Ardisia squamulosa Presl (Myrsinaceae) leaves on spermatogenesis in rats.

BACKGROUND: Several Ardisia species have been found to possess numerous bioactivities but their reproductive toxicity has been poorly explored. In the present study, the effects of the leaf hexane extract of Philippine indigenous Ardisia squamulosa on epididymal sperm count, %viability and %aberration of sperms and weights of seminal vesicle, cauda epididymis, and testes in addition to the weights of liver, kidney, and body were evaluated. METHODS: The extracts at daily dose levels of 1, 10, and 100 mg/Kg BW in 10% polysorbate-80 in corn oil were administered by gavage for 8 successive days to 8-10 weeks old male SD rats and sacrificed after 9 days. Daily body weights and final organ weights were measured. Sperm from the cauda epididymis was extracted and measured according standard sperm parameters (sperm count, morphology, viability and membrane integrity). RESULTS: Significant findings were the decline of left epididymal sperm count to testis weight ratio and increase in %sperm morphological aberration from both cauda epididymis obtained with the 10 mg/Kg BW dose. CONCLUSION: The hexane extract from Ardisia squamulosa had significant effect on sperm count but with negligible effect on sperm morphology and viability.

Hypoglycaemic effects of tea extracts and ent-kaurenoic acid from Smallanthus sonchifolius.

Hypoglycaemic activity was observed in normoglycaemic mice orally administered with the aqueous Smallanthus sonchifolius leaf tea extract, alloxan-induced diabetic mice orally administered with ent-kaurenoic acid (1), and normoglycaemic mice intraperitoneally administered with 1 from S. sonchifolius leaves. A single dose administration of 50 mg kg(-1) BW yacon leaf tea extract demonstrated immediate but relatively short hypoglycaemic activity, with significant effects observed during 1-2 h. Similarly, administration with 100 mg kg(-1) BW yacon leaf tea extract obtained by heavy stirring in hot water demonstrated a more potent activity compared to the positive control at 1.5-2.0 h. Oral administration of 1 did not affect the blood glucose level of the alloxan-induced diabetic mice, but a single intraperitonial injection of 10 mg kg(-1) BW in normoglycaemic mice had consistent percent blood glucose reduction persisting from 1 to 2 h observation periods.

Bioactive triterpenes from Diospyros blancoi.

The ethyl acetate extract of the air-dried leaves of Diospyros blancoi afforded isoarborinol methyl ether (1), a mixture of alpha-amyrin palmitate, alpha-amyrin palmitoleate, beta-amyrin palmitate and beta-amyrin palmitoleate (2) in a 13 : 4 : 3 : 1 ratio, and squalene. The structures of 1, 2 and squalene were elucidated by extensive 1D and 2D NMR spectroscopy. Compounds 1 and 2 exhibited antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Staphylococcus aureus and Trichophyton mentagrophytes, and were found inactive against Bacillus subtilis and Aspergillus niger. Sample 2 exhibited significant analgaesic and anti-inflammatory activities.