Updated Organic Composition and Potential Therapeutic Properties of Different Varieties of Olive Leaves from Olea europaea

Abstract

Olea europaea L. folium merits further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of Madural, Verdeal, and Cobrançosa elementary leaves and leaf sprouts (mamões) collected in the region of Valpaços, Portugal. Organic analysis assessed the moisture content, total carbohydrates, ash, protein, and fat contents, total phenolic content (TPC), vitamin E, and fatty acid (FA) profiles. Moisture content was determined through infrared hygrometry and TPC was determined by a spectrophotometric method. Concerning organic analysis, all leaf samples showed similar moisture content, though Cobrançosa’s leaf sprouts and Verdeal’s elementary leaves had slightly lower contents. Meanwhile, these cultivars also showed a higher TPC, α-tocopherol isomer, and fatty acid composition (FAC). FAC in all samples exhibited higher contents of PUFA and SFA than MUFA, with a predominance of linolenic and palmitic acids. Organic analyses of Cobrançosa’s leaf sprouts and Verdeal’s elementary leaf extracts allow for the prediction of adequate physiological properties regarding neuroinflammatory, neurobehavioral, metabolic, cardiovascular, osteo-degenerative, anti-ageing, pulmonary, and immunological defense disorders. These physiological changes observed in our preliminary in silico studies suggest an excellent nutraceutical, which should be borne in mind during severe pandemic situations.

Updated Mineral Composition and Potential Therapeutic Properties of Different Varieties of Olive Leaves from Olea europaea

“…Fundamentally, the results of the inorganic analysis showed a composition in kg of leaves close to or above the DRI values for the following components: Ca, Cu, Fe, K, Mg, Mn, P, Sb, Sr (except for Verdeal’s leaf sprouts), and Zn. Among those metals currently considered essential for normal biological functioning, we found Na, K, Mg, and Ca and block transition metal elements Mn, Fe, and Cu [ 19 ].…”

“…For this reason, it is crucial to understand the biochemical composition of olive tree leaves from the most relevant cultivars. Therefore, in this context, previous research was performed to assess the organic composition [ 19 ]. The present work aims to assess the inorganic parameters of the elementary leaves and “ mamões ” (leaf sprouts) of cultivars for which only data regarding the organic profile have been reported (data not shown).…”

Potential Therapeutic Properties of Olea europaea Leaves from Selected Cultivars Based on Their Mineral and Organic Profiles

“…The highest value of total fat content was shown by the O. europaea Cobrançosa leaves, at 5.03 ± 0.04% ( Table 2 ). Despite the leaves from the remnant cultivars displaying a lesser amount of total lipidic content, being 4.80 ± 0.50% for O. europaea Verdeal and 4.50 ± 0.30% for O. europaea Madural, respectively ( Table 2 ), these are still greater than the amount of total fat found in any sample of the previous study, where the upper value stands out at 4.01 ± 0.14% in the O. europaea Verdeal cultivar [ 29 ]. This might relate to differences between the cultivation methods, climate patterns, and soil composition concerning the two distinct harvest locations.…”

“…Essentially, the inorganic analysis showed a composition in kg of leaves close to or above the daily recommended intake (DRI) values for the following components: Ca, Cr (except for the O. europaea Madural leaf extracts), Cu, Fe, K, Mg, Mn, Sr, Zn, and P, of which the Zn contents are also line with the last study [ 39 ]. Amidst metals currently considered essential for normal biofunctioning, our results identified Na, K, Mg, and Ca and block transition metal elements Mn, Fe, and Cu [ 29 ]. Chronic low body calcium levels in osteoporosis are usually counteracted through a balanced diet and calcium supplements, often associated with vitamin D and/or Mg [ 39 ].…”

“…Not only do numerous studies confirm that olive leaves are able to decline blood pressure, improve blood flow in the coronary arteries [ 20 , 21 ], regulate arrhythmia, and prevent intestinal smooth muscle spasms [ 22 ], but their antimicrobial potential against bacteria, fungi, and mycoplasma has also been highlighted [ 23 , 24 , 25 , 26 , 27 ]. Like olive oil, the therapeutic benefits of O. europaea L. folium have been credited to low-molecular-weight polyphenols such as oleuropein (up to 60–90 mg/g dry leaf weight), hydroxytyrosol, tyrosol, and vitamin E isomers of tocopherol, elenolic acid derivatives, caffeic acid, p -coumaric acid, and vanillic acid, as well as flavonoids—luteolin, diosmetin, rutin, luteolin-7-glucoside, apigenin-7-glucoside, and diosmetin-7-glucoside [ 28 , 29 ]. The relevance of the whole olive leaf and its extract has been quickly rising in both pharmaceutical and food industries, not only as a functional food but also as a material used in food additives for preservation [ 30 , 31 ].…”