Pharmacological and Pharmacognostic of Citrus aurantium A Comprehensive Review of Its Medicinal Properties and Safety Profile

Abstract

Citrus aurantium, commonly known as bitter orange, has been extensively studied for its pharmacological and pharmacognostic properties. It belongs to the Rutaceae family and is widely used in traditional and modern medicine. The plant is native to Southeast Asia but is now cultivated in many regions globally. Its fruits, flowers, leaves, and peels are used in various pharmaceutical, cosmetic, and culinary applications. The phytochemical profile of Citrus aurantium includes essential oils, flavonoids, alkaloids (such as synephrine), and other bioactive compounds that contribute to its medicinal properties. These components exhibit a broad spectrum of pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial, and anti-obesity effects. Synephrine, the major alkaloid, is often promoted as a natural stimulant and fat-burning agent, making it popular in weight-loss supplements. From a pharmacognostic perspective, Citrus aurantium is valued for its rich chemical composition, which varies depending on the part of the plant used. The fruit peel contains essential oils like limonene and linalool, while the leaves and flowers are rich in flavonoids such as naringin and hesperidin. The plant is also known for its aromatic properties, used extensively in the perfume and flavoring industries.

Introduction

I. INTRODUCTION

Citrus aurantium, commonly known as bitter orange or Seville orange, is a member of the Rutaceae family, valued for its diverse medicinal and commercial uses. Indigenous to Southeast Asia, it has been widely cultivated across regions like the Mediterranean, India, and the Americas, where it has integrated into both traditional healing systems and modern medical practices. Historically, the plant has been utilized for its wide-ranging benefits, from culinary applications to therapeutic remedies.

Phytochemically, Citrus aurantium is a rich source of bioactive compounds, including essential oils, flavonoids, and alkaloids. These constituents are primarily found in the fruit peel, flowers, leaves, and seeds, with synephrine being one of the most significant alkaloids. Synephrine is often highlighted for its stimulant properties, making it a key ingredient in many weight-loss and performance-enhancing supplements.

Other components like flavonoids (naringin, hesperidin) and essential oils (limonene, linalool) contribute to the plant's pharmacological versatility, offering antioxidant, antimicrobial, and anti-inflammatory benefits.

The pharmacological activities of Citrus aurantium extend across a broad range of therapeutic applications. It has been studied for its efficacy in managing obesity, enhancing metabolic rate, supporting digestion, and providing anti-inflammatory relief. Its antimicrobial properties also make it useful in combating infections and promoting wound healing. Furthermore, the essential oils derived from the plant are widely used in aromatherapy and the fragrance industry due to their pleasant and invigorating scent.

However, despite its many benefits, concerns regarding the safety of Citrus aurantium—particularly its synephrine content—have emerged, especially in relation to cardiovascular health.

Some studies have suggested that synephrine can elevate blood pressure and heart rate, raising concerns about its use in individuals with cardiovascular issues.

II. MORPHOLOGY OF CITRUS AURANTIUM (BITTER ORANGE)

Figure 1

Citrus aurantium, commonly known as bitter orange, is a small to medium-sized, evergreen tree belonging to the Rutaceae family. It exhibits a distinctive morphology that is characteristic of many citrus plants.

A. Size and Habit

Citrus aurantium typically grows between 3 to 10 meters in height. The tree has a rounded, dense canopy, and a thick, short trunk covered in rough, grayish-brown bark. The branches are often thorny, with sharp spines that are typical of many citrus species.

B. Leaves

The leaves of Citrus aurantium are simple, elliptical, or ovate, and glossy dark green on the upper surface, with a lighter green underside. They are alternately arranged on the stems, with petioles that are slightly winged, a feature that helps differentiate them from other citrus species. The leaf margins are slightly serrated, and they are aromatic when crushed, releasing a characteristic citrus scent due to the presence of essential oils.

