Evaluation of the alpha-amylase inhibitory activity of Nepalese medicinal plants used in the treatment of diabetes mellitus

Comprehensive analysis of malabar tamarind fruit rind total extract: HPTLC fingerprinting, in-silico exploration of its metabolites for SARS-cov-2 omicron spike protein, antibacterial and antidiabetic potentials with in vitro evaluation of antidiabetic and antioxidant activities

Malabar tamarind tropical fruit, scientifically known as Garcinia gummi-gutta, is indigenous to Southeast Asia. In this work, the total methanolic extract of the Malabar fruit rind was examined by HPTLC fingerprinting, with quantitative evaluation of the total phenolics and flavonoids. Library of previously reported natural metabolites was utilized to demonstrate their affinity for specific target sites, they were evaluated against Omicron SARS-CoV-2 mainly it's Spike Protein, bacterial tyrosinase, and antidiabetic targets such α-glucosidase, pancreatic lipase and also α-amylase enzymes. The molecular docking revealed that the Guttiferone R possessed the highest binding affinity toward the Omicron Spike Protein with a stable binding mode, -8.67 kcal/mol binding energy and a 1.07 Å RMSD value compared to reference, Azithromycin, which has -8.90 kcal/mol binding affinity and a 1.20 Å RMSD value. On the other hand, the identified polyphenolic compounds; Vitexin, Prunin, Naringin, Hinokiflavone, Kaempherol-3-O-rutinoside, Gallic acid, Naringenin, and Catechin, showed remarkable antidiabetic activity by strong inhibitory activity against α-glucosidase and notable activity against α-amylase compared with acarbose as reference. According to antibacterial activity, the identified compounds showed low affinity with weak activity against screened bacterial strains. In-vitro evaluation of Tamarind antioxidant and antidiabetic potentials, it exhibited a free radical-scavenging potential with 71.75 % retardation and α-glucosidase, α-amylase and pancreatic lipase inhibitor activities with an IC50 of 391.3 ± 26.27, 95.03 ± 0.03 and 0.01043 ± 0.0004 μg/mL, respectively that emphasize the molecular docking study. The findings imply that Malabar tamarind fruit rind possess antioxidant, antidiabetic, antibacterial and antiviral activities.

Progress in experimental models to investigate the in vivo and in vitro antidiabetic activity of drugs

Diabetes mellitus is one of the world's most prevalent and complex metabolic disorders, and it is a rapidly growing global public health issue. It is characterized by hyperglycemia, a condition involving a high blood glucose level brought on by deficiencies in insulin secretion, decreased activity of insulin, or both. Prolonged effects of diabetes include cardiovascular problems, retinopathy, neuropathy, nephropathy, and vascular alterations in both macro- and micro-blood vessels. In vivo and in vitro models have always been important for investigating and characterizing disease pathogenesis, identifying targets, and reviewing novel treatment options and medications. Fully understanding these models is crucial for the researchers so this review summarizes the different experimental in vivo and in vitro model options used to study diabetes and its consequences. The most popular in vivo studies involves the small animal models, such as rodent models, chemically induced diabetogens like streptozotocin and alloxan, and the possibility of deleting or overexpressing a specific gene by knockout and transgenic technologies on these animals. Other models include virally induced models, diet/nutrition induced diabetic animals, surgically induced models or pancreatectomy models, and non-obese models. Large animals or non-rodent models like porcine (pig), canine (dog), nonhuman primate, and Zebrafish models are also outlined. The in vitro models discussed are murine and human beta-cell lines and pancreatic islets, human stem cells, and organoid cultures. The other enzymatic in vitro tests to assess diabetes include assay of amylase inhibition and inhibition of α-glucosidase activity.

Metabolomics and in-vitro bioactivities studies of fermented Musa paradisiaca pulp: A potential alpha-amylase inhibitor

