Background: More than 700 plants are reported to be used for medicinal purposes in Nepal; however, many of them are not studied for their scientific evidences. The aims of the present study were the estimation of the total phenolic and flavonoid contents, and the evaluation of the free radical scavenging and α-amylase inhibitory activities of five selected medicinal plants from western Nepal: Aeschynanthus parviflorus Wall. (Gesneriaceae), Buddleja asiatica Lour. (Loganiaceae), Carica papaya L. (Caricaceae), Drepanostachyum falcatum (Nees) Keng f. (Gramineae) and Spondias pinnata (L. f.) Kurz (Anacardiaceae). Methods: The total phenolic content (TPC) and total flavonoid content (TFC) were measured using Folin-Ciocalteu’s phenol reagent and aluminium chloride methods, respectively. A 1,1–diphenyl–2–picrylhydrazyl (DPPH) free radical scavenging assay was used to evaluate the free radical scavenging activity and an α-amylase inhibitory assay was carried out to determine the in vitro antidiabetic activity. Results: The phytochemical screening of five hydroalcoholic plant extracts revealed the presence of various secondary metabolites, including alkaloids, flavonoids, reducing sugars, saponins, terpenoids and tannins. The amounts of total phenolics and flavonoids were found to be the highest in B. asiatica leaf extract, which also showed the most potent free radical scavenging activity. Extract of C. papaya fruits showed the highest α-amylase inhibitory activity, whereas the extracts of B. asiatica leaves and S. pinnata leaves exhibited moderate activity. Conclusions: Some of the medicinal plants selected in this study showed high TPC and TFC values and potent bioactivities. These results may provide the scientific evidences of the traditional uses of these plants. However, further detailed studies on bioactive compounds isolation and identification and evaluation of in vivo pharmacological activities should be performed in future.

Leea asiatica (L.) Ridsdale has been used by different ethnic communities to manage diseased conditions that can be traced to oxidative stress and cellular inflammations but scientific evidences to support the claim are scanty. The objective of this study was to isolate and identify the antioxidants present in the aerial parts of Leea asiatica, perform their molecular docking against proteins to inspect whether the traditional uses of the plant can be validated by an in-silico approach. Quercetin (1), gallic acid (2), kaempferol (3), methyl gallate (4), myricetin 3-O-α-L-rhamnopyranoside (5), (−)-epicatechin-3-O-gallate (6) and (−)-epigallocatechin-3-O-gallate (7) were isolated from the 70 % methanolic extract of the aerial parts. Compounds 2, 4, 6, and 7 are reported for the first time from Leea asiatica. Quercetin (1), gallic acid (2), (−)-epicatechin-3-O-gallate (6) and (−)-epigallocatechin-3-O-gallate (7) showed potent antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Molecular docking with NADPH oxidase and TNF-α revealed that epicatechin-3-O-gallate, epigallocatechin-3-O-gallate and quercetin bound with the least binding energy amongst the isolated compounds as well as standard (Trolox and Prednisolone). By molecular dynamics analysis, epicatechin-3-O-gallate maintained stable conformation with NADPH oxidase and TNF-α and was found to possess good ADMET profile thereby validating the ethnic use of the plant as a medicine in the management of inflammatory conditions by an in vitro and in silico approach.

From the flowers of Bombax ceiba L. (Family: Bombacaceae) twenty-four compounds were isolated and identified, including ten flavonoids, quercetin (1), quercetin-3-O-β-D-glucopyranoside (2), quercetin-3-O-β-D-glucuronopyranoside (3), rutin (4), sexangularetin-3-O-sophoroside (5), vitexin (6), isovitexin (7), vicenin 2 (8), kaempferol-3-O-rutinoside (18), and kaempferol-3-O-β-D-glucuronopyranoside (23); three xanthones, isomangiferin (9), mangiferin (10), and 7-O-methyl mangiferin (11); four coumarins, esculetin (12), scopoletin (13), fraxetin (14), and scopolin (21); and seven other compounds, blumenol C glucopyranoside (15), benzyl-β-D-glucopyranoside (16), phenylethyl rutinoside (17), protocatechulic acid (19), chlorogenic acid (20), methyl chlorogenate (22) and vanillic acid (24). Among these, 13 compounds (3, 5, 6, 9, 11, 14, 15, 16, 17, 18, 22, 23 and 24) were isolated for the first time from B. ceiba.