C. Flowers

The flowers of Citrus aurantium are small (about 2-3 cm in diameter), white, and highly fragrant. They grow either singly or in clusters (cymes) in the leaf axils. The flowers are bisexual, with five white petals surrounding a central cluster of yellow stamens. The scent of the flowers is often described as sweet and intoxicating, and they are a primary source of the essential oil neroli, which is used in perfumes and aromatherapy.

Figure 2 Flower od Citrus aurantium

D. Fruit

The fruit of Citrus aurantium is a round to slightly oblong hesperidium (a type of berry) measuring about 7-10 cm in diameter. The outer rind (exocarp) is thick, rough, and bright orange when ripe, often with a dimpled texture. The rind contains numerous oil glands that give off a strong citrus fragrance. The inner part of the fruit is divided into 10 to 12 segments filled with pulp vesicles. The pulp is juicy but bitter, making the fruit more suitable for medicinal, culinary, and flavoring purposes rather than direct consumption. Inside the segments, seeds (usually 10-12) are present, which are oval, pale, and smooth.

E. Root System

Citrus aurantium develops a strong, deep taproot system that provides good anchorage and allows the tree to tolerate various soil types. Its fibrous lateral roots help in the efficient uptake of nutrients and water.

III. BENEFITS OF CITRUS AURANTIUM IN VARIOUS DISEASES

A. Obesity and Weight Management 

Citrus aurantium is widely recognized for its use in weight-loss products due to its high content of synephrine, a natural alkaloid that acts as a stimulant. Synephrine enhances metabolism by increasing thermogenesis (heat production) in the body and promoting fat oxidation, helping to burn fat more efficiently. This effect is beneficial for individuals struggling with obesity or those looking to manage their weight. Additionally, the plant has appetite-suppressing properties, aiding in the control of food intake.

B. Digestive Disorders 

Traditionally, bitter orange has been used to treat various gastrointestinal disorders. It stimulates the digestive system by increasing the secretion of digestive enzymes and bile, thereby enhancing digestion and alleviating conditions like indigestion, bloating, and constipation. Its flavonoids, particularly naringin and hesperidin, possess anti-inflammatory and antioxidant properties that help soothe the digestive tract and reduce symptoms of gastritis and irritable bowel syndrome (IBS).

C. Cardiovascular Health 

The flavonoids present in Citrus aurantium, especially hesperidin, have shown cardioprotective effects. They help improve blood circulation, reduce inflammation in blood vessels, and decrease cholesterol levels. However, while synephrine can be beneficial for weight management, it is also known to increase heart rate and blood pressure in some individuals, especially when consumed in large quantities. Therefore, people with pre-existing cardiovascular conditions should be cautious when using bitter orange supplements.

D. Respiratory Disorders 

Bitter orange is effective in treating respiratory issues such as bronchitis, colds, and sinus congestion. The essential oils extracted from the fruit’s peel act as natural decongestants and bronchodilators, helping to relieve congestion and promote easier breathing. Additionally, the antimicrobial and anti-inflammatory properties of the plant can assist in reducing inflammation in the respiratory system and combat bacterial or viral infections.

E. Skin Infections and Wound Healing 

The antimicrobial properties of Citrus aurantium make it useful in treating skin infections, cuts, and wounds. Its essential oils, especially limonene and linalool, have antiseptic properties that protect the skin from microbial invasion, accelerating wound healing. Moreover, the antioxidant-rich flavonoids help reduce inflammation and promote faster recovery of damaged skin.

F. Anxiety and Insomnia 

Bitter orange essential oil is commonly used in aromatherapy for its calming and relaxing effects. It has been traditionally used to treat mild anxiety and insomnia by inducing relaxation and improving sleep quality. The soothing aroma of the oil interacts with the central nervous system, providing relief from stress and anxiety symptoms.

Conclusion

Citrus aurantium offers promising pharmacological benefits, but its safety profile, particularly for prolonged use or in individuals with cardiovascular conditions, requires further investigation. As a multifunctional plant, it continues to hold significance in both traditional and modern therapeutic practices

References

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Copyright

Copyright © 2024 Shrutika Nale, Akanksha More, Rajendra Patil. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.