The in-vitro synthesis of bio-compounds via fermentation is a promising route for bioactive molecules intended for disease control and management. Therefore, this study evaluated the effect of fermentation on the antioxidants, antihyperglycemic and anti-inflammatory properties and the resultant chemometric phytochemical profiles of unripe plantain fruits. The results revealed that Escherichia coli and Propionibacterium spp. are suspected as the key fermenters. The E coli showed negative results to the pathogenicity test; Propionibacterium appeared to be opportunistic. A significant increase in the total polyphenols and protein and decreased flavonoids was recorded in the phytochemical profile of the methanolic extract of the fermented unripe plantain pulp; however, the ascorbic acid content was not significantly altered. The 1H NMR fingerprint showed that there is a closely related chemical shift among the shorter fermentation time (days 2-6) and the unfermented, while the more extended fermentation periods (days 7-12) with enhanced bioactivities were closely related based on the chemometrics analyses. Furthermore, the UPLC-QTOF-MS analysis annotated the presence of bioactive compounds in the day-9 fermented sample: polyhydroxy glucose conjugates (3-Methoxy-4-hydroxyphenyl 6-O-(3,4,5-trihydroxybenzoyl)-beta-D-glucopyranoside), short chain peptide (leucyl-glycyl-glycine), amino acid derivatives (4-Aminophenylalanine, and N-Acetylhistidine), linear and cyclic fatty acid derivatives (palmitoyl putrescine, ricinoleic acid, phytosphingosine, gabalid, rubrenoic acid, 2-aminocyclopentanecarboxylic and cystodienioc acid). The synergistic effect of these newly formed compounds and the increase in the phenolic content of the day-9 fermented unripe plantain may account for its more potent antioxidant, anti-inflammatory and antihyperglycemic activity. Therefore, the products obtained from the day 9 fermentation of unripe plantain pulp may serve as potential nutraceutical agents against gastro-enteric sugar digestion and absorption and sugar-induced oxidative stress, inflammation and metabolic disease.

Molecular dynamics study of stigmasterol and beta-sitosterol of Morinda citrifolia L. towards α-amylase and α-glucosidase

Previous in vivo studies of Morinda citrifolia (Rubiaceae) reported that the extract inhibited α-amylase and reduced blood glucose levels in streptozotocin-induced diabetes mice. Moreover, molecular docking studies confirmed that ursolic acid and sterol compounds contained in the fruit interacted with important residues in the binding site of α-amylase and α-glucosidase. Our work aimed to study the complex stability of stigmasterol (which has been isolated from the M. citrifolia fruit for the first time) and beta-sitosterol towards α-amylase and α-glucosidase by employing molecular dynamics simulation on GROMACS 2016.3 embedded with the AMBER99SB-ILDN force field. The simulation was carried out for 100 ns at 310 oK. Based on the RMSD and RMSF graphs, the complexes of stigmasterol/α-amylase and stigmasterol/α-glucosidase are more stable compared to acarbose, the known inhibitor of both enzymes. Moreover, beta-sitosterol indicates a better stability complex with α-glucosidase compared to that of acarbose. Interestingly, the affinity of stigmasterol and beta-sitosterol to both enzymes, in terms of the total binding energy, is stronger than that of acarbose. Taken together, stigmasterol and beta-sitosterol in M. citrifolia fruit may have the potency to be developed as α-amylase and α-glucosidase inhibitors.Communicated by Ramaswamy H. Sarma.

A comprehensive review of Shengdeng in Tibetan medicine: textual research, herbal and botanical distribution, traditional uses, phytochemistry, and pharmacology

"Shengdeng", a group of Tibetan medicines with diverse biological origins, has long been utilized in Tibet for the treatment of rheumatoid arthritis. It showcases remarkable efficacy in alleviating rheumatism, reducing swelling, and relieving pain. This study aimed to clarify the plant species used as "Shengdeng" and summarize their botanical distribution, traditional uses, phytochemistry, and pharmacology to promote its utilization and development. "Shengdeng" is derived from a remarkable collection of 14 plant species belonging to six distinct families. Extensive phytochemical investigations have led to the identification of 355 chemical constituents within "Shengdeng". Pharmacological studies conducted on "Shengdeng" have revealed a wide range of beneficial properties, including antioxidant, anticancer, antimicrobial, antiviral, antiparasitic, anti-inflammatory, and anti-arthritic activities. Notably, flavonoids and triterpenoids emerge as the predominant groups among these constituents, contributing to the therapeutic potential and diverse applications of "Shengdeng". The present review provides a concise summary of the recent advancements in textual research concerning the herbal and botanical distribution, traditional uses, phytochemistry, and pharmacological activities of "Shengdeng". It is crucial to note that future research on "Shengdeng" should prioritize the analysis of its active ingredients and the establishment of rigorous quality standards. These aspects are essential for ensuring consistency, efficacy, and safety in its clinical application.