Ethnomedicinally, more than 2000 plants were found to be used in Nepal. Among them, the red colored rhizome of Angiopteris helferiana and the bark of Saurauia fasciculata have been used widely to treat muscle fatigue, bone pain, fever, postpartum hemorrhage, and thirst by healers in Kaski and Tanahun districts, Nepal. However, scientific evidence towards their traditional uses is lacking till December, 2023. Therefore, we report the phytochemicals, total phenolic content (TPC), total flavonoid content (TFC), total carbohydrate content (TCC), antioxidant and antibacterial activities of A. helferiana and S. fasciculata extracts. Phytochemical analysis indicated that A. helferiana and S. fasciculata extracts were potential sources of chemicals such as phenols, flavonoids, tannins, terpenoids, saponins, and carbohydrates. The TPC, TFC, and TCC of extracts were determined by using an ultraviolet visible spectrophotometer. Among the extracts tested, A. helferiana extracts showed the highest phenolic and carbohydrate contents of 208.33 ± 12.96 mg of gallic acid equivalent/g and 564.16 ± 2.92 mg of D‐glucose equivalent/g of dry extract, respectively. Similarly, S. fasciculata revealed the highest flavonoid content of 30.35 ± 0.1 mg quercetin equivalent/g of dry extract. The extract of A. helferiana and S. fasciculata exhibited potent antioxidant activity by scavenging 2,2‐diphenyl‐1‐picrylhydrazyl radicals with an IC₅₀ of 25.9 µg/ml and 31.07 µg/ml, respectively. The antibacterial activity of the A. helferiana and S. fasciculata extract against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was determined using an agar‐well diffusion protocol that revealed the potential antibacterial activity of A. helferiana against E. coli. The present study will help validate the traditional uses of A. helferiana rhizomes and S. fasciculata barks as a healing medicine and inspire the researcher towards further research, development, and formulation.

Objective. The red rhizome of Angiopteris helferiana has been used widely to treat muscle fatigue, bone pain, and skin infection in Nepal. However, scientific evidence for its bioactive compounds and their bioactivities was lacking till January, 2024. Therefore, we investigated to validate and advance the further use and development. Methods. Column chromatography, including MCI gel CHP20P, Sephadex LH‐20, ODS, and Silica gel, was used for the isolation of compounds from 70% methanol extract of A. helferiana rhizomes. The isolated compounds were evaluated for their TLC‐based antioxidant and antibacterial activity against Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa by adopting the agar well diffusion protocol. Furthermore, in silico molecular docking against the penicillin binding protein of E. coli (PBP1b, PBP2, and PBP3 TPd) and ADME toxicity of the isolated compounds was predicted. Results and Discussion. Angiopteroside (1) and osmundalactone (2) were isolated for the first time from the red rhizomes of A. helferiana. The structure of the isolated compounds was elucidated on the basis of spectroscopic (¹H‐, ¹³C‐, and ¹³C/DEPT‐NMR) and spectrometric (LC MS/ESI and IR) analyses and comparison with reported literature. Both compounds were inactive towards DPPH scavenging activity. Compound 1 showed poor inhibitory activity against E. coli, with inhibition zone range of 2–7 mm. However, both isolated compounds were found to be resistant against S. aureus, K. pneumonia, and P. aeruginosa. Based on in silico molecular docking forecasting, compound 1 revealed the good binding affinity with PBP1b (−6.5 kcal/mol), PBP2 (−5.8 kcal/mol) and PBP3 TPd (−6.1 kcal/mol) compared to positive control meropenem with PBP1b (−6.6 kcal/mol), PBP2 (−6.9 kcal/mol), and PBP3 TPd (−6.6 kcal/mol). Similarly, compound 2 showed weak preference for PBP1b (−4.3 kcal/mol), PBP2 (−4.4 kcal/mol), and PBP TPd (−4.5 kcal/mol). Compounds 1 and 2 were predicted to be safe in terms of hepatotoxicity, cytotoxicity, mutagenicity, and carcinogenicity, with a potential to induce nephrotoxicity similar to that of meropenem. Conclusion. This study successfully isolates two lactones with antibacterial properties and inspires the researcher to further research, development, and formulation.

Diabetes mellitus is a metabolic syndrome and a global health burden that has affected more than 10% of the adult population. Heartwood extracts of Pterocarpus marsupium have traditionally been used to manage diabetes‐like conditions. Numerous studies have been published to validate the plant extract’s potential in treating diabetes mellitus. However, studies focussing on the roles of secondary metabolites from the plant in managing diabetes are lacking. Here, we present an in silico approach to describe the antidiabetic potential of the plant metabolites we had previously isolated from 70% MeOH extracts of the heartwood of the plant. Seven compounds isolated from the plant were docked with 10 macromolecules that are known antidiabetic targets to calculate binding affinity and visualize the ligand–receptor interactions. MD simulations were conducted to investigate the dynamic behaviour and stability of protein–ligand complexes in water environment, providing insights into atomistic interactions between ligands and protein residues. In silico antidiabetic activity was predicted by the Prediction of Activity Spectra for Substances (PASS) program. The PASS application predicted that the discovered phytochemicals have antidiabetic properties. The ADME properties, toxicity profile, medicinal chemistry and drug‐likeness were predicted, and the novel compound bijaysaline was found to possess good binding affinity and drug‐likeliness properties.