Introduction to Bergamot
Bergamot (Citrus bergamia ) is a citrus fruit known for its aromatic and medicinal properties, belonging to the Rutaceae family , mainly widespread in Calabria, Italy. This fruit is renowned for its essential oil used in perfumery and for its cholesterol-lowering properties . In this article we will explore its complex botanical origin, the characteristics of the plant, the properties of flavonoids and its role in reducing cholesterol.
Taxonomy and Nomenclature of the Citrus Genus
The taxonomy and nomenclature of the genus Citrus (family Rutaceae ) are complex and continually evolving with modern molecular biology techniques. The classification of citrus species is difficult to define, considering the large number of interspecific hybrids and cultivars. Flavonoids present in citrus fruits, including bergamot , are important not only for their aromatic value, but also for their medicinal properties, which include positive effects on cholesterol.
Origins of Bergamot
The difficulties in precisely defining the phylogeny of bergamot , i.e. its genetic and geographical origins, are linked to the complexity of its study. Bergamot (Figure 1) is an interspecific hybrid that derives from the crossing of different citrus species: Citrus x aurantium (bitter orange), Citrus x limon (lemon), Citrus x aurantifolia (lime), or even from Citrus medica (citron), as confirmed by recent studies ( Valussi et al., 2021).
Figure 1. Botanical table of bergamot ( from Köhler , HA Köhler's Medizinal-Pflanzen . Arch. Pharm . 1887, 225, 276 ) .
According to some sources, bergamot originated in Calabria or, more generally, in southern Italy . Other theories suggest that bergamot originated outside Italy, in the Antilles , Greece or the Canary Islands , and that it was then introduced to Calabria between the 14th and 16th centuries, where today about 90% of the world's bergamot is produced. Some claim that the fruit was brought to Italy by Christopher Columbus through the Spanish city of Berga in Catalonia , which would have inspired the name of bergamot.
However, the most plausible hypothesis is that the name bergamot derives from the Turkish ' beg -a-mudi ' or ' beg armudu ', which means 'pear of the Prince' or 'pear of the Lord', referring to the shape and importance of the fruit (Dugo and Bonaccorsi, 2013).
There are also disagreements among taxonomists regarding the correct scientific name, as reported in Table 1 .
Table 1. Nomenclature of bergamot according to different institutions and authorities in the field of taxonomy (taken from Valussi et al., 2021) .
|
Authority/institution |
Binomial nomenclature |
|
Integrated Taxonomic Information System |
Citrus aurantium subsp. bergamia (Risso & Poit .) Wight & Arn. ex Eng l . |
|
International Plant Names Index |
Citrus bergamia Risso |
|
Tropics |
Citrus × bergamot Rice & Poit . |
|
World Checklist of Selected Plant Families |
Citrus limon (L.) Osbeck |
|
US Department of Agriculture: Agricultural Research Service |
Citrus × limon (L.) Osbeck var. bergamia (Loisel.) uned . |
|
Mabberley's Plant Book |
Citrus × limon , Bergamot group |
Some authors identify four subgroups of bergamot , different based on the morphology of the plant and the fruit, as well as the flavour and aroma of the latter :
-
Small
-
Torulous
-
Applerose
-
Common
This last group is the most important from an industrial point of view and includes the cultivars 'Castagnaro', 'Femminiello' and 'Fantastico' (or 'Inserto'), the latter, in turn, a more recent hybrid (obtained around 1940) between the first two cultivars ( Dugo and Bonaccorsi, 2013 ) .
Agronomic description of Bergamot
From an agronomic and botanical point of view , the bergamot tree is grafted onto bitter orange rootstock and pruned to 4-5 meters in height, with a leaf cover of about 5 meters in diameter. The bergamot has large, alternate leaves, similar to those of the lemon in color and shape. The flowers, white and characterized by an unmistakable scent, sprout at the beginning of spring (between March and April). The bergamot fruit is a modified berry called hesperidium, with a pear-shaped shape, with a weight that varies between 80 g and 200 g. The outer peel of the bergamot has a variable thickness and can be smooth or wrinkled. The peel is divided into a thin, colored exocarp, called flavedo, and a deeper mesocarp called albedo.
The fruit contains the juicy part of the bergamot, namely the endocarp, with pulp ranging in color from green to pale yellow, with an acidic and bitter taste. Bergamot fruits can be harvested between December and February, when they reach maturity. During maturation, the flavedo develops cavities called lacunae , which fill with essential oil , which can be extracted by cold pressing (Rapisarda et al., 1996; Fatta Del Bosco et al., 2020).
