In vitro study on the antioxidant potentials of the leaves and fruits of Nauclea latifolia

Revitalizing Muscle Regeneration: Cocoa Polyphenols Shield Mitochondrial Integrity and Boost Myogenesis Under Oxidative Stress

In this study, we describe the effect of cocoa polyphenol extract (CPE, from flavanols-rich cocoa) on myogenic differentiation in murine myoblasts (C2C12 cells) exposed to H2O2. The myogenic program was monitored using morphological, ultrastructural, and molecular approaches. Treatment with 100 μM of H2O2 for 1 h decreased cell viability. C2C12 (D1) exposed to H2O2 shows more apoptotic and necrotic cells, and mitochondria appear emptied, with cristae heavily damaged. To evaluate the effect of CPE on myoblast viability and myotube formation, 10 μg/mL of CPE were added 24 h prior to H2O2 treatment and cells were supplemented with fresh CPE every 24 h during differentiation. Supplementation with CPE protected C2C12 myoblasts from H2O2-induced oxidative damage both at early (D1) and late (D6) phases of differentiation, preventing cell death and mitochondrial damage. The number of mitochondria (per area of cell surface) increased 2-fold in both control and in CPE-supplemented and mitochondria in myotubes D6 showed a greater extension of mitochondrial cristae than mitochondria in D1. At D1 and D6 the monolayers showed surface and inner cell features relatively comparable to the untreated control suggesting that CPE supplementation significantly mitigated the effect of H2O2. Preliminary data obtained by the myogenic index (Giemsa staining) suggested that CPE-supplemented cells were partially protected from H2O2-induced myogenesis inhibition. The CPE supplementation seems to preserve the mitochondrial integrity and the myogenic differentiation ability of oxidatively injured C2C12 ensuing further nutraceutical perspectives.

A Review of Medicinal Plants Used in the Management of Microbial Infections in Angola

The use of medicinal plants in the management of microbial infections is significant to the health of the indigenous people in many Angolan communities. The present study provides a comprehensive overview of medicinal plants used for the management of microbial infections in Angola. Relevant information was extracted from research articles published and associated with the use of medicinal plants in the management of microbial infections in Angola (from January 1976 to November 2023). Data or information were gathered from the literature sourced from Wiley Online, SciFinder, Google Scholar, Web of Science, Scopus, ScienceDirect, BMC, Elsevier, SpringerLink, PubMed, books, journals and published M.Sc. and Ph.D. thesis. A total of 27 plant species, representing 19 families, were recorded in this study. Hypericaceae (11%), Lamiaceae (11%), Malvaceae (11%), Phyllanthaceae (11%), Fabaceae (16%) and Rubiaceae (16%) were the most predominant families. The leaves are the most used parts (96%), followed by bark (74%) and root (70%). The data revealed that medicinal plants continue to play significant roles in the management of microbial infections in Angola. In order to explore the benefits of the therapeutic potential of indigenous medicinal plants for diseases related to infections; further scientific research studies are important to produce data on their effectiveness using appropriate test models. This approach might assist with the continuing drive regarding the integration of Angolan traditional medicine within mainstream healthcare systems.

Strategy for the quality control of herbal preparations made of Sarcocephalus latifolius: Development and validation of a UHPLC-PDA method for quantification of angustoline and strictosamide and chemical profiling using LC-QToF

INTRODUCTION

Sarcocephalus latifolius is one of the most used plants in West African traditional medicine to treat malaria.

OBJECTIVE

The aim is to establish a strategy to control the quality of herbal preparations made from S. latifolius.

METHOD

A UHPLC-PDA method was developed for the determination and quantification of the two main bioactive compounds (angustoline and strictosamide) in various parts of the plant. Additionally, an LC-QToF with electrospray ionization method is described for the identification and confirmation of compounds in samples of different parts of the plant.