Metabolomics and molecular networking approach for exploring the anti-diabetic activity of medicinal plants

Metabolomics and molecular networking approaches have expanded rapidly in the field of biological sciences and involve the systematic identification, visualization, and high-throughput characterization of bioactive metabolites in natural products using sophisticated mass spectrometry-based techniques. The popularity of natural products in pharmaceutical therapies has been influenced by medicinal plants with a long history of ethnobotany and a vast collection of bioactive compounds. Here, we selected four medicinal plants Cleistocalyx operculatus, Terminalia chebula, Ficus lacor, and Ficus semicordata, the biochemical characteristics of which remain unclear owing to the inherent complexity of their plant metabolites. In this study, we aimed to evaluate the potential of these aforementioned plant extracts in inhibiting the enzymatic activity of α-amylase and α-glucosidase, respectively, followed by the annotation of secondary metabolites. The methanol extract of Ficus semicordata exhibited the highest α-amylase inhibition with an IC50 of 46.8 ± 1.8 μg mL-1, whereas the water fraction of Terminalia chebula fruits demonstrated the most significant α-glucosidase inhibition with an IC50 value of 1.07 ± 0.01 μg mL-1. The metabolic profiling of plant extracts was analyzed through Liquid Chromatography-Mass Spectrometry (LC-HRMS) of the active fractions, resulting in the annotation of 32 secondary metabolites. Furthermore, we applied the Global Natural Product Social Molecular Networking (GNPS) platform to evaluate the MS/MS data of Terminalia chebula (bark), revealing that there were 205 and 160 individual ion species observed as nodes in the methanol and ethyl acetate fractions, respectively. Twenty-two metabolites were tentatively identified from the network map, of which 11 compounds were unidentified during manual annotation.

Chromogenic Assay Is More Efficient in Identifying α-Amylase Inhibitory Properties of Anthocyanin-Rich Samples When Compared to the 3,5-Dinitrosalicylic Acid (DNS) Assay

The inhibition of carbohydrate digestion by plant bioactive compounds is a potential dietary strategy to counteract type 2 diabetes. Indeed, inhibition of α-amylase, a key enzyme that carries out the bulk of starch digestion, has been demonstrated for a range of bioactive compounds including anthocyanins; however, sample pigmentation often interferes with measurements, affecting colorimetric assay outcomes. Therefore, the present study compared the performance of a direct chromogenic assay, using 2-chloro-4 nitrophenyl α-D-maltotrioside (CNPG3) as a substrate, with the commonly used 3,5-dinitrosalicylic acid (DNS) assay. The direct chromogenic assay demonstrated a 5-10-fold higher sensitivity to determine α-amylase inhibition in various samples, including acarbose as a reference, pure anthocyanins, and anthocyanin-rich samples. The IC50 values of acarbose presented as 37.6 μg/mL and 3.72 μg/mL for the DNS assay and the direct chromogenic assay, respectively, whereas purified anthocyanins from blackcurrant showed IC50 values of 227.4 µg/mL and 35.0 µg/mL. The direct chromogenic assay is easy to perform, fast, reproducible, and suitable for high-throughput screening of pigmented α-amylase inhibitors.

Bioactive Extracts from Salicornia ramosissima J. Woods Biorefinery as a Source of Ingredients for High-Value Industries

Salt-tolerant plants, also known as halophytes, could provide a novel source of feedstock for biorefineries. After harvesting fresh shoots for food, the lignified fraction of Salicornia ramosissima J. Woods could be used to produce bioactive botanical extracts for high-value industries such as nutraceuticals, cosmetics, and biopharmaceuticals. The residual fraction after extraction can be further used for bioenergy or lignocellulose-derived platform chemicals. This work analysed S. ramosissima from different sources and growth stages. After pre-processing and extractions, the obtained fractions were analysed for their contents of fatty acids, pigments, and total phenolics. Extracts were also evaluated for their in vitro antioxidant properties and inhibitory effect towards enzymes related to diabetes, hyperpigmentation, obesity, and neurogenerative diseases. The ethanol extract from the fibre residue and the water extract from completely lignified plants showed the highest concentration of phenolic compounds along with the highest antioxidant potential and enzyme-inhibitory properties. Hence, they should be further explored in the context of biorefinery.

