The Genus Terminalia (Combretaceae): An Ethnopharmacological, Phytochemical and Pharmacological Review

Quorum sensing inhibition by South African medicinal plants species: an in vitro and an untargeted metabolomics study

BACKGROUND

The emergence of antimicrobial resistance (AMR) is imperiling global health, hence, the need to remedy this challenge by discovering new therapeutic strategies and agents. Quorum sensing inhibition (QSI) is opined as a potential novel strategic approach in the fight against AMR by abrogation of bacterial virulence and pathogenicity. Currently, there are no clinically approved QSI drugs. Based on this, this study evaluated the QSI properties of South African plant species.

METHODS

Twenty-nine extracts and their corresponding 203 fractions generated using solid phase extraction were screened for QSI activity in vitro against Chromobacterium violaceum ATCC 12472. Active and inactive fractions of the most potent plant species were analysed using UPLC-HRMS. The acquired mass spectral data was subjected to chemometric analysis.

RESULTS

From the QSI assays, three plant species showed remarkable QSI activity, measured by dose-dependent inhibition of violacein production (IVP), at sublethal concentrations. Terminalia phanerophlebia emerged as the most active species, with the extract and five of its fractions showing good activity in IVP (IVP IC50 ≤ 0.1 mg/mL). This was closely followed by Momordica cardiospermoides whose crude extract and two of its corresponding fractions showed good activity (IVP IC50 ≤ 0.1 mg/mL). Three fractions of Helichrysum odoratissimum also had good activity (IVP IC50 ≤ 0.1 mg/mL) marking it one of the most potent selected species. Chemometric analysis identified five compounds including olivetol and hydroxytyrosol as chemical markers positively associated with the QSI activity of T. phanerophlebia.

CONCLUSION

In conclusion, the findings of our study provided insight into the QSI properties of South African plant species. Further studies will focus on the isolation of the putative active compounds and the in vitro evaluation of their QSI activity.

Ethnoveterinary medicines used by smallholder farmers for treatment of goat ailments in Chikomba, Murewa, Gutu and Mwenezi districts of Zimbabwe: is there cultural consensus in use practices?

ETHNOPHARMACOLOGICAL RELEVANCE

Zimbabwe is a key biodiversity domain in sub-Saharan Africa and ethnoveterinary medicines play an integral role in livestock health. However, knowledge on whether plants are used by only a small proportion of people or whether similar uses exist in different communities and in a more regional context is incompletely documented.

AIM OF THE STUDY

Firstly, the study documented plant-based complementary medicines used for managing goat ailments. Secondly, culturally important medicinal plant species with highest use-reports (UR) as well as botanical and therapeutic consistency were computed. Thirdly, details on whether similar ethnobotanical practices exist in different communities as an indicator of information exchange were explored.

MATERIALS AND METHODS

A total of 200 informants from Gutu, Chikomba, Murewa and Mwenezi districts of Zimbabwe were interviewed. Plant identification was done at the National Herbarium and Botanic Gardens of Zimbabwe. Use-reports were generated and subjected to analysis using Analysis of Variance (ANOVA) in IBM SPSS statistical software.

RESULTS

The impact of parasites and diseases was ranked as the major goat production constraint. A total of 160 homemade remedies were documented, 151 of which comprised a single plant species (Homemade Single Species Herbal Remedy Reports, HSHR). The 151 HSHR prepared using 75 plant species belonging to 34 families referred to 401 UR. The foremost used medicinal plant species were from the Fabaceae family (28 HSHR, 19%). Cassia abbreviata was the most cited plant species (6 HSHR, 4%). The category of ecto- and endoparasites had the highest number of UR out of a total of 9 categories (136 UR, 34%). The most frequently used plant species for this category were Solanum campylacanthum (8 UR, 6%) and Strychnos spinosa (6 UR, 4%). Almost similar numbers of UR were computed across communities for 6 disease categories. Nine different combinations (9 HR, 9 UR) comprising mostly of three plant species were reported for various ailments. Baccharoides adoensis and Terminalia sericea were often reported in these combinations for January disease. Highest levels of therapeutic consistency were computed for Aloe vera and Lippia javanica against ectoparasites (10 out of 24 local studies). Interestingly, 28 new medicinal plant species were documented for the first time in Zimbabwe. Again, these were mostly used for ecto-and endoparasites (8 plant species, 29%).

CONCLUSIONS

Ethnoveterinary medicines play a pivotal role in management of livestock ailments in rural communities of Zimbabwe. However, attention is warranted to ensure transparency in use practices, as well as to conserve and scientifically validate culturally important medicinal plant species such as Aloe vera and Lippia javanica.

Antiparasitic Activities of Plants From the Traditional Senegalese Pharmacopoeia: Isolation of Antitrypanosomal and Antileishmanial Ellagic Acid Derivatives From Terminalia Avicennioides

Parasitic diseases such as trypanosomiasis and leishmaniasis pose significant health challenges in Africa. The Senegalese Pharmacopoeia, known for its many medicinal plants with anti-infectious properties, can be a source of antiparasitic natural products. This study aimed to evaluate the in vitro antiparasitic activities of 33 methanolic extracts from 24 ethnopharmacologically selected plants against Trypanosoma brucei brucei (Tbb) and Leishmania mexicana mexicana (Lmm), as well as their cytotoxic activities on WI-38 cells. The most promising plant species were Balanites aegyptiaca, Eucalyptus camaldulensis, Vachellia nilotica and four Combretaceae species. In a second step, antitrypanosomal and antileishmanial compounds were isolated by preparative high-performance liquid chromatography from one of the most active plant extracts, Terminalia avicennioides leaves. Four ellagic acid derivatives were identified by nuclear magnetic resonance (1D & 2D) and high-resolution electrospray ionization-tandem mass spectrometry (HR-ESI-MS/MS) as 3,4,3-tri-O-methylellagic acid (2), 3,4,5-O-trimethyl-3',4'-O,O-methylideneflavellagic acid (3), hexamethylcoruleoellagic acid (4) and pentamethylflavellagic acid (5). In addition, HR-ESI-MS/MS-based dereplication analysis was performed to putatively identify compounds in active cyclohexane and dichloromethane sub-extracts. Pentamethylflavellagic acid (5) showed the most promising activity against Tbb (half-maximal inhibitory concentration = 6.20 µM). This is the first time that these compounds have been isolated from T. avicennioides and evaluated for their antitrypanosomal and antileishmanial activities.