In Calabria , which produces about 90% of the world's bergamot, cultivation takes place on about 1400 hectares, along the coastal strip of Reggio from Villa San Giovanni to Monasterace , on the Ionian Sea. This area is protected from the north winds by the Aspromonte , and the ideal climatic conditions – with average temperatures among the highest in Italy and the absence of frost – make it possible to grow high-quality bergamot (Amato et al., 2013; Nesci et al., 2014).
From a nutritional point of view, bergamot is rich in vitamins , mineral salts and bioactive phytochemical compounds, with recognized health properties. Bergamot juice is particularly rich in flavonoids , such as neoeriocitrin , neohesperidin , naringin , and rutin , known for their biological activities, including hypocholesterolemic ( Adorisio et al., 2023).
Flavonoids, secondary metabolites derived from phenylalanine and malonyl CoA, are divided into several groups, with flavanones being particularly representative in bergamot juice. These compounds have shown positive health effects, contributing to cardiovascular and metabolic well-being ( Adorisio et al., 2023).
The most representative flavonoids in bergamot juice are :
-
Neoeriocitrin
-
Neohesperidin
-
N herringin a
-
R u tin a
-
Neodesmin a
-
R oifolin a
-
poncirin a
(Figure 2).
Figure 2. Chemical structure, molecular formula and molecular weight (MW) of the main flavonoids present in bergamot juice .
The studies
Systemic inflammation and hypercholesterolemia are recognized as crucial risk factors for the development and progression of cardiovascular diseases, including atherosclerosis. Numerous clinical studies have demonstrated the efficacy of flavanones present in bergamot juice in controlling dyslipidemia and improving the lipid profile.
In a study conducted on 80 subjects with moderate hypercholesterolemia, a bergamot extract containing 150 mg of flavonoids, including neoeriocitrin , neohesperidin and naringin , was administered . After 6 months of treatment, a significant reduction in total cholesterol, LDL and triglycerides was observed, with an increase in HDL cholesterol. In addition, an improvement in carotid arterial wall thickness was found, suggesting that supplementation with bergamot polyphenols may reduce plasma lipids and improve the lipoprotein profile in subjects with moderate hyperlipidemia (Toth et al., 2016).
Another study analyzed the effect of a bergamot-based supplement on subjects with moderate hypercholesterolemia. The intake led to a reduction in C-reactive protein levels, improving parameters of systemic inflammation and endothelial reactivity (Fogacci et al., 2022). Previously, a study had shown that bergamot extract reduced TNF-α levels in overweight subjects with dyslipidemia (Cicero et al., 2019).
In a further study, the lipid-lowering effect of a bergamot-based product, BrumexTM , was observed, which reduced the cholesterol and triglyceride content in HepG2 cells in vitro. A subsequent clinical trial confirmed these results, showing significant improvements in the lipid and lipoprotein profile of participants, including reductions in total cholesterol, LDL, triglycerides and fasting blood glucose levels (Pierdomenico et al., 2023).
Furthermore, a pilot study documented the bioavailability of flavanones from bergamot juice, identifying several plasma and urinary metabolites, including sulfates and glucuronides of hesperidin , naringenin , and eriodictyol . Some of these metabolites showed anti-inflammatory activity, reducing the gene expression of inflammatory markers such as IL-1b, IL-6, IL-8, and TNF-α (Spigoni et al., 2017).
These results suggest that bergamot, thanks to its flavonoids and other bioactive components, could represent a valid support in the management of dyslipidemia and inflammation, with potential benefits for cardiovascular health.
The cholesterol-lowering properties of bergamot juice are summarized in Table 2 .
Table 2. Effects of bergamot on dyslipidemia : clinical studies
|
Bergamot based product |
Pathological condition/ experimental model |
Biomarkers |
Bibliographic references |
|
Brumex TM |
Patients with moderate hypercholesterolemia |
Total cholesterol, triglycerides, LDL cholesterol, non-HDL cholesterol, apolipoprotein B100, fasting blood glucose, glutamic- oxaloacetic transaminase , glutamate-pyruvate transaminase , gamma- glutamyl -transferase |
Pierdomenico et al., 2023 |
|
Nutraceutical product containing bergamot extract |
Patients with moderate hypercholesterolemia |
High sensitivity C-reactive protein , endothelial reactivity |
Fogacci et al., 2022 |
|
Extract Of bergamot |
Overweight patients with dyslipidemia |
High-sensitivity C-reactive protein , TNF- α |
Cicero et al., 2019 |
|
Bergamot extract |
Patients with moderate hypercholesterolemia |
Total cholesterol, LDL cholesterol, triglycerides, HDL cholesterol, intima-media thickness of the carotid arterial wall |
Toth et al., 2016 |
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