Chemical Characterization of Different Extracts of Justicia secunda Vahl and Determination of Their Anti-Oxidant, Anti-Enzymatic, Anti-Viral, and Cytotoxic Properties

Justicia secunda Vahl. is a traditional medicinal plant in tropical regions, including West Africa. The present study examined the chemical profiles and biological properties of J. secunda extracts obtained with different solvents (dichloromethane, ethyl acetate, methanolic and aqueous: macerated and infused). Chemical components were characterized by liquid chromatography-mass spectrometry (LC-MS), and over 50 compounds were identified, including flavonoids, phenolic acids, and alkaloids. Antioxidant, enzyme inhibitory, cytotoxic, and antiviral properties were selected as biological properties. Total phenolic and flavonoid contents in methanol (58.07 mg gallic acid equivalent (GAE)/g and 13.07 mg rutin equivalent (RE)/g) and water (infused) (36.34 mg GAE/g and 8.52 mg RE/g) were higher than in other extracts. Consistent with the levels of total bioactive components, the methanol and water extracts exhibited stronger antioxidant abilities. However, the dichloromethane and ethyl acetate extracts were more active on α-amylase and α-glucosidase than other extracts. Aqueous extracts exerted selective anticancer properties toward human pharyngeal cancer cell lines, whereas the methanolic extract decreased the human herpesvirus type-1 (HHV-1) infectious titer by 2.16 log and the viral load by 1.21 log. Overall, J. secunda could be considered a multifunctional bioactive raw material in the preparation of potent applications to manage diseases related to oxidative stress, including cancer, diabetes, and Alzheimer's.

Potential of enhancing anti-obesogenic agriceuticals by applying sustainable fertilizers during plant cultivation

Overweight and obesity are two of the world's biggest health problems. They are associated with excessive fat accumulation resulting from an imbalance between energy consumed and energy expended. Conventional therapies for obesity commonly include synthetic drugs and surgical procedures that can lead to serious side effects. Therefore, developing effective, safe, and readily available new treatments to prevent and treat obesity is highly relevant. Many plant extracts have shown anti-obesogenic potential. These plant extracts are composed of different agriceuticals such as fibers, phenolic acids, flavonoids, anthocyanins, alkaloids, lignans, and proteins that can manage obesity by suppressing appetite, inhibiting digestive enzymes, reducing adipogenesis and lipogenesis, promoting lipolysis and thermogenesis, modulating gut microbiota and suppressing obesity-induced inflammation. These anti-obesogenic agriceuticals can be enhanced in plants during their cultivation by applying sustainable fertilization strategies, improving their capacity to fight the obesity pandemic. Biofertilization and nanofertilization are considered efficient, eco-friendly, and cost-effective strategies to enhance plant growth and development and increase the content of nutrients and bioactive compounds, representing an alternative to overproducing the anti-obesogenic agriceuticals of interest. However, further research is required to study the impact of anti-obesogenic plant species grown using these agricultural practices. This review presents the current scenario of overweight and obesity; recent research work describing different plant species with significant effects against obesity; and several reports exhibiting the potential of the biofertilization and nanofertilization practices to enhance the concentrations of bioactive molecules of anti-obesogenic plant species.

Bioactive Compounds, Pharmacological Actions, and Pharmacokinetics of Genus Acacia

Plants are a promising source of bioactive compounds that can be used to tackle many emerging diseases both infectious and non-infectious. Among different plants, Acacia is a very large genus and exhibits a diverse array of bioactive agents with remarkable pharmacological properties against different diseases. Acacia, a herb found all over the world, contains approximately more than 1200 species of the Fabaceae family. In the present review, we have collected detailed information on biochemical as well as pharmacological properties. The data were retrieved using different databases, such as Elsevier, PubMed, Science Direct, Google Scholar, and Scopus, and an extensive literature survey was carried out. Studies have shown that Acacia possesses several secondary metabolites, including amines, cyanogenic glycosides, flavonoids, alkaloids, seed oils, cyclitols, fluoroacetate, gums, non-protein amino acids, diterpenes, fatty acids, terpenes, hydrolyzable tannins, and condensed tannins. These compounds exhibit a wide range of pharmaceutical applications such as anti-inflammatory, antioxidant, antidiarrheal, antidiabetic, anticancer, antiviral, liver protective effects, and so on. Thus, the literature shows the tremendous phytochemical impact of the genus Acacia in medicine. Overall, we recommend that more research should be conducted on the medicinal value and isolation and purification of the effective therapeutic agents from Acacia species for the treatment of various ailments.

