Arbutus unedo L., (Ericaceae) inhibits intestinal glucose absorption and improves glucose tolerance in rodents.

ETHNOPHARMACOLOGICAL RELEVANCE: Arbutus unedo L., (Ericaceae) is one of the most traditional plants commonly used to treat diabetes in people living in Eastern Morocco region particularly in Taza and Beni Mellal. AIM OF THE STUDY: The aim of the study was to find if there is a scientific support to the ethnopharmacological relevance use of Arbutus unedo L., roots bark (AU) to treat diabetes. MATERIALS AND METHODS: We studied the effects of crude aqueous extract of AU on intestinal glucose absorption using short-circuit current technique in vitro and oral glucose tolerance test in vivo. RESULTS: The aqueous extract of AU (10 µg/mL to 1 mg/mL) induced concentration-dependent inhibition of sodium-dependent glucose transport across isolated mouse jejunum. The maximal inhibition was obtained with 1 mg/mL, which exhibited more than 80% of the Phloridzin inhibition with an IC50 close to 216 µg/mL. A 6-week AU ingestion (2 g/(kg day)), improved oral glucose tolerance as efficiently as metformin (300 mg/(kg day)). Arbutus unedo L. and metformin also reduced body weight. CONCLUSIONS: Arbutus unedo L. roots bark aqueous extract directly inhibited the electrogenic intestinal absorption of glucose in vitro. In addition it improved oral glucose tolerance and lowered body weight in rats after chronic oral administration in vivo. These results add a scientific support to the ethnopharmacological relevance use of Arbutus unedo L. roots bark to treat diabetes.

Integrative herbal treatments of diabetes in Beni Mellal region of Morocco.

OBJECTIVES: Diabetes is one of the most life-threatening chronic metabolic disorders and is considered a global health problem due to its prevalence and incidence. In Morocco, several herbal preparations are utilized to treat this disease. For this reason, the current study aimed to identify and to collect data about the medicinal plants utilized in folk medicine for the treatment of diabetes in the Beni Mellal region of Morocco. METHODS: An ethnobotanical survey was carried out among 400 herbalists, competent villagers and traditional healers from the Beni Mellal region through direct interviews using a semistructured questionnaire. RESULTS: Forty-five medicinal plants belonging to 25 families were identified for their use in diabetes treatment. Interview results showed that the most frequently used plants were Olea europaea, Salvia officinalis, Allium sativum and Trigonella foenum-graecum, with a relative frequency of citation values of 24.3%, 23.0%, 22.5% and 20.5%, respectively. Moreover, in this study, the Fabaceae family was the most commonly reported plant family, and the leaves and roots were the most commonly used parts, for the treatment of diabetes. CONCLUSION: The Beni Mellal region of Morocco has an important floristic biodiversity of plants used to treat diabetes in traditional medicinal practice. This result provides a good database for pharmacological screenings in the search for plant-based antidiabetic medications.

Nigella sativa inhibits intestinal glucose absorption and improves glucose tolerance in rats.

AIM OF THE STUDY: Nigella sativa L. (Ranunculaceae) seeds have been used traditionally for centuries, notably for treating diabetes. MATERIALS AND METHODS: We studied the effects of the crude aqueous extract of Nigella sativa seeds on intestinal glucose absorption in vitro using a short-circuit current technique and in vivo using an oral glucose tolerance test. RESULTS: The aqueous extract of Nigella sativa (0.1 pg/ml to 100 ng/ml) exerted dose-dependent inhibition of sodium-dependent glucose transport across isolated rat jejunum. Maximal inhibition exceeded 80% and IC50 was close to 10 pg/ml. An oral glucose tolerance test was carried out in rats after the initial dose and after a 6-week treatment of Nigella sativa (2 g/(kg day)), and compared to metformin (300 mg/(kg day)). Chronic Nigella sativa treatment improved glucose tolerance as efficiently as metformin. Nigella sativa and metformin also reduced body weight without any toxic effect. CONCLUSIONS: To our knowledge, this is the first demonstration that Nigella sativa directly inhibits the electrogenic intestinal absorption of glucose in vitro. Together with the observed improvement of glucose tolerance and body weight in rats after chronic oral administration in vivo, these effects further validate the traditional use of Nigella sativa seeds against diabetes.