Antioxidant and Wound Healing Potential of Essential Oil from Citrus reticulata Peel and Its Chemical Characterization

Abstract

Background: Fruit peels are considered as waste and contribute towards a major proportion of biomass. They might be a good source of various therapeutic benefits. Peels biomass of citrus fruits are usually considered as garbage. Such peels may have many important and valuable medicinal components with pharmacological activities. Citrus reticulata, (of family Rutaceae, local name tangerine) is a local seasonal fruit in Pakistan which is a very good example regarding wastage of its peels. Objective: The study is based on exploration of a citrus fruit peel derived essential oil, its chemical characterization, identification of various bioactive components and the exploration of pharmacological potentials (antibacterial and wound healing activity). Method: Essential oil was recovered by hydro-distillation of freshly collected peels. Chemical constituents of oil were determined by gas chromatography-mass spectroscopy (GC-MS) analysis. Antioxidant activities were evaluated by total phenolic contents, total flavonoid content, DPPH scavenging activity and reducing power assay. Antibacterial activity was determined using disc diffusion assay. In vivo wound healing potential was determined in rabbits after topical administration of oil. Wound scoring was calculated followed by histological study. Results: GC-MS analysis showed presence of various components with greatest proportion of D-Limonene (89.31%). Total flavonoid and phenolic contents were found to be 14.63 ± 0.95 mg CE/g and 17.03 ± 3.24 mg GAE/g respectively while DPPH activity was found to be 73.32%. Better antibacterial activity was shown against E. coli. In vivo studies showed significant reduction in wound diameter in essential oil treatment groups. Further the essential oil was found non-irritant in draize scoring. Conclusion: The study concluded that essential oil of this fruit peel might be used for antibacterial and wound healing purposes.

The Second Life of Citrus Fruit Waste: A Valuable Source of Bioactive Compounds

“…However, a hydrodistillation method was employed to extract EO from Blanco peel, mainly constituted by limonene (89.31%), which exhibits antibacterial activity against Cutibacterium acnes and common microorganisms such as S. aureus , B. subtilis and E. coli [ 79 ]. In addition, besides the antimicrobial potential, EO from C. reticulata peel has been able to significantly reduce wound diameter in vivo, thus showing wound healing property [ 80 ]. Mandarin peels contain also a high total flavonoid content compared to lemon and grapefruit peels, and have been demonstrated to possess moderate cytotoxic activity against the HL-60 cell line, an experimental model of acute myeloid leukemia [ 81 ].…”

Fruit Peels: Food Waste as a Valuable Source of Bioactive Natural Products for Drug Discovery

“…Pear fruit peels also produced cinnamtannins B1 (130), aesculitannin A ( 131) and (−)-epicatechin-(4β→6)-(−)-epicatechin-(4β→8, 2β→O→7)-(−)-epicatechin (132) [95] and these proanthocyanidin trimers displayed anticancer, antibacterial and antioxidative effects [96][97][98][99]. (136) and quercetin (137) (Figure 16). The flavones 135 and 136 illustrated antioxidant effects with IC50: 43.5 and 39.1 µ g/mL, respectively [100].…”

“…It was found that isovitexin (145), vitexin (146), orientin (147), vitexin-2′′-Orhamnoside (148) and vitexin-4′′-O-glucoside (149) were reported from Benincasae exocarpium fruit peels and screened for antidiabetic effects. (136) and quercetin (137) (Figure 16). The flavones 135 and 136 illustrated antioxidant effects with IC 50 : 43.5 and 39.1 µg/mL, respectively [100].…”

“…Figure 15. Structures of flavonoids 127-132.The pear (Pyrus ussuriensis) peels produced flavones, including rutin(133), (−)-catechin(134), tricin 4′-O-[threo-β-guaiacyl-(7′′-O-methyl)-glyceryl] ether(135), tricin 4′-O-[threo-β-guaiacyl-(7′′-O-methyl-9′′-O-acetyl)-glyceryl] ether(136) and quercetin (137) (Figure16). The flavones 135 and 136 illustrated antioxidant effects with IC50: 43.5 and 39.1 µ g/mL, respectively[100].…”

Dynamic variation of the phytochemical and volatile compounds in the pericarp ofCitrus reticulata‘‘Chachi’’ (Rutaceae) during 2 years of storage

“…. There are abundant volatile oil and flavonoids observed in CRCP, of which volatile oil has been proven to be the characteristic substance contributing to the aroma of CRCP and possessing antioxidant properties (Ishfaq et al, 2021). The flavonoids are primarily divided into dihydroflavones and polymethoxyflavones (PMFs) (Tistaert et al, 2011), and the phytochemical studies have illustrated that the flavonoids could regulate gut microbiome and perform anti-tumor, anti-neuroinflammatory activities (Duan et al, 2017;Ho and Kuo, 2014;Zeng et al, 2020).…”