TeMac™ ameliorates memory impairment and cholinergic dysfunction in rats induced by scopolamine

Alzheimer's disease (AD) is associated with cognitive impairments which are linked to a deficit in cholinergic function. The objective of this study was to evaluate the ability of TeMac™ to prevent memory impairment in scopolamine-rats model of Alzheimer's disease and by in silico approaches to identify molecules in TeMac™ inhibiting acetylcholinesterase. The cholinergic cognitive dysfunction was induced by intraperitoneal injection of scopolamine (1 mg/kg daily) in male Wistar rats for seven consecutive days. TeMac™ at 400 mg/kg body weight was orally administrated 60 min after scopolamine. Donepezil was used as a reference drug. The cognitive deficits were assessed by the Morris Water Maze and novel object recognition tests. After killing the rats, brains were immediately collected and used to carry out cholinesterase enzyme activity and histopathological analyses. Liquid chromatography-mass spectrometry (LC-MS) characterization of the TeMac™ was carried out and the identified molecules were tested in silico for their ability to cross the Blood-Brain Barrier (BBB) and inhibit acetylcholinesterase using molecular docking. The administration of the TeMac™ led to the prevention of memory deficits in rats by reducing significantly the cholinesterase enzymes activities and protecting against morphological alterations and loss of neurons in hippocampus. Seven major compounds were identified in TeMac™. Molecular docking simulations confirm the ability of oleaterminaloic acid B and stigmasterol to cross the BBB and interact with peripheral site and the acyl pocket of acetylcholinesterase. All these observations suggest that TeMac™ can therefore be used as an alternative for the management of AD-related cognitive impairments.

Comparative phytochemical profile and biological activity of three Terminalia species as alternative antimicrobial therapies

Ethnopharmacological relevance

Medicinal plants can help combat antibiotic resistance by providing novel, active molecules. Three plant species of the Terminalia genus are widely used in traditional medicine in the Mouhoun region for the treatment of cutaneous and respiratory diseases. Therefore, it is important to determine the ethnopharmacological potential of bark extracts from the trunks of these three Terminalia species.

Aim of the study

This study compared the phytochemical and biological activities of extracts from three Terminalia species to determine their ethnopharmacology.

Materials and methods

The medicinal properties of the extracts were assessed based on their ability to inhibit the growth of the following microorganisms: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, Candida krusei, Candida glabrata, and Candida tropicalis. The significant interest in these medicinal plants among the local communities were elucidated by their antioxidant properties and phytochemical composition, along with the detection key bioactive compounds. Major phytochemical groups and phenolic compounds were determined using high-performance liquid chromatography with a diode array detector. These phytochemical findings were validated by evaluating the antioxidant capacity of the extracts using DPPH, FRAP, and ABTS assays.

Results

Hydroethanolic, ethanolic, and hexane extracts from the bark of three Terminalia species inhibited the growth of both bacteria and fungi, as evidenced by their minimum inhibitory concentrations (MICs).The findings showed that Terminalia species were most effective against various tested bacteria and fungi, with MICs ranging from 0.1 to 6.25 mg/mL. Terminalia avicennioides, Terminalia macroptera, and Terminalia laxiflora extracts demonstrated 50 % inhibition of DPPH at concentrations ranging from 0.04 to 0.6 mg/mL. Phytochemical analysis revealed the presence of several families of chemical compounds, such as total phenolics and flavonoids. Phenolic compounds identified by HPLC in ethanolic extracts of T. avicennioides, such as isorhamnetin, quercetin, and ferulic acid, are recognised for their antimicrobial and antioxidant properties.

Conclusion

These findings establish an ethnobotany for these three Terminalia species, with their chromatographic characteristics facilitating the identification of key molecules of interest. The ethanolic extract of T. avicennioides can be used in phytomedicinal formulations against bacterial (P. aeruginosa and S. aureus) and fungal (C. albicans and C. glabrata) infections, both of which are recurrently recorded in certain skin and respiratory tract diseases.

Antioxidant properties, anti-nutritive and toxic factors of Terminalia sericea in Onderstepoort

Anti-nutritive and toxic factors in plants adversely affect animal health and production. Hence, the aims of the study were to (1) carry out qualitative and quantitative analysis of these factors in Terminalia sericea that grows abundantly in Onderstepoort; (2) evaluate an affordable, efficient and reliable method that reduces these factors and (3) evaluate antioxidant properties of the phenolic compounds. Thus, sequential organic and aqueous extractions were carried out on T. sericea leaves and feed pellets. Extracts were subjected to qualitative analysis to confirm the presence of 11 phytochemicals. While quantitative analysis of nine phytochemicals was carried out on spectrophotometry, the phenolic extracts were further tested for antioxidant activity on 2,2-diphenyl-picrylhydrazyl (DPPH) assay where gallic acid (GA), quercetin (Q) and ascorbic acid (AA) were used as standards. The contents of GA, Q and AA in the phenolic extracts were determined on high-performance liquid chromatography (HPLC). Aqueous extraction was an effective method as most phytochemicals were extracted. Nine phytochemicals were qualitatively analysed in T. sericea. The highest contents of 1.97% and 2.37 ± 0.077 mg/g gallic acid equivalent with a significant difference (p  0.05) were determined in oxalates and phenolics, respectively. Furthermore, 83.1% DPPH inhibition (IC50 = 0.0432 µg/mL) was determined relative to the standards (85.27% - 85.96%; IC50 = 0.000009 µg/mL - 0.00042 µg/mL). Subsequently, HPLC results showed that T. sericea contained high concentration of AA (62.5 ± 2.13 µg/mL) to confirm antioxidant properties of the leaves.Contribution: Though T. sericea leaves have antioxidant activities, the alkaloid contents may pose a threat to the livestock. Therefore, farmers around Onderstepoort should protect their livestock from feeding on these leaves.

Targeting FAK, VEGF, and MTA1 proteins with Terminalia elliptica: a computational approach for anticancer activity

Cancer remains a significant global health challenge, prompting exploration into alternative treatments such as those derived from natural compounds found in traditional medicine. Recent research has underscored the role of proteins like Focal Adhesion Kinase (FAK), Vascular Endothelial Growth Factor (VEGF), and Metastasis-Associated Protein 1 (MTA1) in driving cancer cell proliferation and survival. Here, we investigated the potential of a single molecule to modulate these key proteins involved in metastasis, offering a promising avenue for cancer therapy. Terminalia elliptica, commonly known as Asna, possesses a diverse range of medicinal properties, including antimicrobial, anti-inflammatory, anticancer, antidiabetic, antiaging, hepatoprotective, antioxidant, and neuroprotective activities. Our study aimed to explore the anticancer potential of Terminalia elliptica by identifying bioactive compounds capable of targeting FAK, VEGF, and MTA1 to impede cancer metastasis. Through in silico analysis, we conducted network analysis using Cytoscape to assess the significance of these bioactive compounds in the inhibition of signaling pathways driving metastasis. The utilization of these bioactives as potential candidates for targeted therapy of VEGF, FAK, and MTA1 regulated pathways was preliminarily assessed by Molecular Docking and MD Simulation. Our findings revealed that phytobioactives namely, Chebulinic Acid of Terminalia elliptica, exhibited notable binding affinity and interaction with FAK, and Chebulagic Acid with VEGF, and MTA1. This discovery holds promise as a novel therapeutic approach for combating cancer, offering potential benefits in cancer treatment and management.

