Natural Antioxidants of the Underutilized and Neglected Plant Species of Asia and South America

Background:

Plants have played an essential role in the search for new compounds for the most diverse therapeutic purposes. Recently, more attention is paid to natural antioxidants because of the possible insecurity of synthetic antioxidants

Objective:

The review is aimed at summarizing the most important and common natural antioxidants and their resources from medicinal plants.

Method:

The research was performed using data bases of PubMed, Google Scholar, Science Direct, Taylor and Francis, etc. to search for all collected scientific publications.

Results:

The most important medicinal plants with antioxidant activities in Iran are Artemisia, berberry fruit, borage, calendula, coriander, cumin, green tea, hawthorn, jujube, pomegranate, rose, rosemary, black zira, tea, and thyme. Important traditional medicinal plants with antioxidant activities in China are Asparagus, bindii, blueberries, camellia, Chinese bayberry, Chinese bitter melon, Chinese cabbage, Chinese cherry, Chinese jujube, Chinese olive, pomegranate, Chinese rose tea, Chinese toon, Chinese watermelon, black tea, knotweed, Chinese quince, Chinese rhubarb, sumac, wolfberry, dendrobium, drumstick tree, Fiscus species, ginger, ginkgo, goji berry, grape, Jerusalem thorn, kiwifruit seed oil, and liquorice root. Anacardium occidentale L., Ananas comosus (L.) Merril, Baccharis trimera (Less) DC., Carapa guianensis Aubl., Casearia sylvestris Sw., Cordia verbenacea DC., Croton lechleri Müll. Arg., and Eugenia uniflora L., are the main medicinal plants with antioxidant activities in Brazil.

Conclusion:

Antioxidants are those molecules which are involved in the scavenging of these reactive species causing oxidative stress, and defined as those substances which could prevent the oxidation of the substrate at low concentrations. The main derived exogenous natural antioxidants are derived from medicinal plants, fruits, foods, flowers, and traditional herbal medicines in different parts of the world.

Diosgenin and galactomannans, natural products in the pharmaceutical sciences

Background

Diosgenin is an isospirostane derivative, which is a steroidal sapogenin and the product of acids or enzymes hydrolysis process of dioscin and protodioscin. Galactomannans are heteropolysaccharides composed of D-mannose and D-galactose, which are major sources of locust bean, guar, tara and fenugreek.

Methods

Literature survey was accomplished using multiple databases including PubMed, Science Direct, ISI web of knowledge and Google Scholar.

Results

Four major sources of seed galactomannans are locust bean (Ceratonia siliqua), guar (Cyamopsis tetragonoloba), tara (Caesalpinia spinosa Kuntze), and fenugreek (T.foenum-graecum). Diosgenin has effect on immune system, lipid system, inflammatory and reproductive systems, caner, metabolic process, blood system, blood glucose and calcium regulation. The most important pharmacological benefits of galactomannan are antidiabetic, antioxidant, anticancer, anticholinesterase, antiviral activities, and appropriate for dengue virus and gastric diseases.

Conclusions

Considering the importance of diosgenin and galactomannans, the obtained findings suggest potential of diosgenin and galactomannans as natural products in pharmaceutical industries.

Clinical trials with plants in diabetes mellitus therapy: a systematic review

INTRODUCTION

The chronic metabolic disorder diabetes mellitus is a fast-growing global problem with huge social, health, and economic consequences, having one of the highest morbidities and mortality rates. Prolonged use of many available medications can produce undesirable side effects. Thus, plants appear as an important source of bioactive resources for the discovery of new treatments for diabetes.

AREAS COVERED

In this sense, this systematic review focused on clinical trials involving plants of National List of Medicinal Plants of Interest to the Unified Health System (RENISUS) (or compounds) with antidiabetic properties. We analyzed indexed studies in PubMed following the reporting guidelines of PRISMA.

EXPERT OPINION

Of the 51 clinical trials found, Curcuma longa, Glycine max, Zingiber officinale, Punica granatum, Aloe vera, Momordica charantia are the species with the greatest amount of clinical trials and the attenuation of insulin resistance, decreased fasting blood glucose and glycosylated hemoglobin levels are some of the main mechanisms by which these plants exert hypoglycemic effects. Thus, we speculate that the Clinical Pharmacology should explore the field of plant-based compounds that will keep concentrating the attention of researchers, and therefore, we gathered studies in advanced stages that highlight the role of plants in the diabetes therapy.