Carob (Ceratonia siliqua L.): A Comprehensive Review on Traditional Uses, Chemical Composition, Pharmacological Effects and Toxicology (2002-2022)

Carob (Ceratonia siliqua L.) is an evergreen tree widely cultivated in the Mediterranean contour thanks to its nutritional and economic value. Carob fruit (pods) and leaf preparations are used in traditional medicine as gastro-protective, anti-diarrheal, analgesic, laxative, hypocholesterolemic and anti-diabetic agents. Recent studies indicated that carob pods contain a variety of nutritional elements, including high amounts of carbohydrates, proteins (in seeds), and an appreciable amount of dietary fiber but low-fat content. Phytochemicals present in all parts of the plant are phenolic acids, flavonoids, hydrolysable and condensed tannins and volatile compounds, together with the functional sugar D-pinitol found in pods. These compounds were associated with many in vitro and in vivo pharmacological activities, including antioxidant, gastroprotective, anti-inflammatory, hypoglycemic, hypolipidemic, cardioprotective, anti-proliferative and cytotoxic activities. Clinical trials demonstrated a beneficial effect of carob fiber on cholesterolemia and the in vivo toxicological studies reported the safety of carob pulp and seeds, besides the low toxicity of leaves. This study aims to review the recent knowledge about the ethnopharmacological uses, nutritional and bioactive compounds available in Ceratonia siliqua, besides pharmacological effects and toxicity of carob pulp (unripe and ripe), seeds and leaves.