Aqueous Ethanolic Extract of Adiantum incisum Forssk. Protects against Type 2 Diabetes Mellitus via Attenuation of α-Amylase and Oxidative Stress

Purpose : This study was designed to investigate the antidiabetic effects of the aqueous ethanolic extract of Adiantum incisum Forssk. whole plant (AE-AI) in order to validate the folkloric claim. Methods : Streptozotocin (STZ) was used to induce type 2 diabetes mellitus (TII DM) in male Sprague-Dawley rats. STZ-induced diabetic rats were later treated orally with either AE-AI (125, 250, and 500 mg/kg) or glibenclamide for 35 days. Blood glucose levels were measured weekly and on day 35, animals were sacrificed, and blood samples and tissues were harvested for subsequent antioxidant and histopathological analyses. AE-AI was also analyzed in vitro for phytochemical, antioxidant, and α-amylase inhibitory assays. Results : The phytochemical screening of AE-AI confirmed the presence of essential bioactive compounds like cardiac glycosides, flavonoids, phenolic compounds, saponins, and fixed oils. AE-AI demonstrated abundant amounts of total phenolic and flavonoid contents and displayed prominent antioxidant activity as assessed via DPPH, phosphomolybdate, and nitric oxide scavenging assays. AE-AI treatment also showed α-amylase inhibitory activity comparable to acarbose. In addition, AE-AI treatment exhibited a wide margin of safety in rats and dose-dependently reduced STZ-induced blood glucose levels. Moreover, AE-AI increased the levels of GSH, SOD, catalase, and reduced MDA, and therefore prevented pathological effects of STZ on the kidney, liver, and pancreas. The blood glucose regulatory effect and antioxidant activity of AE-AI also aided in normalizing TII DM-mediated dyslipidemias. GC-MS analysis also demonstrated several potential antidiabetic phytoconstituents in AE-AI. Conclusion : These findings reveal that AE-AI possesses certain pharmacologically active compounds that can effectively treat STZ-induced TII DM owing to its antioxidant and α-amylase inhibitory potentials.

In Vitro and In Silico Analysis of Bergenia ciliata and Mimosa pudica for Inhibition of α-Amylase

The discovery of antidiabetic natural products is a flourishing field of opportunity in the sector of drug discovery. Various medicinal plants with diverse chemical constituents have been extensively studied for drug development. Bergenia ciliata and Mimosa pudica have been traditionally used for the treatment of diabetes and consist of valuable phytochemicals. In this study, we have analyzed total phenolic and flavonoid content along with the antioxidant and α-amylase inhibitory activity. The crude extract of B. ciliata contains higher levels of TPC whereas higher TFC was observed in M. pudica. The strong antioxidant activity was shown by B. ciliata with an IC50 value of 125.86 ± 4.16 μg/mL. The ethyl acetate extract of B. ciliata and M. pudica showed higher α-amylase inhibitory activity with an IC50 value of 13.97 ± 0.10 and 11.97 ± 0.36 μg/mL, respectively. The biological potential of the reported phytochemicals was also assessed by using bioinformatic tools. Furthermore, the active phytochemicals from these plants were docked with human pancreatic α-amylase to study their inhibitory activities to this enzyme. The docking analysis revealed that catechin has lower binding energy (−8.6 kcal/mol) as compared to the commercial drug acarbose (−7.3 kcal/mol) indicating higher affinity towards the enzyme. This study additionally sheds more light on medicinal plants’ antidiabetic activity. So, this study will aid in the investigation of the biological properties of these plants as well as the identification of potential compounds with antidiabetic properties.

Antidiabetic, cytotoxic and antioxidant activities of Rhodomyrtus tomentosa leaf extracts

As part of our project on exploring Indonesian medicinal plants for antidiabetic and anticancer agents, this study was conducted to investigate the total phenolic and flavonoid contents, and antioxidant, cytotoxic and antidiabetic properties of R. tomentosa leaf extracts. The antioxidant activity was tested using DPPH, ABTS, and FRAP methods. In vitro cytotoxic assay was performed against MCF-7, HeLa, A549, and B16 cancer cell lines. The in vitro antidiabetic testing was determined using α-glucosidase and α-amylase inhibitory evaluation, while STZ-induced diabetic rats were used for in vivo study. The highest values of total phenolic (191.97 ± 0.19 mg GAE g-1) and flavonoid (29.11 ± 0.05 mg QE g-1) contents were recorded in methanolic extract. This extract also showed the highest DPPH and ABTS activities with IC50 values of 7.79 ± 0.03 and 4.03 ± 0.02 μg mL-1, respectively, as well as the highest FRAP activity with a value of 64.05 ± 0.54 μM Fe2+ g-1. The methanol extract had cytotoxicity against MCF-7, HeLa, A549, and B16 cancer cell lines with IC50 values of 123.49 ± 0.79, 28.28 ± 0.17, 168.88 ± 1.14, and 42.44 ± 0.18 μg mL-1, respectively. In vitro antidiabetic evaluation indicated that the MeOH extract inhibited α-glucosidase and α-amylase with IC50 values of 45.73 ± 1.06 and 41.31 ± 1.12 μg mL-1, respectively. A dose of 400 mg kg-1 body weight of the MeOH extract reduced rats' blood glucose rate and serum blood glucose by 48.51% and 17.73%, respectively after 15 days of treatment. Taken together, these findings suggested that the methanolic extract of R. tomentosa leaves can be used as a potential source of antioxidant, cytotoxic, and antidiabetic agents.

