Apoptotic effect of beta-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 (-)-alpha-pinene, (-)-beta-pinene and limonene. EOs showed an IC(50) lower than all isolated compounds, except for (-)-beta-pinene in OSCC cells. The (-)-beta-pinene induced cell death with apoptotic characteristics. Commercial standards showed greater selectivity than EOs, and (-)-beta-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.