Leishmanicidal and immunomodulatory activity of Terminalia catappa in Leishmania amazonensisin vitro infection

Leishmaniases are infectious-parasitic diseases that impact public health around the world. Antileishmanial drugs presented toxicity and increase in parasitic resistance. Studies with natural products show an alternative to this effect, and several metabolites have demonstrated potential in the treatment of various diseases. Terminalia catappa is a plant species with promising pharmaceutical properties. The objective of this work was to evaluate the therapeutic potential of extracts and fractions of T. catappa on Leishmania amazonensis and investigate the immunomodulatory mechanisms associated with its action. In anti-Leishmania assays, the ethyl acetate fraction exhibited activity against promastigotes (IC50 86.07 ± 1.09 μg/mL) and low cytotoxicity (CC50 517.70 ± 1.68 μg/mL). The ethyl acetate fraction also inhibited the intracellular parasite (IC50 25.74 ± 1.08 μg/mL) with a selectivity index of 20.11. Treatment with T. catappa ethyl acetate fraction did not alter nitrite production by peritoneal macrophages stimulated with L. amazonensis, although there was a decrease in unstimulated macrophages treated at 50 μg/mL (p = 0.0048). The T. catappa ethyl acetate fraction at 100 μg/mL increased TNF-α levels (p = 0.0238) and downregulated HO-1 (p = 0.0030) and ferritin (p = 0.0002) gene expression in L. amazonensis-stimulated macrophages. Additionally, the total flavonoid and ellagic acid content for ethyl acetate fraction was 13.41 ± 1.86 mg QE/g and 79.25 mg/g, respectively. In conclusion, the T. catappa ethyl acetate fraction showed leishmanicidal activity against different forms of L. amazonensis and displayed immunomodulatory mechanisms, including TNF-α production and expression of pro and antioxidant genes.

Antiulcer activity and mechanism of action of the hydroethanolic extract of leaves of Terminalia argentea Mart. In different in vivo and in vitro experimental models

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia argentea Mart. (Combretaceae) is a deciduous tree commonly found in Brazil, Bolivia, and Paraguay. It occurs in all regions of Brazil and is widespread in the Amazon, Cerrado, Pantanal, Atlantic Rain Forest, and Caatinga Biomes. In the traditional medicine of Brazil, people widely use tea or decoction of its leaf materials for treating gastritis, ulcers, wound healing, and inflammation.

AIM OF THE STUDY

The current study aims to evaluate the gastroprotective and ulcer-healing activities of the hydroethanolic extract of T. argentea leaves (HETa) and investigate the underlying mechanisms of action through in vivo and in vitro experiments.

METHODS

We extracted the leaves of T. argentea with a 70% hydroethanolic solution (HETa) and performed phytochemical analysis using high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MSn). We researched the antiulcer activity using in vivo and in vitro experiments, administering three doses (2, 10, and 50 mg/kg) and different concentrations of 1, 5, and 20 μg/mL, respectively. We verified the acute antiulcer activity using chemical models (acidified ethanol (EtOH/HCl) and indomethacin (IND)) and physiological models (water-immersion stress (WRS)). To induce chronic ulcers, used acetic acid and treated the animals for seven days. To investigate the mechanism of action, conducted assays of antioxidant activity, measured the dosage of inflammatory cytokines, quantified mucus, treated with inhibitors (IND, L-NAME, glibenclamide, and yohimbine), performed histopathological analysis, and measured gastric acid secretion. Furthermore, we performed in vitro experiments on murine macrophage cell lines (RAW 264-7 cells) to quantify nitrite/nitrate and cytokine production and on V79-4 cells to verify cell proliferation/migration.

RESULTS

We conducted HPLC and ESI-MSn analyses to obtain a fingerprint of the chemical composition of the HETa, revealing the presence of phenolics (caffeoyl ellagic acid), flavonoids (rutin, quercetin xyloside, quercetin rhamnoside, quercetin glucoside, quercetin galloyl xyloside, quercetin), and tannins (terminalin), respectively. The three doses of HETa reduced acute and chronic ulcers in different models. The mechanism of action involves increasing mucus production and angiogenesis, and it partially involves prostaglandins, nitric oxide, K+ATP channels, and α2-adrenergic receptors. HETa also exhibited antioxidant potential, reducing myeloperoxidase (MPO) activity, and increasing glutathione (GSH) levels. Moreover, it demonstrated anti-inflammatory action by reducing nitrite/nitrate levels and pro-inflammatory cytokine concentrations in vivo, and it increased in vitro proliferation/migration of fibroblasts.

CONCLUSIONS

The study shows that HETa presents a potent preventive and curative antiulcer effect in different ulcer models, supporting the popular use of homemade preparations of T. argentea leaves. The preventive and gastric healing ulcer activity of HETa involves multiple targets, including increasing the gastric mucus barrier, antioxidant defenses, and anti-inflammatory effects on gastric mucosa repair. Phytochemical analysis identified the presence of phenolic compounds, flavonoids, and tannins in HETa, and the antiulcer activity may be attributable to the combined effect of these constituents.

In Vitro Antioxidant and Antitrypanosomal Activities of Extract and Fractions of Terminalia catappa

Chagas disease is a severe infectious and parasitic disease caused by the protozoan Trypanosoma cruzi and considered a public health problem. Chemotherapeutics are still the main means of control and treatment of the disease, however with some limitations. As an alternative treatment, plants have been pointed out due to their proven pharmacological properties. Many studies carried out with Terminalia catappa have shown several biological activities, but its effect against T. cruzi is still unknown. The objective of this work is to evaluate the therapeutic potential of extracts and fractions obtained from T. catappa on the parasite T. cruzi, in addition to analyzing its antioxidant activity. T. catappa ethyl acetate fraction were produced and submitted the chemical characterization by Liquid Chromatography Coupled to Mass Spectrometry (LC-MS). From all T. catappa extracts and fractions evaluated, the ethyl acetate and the aqueous fraction displayed the best antioxidant activity by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging method (IC₅₀ of 7.77 ± 1.61 and 5.26 ± 1.26 µg/mL respectively), and by ferric ion reducing (FRAP) method (687.61 ± 0.26 and 1009.32 ± 0.13 µM of Trolox equivalent/mg extract, respectively). The ethyl acetate fraction showed remarkable T. cruzi inhibitory activity with IC₅₀ of 8.86 ± 1.13, 24.91 ± 1.15 and 85.01 ± 1.21 µg/mL against epimastigotes, trypomastigotes and intracellular amastigotes, respectively, and showed no cytotoxicity for Vero cells (CC₅₀ > 1000 µg/mL). The treatment of epimastigotes with the ethyl acetate fraction led to drastic ultrastructural changes such as the loss of cytoplasm organelles, cell disorganization, nucleus damage and the loss of integrity of the parasite. This effect could be due to secondary compounds present in this extract, such as luteolin, kaempferol, quercetin, ellagic acid and derivatives. The ethyl acetate fraction obtained from T. catappa leaves can be an effective alternative in the treatment and control of Chagas disease, and material for further investigations.