Phytochemical Analysis and Antioxidant and Antidiabetic Activities of Extracts from Bergenia ciliata, Mimosa pudica, and Phyllanthus emblica

Diabetes is a metabolic disorder of high blood sugar levels which leads to various chronic health-related complications. The digestive enzymes α-amylase and α-glucosidase play a major role in the hydrolysis of starch to glucose; hence, inhibiting these enzymes is considered an important strategy for the treatment of diabetes. Medicinal plants such as Bergenia ciliata, Mimosa pudica, and Phyllanthus emblica are commonly used in traditional remedies due to their numerous health benefits. This study aimed to determine the phytochemicals as well as TPC and TFC contents in these plant extracts along with their antioxidant and enzyme inhibitory activity against α-glucosidase and α-amylase. The ethyl acetate extracts of selected plants have shown higher TPC and TFC contents. The aqueous extract of B. ciliata (IC₅₀: 16.99 ± 2.56 μg/mL) and ethyl acetate extract of P. emblica (IC₅₀: 11.98 ± 0.36 μg/mL) and M. pudica (IC₅₀: 21.39 ± 3.76 μg/mL) showed effective antioxidant activities. Furthermore, ethyl acetate extract of B. ciliata showed significant inhibitory activity against α-amylase and α-glucosidase with IC₅₀ values of 38.50 ± 1.32 μg/mL and 3.41 ± 0.04 μg/mL, respectively. Thus, secondary metabolites of these medicinal plants can be repurposed as effective inhibitors of digestive enzymes.

Phytochemical Analysis and In Vitro Antioxidant and Antibacterial Activity of Different Solvent Extracts of Beilschmiedia roxburghiana Nees Stem Barks

Plants have long been considered as a basis of medicines for different indigenous cultures around the globe. They continue as a prominent source of important phytoconstituents which exhibit significant biological activities. In this study, we performed the phytochemical screening, estimation of total phenolic and flavonoids, antioxidants, and antimicrobial activities of the stem bark of Beilschmiedia roxburghiana Nees using different solvents. The total phenolic and total flavonoid contents ranged from 106.73 ± 1.62 mg GAE/g and 99.32 ± 0.66 mg QE/g (methanol extract) to 65.59 ± 1.79 mg GAE/g and 29.98 ± 0.90 mg QE/g (n-hexane extract), respectively. The maximum 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity with a half-maximal inhibitory concentration (IC₅₀) of 39.86 ± 3.69 μg/mL was observed for methanol extract followed by aqueous (IC₅₀ = 43.55 ± 6.16 μg/mL), ethyl acetate (IC₅₀ = 44.30 ± 5.88 μg/mL), dichloromethane (IC₅₀ = 71.50 ± 4.70 μg/mL), and the lowest activity was observed for n-hexane extract. The disc diffusion method revealed that the ethyl acetate extract exhibited relatively higher activity against Salmonella typhi (ZOI = 13 mm), and moderate activities against Shigella sonnei, Acinetobacter baumannii, Klebsiella pneumoniae, and Staphylococcus aureus (ZOI = 12 mm). The methanol and aqueous extracts showed nearly parallel and the n-hexane and dichloromethane extracts exhibited mild antibacterial activities. The results indicated that the polarity index of the extracting solvents amplified the biological activities of the extract. The study is helpful to support the validity of the traditional application of the plant as natural medicine.

