Aeginetia indica, a perennial herb from the Orobanchaceae family, generally grows as a root parasite and is widely distributed in the forests of South and South-Asian countries. The plant has valuable uses in herbal medicine against various diseases, such as diabetes, liver diseases, and arthritis. The present study was designed to investigate the antidiabetic and hepatoprotective effects of the methanol extract of the whole plant of A. indica in a mouse model followed by the isolation of bioactive compounds and their in-silico studies. The hepatoprotective effects were evaluated in a paracetamol-induced hepatotoxicity mouse model. The antidiabetic effects were examined by an oral glucose tolerance test and in an alloxan-induced diabetes mouse model. The plant extract, at a dose of 400 mg/kg, caused a significant reduction (p < 0.001) in liver enzyme concentrations, including alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase, similar to the effects of standard drug silymarin. The plant extract, at 400 mg/kg, also significantly reduced (p < 0.001) the fasting blood glucose concentration by 27.33 % after 3 h, compared with a reduction of 45.31 % in response to glibenclamide. In the alloxan-induced diabetes model mice, significant reductions (p < 0.05) in elevated glucose concentrations were observed on days 10 and 20 in mice treated with plant extract and glibenclamide. Chromatographic analyses and nuclear magnetic resonance (NMR) studies identified the presence of β-sitosterol, stigmasterol, and oleic acid in the extract. The possible mechanism underlying the antidiabetic effects was revealed by molecular docking analyses examining the binding of β-sitosterol and stigmasterol with sirtuin 4, an NAD-dependent deacylase enzyme that downregulates leucine-induced and glutamate dehydrogenase-induced insulin secretion. The binding affinities between sirtuin 4 and β-sitosterol, stigmasterol, and NAD were found to be -8.6 kcal/mol, -7.2 kcal/mol and -9.5 kcal/mol, respectively, indicating the probable competition between NAD and the isolated components for sirtuin 4. The present study revealed that A. indica exerted protective effects against alloxan-induced diabetes and paracetamol-induced hepatotoxicity in mice, which supports the findings regarding the use of A. indica during traditional medical practice.

Context: Ageratum conyzoides Linn. (Asteraceae) is an annual herbaceous plant with a long history of traditional medicinal and agricultural uses; it is usually grown in the northeast part of Bangladesh. Objective: The ethanol extract of the plant leaves was evaluated for preliminary phytochemical screening with its antinociceptive and antioxidant activities. Materials and methods: The preliminary phytochemical analysis was performed on the basis of standard procedures. The analgesic activity of the extract was investigated using the acetic acid-induced writhing method in mice. Five complementary tests such as DPPH free radical scavenging, nitric oxide (NO) scavenging, reducing power, Fe⁺⁺ ion chelating ability and total phenolic content were used for determining antioxidant activities. Results: The results of preliminary phytochemical analysis showed the presence of alkaloids, reducing sugars, saponins, gums, steroids, tannins and flavonoids. The extract possessed a significant dose-dependent DPPH free radical scavenging activity with an IC₅₀ value of 18.91 μg/ml compared to ascorbic acid (IC₅₀: 2.937 μg/ml) and butylated hydroxyanisole (IC₅₀: 5.10 μg/ml). The IC₅₀ value of the extract for NO scavenging (41.81 μg/ml) was also found to be significant compared to the IC₅₀ value of ascorbic acid (37.93 μg/ml). Moreover, the extract showed reducing power activity and Fe⁺⁺ ion chelating ability. The total phenolic amount was also calculated as quite high (378.37 mg/g of gallic acid equivalents) in the crude ethanol extract. Discussion and conclusion: Therefore, the obtained results tend to suggest the antinociceptive and antioxidant activities of the ethanol extract of the plant leaves and justify its use in folkloric remedies.

Castanopsis tribuloides belongs to the oak species (Fagaceae) and it is commonly distributed in evergreen forests of Bangladesh, India, Myanmar, Nepal, China, and Thailand. Our present study aimed at uncovering the antipyretic potential of methanol extract of C. tribuloides bark (CTB) in the mice models. Baker's yeast pyrexia model was employed to determine the antipyretic potentials of the extract. Besides, molecular docking and dynamics simulation of CTB phenolic compounds were explored to validate the experimental results and gain insight into the possible antipyretic mechanism of action that can lead to the design and discovery of novel drugs against mPGES-1. The results revealed that CTB (400 mg/kg) significantly inhibited (P < 0.001) the elevated body temperature of mice since 0.5 h, which is more prominent than the standard. At dose 200 mg/kg, the bark extract also produced significant (P < 0.05) antipyretic activity since 2 h. HPLC-DAD analysis identified and quantified nine polyphenolic compounds from the extract, including rutin hydrate, (-) epicatechin, caffeic acid, catechin hydrate, catechol, trans-ferulic acid, p-coumaric acid, vanillic acid, and rosmarinic acid. Molecular docking study suggested probable competition of these phenolic compounds with glutathione, an essential cofactor for microsomal prostaglandin E synthase-1 (mPGES-1) activity. Additionally, RMSF, RMSD, Rg, and hydrogen bonds performed during MD simulations revealed that rutin hydrate (rich in CTB) bound to the mPGES-1 active site in a stable manner and thus inactivating mPGES-1. Therefore, it can be concluded that rutin hydrate reduces pyrexia in mice via downregulating PGE2 synthesis by inhibiting mPGES-1 activity.