Potential of coumarins against Covid-19.

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Background: Hyphaene thebaica L. Mart. (Doum-palm), rich in total phenolics content, is known for its medicinal value in the treatment of several health conditions, such as hypertension, and diabetes mellitus. Aim of the Study: To investigate the hypoglycaemic activity of the dichloromethane, ethyl acetate, and aqueous fractions from doum palm leaves. Then, to characterize the metabolic profile of the most active fraction by LC-HR-MS/MS analysis to detect the responsible metabolites for this activity. Material and Methods: The present study examined the in vitro inhibitory effect of the extract fractions from Doum Palm Leaves at concentrations ranging from 7.81 to 1000.00 μg/ml on α-glucosidase activity, an enzyme responsible for carbohydrate-hydrolysis to monosaccharides and intestinal glucose absorption. Metabolic profiling for the dichloromethane fraction was obtained with LC-HR-MS/MS. Results: The dichloromethane (DCM) fraction inhibited α-glucosidase activity in vitro with an IC 50 of 52.40 μg/ml. Twenty-three compounds were identified in the DCM fraction by LC-HR-MS/MS analysis. Most of them were reported for their potential antidiabetic activity. Nevertheless, the III-DCM subfraction (IC 50 3.79 ± 0.17 μg/ml) and the IV-DCM subfraction (IC 50 5.13 ± 0.24 μg/ml) had the best inhibitory activity against α-glucosidase compared with acarbose (IC 50 2.33 ± 0.11 μg/ml). Conclusions: The results support the use of these fractions obtained from Doum palm leaves to effectively inhibit a crucial enzyme linked to type 2 diabetes and suppress carbohydrate absorption from intestine, and thereby reducing the postprandial increase of blood glucose.

Ammi visnaga fruits (L.) Lam., is widely used for its antispasmodic and vasodilating effects. These effects are attributed to its main content of khellin. In our research, we studied the effect of UV-C stress on the metabolite production of the fruits. Fruits were subjected to UV-C treatment for ½, 1, 2, 3, 4 and 5 hr The change in the metabolic profile was studied by the quantification of total phenolics, total flavonoids and khellin in the methanolic extracts of the fruits applied to stress and extracts of control fruits. Total phenolics and total flavonoids were quantified colorimetrically using appropriate reagent for each. Folin-Ciocalteau reagent was applied for the quantification of total phenolics while 2% AlCl 3 solution was applied for the quantification of flavonoids. On the other hand, khellin was quantified by HPLC analysis. Our results showed that the concentrations of total phenolics, total flavonoids and khellin contents of the fruit extracts are significantly increased by exposing the fruits to UV-C stress with maximum production at 1 and 2 hr.