Oral sub-chronic treatment with Terminalia phaeocarpa Eichler (Combretaceae) reduces liver PTP1B activity in a murine model of diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

The endemic Brazilian medicinal plants of the genus Terminalia (Combretaceae), popularly known as capitão, comprising the similar species Terminalia phaeocarpa Eichler and Terminalia argentea, are traditionally and indistinguishably used in the country to treat diabetes.

AIM OF THE STUDY

The present work investigated the effect of 28 days of treatment with the crude ethanolic extract (CEE) and its derived ethyl acetate fraction (EAF) from T. phaeocarpa leaves in a mice model of diabetes.

MATERIALS AND METHODS

Streptozotocin-nicotinamide-fructose diabetic model was used to evaluate the antidiabetic activity of 28 days of treatment with the CEE and EAF from the leaves of T. phaeocarpa and metformin as a positive control. Serum levels of total cholesterol, triglycerides, uric acid, ALP, AST, and ALT were measured with specific commercial kits and glucose with a strip glucometer. The thiobarbituric acid method measured the liver MDA level, while a colorimetric assay measured the GSH level and PTP1B activity. A UPLC-DAD profile was obtained to identify the main polyphenolic compound in the EAF.

RESULTS

Treatment with CEE and EAF reduced plasma glucose in diabetic mice. At the end of the treatment, the plasma glucose level was significantly lower in EAF-treated (100 mg/kg) diabetic mice (106.1 ± 13.7 mg/dL) than those treated with 100 mg/kg CEE (175.2 ± 20.9 mg/dL), both significantly lower than untreated diabetic mice (350.4 ± 28.1 mg/dL). The serum levels of total cholesterol, triglycerides, uric acid, ALP, AST, and ALT were significantly reduced in diabetic mice treated with CEE and EAF. In the livers of diabetic mice, the treatment with CEE and EAF reduced MDA levels and the activity of the enzyme PTP1B (96.9 ± 3.7%, 113.8 ± 2.8%, and 134.8 ± 4.6% for CEE-, EAF-treated, and untreated diabetic mice, respectively). Galloylpunicalagin was the main polyphenol observed in the EAF of T. phaeocarpa.

CONCLUSION

The present results demonstrate the significant antidiabetic effect of CEE and EAF of T. phaeocarpa and their reduction on the markers of liver dysfunction in diabetic mice. Moreover, the antidiabetic activity of T. phaeocarpa might be associated with lowering the augmented activity of the PTP1B enzyme in the liver of diabetic mice.

Treatment Management of Diabetic Wounds Utilizing Herbalism: An Overview

BACKGROUND AND OBJECTIVES

Diabetes Mellitus, commonly known as DM, is a metabolic disorder which is characterized by high blood glucose level, i.e., chronic hyperglycemia. If it is not managed properly, DM can lead to many severe complexities with time and can cause significant damage to the kidneys, heart, eyes, nerves and blood vessels. Diabetic foot ulcers (DFU) are one of those major complexities which affect around 15-25% of the population diagnosed with diabetes. Due to diabetic conditions, the body's natural healing process slows down leading to longer duration for healing of wounds only when taken care of properly. Herbal therapies are one of the approaches for the management and care of diabetic foot ulcer, which utilizes the concept of synergism for better treatment options. With the recent advancement in the field of nanotechnology and natural drug therapy, a lot of opportunities can be seen in combining both technologies and moving towards a more advanced drug delivery system to overcome the limitations of polyherbal formulations.

METHODS

During the writing of this document, the data was derived from existing original research papers gathered from a variety of sources such as PubMed, ScienceDirect, Google Scholar.

CONCLUSION

Hence, this review includes evidence about the current practices and future possibilities of nano-herbal formulation in treatment and management of diabetic wounds.

Bioautography-guided HPTLC-MS as a rapid hyphenated technique for the identification of antimicrobial compounds from selected South African Combretaceae species

INTRODUCTION

Many species within Combretaceae are traditionally used for the treatment of bacterial infections. The similarity in chemistry and antimicrobial activities within the family pose a challenge in selecting suitable species for herbal drug development.

OBJECTIVE

This study aimed at rapidly identifying antimicrobial compounds using bioautography-guided high-performance thin-layer chromatography coupled with mass spectrometry (HPTLC-MS).

METHODS

Hierarchical cluster analysis of ultra-performance liquid chromatography-mass spectrometry data from the methanol extracts of 77 samples, representing four genera within Combretaceae, was carried out. Based on groupings on the dendrogram, 15 samples were selected for bioautography analysis against four pathogens (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhimurium). Active compounds were identified using HPTLC-MS analysis of bands corresponding to the inhibition zones.

RESULTS

Bioautography revealed 15 inhibition zones against the four pathogens, with the most prominent present for Combretum imberbe. Analysis of the active bands, using HPTLC-MS indicated that flavonoids, triterpenoids and combretastatin B5 contributed to the antibacterial activity. The compounds corresponding to molecular ions m/z 471 (Combretum imberbe) and 499 (Combretum elaeagnoides) inhibited all four pathogens, and were identified as imberbic acid and jessic acid, respectively. Chemotaxonomic analysis indicated that arjunic acid, ursolic acid and an unidentified triterpenoid (m/z 471) were ubiquitous in the Combretaceae species and could be responsible for their antibacterial activities.

CONCLUSION

Application of HPTLC-MS enabled the rapid screening of extracts to identify active compounds within taxonomically related species. This approach allows for greater efficiency in the natural product research workflow to identify bioactive compounds in crude extracts.

Phytochemical Profile, Antioxidant Potential, Proximate and Trace Elements Composition of Leaves, Stems and Ashes from 12 Combretum spp. Used as Food Additives

In this study, twelve Combretum spp. were investigated for their phytochemical content, antioxidant potential, and their proximate and trace elements/minerals composition. The qualitative phytochemical composition of the leaves, stems, and ashes of Combretum plants analysed revealed the presence of saponins, tannins, terpenoids, steroids, cardiac glycosides, and flavonoids. The following phytoconstituents were lost in the ashes; tannins apart from C. mkuzense and C. padoides; cardiac glycosides; and flavonoids. The quantitative phytochemical analyses revealed that both the leaves, stems, and some ashes such as C. apiculatum and C. vendae contained levels of phenolic compounds, tannins, and flavonoids. DPPH screening method indicated great scavenging activity with the 70% acetone leaf extracts of C. kraussii, C. zeyheriim, and C. mkuzense. There was a significant decrease in the antioxidant activity in the ashes compared to the leaves and the stems. AOAC and ICPE protocols performed the proximate and nutritional analysis of the 70% acetone extracts. The extracts had substantial amounts of ash, moisture, protein, and energy. The leaves and ashes of C. adenogonium and C. apiculatum could provide a good source of calcium in the diet. This study presents valuable information on the phytochemical composition, nutritional composition, and antioxidant properties of some Combretum species.