α-Amylase Inhibitory Activity of Catunaregam spinosa (Thunb.) Tirveng.: In Vitro and In Silico Studies

α-Amylase is an enzyme involved in the breaking down of large insoluble starch molecules into smaller soluble glucose molecules. Catunaregam spinosa (Thunb.) Tirveng. (syn. Randia dumetorum (Retz.) Lam., Family: Rubiaceace) has been used as traditional medicine for the treatment of gastrointestinal problems, skin diseases, and diabetes. In this context, we studied the in vitro α-amylase inhibiting properties of methanol extracts of leaves and bark of C. spinosa. The methanol extract of bark was further fractionated into hexane, dichloromethane and ethyl acetate, and water-soluble fractions, and their α-amylase inhibitory activity was evaluated. In silico molecular docking and ADMET analysis of several compounds previously reported from the bark of C. spinosa were also performed. The in vitro α-amylase inhibition activity assay of the dichloromethane fraction of extract of bark (IC₅₀: 77.17 ± 1.75 μg/mL) was more potent as compared to hexane and ethyl acetate fractions. The in silico molecular docking study showed that previously reported compounds from the stem bark such as balanophonin, catunaregin, β-sitosterol, and medioresinol were bounded well with the active catalytic residue of porcine pancreatic α-amylase indicating better inhibition. The ADMET analysis showed the possible drug-likeness and structure-activity relationship of selected compounds. These compounds should be studied further for their potential α-amylase inhibition in animal models.

A Comprehensive Review on the Chemical Composition and Pharmacological Activities of Acacia catechu (L.f.) Willd

With the emergence of epidemics, pandemics, and infectious diseases, several research activities have been carried out on natural products to tackle them. As there are structural diversities in natural products, researchers are focused on exploring them for treatment and/or management of various infections and/or diseases. Acacia catechu (L.f.) Willd. belonging to the order Fabales and family Fabaceae shows a wide range of pharmacological functions in the management of diseases in humankind. This review was carried out to gather and provide information about the chemical constituents and pharmacological activities of A. catechu through the literature survey of scientific articles. On preliminary assessments, A. catechu is demonstrated as a significant wellspring of bioactive compounds with a wide range of biological and pharmaceutical applications such as antidiabetic, antioxidant, antimicrobial, anticancer, antidiarrheal, anti-inflammatory, antiviral, hepatoprotective, immunomodulatory, and so on. Although the metabolites from the plant are reported with diverse pharmacological applications, there is little information in regards to toxicity and clinical trials on bioactive compounds of this plant. Further research on diverse bioactive compounds from the plant is required to develop them as a successful potent drug.

Volatile Compounds and Antioxidant and Antimicrobial Activities of Selected Citrus Essential Oils Originated from Nepal

Citrus species of plants are among the most commercially cultivated crops, mainly for their fruit. Besides, the generally consumed flesh inside the fruit, the peel is quite important too. Essential oils extracted from the peel have a history of being used by humankind for centuries. These essential oils are rich in antioxidants and antimicrobial agents. Comparative investigation of volatile constituents, and antioxidant and antimicrobial activities were undertaken. The essential oils were evaluated through gas chromatography-mass spectrometry (GC-MS), and enantiomeric composition by chiral GC-MS. Similarly, the antioxidant properties were evaluated by 2,2-diphenyl-1-picrylhydrazyl scavenging assay, and antimicrobial activities were assayed using the disk diffusion method. The highest extraction yield of 1.83% was observed in Citrus sinensis Osbeck. GC-MS analysis showed limonene (63.76-89.15%), γ-terpinene (0.24-6.43%), β-pinene (0.15-6.09%), linalool (0.35-3.5%), sabinene (0.77-2.17%), myrcene (0.74-1.75%), α-terpineol (0.28-1.15%), and α-pinene (0.2-0.58%) as the major constituents of the essential oil of the Citrus species studied. For the first time, through our study, chiral terpenoids have been observed from Citrus grandis Osbeck essential oil. The order of antioxidant activity is as follows: Citrus grandis Osbeck red flesh > Citrus reticulata Blanco > Citrus sinensis Osbeck > Citrus grandis Osbeck white flesh. Except for Citrus grandis Osbeck white flesh (52.34 µL/mL), all samples demonstrated stronger antioxidant activities than those of the positive control, quercetin (5.60 µL/mL). Therefore, these essential oils can be used as a safe natural antioxidant to prevent product oxidation. Likewise, citrus peel essential oil showed antimicrobial activity against tested bacterial strains, albeit marginal.

