Terpene is an organic hydrocarbon compound which is volatile in nature. It is produced in the epidermal cells i.e. glandular trichomes[2], in the plants. It is found in the essential oils and is known to possess an aroma.

Lime and citrus peels contain a high dosage of a terpene compound called d-limonene. In lab studies with animals, d-limonene had a considerable positive effect on cancer cells. More recently, in a study conducted by the University of Arizona on a group of 43 women with operable breast cancer, those given 2 grams of limonene daily showed a 22% reduction in the expression of tumor markers. Another study linked citrus peels to a reduced risk of cancerous skin cells. The limonene terpene has been objectively linked to anti-inflammatory, anti-carcinogenic, and anxiety-fighting effects.

Lime juice is a proven antibacterial and antiviral. It has powerful antiviral properties on the mucous membranes in the nose and throat when ill, and boosts the immune system internally. The fruits’ anti-inflammatory properties help fight respiratory tract infections, sore throats and inflammation of the tonsils.

“ In an increasing search for natural products that may heal the ulcers and avoid its recurrence, limonene appears as a promising candidate. Hypothesis/purpose: The present study aimed to investigate the protective effect of limonene in ethanol-induced gastric ulcers, in addition, to investigate the involvement of antioxidant and anti-inflammatory activities, besides the modulation of gene expression.Results demonstrate that oral treatment with limonene exerts gastroprotection through local mucosal defense mechanisms, such as increasing the mucus production, modulation of the oxidative stress and inflammatory response and inhibition of Nf-κb expression.” (5)

The stress-induced hormone corticosterone initiates oxidative stress and inflammatory responses, culminating in cell apoptosis and neurological changes. d-Limonene increased levels of the antioxidant enzymes superoxide dismutase d-Limonene has a neuroprotective effect on corticosterone-induced PC12 cell injury induced by activating the AMPKα signaling pathway, and thereby inhibiting reactive oxygen species and inflammatory factors. These data suggest that d-limonene might protect against neuronal death to improve depressive symptoms.(6)

“Stress is closely linked by its biological mechanisms to inflammation and by its consequences to accelerated aging. Stress triggers a hormonal response along the hypothalamus-pituitary-adrenal (HPA) axis, which can disrupt the ortho/parasympathetic balance essential for a harmonious life. Proper nutrition, adequate physical activity, and limiting the harmful influence of stress play important roles in avoiding the development of disease and promoting healthy aging. d-Limonene, a monoterpene shown to reduce inflammatory parameters in several pre-clinical and clinical models, could also produce an anti-stress action by altering ortho/parasympathetic parameters as well as central neurotransmitter functions.”(7)