Hydrolysable tannins, physicochemical properties, and antioxidant property of wild-harvested Terminalia ferdinandiana (exell) fruit at different maturity stages

Terminalia ferdinandiana Exell., also known as Kakadu plum, is a wild-harvested native Australian fruit with limited information on how maturity is affecting the phytonutritional properties and bioactivities of the fruit. Thus, this study investigated changes in hydrolysable tannins, phenolic acids, sugar profile, standard physicochemical parameters, and antioxidant-scavenging capacity of wild-harvested Kakadu plum fruits at four different maturity stages, from immature to fully mature. Fruits harvested <25, 25-50, 50-75, and 75-100% degree of fullness were classified as highly immature (stage 1), immature (stage 2), semi-mature (stage 3), and fully mature (stage 4), respectively. Results showed that chebulagic acid, geraniin, chebulinic acid, castalagin, punicalagin, and gallic acid continuously decreased during fruit maturity, while elaeocarpusin, helioscopin B, corilagin, 3,4,6-tri-O-galloyl-S-glucose, and ellagic acid increased at the beginning of fruit growth (from stage 1 to 2), but decreased when the fruits reached their full maturity (stage 4). The levels of hydrolysable tannins and phenolic acids in fully mature fruits (stage 4) were significantly (p ≤ 0.05) lower than that in their immature counterparts (stages 1 and 2). Total phenolic content (TPC) and DPPH antioxidant radical-scavenging activity did not vary significantly between different maturity stages. Pearson's correlation coefficient test indicated that TPC and DPPH positively (p ≤ 0.05) correlate with most of the studied tannin compounds. Sugars (glucose, fructose, and sucrose), total soluble solid content, and titratable acidity increased during the fruit development. Furthermore, principal component analysis (PCA) revealed the difference between the immature and mature samples, based on their nutritional profile and bioactive compounds. The PCA results also suggested a considerable variability between the individual trees, highlighting the challenges of wild-harvest practice.

Gastroprotective and Antioxidative Effects of the Traditional Thai Polyherbal Formula Phy-Blica-D against Ethanol-Induced Gastric Ulcers in Rats

Phy-Blica-D is a traditional Thai polyherbal formula that has reduced oxidative stress in non-communicable diseases. However, evidence supporting the gastroprotective effects of Phy-Blica-D has not been previously reported. Therefore, this study aimed to evaluate the gastroprotective effects of Phy-Blica-D against gastric ulcers in rats and investigate the potential underlying mechanism. To estimate the possible mechanisms of action, we examined the levels of oxidative stress markers, such as reactive oxygen species (ROS) and malondialdehyde (MDA), as well as antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH). According to our results, rats treated with only 80% ethanol (vehicle group) exhibited significant increases in their ulcer area and ulcer index (UI). Moreover, the levels of ROS and MDA markedly increased in the vehicle group compared with the normal control group. Daily oral administration of Phy-Blica-D (500 and 1000 mg/kg) for 7 days not only significantly decreased the ulcer area and UI, but also remarkably decreased the ROS and MDA levels in gastric tissue. Gastric ulcers induced by ethanol had significantly decreased antioxidant enzyme activities (CAT and SOD) and non-enzymatic antioxidant (GSH), whereas pretreatment with Phy-Blica-D significantly improved the activities of CAT, SOD, and GSH. Moreover, after exposure to ethanol, the rats exhibited a significantly increased level of inducible nitric oxide synthase (iNOS), which was reduced after treatment with Phy-Blica-D. These findings suggest that Phy-Blica-D potentially exerts its gastroprotective effects by suppressing oxidative stress and stimulating antioxidant enzymes, which is one of the causes of destruction of cell membranes, and it is involved in the pathogenesis of acute gastric ulcers induced by ethanol.

Combination of natural antivirals and potent immune invigorators: A natural remedy to combat COVID-19

The flare-up in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that emerged in December 2019 in Wuhan, China, and spread expeditiously worldwide has become a health challenge globally. The rapid transmission, absence of anti-SARS-CoV-2 drugs, and inexistence of vaccine are further exacerbating the situation. Several drugs, including chloroquine, remdesivir, and favipiravir, are presently undergoing clinical investigation to further scrutinize their effectiveness and validity in the management of COVID-19. Natural products (NPs) in general, and plants constituents specifically, are unique sources for various effective and novel drugs. Immunostimulants, including vitamins, iron, zinc, chrysin, caffeic acid, and gallic acid, act as potent weapons against COVID-19 by reinvigorating the defensive mechanisms of the immune system. Immunity boosters prevent COVID-19 by stimulating the proliferation of T-cells, B-cells, and neutrophils, neutralizing the free radicals, inhibiting the immunosuppressive agents, and promoting cytokine production. Presently, antiviral therapy includes several lead compounds, such as baicalin, glycyrrhizin, theaflavin, and herbacetin, all of which seem to act against SARS-CoV-2 via particular targets, such as blocking virus entry, attachment to host cell receptor, inhibiting viral replication, and assembly and release.

Regulation of the redox signaling and inflammation by Terminalia myriocarpa leaves and the predictive interactions of it's major metabolites with iNOS and NF-ĸB

ETHNOPHARMACOLOGICAL RELEVANCE

The present study was designed to investigate the regulation of the redox signaling and inflammation by ethanolic leaf extract of Terminalia myriocarpaVan Heurck & Müller (ETM), inspired by the reported antioxidant potential of the plant bark and the anti-edema effect of the same genus.

MATERIALS AND METHODS

HPLC-DAD dereplication study was conducted to detect the major polyphenolic secondary metabolites. In-vitro DPPH free radical scavenging assay, nitric oxide (NO) scavenging assay, Fe²⁺ ion chelating ability assay and reducing power assay were conducted to evaluate the antioxidant capacity. The molecular mechanism of anti-inflammation was investigated via assessing the NO and NF-ĸB inhibiting properties in different cell lines. In-vivo carrageenan and histamine-induced edema tests were conducted using established animal models. Pro-inflammatory proteins iNOS and NF-κB were docked against the major metabolites of ETM in the in-silico study.

