Anti-proliferative and apoptotic activities of constituents of chloroform extract of Juglans regia leaves

OBJECTIVES

To evaluate anti-proliferative as well as apoptotic activities of compounds identified in chloroform extract of Juglans regia leaves, on human breast and oral cancer cell lines (MCF-7 and BHY).

MATERIALS AND METHODS

Column chromatography, MTT assay, flowcytometry and western blotting have all been used in the study.

RESULTS

Bioassay-guided fractionation of chloroform extract of J. regia afforded isolation of 5-hydroxy-3,7,4'-trimethoxyflavone [1], lupeol [2], daucosterol [3], 4-hydroxy-α-tetralone [4], β-sitosterol [5], 5,7- dihydroxy-3,4'-dimethoxyflavone [6] and regiolone [7]. Structures of the compounds were established on the basis of spectroscopic analyses [Nuclear magnetic resonance (NMR) and mass]. All compounds inhibited proliferation of MCF-7 (human breast adenocarcinoma) and BHY (human oral squamous carcinoma) cells in a concentration-dependent manner. Compounds 6 and 7 had potent cytotoxic effects on both MCF-7 and BHY cells (IC50 21-51 μm), yet were not toxic to normal cells. MCF-7 growth inhibition was attributed to apoptosis; population of apoptotic cells increased from 1.12% in controls to 5.64 and 8.1% after 48-h treatment with compounds 6 and 7, indicating their potential at inducing early and late apoptosis. The caspase cascade was not activated, as indicated by only insignificant cleavage of caspase-3.

CONCLUSIONS

Our results suggest that compounds 6 and 7 can induce apoptosis in MCF-7 cells through the caspase-3 independent pathway.

Lignans and neolignans from Stelleropsis antoninae

BACKGROUND AND THE PURPOSE OF THE STUDY

Stelleropsis antoninae Pobed. (Family: Thymelaeaceae) grows wildly as an herbaceous plant in Iran. Most of the Thymelaeaceous plants contain lignans and neolignans, which have important pharmacologically properties. In the present study, the isolation and identification of the main lignans and neolignans of S. antoninae, which has not been previously reported is described and compared to other species.

METHODS

Column (CC) and High Performance Liquid Chromatographic (HPLC) methods were used for the isolation and purification, and (1)H-NMR, (13)C-NMR, HMBC, HMQC, H-H COSY and MS were employed for the identification of the compounds isolated from the methanol extract.

RESULTS

From the methanol extract of the aerial parts of S. antoninae four lignans, syringaresinol (1), syringaresinol 4-O-β-D-glucopyranoside (4), syringaresinol 4-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (5), liriodendrin (6), and two neolignans, 5-methoxylariciresinol 4'-O- β-D-glucopyranoside (3) and dehydrodiconiferyl alcohol 4-O-β -D-glucopyranoside (2) were isolated and identified.

MAJOR CONCLUSION

The results of this study show that siringaresinol, a well-known bioavtive compound, and its glucosides are the main lignans, and lariciresinol and coniferyl alcohol derivatives are the main neolignans of S. antoninae.

A review on phytochemistry and medicinal properties of the genus Achillea

Achillea L. (Compositae or Asteraceae) is a widely distributed medicinal plant throughout the world and has been used since ancient time. Popular indications of the several species of this genus include treatment of wounds, bleedings, headache, inflammation, pains, spasmodic diseases, flatulence and dyspepsia. Phytochemical investigations of Achillea species have revealed that many components from this genus are highly bioactive. There are many reports on the mentioned folk and traditional effects. Although, the medicinal properties of Achillea plants are recognized worldwide, there are only one review article mainly about the structures of the phytochemical constituents of Achillea. The present paper reviews the medicinal properties of various species of Achillea, which have been examined on the basis of the scientific in vitro, in vivo or clinical evaluations. Various effects of these plants may be due to the presence of a broad range of secondary active metabolites such as flavonoids, phenolic acids, coumarins, terpenoids (monoterpenes, sesquiterpenes, diterpenes, triterpenes) and sterols which have been frequently reported from Achillea species.

