Limonene

Limonene is a monoterpene-type compound typically found in essential oils of plants. Manufacturers frequently use limonene as a flavor and scent in food, household, and personal care products. In turmeric, limonene is found in the rhizome, leaf, and in the rhizome's essential oil.

Limonene is also found in many citrus fruits (e.g., oranges, grapefruit, lemons, and lime) and herbs. These include angelica, anise, bay leaf, bergamot, pepper, caraway, cardamom, celery seed, chaste-tree, cilantro, cinnamon, citronella, cumin, dill, echinacea, eucalyptus, fennel, frankincense, hops, horehound, juniper berries, lavender, magnolia, mint, myrrh, Queen Anne's lace, rosemary, sage, St. John's wort, tamarind, tarragon, tea tree, and winter and summer savory. Research suggests these antioxidant fruits and herbs could help relieve stress, thinning hair, acne, wrinkles, and cellulite.

Limonene is a potent antioxidant and anti-inflammatory substance. In studies, limonene also shows the following properties and healthful activities:

• Acts as an antiviral agent against the flu, including influenza A (bird and swine flu) and influenza B.
• Has antibacterial properties.
• Can inhibit fungal infections.
• Stops cancer tumor growth by itself or combined with chemotherapy (including leukemia, stomach, prostate, and colon cancer).
• May help prevent breast, colon, liver, and lung cancer.
• Boosts the immune system.
• Reduces inflammatory protein levels in pleurisy.
• Helps regulate insulin.
• Protects against fatty liver disease.
• Helps dissolve gallstones.
• Relieves symptoms of gastric reflux.
• Possesses sedative and stress-reducing properties.
• Could help with epilepsy.

Limonene is also a good pesticide. It's toxic to:

• Bugs that attack garden vegetables (such as the European corn borer).
• Pesky insects such as the common housefly, termite, and cockroach.
• Bugs found in stored grains (e.g., in flour and rice).
• Rats.