chemical composition of essential oils of citrus limon peel from three moroccan regions and their antioxidant, anti-inflammatory, antidiabetic and dermatoprotective properties

Introduction: the current study aimed to explore the in vitro antioxidant, anti-inflammatory, antidiabetic, and dermatoprotective properties of lemon peel essential oil (eo). methods: the chemical composition of lemon eos extracted from the lemon of three cities in morocco was investigated using gas chromatography-mass spectrometry (gc-ms) analysis. the antioxidant property was estimated by two complementary tests: ferric ion reducing antioxidant power (frap) and 1,1-diphenyl-2-picrylhydrazyl (dpph). the in vitro anti-inflammatory activity was assessed by the inhibition of albumin denaturation and proteinase. inhibitory properties of α-glucosidase and α-amylase were used to reveal the antidiabetic activity of lemon peel eos. dermatoprotective property was evaluated by the tyrosinase inhibition method. results: in addition to high amounts of polyphenols and flavonoids, gc-ms analysis of lemon peel eos demonstrated the presence of d-limonene, β–pinene, and γ-terpinene as the main compounds in the three samples studied. lemon peel eos exhibited significant antioxidant activities by ic50 values ranging from 40.57 µg/ml to 100.22 µg/ml and 113.63 µg/ml to 180.90 µg/ml obtained by dpph and frap tests, respectively. in vitro inhibition of enzymes involved in inflammatory response revealed that lemon peel eos presented remarkable inhibitory activities against albumin denaturation (230.48 µg/ml > ic50 < 341.13 µg/ml) and proteinase (199.70 µg/ml > ic50 < 307.05 µg/ml). moreover, lemon peel eos demonstrated powerful inhibition of α-amylase and α-glucosidase with various ic50 values (1689.06 µg/ml > ic50 > 4000 µg/ml and 1021.58 µg/ml > c50 < 2467.62 µg/ml), respectively. these eos also revealed significant inhibition of tyrosinase with ic50 values ranging from 248.42 μg/ml to 378.02 μg/ml. conclusion: these results revealed that lemon peel eos might constitute a new product with beneficial biological abilities against the mentioned complications.