Studies of Phytochemicals, Antioxidant, and Antibacterial Activities of Pinus gerardiana and Pinus roxburghii Seed Extracts

Abstract

Pine seeds are considered as nonwood forest products (NWFP) with regularly increasing market’s demand. They can be eaten in various ways such as roasted or raw. In addition, they are included in various traditional dishes like in cookies, sauces, candies, cakes, breads, and other bakery items and, moreover, for medicinal purposes. GC-MS study is performed to analyze the phytochemical compounds present in the seed extracts of Pinus roxburghii (Chir) and Pinus gerardiana (Chilgoza). In total, 25 compounds were identified each in Chir and Chilgoza. In Chir seeds, abundantly present compounds were 2,4-di-tert-butylphenol (16.6%), followed by ç-Terpinene (9.9%) and cyclohexanol, 4-ethenyl-4-methyl-3-(1-methylethenyl)-, (1à,3à,4á) (9.8%), whereas in Chilgoza seeds, the maximum amount of compound was 1-hexyl-1-nitrocyclohexane (17.3%), followed by phenol, 2,6-bis(1,1-dimethylethyl) (15.4%), and heptadecane, 2-methyl (8.4%). The total phenolic content of Chir seed sample was $1536\pm 4.35$ (mg GAE/100 g), whereas in the Chilgoza seed extract was $642.66\pm 2.08$ (mg GAE/100 g). The application of RP-HPLC-DAD system revealed that Chir and Chilgoza seeds have maximum quantity of catechin ( $15.77\pm 0.16$  μg/mg and $17.49\pm 0.32$  μg/mg, respectively). Both Chir and Chilgoza seed extracts exhibited significant antioxidant (radical scavenging) potential, through H2O2 ( $618.94\pm 21.45$  μg/mL and $575.16\pm 19.88$  μg/mL) and DPPH ( $552.60\pm 13.03$  μg/mL and $429.15\pm 3.80$  μg/mL) assays, respectively. Additionally, a well-known antibacterial potential was also found in both plants’ dichloromethane extracts, with 64 to 256 μg/mL of minimum inhibitory concentrations. As a whole, result shows the importance of both plants as a naturally occurring phytochemical source with significant antibacterial and antioxidant activity.