Isolation of a new quinic acid derivative and its antibacterial modulating activity

BACKGROUND AND THE PURPOSE OF THE STUDY

The species Hymenocrater calycinus, belongs to the plant family Lamiaceae and grows wildly in the north-east of Iran. Previously, the antimicrobial activity of the plant extracts was reported. In the present study, the bioactivity-guided fractionation of the methanol extract of H. calycinus and the combination effects of the isolated compound with cell wall active agents against S. aureus and E. coli was investigated.

METHODS

Column and thin layer chromatographic methods were used for isolation and purification and spectroscopic data (MS, (1)H- and (13)C-NMR, HMQC, HMBC and (1)H-(1)H COSY) were employed for identification of the compound isolated from the extract. A disk diffusion method was used to determine the antibacterial activity of the isolated compound against S. aureus and E. coli in comparison with 7 different antibiotics.

RESULTS

The isolated compound 1 was identified as 3-(3, 4- dihydroxyphenyl) lactic acid 2-O-quinic acid. Compound 1 (500 µg/disc) enhanced antibacterial effect of ampicillin, ciprofloxacin, vancomycin and cefepime against S. aureus and activated the effects of ampicillin and vancomycin against E. coli.

CONCLUSION

Results showed that the compound 1 was not active against both tested strains at any concentration below 1 mg/disk, and as a result the enhancing effect of the compound could be due its association with antibiotics.

1-methyl malate from Berberis integerrima fruits enhances the antibacterial activity of ampicillin against Staphylococcus aureus

The enhancement of the antibacterial activity of ampicillin by different extracts of Berberis integerrima fruits was evaluated against Staphylococcus aureus. Disk diffusion and agar dilution methods were used to determine the antibacterial activity of ampicillin in the absence and presence of different plant extracts or various fractions eluted by column chromatography. A clinical isolate of S. aureus was used as a test strain. The active component of B. integerrima fruits involved in the enhancement of ampicillin activity was purified and identified as 1-methyl malate using different spectroscopic methods. Both the ethanol extract of B. integerrima fruits and 1-methyl malate enhanced the antibacterial activity of ampicillin. The total extract as well as 1-methyl malate increased the antibacterial activity of ampicillin against the test strain. The potency of ampicillin against the test strain was increased 64-fold when tested with a sub-toxic concentration of total extract of B. integerrima fruits. Also, 1-methyl malate increased the bactericidal activity of ampicillin. In the presence of 2 mg/mL of 1-methyl malate the MIC of ampicillin for S. aureus decreased from 128 to 1 microg/mL (128-fold).

The effect of Plantago ovata on humoral immune responses in experimental animals

The effect of the aqueous extract of Plantago ovata (PO) (Plantaginaceae) consisting of a mixture of polysaccharides and glycoside on humoral immune responses was studied. In rabbits, after oral administration of PO (0.5 g/kg) a significant decrease in anti-HD antibody titre was observed in primary response. Intraperitoneal injection of 0.25 g/kg of PO in mice prior to immunisation with sheep red blood cells (SRBC) resulted in a significant decrease in hemagglutinating antibody (HD) titre. Oral administration and intraperitoneal injection of 0.25 and 0.5 g/kg of PO resulted in a significant increase in white blood cells (WBC) and spleen leukocytes counts. The spleen weight also increased with intraperitoneal injection (0.25 and 0.5 g/kg) and oral administration of 0.5 g/kg of PO. Present results indicate that PO can suppress the humoral immune responses, especially in primary immune response.

Immunosuppressive activity of Achillea talagonica on humoral immune responses in experimental animals

In this study the aqueous extract of Achillea talagonica consisting of a mixture of alkaloids, terpenoids and flavonoids was used. This genus has long been used in Iran for treatment of fever, skin inflammation, asthma and liver ailments. Effects of this plant were studied on humoral antibody responses in BALB/c mice and albino rabbits. Intraperitoneal administration of 0.25, 0.5, 1.0 and 2.0 g/kg x 7 days in mice prior to immunization with sheep red blood cells, resulted in a significant dose dependent decrease in haemagglutinating antibody (HA) titre. By decreasing the dosage, a significant decrease in HA titre was also observed. In rabbits after intrascapular injection of 0.5 g/kg, in primary response, a significant decrease in anti-HD titre was found, but no change observed in secondary response.