RESULTS

HPLC dereplication analysis revealed the presence of considerable amount of ellagic acid, where methyl-(S)-flavogallonate was previously reported in T. myriocarpa. Significant antioxidant activity was found in every in- vitro redox assay conducted. NO was reduced in RAW 264.7 cells, showing 83.67 ± 4.18% inhibitory activity at the highest tested concentration. TNF-α induced NF-κB was also observed to be reduced in 293/NF-кB-luc cells with an inhibitory activity of 66.23 ± 0.81% at the highest dose tested. In-vivo carrageenan-induced edema test demonstrated significant anti-inflammatory activity (p < 0.05; p < 0.01) at both doses of 250 and 500 mg/kg with 60.10% highest reduction in rat paw volume. Using same doses, histamine-induced edema test exhibited mentionable anti-inflammatory potential (p < 0.05; p < 0.01) with 67.91% highest reduction in rat paw volume. Moreover, ellagic acid and methyl-(S)-flavogallonate showed significant binding affinity with iNOS (-8.5 and -8.7 Kcal/moL, respectively) and NF-κB (-7.3 and -7.3 Kcal/moL, respectively).

CONCLUSION

Mentionable basis was found on behalf of the anti-inflammatory and antioxidant potentials of ETM which might be correlated with its NF-ĸB inhibiting properties.

Termitomenins F and G, Two New Lignan Glucosides from Terminalia chebula var. tomentella (Kurz) C. B. Clarke

The extensive chemical investigation on the branches and leaves of Terminalia chebula var. tomentella (Combretaceae) led to the isolation of two new lignan glucosides with a furofuran skeleton, termitomenins F (1) and G (2). In addition, 19 known compounds including five lignan glucosides (3-7), six hydrolyzable tannins (8-13) and eight simple phenolics (14-21) were also identified. Their structures were determined by comprehensive spectroscopic analyses. It is noted that 8 and 9 were C-glycosidic hydrolyzable tannins with one hexahydroxydiphenoyl and one gallagyl group linked to an open-chain glucosyl C-1/O-2/O-3 and O-4/O-6, respectively, which were rarely found in plants. Nine known compounds, 6-9, 13, and 18-21, were procured from the titled plant for the first time, while 3-5, 10-12 and 14-17 were also found in the fruits. Notably, the known hydrolyzable tannins 8-13 exhibited stronger α-glucosidase inhibitory activities with IC50 values ranging from 0.10 to 3.12 μM, than the positive control, quercetin (IC50 = 9.38 ± 0.33 μM).

Malaria in Guinean Rural Areas: Prevalence, Management, and Ethnotherapeutic Investigations in Dionfo, Sub-Prefecture of Labe

As part of a validation program of antimalarial traditional recipes, an ethnotherapeutic approach was applied in Dionfo, a meso-endemic Guinean rural area where conventional health facilities are insufficient. A prevalence investigation indicated a malarial burden of 4.26%. Ethnomedical and ethnobotanical surveys led to a collection of 63 plant species used against malaria from which Terminalia albida (Combretaceae) was one of the most cited. Ethnotherapeutic evaluation of a remedy based on T. albida was applied to 9 voluntary patients suffering from uncomplicated malaria. Treatment of 7 to 14 days led to an improvement of clinical symptoms and a complete parasite clearance achievement of 8/9 patients without side effects. In addition to antiplasmodial activity in vitro and in vivo previously described, this study indicates an efficacy to support the antimalarial traditional use of T. albida, which could constitute a first-aid treatment when access to other medicines is delayed in the Dionfo community. Ethnotherapeutical investigation could be a valuable approach to guide subsequent investigations on traditional remedies.

Multiple in vitro biological effects of phenolic compounds from Terminalia chebula var. tomentella

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia chebula (TC), a well-known Indian Ayurvedic medicine introduced into China in the Sui and Tang Dynasties, has been recorded and used medicinally as Fructus Chebulae, together with its variety tomentella (TCT) in the Chinese Pharmacopoeia. They have been also used commonly for the treatment of diabetes mellitus by Tibetan medicine.

AIM OF THE STUDY

To investigate the main bioactive and therapeutic principles in the fruits of TCT, based on the extensive evaluation of their anti-inflammatory and hypoglycemic activities.

MATERIALS AND METHODS

The TCT fresh fruits were analyzed by HPLC and separated further by column chromatography and preparative HPLC. The isolated compounds were identified by extensive spectroscopic analyses, including 1D/2D NMR, MS, UV, IR and ECD. Anti-inflammatory activity was evaluated by inhibition of NO production in RAW264.7 cells. The specific iNOS (PDB ID: 3E7G) structure was prepared by Discovery Studio 4.0, and the molecular docking simulation was performed on GOLD (version 5.2.2). Hypoglycemic activity was measured using the substrate solution of 4-nitrophenyl-α-d-glucopyranoside enzyme and buffer solution.

RESULTS

The HPLC analysis method of polyphenols in the fruits of TCT was established, and 13 main chromatographic peaks were identified, including six hydrolyzable tannins (2, 4-7, 10-11), three simple phenols (12-14), and one oleanane pentacyclic triterpene, arjungenin. Extensive chromatographic separation of TCT fresh fruits yielded 14 compounds, including one new natural hydrolyzable tannin, 2,3-(S)-HHDP-6-O-galloyl-d-glucose (1). The known compounds were identified as 10 hydrolyzable tannins (2-11) and three simple phenols (12-14). Compounds 10 (IC₅₀ = 36.43 ± 0.21 μM), 11 (IC₅₀ = 42.28 ± 0.09 μM) displayed stronger NO inhibitory activity than the positive control L-NMMA (IC₅₀ = 42.34 ± 0.66 μM), while 2, 4, and 9 showed moderate inhibitory activity against NO production. Further molecular docking simulation of specific iNOS on 10 and 11, as well as five previously isolated lignans 15-19 showed that there were no obvious rules between docking results and the in vitro NO inhibitory activity for hydrolyzable tannins (10 and 11), while the mechanism of anti-inflammatory activity for lignans was related to the substitution of conjugated aldehyde groups. Moreover, most of the hydrolyzable tannins (1-2, 4-5, 9-11) and simple phenol (12) displayed stronger inhibitory effects on α-glucosidase than the positive control, quercetin (IC₅₀ = 6.118 ± 0.071 μM), with IC₅₀ values ranging from 0.079 to 16.494 μM. Among these bioactive isolates, the hydrolyzable tannins 2, 4-5, and 9-11, and simple phenol 12 are major chemical components in TCT fruit.

CONCLUSIONS

The results showed that lignans and hydrolyzed tannins are the main active ingredients of TCT fruits, responsible for the traditional treatment of sore throat and cough. Moreover, hydrolyzed tannins and simple phenolic compounds with potential hypoglycemic activity are closely related to the ethno-pharmacological uses of TCT fruits on diabetes in Tibetan medicine.

Potential of Malawi's medicinal plants in Covid-19 disease management: A review

The Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered an international pandemic that has led to significant public health problems. To date, limited evidence exists to suggest that drugs are effective against the disease. As possible treatments are being investigated, herbal medicines have shown potential for producing novel antiviral agents for the COVID-19 disease.

