Anticholinesterase and Antioxidant Effects of Traditional Herbal Medicines used in the Management of Neurodegenerative Diseases in Mauritius

Bioactive plant constituents from traditional herbal medicines can simultaneously protect neurons against oxidative stress and act as cholinesterase inhibitors, two key factors involved in the pathogenesis of neurodegenerative diseases. This study thus aimed at investigating the antioxidant and anticholinesterase activities of five herbal medicines, including 3 polyherbal formulas (F1, F2, F4) and 2 singleherb formulas (F3 and F5), currently used in Mauritius. Antioxidant activities were determined by the reducing potential, scavenging and chelating properties while the pro-oxidant effects was characterized by the copper-phenanthroline assay. While all extracts exhibited antioxidant activity, different extent of such property was observed in each assay. F3 containing Gingko biloba L. demonstrated a higher ferric reducing antioxidant potential (1654 ± 37.8 μmol Fe (II) equivalent/g dry weight) compared to the other extracts. The elixir F2 consisting of Gingko biloba L., Hypericum perforatum L. and Salvia miltiorrhiza Bunge was a potent scavenger of hypochlorous acid and hydroxyl radical and was a strong iron (II) chelator. All extracts inhibited acetylcholinesterase enzyme in a dose-dependent manner, which correlated strongly with total phenolics (r=0.894, p<0.01) and total proanthocyanidins (r=0.937, p<0.01). These findings suggested that activities of the locally available herbal drugs used to slow the progression of neurodegenerative disorder might be partly ascribed to their antioxidant and anticholinesterase activity.KEY WORDS: Cholinesterase inhibitors; Oxidative stress; Pro-oxidant activities; Traditional herbal medicine; Neurodegenerative disease

In vitro cytotoxic and apoptotic activity of the Mauritian marine sponge Neopetrosia exigua

Marine sponges belonging to the genus Neopetrosia represent a quasi-inexhaustible source of novel cytotoxic compounds. Yet studies delineating their molecular mechanisms of action in cancer cells remain scarce. We investigated the cytotoxic and apoptosis inducing potential of the Mauritian marine sponge Neopetrosia exigua derived crude extract, hexane and ethyl acetate fraction. Their cytotoxic activity was screened against four cancer cell lines and two non-malignant cell lines via the Alamar Blue metabolic assay. The level of intracellular reactive oxygen species (ROS) production, endogenous antioxidant enzyme activity (catalase and superoxide dismutase) and mitochondrial membrane potential were determined. The ability of the active extract to induce apoptosis in cancer cells and modulate the expression levels of apoptotic markers (caspases and polyADP-ribose polymerase (PARP)) was further evaluated via western blot. The ethyl acetate fraction (NEEAF) displayed the highest inhibitory effect with an IC50 of 6.87 μg/mL against the liver hepatocellular carcinoma cell line (HepG2). Mechanistically, NEEAF induced morphological hallmarks characteristic of apoptosis, increased ROS production, decreased catalase and superoxide dismutase activity and mitochondrial membrane depolarisation in a concentration-dependent manner compared to the control (p<0.05). In addition, NEEAF induced the activation of caspase-9, -7, -3 and cleavage of PARP. Overall, this study provides biochemical evidence for oxidative stress-mediated cytotoxicity and apoptosis in HepG2 cells by NEEAF. Further in-depth investigations are needed to isolate the active constituents, which may potentially lead to the development of novel anticancer therapeutics. Significance: • Marine sponges represent an untapped goldmine of structurally unique compounds with interesting anticancer properties. • This important initial investigative work will set the stage for more in-depth mechanistic studies and chemical characterisation of potentially novel bioactive compounds from the genus Neopetrosia. • This work will also help to strengthen frameworks oriented towards the conservation of Neopetrosia species in the Western Indian Ocean region

Towards policies that capture the expected value of biomolecular diversity for drug discovery, human health, and well-being

This paper aims to help policy makers with a characterization of the intrinsic value of biodiversity and its role as a critical foundation for sustainable development, human health, and well-being. Our objective is to highlight the urgent need to overcome economic, disciplinary, national, cultural, and regional barriers, in order to work out innovative measures to create a sustainable future and prevent the mutual extinction of humans and other species. We emphasize the pervasive neglect paid to the cross-dependency of planetary health, the health of individual human beings and other species. It is critical that social and natural sciences are taken into account as key contributors to forming policies related to biodiversity, conservation, and health management. We are reaching the target date of Nagoya treaty signatories to have accomplished measures to prevent biodiversity loss, providing a unique opportunity for policy makers to make necessary adjustments and refocus targets for the next decade. We propose recommendations for policy makers to explore novel avenues to halt the accelerated global loss of biodiversity. Beyond the critical ecological functions biodiversity performs, its enormous untapped the repertoire of natural molecular diversity is needed for solving accelerating global healthcare challenges

