Linoleic acid‐rich guava seed oil: Safety and bioactivity

Abstract

Guava (Psidium guajava) is a widely consumed fruit and has been commercialized in markets. The seeds are by-products of the processing procedures performed by the commercial guava juice industry. They are considered a nutritional resource that has been poorly utilized as they contain essential fatty acids such as linoleic acid (LA) and phenolics in abundance. In the study, guava seed oil (GSO) was used, which was obtained by hexane extraction of guava seeds to determine composition and test toxicity, cell migration, cancer cell viability, and plasmodium growth. GSO was found to be relatively nontoxic to normal hepatocytes and peripheral blood mononuclear cells, with mice for 14 days showing median lethal dose (LD 50 ) > 10 mg/kg and rats for up to 90 days. Surprisingly, the oil inhibited the proliferation of the human erythroleukemic cells in a dose-dependent manner with the half maximal inhibitory concentration values of 155 and 137 μg/ml at 24 and 48 hr, respectively. Importantly, GSO at 500 μg/ml was found to increase the degree of migration of keratinocytes (HaCaT). These observations suggest that edible P. guajava seed oil, which is abundant with linoleic acid and antioxidants, can promote skin wound healing and inhibit the proliferation of leukemic cells.

Phytosterol, Lipid and Phenolic Composition, and Biological Activities of Guava Seed Oil

“…Notably, Eschscholtzxanthin is one of the red pigment carotenoids that is synthesized in the leaves of several plants as a response to photoinhibitory conditions during winter acclimation and displays antioxidant activity [43]. Consistently, we have demonstrated the anti-leukemic and anti-plasmodium activities of GSO [24]. Recently, we reported that the hexane extract of GSO was abundant with α-tocopherol (23.0 mg/kg) and β-tocotrienol (70.5 mg/kg) [17,44].…”

“…The GSO obtained was decolorized with activated charcoal and stored in a plastic container in the dark at 4 • C for further study. From the chromatographic analyses, we found that the GSO contained linoleic acid, palmitic acid and oleic acid (69.95%, 6.14% and 10.47% of total fatty acids, respectively), with a n3/n6 ratio of 1:224; α-tocopherol (23.0 mg/kg); β-tocopherol (1.5 mg/kg); γ-tocopherol (1.4 mg/kg); β-tocotrienol (70.5 mg/kg); δ-tocotrienol (17.4 mg/kg) and γ-tocotrienol (4.0 mg/kg) [24].…”

“…GSO possessed strong anti-oxidation and inhibitory activities against low-density lipoprotein peroxidation and Gram-negative bacteria [22,23]. Recently, we have revealed that the edible hexane extract of GSO is rich in linoleic acid, and contains some amounts of tocopherols, tocotrienols and phenolic compounds [24]. It is highly likely that phytochemicals in GSO present nutraceutical effects and benefits for health in humans.…”

Antiulcer Potential of Psidium guajava Seed Extract Supported by Metabolic Profiling and Molecular Docking

“…The identified compounds as shown in Figure 1 were assorted into different chemical classes. Identification of the compounds was achieved based on HR-ESIMS data and comparison with literature data as follows: Cis-3-Hexenyl isobutyrate (1) [37], cinnamyl acetate (2) [38], coumaric acid (3) [39], β-sitosterol (4) [39], α-tocopherol (5) [39], linoleic acid (6) [39], palmitic acid (7) [39], stearic acid (8) [39], oleic acid (9) [39], linolenic acid (10) [39], vanillic acid (11) [39], 4-Hydroxybenzaldehyde (12) [39], vanillin (13) [39], syringaldehyde (14) [39], coniferylaldehyde (15) [39], sinapaldehyde (16) [39], abscisic acid (17) [39], cinnamic acid (18) [39], cinnamaldehyde (19) [39], campesterol (20) [39], stigmastanol (21) [39], stigmasterol (22) [39] and quercetin 4 -glucuronide (23) [40]. Guava seed extract provided substantial protection against the ulcerogenic effects of indomethacin in a dose-dependent manner (Table 1).…”

“…The anti-inflammatory, antihypertensive, blood glucose lowering effect, antiviral and cough sedative activities are the key factors which labelled the guava fruit to be a perfect candidate to protect against COVID-19 infection especially for chronic diseased individuals [ 20 ]. Guava seeds (PGE) as a waste product of the commercially important fruit was evaluated as an inhibitor for the proliferation of the human erythroleukemic cells with low toxicity [ 21 ], the seed oil contains unsaturated fatty acids especially, linoleic acid and possessed a high antioxidant activity [ 22 ]. In addition to seed fatty acids, the seeds were found to be rich with proteopolysaccharides with potent anti-inflammatory and immunomodulatory effects [ 23 ], peptides from guava seeds were reported to perform antimicrobial effects against gram-negative bacteria [ 24 ], the phenolic content of the seeds extracted by supercritical fluid extraction performed a high antioxidant activity [ 25 ].…”