Ceratonia siliqua (Carob) is an evergreen Mediterranean tree, and carob pods are potentially nutritive and have medicinal value.
1. Introduction
Plants are of great interest in drug discovery and are the main source of our modern medicine. About 25% of modern medicines are derived from a plant origin and only 5–15% of plants are being investigated for their medicinal use
[1]. Today, medicinal herbs and functional foods are being widely studied resulting in lucrative therapeutic potentials
[2]. Where the secondary metabolites, which possessed antioxidant properties can fight several pathological disorders such as cancer, heart disease, hypertension, dementia, and stroke
[3]. However, chemotherapies have many adverse effects; several anti-diabetic drugs such as Rosiglitazone and Alogliptin can have severe complications. Therefore, scientists have tried to find naturally occurring anti-diabetic compounds as they have low toxic effects
[4]. In addition, the WHO has stated that if there is no action taken to develop/find new antibiotic agents, the deaths due to infection resistance will be greater than cancer
[5]. Bacteria develop resistance against antibiotics due to the presence of multi-drug resistance (MDR) pumps which are predominant in
Staphylococcus aureus,
Pseudomonas aeruginosa,
Escherichia coli, etc. Therefore, researchers are trying to find MDR inhibitors, especially those derived from medicinal plants, due to their diversity to increase the efficacy of antibiotics
[6].
Ceratonia siliqua L., Carob, is an evergreen tree that belongs to the
Leguminosae family. It is widely cultivated in most Mediterranean basin countries
[7]. The carob fruit (bean) is called a pod and is composed of two parts: the seeds (10%) and the pulp (90%). The pulp consists of two parts: a leathery outer layer (pericarp) and a softer inner area (mesocarp) which contain the seeds
[8][9][8,9]. Carob pulp contains a wide range of biologically active compounds, including polyphenols, sugars, cyclitols, amino acids, fibers, and minerals, whereas carob seeds contain gum, polyphenols, and proteins
[10]. Due to its chemical composition, carob and its ethanolic extract have a strong antioxidant activity and possess several valuable therapeutic functions, such as lipid-lowering
[11], anti-proliferative, anti-cardiovascular
[12], and nephroprotective properties
[13]. In addition, carob has exhibited significant pharmacological activities in the digestive tract including antidiarrheal, antibacterial, anti-ulcer, and anti-inflammatory actions, and possesses a laxative effect on gastrointestinal propulsion
[14].
2. The Phytochemical Ingredients of the CPAE
The phytochemical analysis revealed that CPAE contained many active compounds including total phenolics, flavonoids, carbohydrates, amino, acids, and alkaloids (
Table 1).
Table 1. Quantitative phytochemical component of the carob pod aqueous extract.
Parameters |
Concentration |
Total flavonoids (Rutin/100 mg CPAE) |
0.752 ± 0.11 |
Total phenolics (GA/100 mg CPAE) |
0.348 ± 0.07 |
Total amino acids (mg/mL) |
43.28 ± 2.1 |
Total alkaloids (mg/mL) |
15.3 ± 0.98 |
Total carbohydrates (mg/mL) |
5.1 ± 0.23 |