In vitro antioxidant, antibacterial, cytotoxic, and epigenetic screening of crude extract and fractions of the marine sponge Neopetrosia exigua from Mauritius waters

DATA AVAILABILITY : All data generated or analysed during this study are included in this published article [and its supplementary information file].The marine sponge Neopetrosia exigua is known as a goldmine of novel compounds, yet its pharmacological activities remain poorly characterised. Herein, this study investigates the bioactivities of N. exigua collected from Mauritius waters. The crude extract (dichloromethane: methanol), hexane, ethyl acetate and aqueous fractions obtained from N. exigua were subjected to in vitro antioxidant assays. Their antibacterial activities were evaluated using the broth microdilution method to determine the minimum inhibitory concentration (MIC). The cytotoxic and epigenetic activities were further screened using the MTT assay and a cell-based image system that measures de-repression of a silenced Green Fluorescent Protein (GFP) reporter gene, respectively. Higher antioxidant activity was recorded for the ethyl acetate fraction as demonstrated by its significant ferric reducing antioxidant power, radical scavenging, and metal chelating activities relative to control (p < 0.05). The best antibacterial profile was presented by the ethyl acetate fraction against Cutibacterium acnes (MIC: 0.039 mg/ml), Streptococcus mutans (MIC: 0.078 mg/ml) and Mycobacterium smegmatis (MIC: 0.313 mg/ml). Similarly, the fraction displayed significant cytotoxicity against the human liposarcoma SW872 cells with IC50 value of 44.34 ± 2.64 μg/ml and GFP re-activation capacity of 43.79 ± 3.19% (p < 0.05). This work conveys interesting data on the antioxidant, antimicrobial, and anticancer properties of N. exigua. In particular, this study indicates the promising potential of N. exigua as a reservoir of epigenetically active agents that can modulate transcription of silenced genes involved in carcinogenesis. Hence, further investigations to isolate the active constituents is actively warranted.The Mauritius Research and Innovation Council under the National Research and Innovation Chair Program, the African German Network of Excellence in Science for Junior researchers Mobility Grant 2017 and the North-South Interdisciplinary Grant of the Global Young Academy.https://www.elsevier.com/locate/sciafam2024Plant Production and Soil ScienceSDG-14:Life below wate

Mauritian Endemic Medicinal Plant Extracts Induce G2/M Phase Cell Cycle Arrest and Growth Inhibition of Oesophageal Squamous Cell Carcinoma in Vitro

Terrestrial plants have contributed massively to the development of modern oncologic drugs. Despite the wide acceptance of Mauritian endemic flowering plants in traditional medicine, scientific evidence of their chemotherapeutic potential is lacking. This study aimed to evaluate the in vitro tumor cytotoxicity of leaf extracts from five Mauritian endemic medicinal plants, namely Acalypha integrifolia Willd (Euphorbiaceae), Labourdonnaisia glauca Bojer (Sapotaceae), Dombeya acutangula Cav. subsp. rosea Friedmann (Malvaceae), Gaertnera psychotrioides (DC.) Baker (Rubiaceae), and Eugenia tinifolia Lam (Myrtaceae). The cytotoxicities of the extracts were determined against six human cancer cell lines, including cervical adenocarcinoma, colorectal carcinoma, oesophageal adenocarcinoma, and oesophageal squamous cell carcinoma. The potent extracts were further investigated using cell cycle analysis and reverse phase protein array (RPPA) analysis. The antioxidant properties and polyphenolic profile of the potent extracts were also evaluated. Gas chromatography mass spectrometry (GC-MS) analyses revealed the presence of (+)-catechin and gallocatechin in E. tinifolia and L. glauca, while gallic acid was detected in A. integrifolia. L. glauca, A. integrifolia, and E. tinifolia were highly selective towards human oesophageal squamous cell carcinoma (KYSE-30) cells. L. glauca and E. tinifolia arrested KYSE30 cells in the G2/M phase, in a concentration-dependent manner. RPPA analysis indicated that the extracts may partly exert their tumor growth-inhibitory activity by upregulating the intracellular level of 5′AMP-activated kinase (AMPK). The findings highlight the potent antiproliferative activity of three Mauritian endemic leaf extracts against oesophageal squamous cell carcinoma and calls for further investigation into their chemotherapeutic application

