Curcumin is the yellow-colored bioactive constituent of the perennial plant, Curcuma longa L., which possesses a wide range of physiological and pharmacological properties such as antioxidant, anti-inflammatory, anticancer, neuroprotective and anti-diabetic activities. Anti-diabetic activity of curcumin may be due to its potent ability to suppress oxidative stress and inflammation. Moreover, it shows a beneficial role on the diabetesinduced endothelial dysfunction and induces a down-regulation of nuclear factor-kappa B. Curcumin possesses a protective role against advanced glycation as well as collagen crosslinking and through this way, mitigates advanced glycation end products-induced complications of diabetes. Curcumin also reduces blood glucose, and the levels of glycosylated hemoglobin in diabetic rat through the regulation of polyol pathway. It also suppresses increased bone resorption through the inhibition of osteoclastogenesis and expression of the AP-1 transcription factors, c-fos and c-jun, in diabetic animals. Overall, scientific literature shows that curcumin possesses anti-diabetic effects and mitigates diabetes complications. Here we report a systematical discussion on the beneficial role of curcumin on diabetes and its complications with emphasis on its molecular mechanisms of actions.

Citrus aurantium L. (Rutaceae), commonly known as bitter orange, possesses multiple therapeutic potentials. These biological credentials include anticancer, antianxiety, antiobesity, antibacterial, antioxidant, pesticidal, and antidiabetic activities. The essential oil of C. aurantium was reported to display marked pharmacological effects and great variation in chemical composition depending on growing locations but mostly contained limonene, linalool, and β‐myrcene. Phytochemically, C. aurantium is rich in p‐synephrine, an alkaloid, and many health‐giving secondary metabolites such as flavonoids. Animal studies have demonstrated a low affinity of p‐synephrine for adrenergic receptors and an even lower affinity in human models. The present review focuses on the different biological activities of the C. aurantium in animal and human models in the form of extract and its pure secondary metabolites. Finally, it is concluded that both the extract and isolated compounds have no unwanted effects in human at therapeutic doses and, therefore, can confidently be used in various dietary formulations.

Drying is one of the foremost and important steps during the processing of agricultural crops, medicinal plants and herbs to preserve their properties. The present review provides a detailed overview regarding the effect of drying techniques on the physio-chemical properties (microstructure, color, aroma composition) and bioactive compounds (phenolic compounds, carotenoids, essential oils, etc.) of plant materials. Factors affecting different drying processes and their optimization strategies have also been discussed. Furthermore, current trends in the development of drying techniques for plant materials in terms of the retention of their bioactive compounds are critically analyzed. Based on the published research articles, oven drying, and microwave drying are the preferable techniques for most plant parts; while for drying the plant extract, freeze/spray drying methods have gained higher interest. Finally, recommendations are made considering the better use of drying techniques for both plant materials and retention of their bioactive compounds.