Aim

This review explored the potential of Malawi's traditional medicinal plants for the management of COVID-19.

Methods

The authors searched on PubMed and Google scholar for medicinal plants that are used in Malawi and published in openly available peer reviewed journals. Plants linked with antiviral treatment, anti-COVID-19 activity or COVID-19 symptoms management were targeted. These included activity against pneumonia, inflammation, cough, difficulty in breathing, pain/aches, fever, diarrhoea, rheumatism, fatigue, asthma, immunocompromised and cardiovascular diseases.

Results

11 studies were found with 306 plant species. 127 plant species had at least one COVID-19 related pharmacological activity. Of these plant species, the number of herbal entities used for each indication was: pain/aches (87), fever (2), pneumonia (9), breathing/asthma problems (5), coughing (11), diarrhoea (1), immunosuppression (8), blood issues (10), fatigue (2), heart problems (11), inflammation (8), rheumatism (10) and viral diseases (12). Thirty (30) species were used for more than one disease and Azedarachta indica topped the list (6 of the 13 COVID-19 related diseases). The majority of the species had phytochemicals known to have antiviral activity or mechanisms of actions linked to COVID-19 and consequent diseases' treatment pathways.

Conclusion

Medicinal plants are a promising source of compounds that can be used for drug development of COVID-19 related diseases. This review highlights potential targets for the World Health Organization and other research entities to explore in order to assist in controlling the pandemic.

Polyphenol-rich extract and fractions of Terminalia phaeocarpa Eichler possess hypoglycemic effect, reduce the release of cytokines, and inhibit lipase, α-glucosidase, and α-amilase enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

species of Terminalia (Combretaceae) are used to treat diabetes and metabolic disorders in Asia, Africa, and America. Terminalia phaeocarpa Eichler is an endemic tree from Brazil, popularly known as capitão. This species is closely related to Terminalia argentea Mart., also vulgarly known as capitão, a native but not endemic tree. Due to their phenotype similarity, these species might eventually prove inseparable and they are indistinctly used by locals to treat diabetes, among other diseases. The potential antidiabetic effect of T. argentea has been previously reported, whereas the biological effects and chemical composition of T. phaeocarpa have never been addressed so far.

AIM OF THE STUDY

investigate the hypoglycaemic effect of an ethanol extract (EE) of T. phaeocarpa leaves and its ethyl acetate (FrEtOAc) and hydromethanolic (FrMEOH) fractions, in addition to their activity on the release of pro-inflammatory mediators and inhibition of lipase, α-amylase, and α-glucosidase enzymes. Additionally, it aimed to characterize the chemical composition of the extract and fractions, seeking to identify the compounds related to the biological activities.

MATERIALS AND METHODS

The effect on the release of TNF-α, IL-1β, and CCL-2 was evaluated in LPS-stimulated THP-1 cells (ATCC TIB-202). The inhibition of lipase, α-amylase, and α-glucosidase was tested in vitro, whereas the hypoglycemic effect was assayed in the oral starch tolerance test. The chemical composition was investigated by extensive UHPLC-DAD-ESI-MS/MS analyses.

RESULTS

The extract and derived fractions reduced TNF-α (EE pIC₅₀ = 4.58 ± 0.01; FrEtOAc pIC₅₀ = 4.69 ± 0.01; FrMeOH pIC₅₀ = 4.54 ± 0.02) and IL-1β (EE pIC₅₀ = 4.86 ± 0.02; FrEtOAc pIC₅₀ = 4.86 ± 0.02; FrMeOH pIC₅₀ = 4.75 ± 0.01) release by LPS-stimulated THP-1 cells in a concentration-dependent manner, whereas the inhibitory effect on CCL-2 release did not reach a clear linear relationship for the tested concentrations. The extract and fractions also inhibited in vitro the activity of lipase (EE pIC₅₀ = 3.97 ± 0.12; FrEtOAc pIC₅₀ = 3.87 ± 0.04; FrMeOH pIC₅₀ = 3.67 ± 0.14), α-amylase (EE pIC₅₀ = 4.46 ± 0.27; FrEtOAc pIC₅₀ = 5.47 ± 0.27; FrMeOH pIC₅₀ = 4.26 ± 0.22), and α-glucosidase (EE pIC₅₀ = 5.46 ± 0.05; FrEtOAc pIC₅₀ = 5.79 ± 0.11; FrMeOH pIC₅₀ = 5.74 ± 0.05). The pIC₅₀ values of the test samples were lower than those obtained with orlistat (7.59 ± 0.08) and acarbose (6.04 ± 0.37 and 7.63 ± 0.04) employed as the positive controls respectively in the lipase, α-amylase, and α-glucosidase assays. When assayed in the oral starch tolerance test, the extract and fractions also reduced animal glycaemia. UHPLC-DAD-ESI-MS/MS analyses of the extract and fractions led to the identification of 38 phenolic compounds, mainly phenolic acids, ellagitannins and flavonoids, among others, all of them first-time described for the species.

CONCLUSION

Based on our findings, T. phaeocarpa has hypoglycaemic activity and polyphenols are the probable bioactive compounds, which support the ethnomedical use of the species.

Antiplasmodial Oleanane Triterpenoids from Terminalia albida Root Bark

Phytochemical investigation of the n-BuOH extract of the roots of Terminalia albida Sc. Elliot (Combretaceae) led to the isolation and identification of 10 oleanane triterpenoids (1-10), among which six new compounds, i.e., albidanoside A (2), albidic acid A (4), albidinolic acid (5), albidienic acid (8), albidolic acid (9), and albidiolic acid (10), and two triterpenoid aglycones, i.e., albidic acid B (6) and albidic acid C (7), were isolated here for the first time from a natural source, along with two known compounds. The structures of these constituents were established by means of 1D and 2D NMR spectroscopy and ESI mass spectrometry. The isolated compounds were evaluated for their antiplasmodial and antimicrobial activity against the chloroquine-resistant strain Plasmodium falciparum K1, Candida albicans, and Staphylococcus aureus. Compounds 1-4, 6, 7, and 8 showed moderate antiplasmodial activity with IC₅₀ values between 5 and 15 μM. None of the tested compounds were active against C. albicans or S. aureus. These findings emphasize the potential of T. albida as a source for discovery of new antiplasmodial compounds.

