The inhibition of α-glucosidase and α-amylase, enzymes involved in the digestion of carbohydrates, can significantly reduce the post-prandial increase of blood glucose and therefore can be an important strategy in the management of blood glucose level in type 2 diabetic and borderline patients. Currently, there is renewed interest in plant-based medicines and functional foods modulating physiological effects in the prevention and cure of diabetes and obesity. The plant kingdom is a wide field to search for natural effective oral hypoglycaemic agents that have slight or no side effects. More than ca. 1200 plant species have been recorded to be used empirically worldwide for their alleged hypoglycaemic activity. Therefore, natural α-glucosidase and α-amylase inhibitors from plant sources offer an attractive strategy for the control of hyperglycaemia. This article reviews recent data on plant extracts and isolated natural compounds that are being tested for their hypoglycaemic activity, highlights ongoing research and considers the future perspectives.

Essential oils are complex mixtures of hydrocarbons and their oxygenated derivatives arising from two different isoprenoid pathways. Essential oils are produced by glandular trichomes and other secretory structures, specialized secretory tissues mainly diffused onto the surface of plant organs, particularly flowers and leaves, thus exerting a pivotal ecological role in plant. In addition, essential oils have been used, since ancient times, in many different traditional healing systems all over the world, because of their biological activities. Many preclinical studies have documented antimicrobial, antioxidant, anti-inflammatory and anticancer activities of essential oils in a number of cell and animal models, also elucidating their mechanism of action and pharmacological targets, though the paucity of in human studies limits the potential of essential oils as effective and safe phytotherapeutic agents. More well-designed clinical trials are needed in order to ascertain the real efficacy and safety of these plant products.

Abstract:  Tyrosinase (EC 1.14.18.1), a copper‐containing enzyme, can cause enzymatic browning in raw fruits, vegetables, and beverages. Browning is an undesirable reaction that is responsible for less attractive appearance and loss in nutritional quality. These phenomena have encouraged researchers to seek new potent tyrosinase inhibitors for use in the food industry. This article reviews recent studies on tyrosinase inhibitors of natural and synthetic origins. The information offered here should help food industry in developing and using potential tyrosinase inhibitors desirable efficacy and safety, and for improving food quality.

Iridoids represent a large group of cyclopenta[c]pyran monoterpenoids that occur wide-spread in nature, mainly in dicotyledonous plant families like Apocynaceae, Scrophulariaceae, Diervillaceae, Lamiaceae, Loganiaceae and Rubiaceae. Recently, more extensive studies revealed that iridoids exhibit a wide range of bioactivity, such as neuroprotective, antinflammatory and immunomodulator, hepatoprotective and cardioprotective effects. Anticancer, antioxidant, antimicrobic, hypoglycaemic, hypolipidemic, choleretic, antispasmodic and purgative properties were also reported. The aim of the present review is to discuss the recent developments on biological and pharmacological activities of iridoids, supporting the new therapeutic possibilities for the use of these compounds.

The chemical composition of the essential oils of Laurus nobilis, Juniperus oxycedrus ssp. oxycedrus, Thuja orientalis, Cupressus sempervirens ssp. pyramidalis, Pistacia palaestina, Salvia officinalis, and Satureja thymbra was determined by GC/MS analysis. Essential oils have been evaluated for their inhibitory activity against SARS‐CoV and HSV‐1 replication in vitro by visually scoring of the virus‐induced cytopathogenic effect post‐infection. L. nobilis oil exerted an interesting activity against SARS‐CoV with an IC₅₀ value of 120 μg/ml and a selectivity index (SI) of 4.16. This oil was characterized by the presence of β‐ocimene, 1,8‐cineole, α‐pinene, and β‐pinene as the main constituents. J. oxycedrus ssp. oxycedrus oil, in which α‐pinene and β‐myrcene were the major constituents, revealed antiviral activity against HSV‐1 with an IC₅₀ value of 200 μg/ml and a SI of 5.