Pluripharmacological potential of Mascarene endemic plant leaf extracts

DATA AVAILABILITY : Data will be made available on request.Please read abstract in the article.The Mauritius Research Innovation Council under the National Research and Innovation Chair Program studentship and the Royal Society and Royal Society of Chemistry international exchange award.https://www.elsevier.com/locate/babhj2024Plant Production and Soil ScienceSDG-15:Life on lan

Biodiversity, drug discovery, and the future of global health:Introducing the biodiversity to biomedicine consortium, a call to action

First paragraph: Looking to nature for medicine is nothing new – we have been doing it for tens of thousands of years and although modern pharmaceutical science has come a long way from those ancient roots, nature is and will always be an important source of useful compounds and inspiration. Dismissing nature in this regard is a huge mistake as evolution is the greatest problem solver and the myriad compounds produced by the immense variety of species we share the planet with have been honed by three billion years of trial and error. However, with every bit of habitat that disappears under the plough or concrete we impoverish nature and deprive ourselves of potential medicines.Additional co-authors: Uttam Babu Shrestha, Milica Pešić, Alexander Kagansk

Biodiversity, drug discovery, and the future of global health: Introducing the biodiversity to biomedicine consortium, a call to action

Looking to nature for medicine is nothing new – we have been doing it for tens of thousands of years and although modern pharmaceutical science has come a long way from those ancient roots, nature is and will always be an important source of useful compounds and inspiration. Dismissing nature in this regard is a huge mistake as evolution is the greatest problem solver and the myriad compounds produced by the immense variety of species we share the planet with have been honed by three billion years of trial and error. However, with every bit of habitat that disappears under the plough or concrete we impoverish nature and deprive ourselves of potential medicines

Underestimating the Toxicological Challenges Associated with the Use of Herbal Medicinal Products in Developing Countries

Various reports suggest a high contemporaneous prevalence of herb-drug use in both developed and developing countries. The World Health Organisation indicates that 80% of the Asian and African populations rely on traditional medicine as the primary method for their health care needs. Since time immemorial and despite the beneficial and traditional roles of herbs in different communities, the toxicity and herb-drug interactions that emanate from this practice have led to severe adverse effects and fatalities. As a result of the perception that herbal medicinal products have low risk, consumers usually disregard any association between their use and any adverse reactions hence leading to underreporting of adverse reactions. This is particularly common in developing countries and has led to a paucity of scientific data regarding the toxicity and interactions of locally used traditional herbal medicine. Other factors like general lack of compositional and toxicological information of herbs and poor quality of adverse reaction case reports present hurdles which are highly underestimated by the population in the developing world. This review paper addresses these toxicological challenges and calls for natural health product regulations as well as for protocols and guidance documents on safety and toxicity testing of herbal medicinal products

Mushroom-Derived Compounds as Metabolic Modulators in Cancer

Cancer is responsible for lifelong disability and decreased quality of life. Cancer-associated changes in metabolism, in particular carbohydrate, lipid, and protein, offer a new paradigm of metabolic hits. Hence, targeting the latter, as well as related cross-linked signalling pathways, can reverse the malignant phenotype of transformed cells. The systemic toxicity and pharmacokinetic limitations of existing drugs prompt the discovery of multi-targeted and safe compounds from natural products. Mushrooms possess biological activities relevant to disease-fighting and to the prevention of cancer. They have a long-standing tradition of use in ethnomedicine and have been included as an adjunct therapy during and after oncological care. Mushroom-derived compounds have also been reported to target the key signature of cancer cells in in vitro and in vivo studies. The identification of metabolic pathways whose inhibition selectively affects cancer cells appears as an interesting approach to halting cell proliferation. For instance, panepoxydone exerted protective mechanisms against breast cancer initiation and progression by suppressing lactate dehydrogenase A expression levels and reinducing lactate dehydrogenase B expression levels. This further led to the accumulation of pyruvate, the activation of the electron transport chain, and increased levels of reactive oxygen species, which eventually triggered mitochondrial apoptosis in the breast cancer cells. Furthermore, the inhibition of hexokinase 2 by neoalbaconol induced selective cytotoxicity against nasopharyngeal carcinoma cell lines, and these effects were also observed in mouse models. Finally, GL22 inhibited hepatic tumour growth by downregulating the mRNA levels of fatty acid-binding proteins and blocking fatty acid transport and impairing cardiolipin biosynthesis. The present review, therefore, will highlight how the metabolites isolated from mushrooms can target potential biomarkers in metabolic reprogramming