Anticancer Activity and Molecular Targets of Piper cernuum Substances in Oral Squamous Cell Carcinoma Models.

Oral squamous cell carcinoma (OSCC) is a worldwide public health problem, with high morbidity and mortality rates. The development of new drugs to treat OSCC is paramount. Piper plant species have shown many biological activities. In the present study, we show that dichloromethane partition of Piper cernuum (PCLd) is nontoxic in chronic treatment in mice, reduces the amount of atypia in tongues of chemically induced OSCC, and significantly increases animal survival. To identify the main active compounds, chromatographic purification of PCLd was performed, where fractions 09.07 and 14.05 were the most active and selective. These fractions promoted cell death by apoptosis characterized by phosphatidyl serine exposition, DNA fragmentation, and activation of effector caspase-3/7 and were nonhemolytic. LC-DAD-MS/MS analysis did not propose matching spectra for the 09.07 fraction, suggesting compounds not yet known. However, aporphine alkaloids were annotated in fraction 14.05, which are being described for the first time in P. cernuum and corroborate the observed cytotoxic activity. Putative molecular targets were determined for these alkaloids, in silico, where the androgen receptor (AR), CHK1, CK2, DYRK1A, EHMT2, LXRß, and VEGFR2 were the most relevant. The results obtained from P. cernuum fractions point to promising compounds as new preclinical anticancer candidates.

Apoptotic effect of ß-pinene on oral squamous cell carcinoma as one of the major compounds from essential oil of medicinal plant Piper rivinoides Kunth.

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck malignancy. Research on essential oils (EOs) has shown important cytotoxic and anti-tumor properties, among others. Piperaceae species are rich in EOs and here we highlight Piper rivinoides Kunth. We investigated the crude EOs from P. rivinoides, their pure major constituents and an enriched fraction with the main EO compounds (EF) as cytotoxic and selective OSCC agents. EOs presented as main compounds (-)-α-pinene, (-)-ß-pinene and limonene. EOs showed an IC50 lower than all isolated compounds, except for (-)-ß-pinene in OSCC cells. The (-)-ß-pinene induced cell death with apoptotic characteristics. Commercial standards showed greater selectivity than EOs, and (-)-ß-pinene was the most selective among them. EF showed higher selectivity compared to crude EOs and carboplatin, turning it into a good candidate as an anticancer fraction. These results are important for the possible development of new treatments for OSCC.

Ageing is associated with brown adipose tissue remodelling and loss of white fat browning in female C57BL/6 mice.

Fat storage changes throughout life and affects body metabolism. Ageing impact on brown (BAT) and white adipose tissue (WAT) deserves attention, especially in females, because they are less prone to age-induced weight gain. While in male mice the impact of ageing on adipose tissue remodelling is well characterized, the effects in female mice remain largely unclear. Thus, we investigated BAT and WAT remodelling during ageing in female C57BL/6 mice. At 3 months, body weight was 24 ± 0.3 g (mean±SD), and it increased from 6 to 9 months of age (+20%, P < 0.0001). Oral glucose tolerance test showed no disturbance of glucose metabolism. All WAT depots became heavier, and white adipocytes hypertrophied. The subcutaneous and visceral WAT had clusters of beige cells in younger mice, but they were progressively lost by ageing, indicating loss of WAT browning. Older mice had hypertrophied classic brown adipocytes that had larger cytoplasmic lipid droplets than younger mice. Pearson's correlation showed that WAT mass has a weak correlate with BAT mass, although white adipocyte diameter has a strong correlation with classic brown adipocyte size. In conclusion, our results indicate that female C57BL/6 mice have a progressive age-dependent loss of subcutaneous and visceral WAT browning, and this process runs in parallel with BAT morphological changes towards a fat storer phenotype, independent of cycling or disturbances in glucose metabolism.