- Open Access funded by Alexandria University Faculty of Medicine
- Under a Creative Commons license
Abstract
Background
Pancreatic cancer is one of the most lethal malignant tumors which remains a rampant killer across the globe. Lack of early diagnosis and toxic drugs have failed to improve the survival rate of pancreatic cancer patients, thus new agents that are safe, available and effective are urgently needed.
Objective
The study aimed to investigate the efficacy of Agarwood essential oils in the inhibition of metastasis and induction of apoptosis in the pancreatic cell line (MIA PaCa-2).
Methods
Essential oils of Aquilaria crassna were obtained by hydrodistillation. Chemical characterization was analyzed using FTIR and GCMS. The effects of essential oils against three steps of metastases have been investigated, including cell proliferation, migration and clonogenicity. Hoechst and rhodamine assays confirmed the mechanism of pancreatic cancer cell death.
Results
The results showed that essential oils exhibited potent cytotoxic activity against MIA PaCa-2 cells with an IC50 (11 ± 2.18 μg/ml). Cell migration was effectively inhibited at (10 μg/ml). Moreover, at a sub-toxic dose (5 μg/mL), essential oils obstructed the colony formation properties of MIA PaCa-2 significantly. The mechanism of cell death was determined due to the induction of nuclear condensation and disruption of mitochondrial membrane potential in the cells. Interestingly, several active components were existed in the chemical profile of the essential oils extract such as β-Caryophyllene, 1-Phenanthrenecarboxylic acid, azulene, naphthalene and Cyclodecene.
Conclusion
The present study elucidated for the first time the anti-pancreatic cancer properties of A. crassna essential oils, It can be concluded that the anticancer effects of the extract could be due to the synergistic effect of the biologically active phytoconstituents present in the essential oils.
Graphical abstract
Keywords
- Essential oils;
- Agarwood;
- Aquilaria crassna;
- Pancreatic cancer
1. Introduction
Cancer is the general name for a heterogeneous group of more than 100 diseases which arises from dysregulation of the normal cellular mechanism, characterized by alterations in expression of multiple genes, leading to local tissue invasion and eventually metastasis.1 Pancreatic cancer is one of the most aggressive malignant solid tumors which remains the fourth leading cause of cancer-related death with an overall 5-year survival rate of less than 5%. Recently, about 227,000 cases of deaths were reported annually worldwide.2 and 3 Several risk factors have been implicated in this malignant disease including smoking, alcohol, diet, age and family history.4 However, the most critical hurdle in the pancreatic cancer therapy is metastatic nature of the disease, where the malignant cells detach from the primary tumor location and grow in distant organs.5Clinical studies have estimated that only 10% of mortality is caused by the primary tumors, whereas metastasis alone contributes about 90% of cancer deaths.6 Plants have been utilized for medicinal purposes since the early stage of civilizations. According to a botanical survey approximately there are 350,000 plants species that have been identified and recorded globally out of which, about 35,000–70,000 plants have been used for medicinal purposes and wonderingly, just 0.5% of it has been chemically studied and pharmacologically validated so far.7 The World Health Organization (WHO) has estimated that 80% of population in the developing countries relies on traditional herbal medicine for the primary health care needs. In more recent times, phytochemicals such as paclitaxel, vincristine, and camptothecin have become major and significant sources for chemotherapy in cancer treatment protocols, which provided the most successful, alternative and complementary anticancer regimen8.
Aquilaria crassna (Thymelaeaceae) is an evergreen tree. It is an important traditional medicinal plant, used to treat various infectious ailments including inflammatory diseases. It has also been used by Arabs and Japanese to treat digestive and sedative disorders. 9 and 10 Extracts of A. crassna have revealed significant antioxidant and cytotoxic properties. 11 Moreover, different parts of A. crassna have been studied and explored dynamic biological effects such as antioxidant, anti-ischemic, antifungal, and antibacterial effects. 12, 13, 14 and 15 To the best of our knowledge, there is no report on essential oils (EOs) extracted from Agarwood used against human pancreatic cancer. In the present study anti-metastatic properties of EOs on highly invasive and metastatic pancreatic cancer cell line (MIA PaCa-2) was evaluated. In addition, chemical profile of EOs of A. crassna was studied to identify the active principles present in the plant.
2. Materials and methods
2.1. Plants material and extraction of essential oils
Fresh sample of A. crassna stem bark was obtained from a local farm in Kajang, Selangor, Malaysia, in the year 2013. In addition, flowers and leaves with twigs were collected for taxonomical authentication and deposited at the School of Biological Sciences, USM (Ref. No. USM/122083). The bark of A. crassna was cleaned thoroughly, cut into small slices and ground mechanically. Ground material of the stem bark (500 g) was macerated with distilled water (5 L) at room temperature (25 ± 2 °C) for 1 week. Finally, hydrodistillation was employed on the extract for 48 h at boiling temperature of water. Essential oils (EOs) were obtained by Clevenger-type apparatus. The EOs were collected as pale-yellow liquid with 12.6 g yield.
