Volatile constituents of Pinus roxburghii from Nepal

Background

Pinus roxburghii Sarg. Is one of 3 species of pine found in Nepal, the oil of which is traditionally used to treat cuts, wounds, boils, and blisters.

Objective

To obtain, analyze, and examine the anti-microbial and cytotoxic activities of the essential oils of P. roxburghii.

Materials and Methods

Three plant parts (cone, needle, and bark) of Pinus roxburghii were collected in Biratnagar, Nepal. The essential oils were obtained by hydrodistillation, and the chemical compositions were determined by GC-MS. The needle and cone essential oils were screened for anti-microbial activity against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Aspergillus niger; brine shrimp (Artemia salina) lethality; and in-vitro cytotoxicity against MCF-7 cells.

Results

GC-MS analysis for the cone oil revealed 81 compounds with 78 components being identified (95.5% of the oil) while 98.3% of needle oil was identified to contain 68 components and 98.6% of the bark oil (38 components) was identified. The 3 essential oils were dominated by sesquiterpenes, particularly (E)-caryophyllene (26.8%-34.5%) and a-humulene (5.0%-7.3%) as well as monoterpene alcohols terpinen-4-ol (4.1%-30.1%) and a-terpineol(2.8%-5.0%). The monoterpene q-3-carene was present only in needle and cone essential oils (2.3% and 6.8%, respectively). Bio-activity assays of the cone essential oil of P. roxburghii showed remarkable cytotoxic activity (100% killing of MCF-7 cells at 100 μg/ mL) along with notable brine shrimp lethality (LC₅₀=11.8 μg/mL). The cone essential oil did not show anti-bacterial activity, but it did exhibit anti-fungal activity against Aspergillus niger (MIC=39 μg/mL).

Conclusion

The bioactivity of P. roxburghii essential oil is consistent with its traditional medicinal use.