LC-HRMS Profiling and Antidiabetic, Antioxidant, and Antibacterial Activities of Acacia catechu (L.f.) Willd

Acacia catechu (L.f.) Willd is a profoundly used traditional medicinal plant in Asia. Previous studies conducted in this plant are more confined to extract level. Even though bioassay-based studies indicated the true therapeutic potential of this plant, compound annotation was not performed extensively. This research is aimed at assessing the bioactivity of different solvent extracts of the plant followed by annotation of its phytoconstituents. Liquid chromatography equipped with high resolution mass spectrometry (LC-HRMS) is deployed for the identification of secondary metabolites in various crude extracts. On activity level, its ethanolic extract showed the highest inhibition towards α-amylase and α-glucosidase with an IC₅₀ of 67.8 ± 1 μg/mL and 10.3 ± 0.1 μg/mL respectively, inspected through the substrate-based method. On the other hand, the plant extract showed an antioxidant activity of 23.76 ± 1.57 μg/mL, measured through radical scavenging activity. Similarly, ethyl acetate and aqueous extracts of A. catechu showed significant inhibition against Staphylococcus aureus with a zone of inhibition (ZoI) of 13 and 14 mm, respectively. With the LC-HRMS-based dereplication strategy, we have identified 28 secondary metabolites belonging to flavonoid and phenolic categories. Identification of these metabolites from A. catechu and its biological implication also support the community-based usage of this plant and its medicinal value.

Antidiabetic, Antimicrobial, and Molecular Profiling of Selected Medicinal Plants

Natural products have been the center of attraction ever since they were discovered. Among them, plant-based natural products were popular as analgesics, anti-inflammatory, antidiabetic, and cosmetics and possess widespread biotechnological applications. The use of plant products as cosmetics and therapeutics is deep-rooted in Nepalese society. Although there are few ethnobotanical studies conducted, extensive research of these valuable medicinal plants has not been a priority due to the limitation of technology and infrastructure. Here, we selected 4 traditionally used medicinal plants to examine their bioactive properties and their enzyme inhibition potential. α-Glucosidase and α-amylase inhibitory activities were investigated using an in vitro model followed up by antioxidant and antimicrobial activities. The present study shows that ethyl acetate fraction of Melastoma melabathrium (IC₅₀ 9.1 ± 0.3 µg/mL) and water fraction Acacia catechu (IC₅₀ 9.0 ± 0.6 µg/mL) exhibit strong α-glucosidase inhibition. Likewise, the highest α-amylase inhibition was shown by crude extracts of Ficus religiosa (IC₅₀ 29.2 ± 1.2 µg/mL) and ethyl acetate fractions of Shorea robusta (IC₅₀ 69.3 ± 1.1 µg/mL), and the highest radical scavenging activity was shown by F. religiosa with an IC₅₀ 67.4 ± 0.6 µg/mL. Furthermore, to identify the metabolites within the fractions, we employed high-resolution mass spectrometry (LC-HRMS) and annotated 17 known metabolites which justify our assumption on activity. Of 4 medicinal plants examined, ethyl acetate fraction of S. robusta, ethyl acetate fraction of M. melabathrium, and water or ethyl acetate fraction of A. catechu extracts illustrated the best activities. With our study, we set up a foundation that provides authentic evidence to the community for use of these traditional plants. The annotated metabolites in this study support earlier experimental evidence towards the inhibition of enzymes. Further study is necessary to explore the clinical efficacy of these secondary molecules, which might be alternatives for the treatment of diabetes and pathogens.

Pharmacologic activities of phytosteroids in inflammatory diseases: Mechanism of action and therapeutic potentials

Natural products and their derivatives are known to be useful for treating numerous diseases since ancient times. Because of their high therapeutic potentials, the use of different medicinal plants is possible to treat varied inflammation-mediated chronic diseases. Among natural products, phytosteroids have emerged as promising compounds mostly because they have diverse pharmacological activities. Currently, available medications exert numerous systemic toxicities, including hypertension, immune suppression, osteoporosis, and metabolic abnormalities. Thus, further research on phytosteroids to subside these complications is of significant importance. In this study, the information on phytosteroids, their types, and actions against inflammation, and allergic complications was collected by a systematic survey of literature on several scientific search engines. The literature review suggested that phytosteroids exhibit antiinflammatory action via different modes through transrepression or selective COX-2 enzymes. Also, in silico ADMET analysis was carried out on available phytosteroids to uncover their pharmacokinetic properties. Our analysis has shown that eight compounds: withaferin A, stigmasterol, β-sitosterol, guggulsterone, diosgenin, sarsasapogenin, physalin A, and dioscin, -isolated from medicinal plants show similar pharmacokinetic properties as compared to dexamethasone, commercially available glucocorticoid. These phytosteroids could be useful for the treatment of inflammatory diseases, such as rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, asthma, and cardiovascular diseases. Thus, systematic research is required to explore potent phytosteroids with lesser side effects, which might substitute the current medications.