Antibacterial Activity and Time-kill Assay of Terminalia catappa L. and Nigella sativa L. against Selected Human Pathogenic Bacteria

The current investigation aims to test the susceptibility of human pathogenic clinical isolates and MTCC strains to leaf and seed extracts of Terminalia catappa and Nigella sativa. Disc diffusion assay, micro dilution assay and minimum Bactericidal Concentration investigated the susceptibility of bacteria to the test extracts. The active extract was subjected to phytochemical screening, separation of the phytochemicals by Thin Layer Chromatography, bioactivity guided assay and Time- kill assay. Acetone and methanol extracts of T.catappa revealed, significant inhibition of clinical origin Staphylococcus aureus followed by Proteus vulgaris and the MTCC strains Staphylococcus aureus, Salmonella typhi, Pseudomonas aeroginosa and Bacillus subtilis. Nigella sativa inhibited the growth of clinical origin Staph.aureus and MTCC strain of Staph.aureus, Salmonella typhi and B.subtilis. Minimum inhibitory concentration for all the test bacteria was reported in the range of 5000μg/ml to 9 μg/ml in T. catappa extract. Most sensitive being the clinical isolate Staph. aureus and Proteus vulgaris. The bactericidal concentration for the test bacteria was found to be between 5000μg/ml and 625μg/ml. Phyto-chemical analysis of leaf extracts of T. catappa found to have dominated by polyphenols (Terpenoids, steroids, flavonoids, flavones, saponins and tannins) and N.sativa extracts recorded the presence of alkaloids, proteins and oils and fats. TLC profiling of the acetone extract revealed many antibacterial active bands. Bands having Retention factor 0.47 and 0.52 were active against the test bacteria. Time kill assay of the acetone extract of T. catappa were carried out for the first time. The extract exhibited dose dependent bactericidal and bacteriostatic activity against the clinical isolates.

Traditional Applications of Tannin Rich Extracts Supported by Scientific Data: Chemical Composition, Bioavailability and Bioaccessibility

Tannins are polyphenolic compounds historically utilized in textile and adhesive industries, but also in traditional human and animal medicines or foodstuffs. Since 20th-century, advances in analytical chemistry have allowed disclosure of the chemical nature of these molecules. The chemical profile of extracts obtained from previously selected species was investigated to try to establish a bridge between traditional background and scientific data. The study of the chemical composition of these extracts has permitted us to correlate the presence of tannins and other related molecules with the effectiveness of their apparent uses. The revision of traditional knowledge paired with scientific evidence may provide a supporting background on their use and the basis for developing innovative pharmacology and food applications based on formulations using natural sources of tannins. This traditional-scientific approach can result useful due to the raising consumers' demand for natural products in markets, to which tannin-rich extracts may pose an attractive alternative. Therefore, it is of interest to back traditional applications with accurate data while meeting consumer's acceptance. In this review, several species known to contain high amounts of tannins have been selected as a starting point to establish a correlation between their alleged traditional use, tannins content and composition and potential bioaccessibility.

Plants of the Genus Terminalia: An Insight on Its Biological Potentials, Pre-Clinical and Clinical Studies

The evaluation and confirmation of healing properties of several plant species of genus Terminalia based on their traditional uses and the clinical claims are of utmost importance. Genus Terminalia has received more attention to assess and validate the therapeutic potential and clinical approval due to its immense folk medicinal and traditional applications. Various species of Terminalia genus are used in the form of herbal medicine and formulations, in treatment of diseases, including headache, fever, pneumonia, flu, geriatric, cancer, to improve memory, abdominal and back pain, cough and cold, conjunctivitis, diarrhea, heart disorder, leprosy, sexually transmitted diseases, and urinary tract disorders. These are reported to possess numerous biological properties, counting: antibacterial, antifungal, antiinflammatory, antiviral, antiretroviral, antioxidant, and antipa7rasitic. This current research review aims to update the detailed biological activities, pre-clinical and clinical studies of various extracts and secondary metabolites from several plant species under the genus Terminalia, along with information on the traditional uses and chemical composition to develop a promising strategy for their potential applications in the form of medicine or use in modern drug formulations for treating diseases like pneumonia, flu, and other types of viral infections or controlling human contagions.

Terminalia bellirica (Gaertn.) roxb. (Bahera) in health and disease: A systematic and comprehensive review

BACKGROUND

Terminalia bellirica (Gaertn.) Roxb. is one of the oldest medicinal herbs of India, Pakistan, Nepal, Bangladesh and Sri Lanka as well as South-East Asia. Its medicinal utility has been described in the different traditional medicinal systems, such as Ayurveda, Unani, Siddha, and traditional Chinese medicine.

PURPOSE

The present study is aimed at providing a comprehensive overview on the traditional medicinal use, major phytoconstituents, biological and pharmacological activities and related mechanisms of actions and clinical studies of T. bellirica. Another objective is to describe current limitations and future direction of T. bellirica-related research.

METHODS

PubMed, ScienceDirect, Scopus, Cochrane Library, and EBOSCO host databases were selected to explore literature published between 1980 and 2020 (till March). Keywords used in various combinations comprised of Terminalia bellirica, phytoconstituents, health effects, pharmacological activities, molecular targets, in vitro, in vivo, clinical studies, and disease prevention.

RESULTS

A broad spectrum in vitro and in vivo studies suggested various biological and pharmacological effects, including antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, hepatoprotective, renoprotective, antidiabetic, anti-hyperlipidemic, and anticancer activities. Diverse bioactivities of T. bellirica have been ascribed to the presence of many bioactive phytochemicals, such as glucoside, tannins, gallic acid, corilagin, ellagic acid, ethyl gallate, galloyl glucose, chebulagic acid, and arjunolic acid.

CONCLUSION

Preclinical and clinical studies have suggested that T. bellirica plant and its phytoconstituents have immense potential for prevention and treatment of various diseases. Additional in vivo studies and clinical trials are warranted to realize the complete medicinal attributes of this plant.

Virtual Screening Identifies Chebulagic Acid as an Inhibitor of the M2(S31N) Viral Ion Channel and Influenza A Virus

The increasing prevalence of drug-resistant influenza viruses emphasizes the need for new antiviral countermeasures. The M2 protein of influenza A is a proton-gated, proton-selective ion channel, which is essential for influenza replication and an established antiviral target. However, all currently circulating influenza A virus strains are now resistant to licensed M2-targeting adamantane drugs, primarily due to the widespread prevalence of an M2 variant encoding a serine to asparagine 31 mutation (S31N). To identify new chemical leads that may target M2(S31N), we performed a virtual screen of molecules from two natural product libraries and identified chebulagic acid as a candidate M2(S31N) inhibitor and influenza antiviral. Chebulagic acid selectively restores growth of M2(S31N)-expressing yeast. Molecular modeling also suggests that chebulagic acid hydrolysis fragments preferentially interact with the highly-conserved histidine residue within the pore of M2(S31N) but not adamantane-sensitive M2(S31). In contrast, chebulagic acid inhibits in vitro influenza A replication regardless of M2 sequence, suggesting that it also acts on other influenza targets. Taken together, results implicate chebulagic acid and/or its hydrolysis fragments as new chemical leads for M2(S31N) and influenza-directed antiviral development.