RESULTS

With the UHPLC-PDA method, separation was achieved within 5 min using a C18 column stationary phase at a temperature of 45°C and a gradient system with a mobile phase of water and acetonitrile, both containing 0.1% formic acid. The method was validated for linearity, accuracy, precision (repeatability and intermediate precision), limit of detection (LOD), and limit of quantification (LOQ). The LOD and LOQ of angustoline were found to be 0.3 and 0.8 μg/ml, respectively, and those of strictosamide were found to be 0.1 and 0.3 μg/ml, respectively. Using the LC-QToF method, 90 secondary metabolites, including four isolated compounds from the plant's roots, were identified from leaf, bark, and root samples of S. latifolius.

CONCLUSION

This work is the first to propose a strategy to control the quality of herbal preparations made from S. latifolius. The developed method allows the quantification of the main bioactive compounds and the established chemical profile allows to distinguish the plant from any other species.

Antioxidant, Anti-Inflammatory, and Anti-Aging Potential of a Kalmia angustifolia Extract and Identification of Some Major Compounds

Skin aging is the most visible element of the aging process, giving rise to a major concern for many people. Plants from the Ericaceae family generally have antioxidant and anti-inflammatory properties, making them potential anti-aging active ingredients. This study aimed to evaluate the safety and anti-aging efficacy of a Kalmia angustifolia extract using reconstructed skin substitutes. The safety evaluation was performed using a 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay, while the efficacy was determined by assessing antioxidant and anti-inflammatory activity and analyzing skin substitutes reconstructed according to the self-assembly method by histology and immunofluorescence staining (elastin, collagen-1, collagen-3, aquaporin-3). The cell viability assay established the safety of the extract at a concentration up to 200 μg/mL. The Oxygen Radical Absorbance Capacity (ORAC) assay and a cell-based assay using 2',7'-dichlorofluorescein-diacetate (DCFH-DA) revealed a strong antioxidant activity with an ORAC value of 16 µmol Trolox Equivalent/mg and a half-maximal inhibitory concentration (IC50) of 0.37 ± 0.02 μg/mL, while an interesting anti-inflammatory activity was found in the inhibition of NO production, with an inhibition percentage of NO production of 49 ± 2% at 80 µg/mL. The isolation and characterization of the extract allowed the identification of compounds that could be responsible for these biological activities, with two of them being identified for the first time in K. angustifolia: avicularin and epicatechin-(2β-O-7, 4β-6)-ent-epicatechin. Histological analyses of skin substitutes treated with the extract showed an increase in dermal thickness compared with the controls. K. angustifolia extract enhanced the expression of elastin and collagen-1, which are usually decreased with skin aging. These results suggest that K. angustifolia has promising antioxidant efficacy and anti-aging potential.

Ameliorative Potential of Hydroethanolic Leaf Extract of Parquetina nigrescens on d-Galactose-Induced Testicular Injury

BACKGROUND

There is an increasing need for botanicals to be used as an alternative and complementary medicine in the management of male infertility. Male infertility has been a major health/social challenge to people all over the world. This study, therefore, investigated the ameliorative potential of hydroethanolic leaf extract of Parquetina nigrescens (HELEPN) against d-galactose-induced testicular injury.

METHODS

Thirty male Wistar rats were randomly allotted into six groups (n = 5). Group I (Normal control), Group II (300 mg/kg b.w. d-galactose), Group III and IV (250 and 500 mg/kg b.w. HELEPN, respectively), Group V and VI (both received 300 mg/kg b.w. of d-galactose with 250 and 500 mg/kg b.w of HELEPN, respectively). d-galactose administration started two weeks prior to HELEPN treatment which lasted for six weeks. All assays were carried out using established protocols.

RESULTS

Administration of HELEPN at 250mg/kg and 500mg/kg concomitantly with d-galactose improved paired and relative testicular weights, levels of gonadotropins (LH and FSH) and testosterone, and poor sperm quality. HELEPN treatment reduced the levels of oxidative stress biomarkers (MDA, 8-OHDG, and AGEs) and inflammatory response (TNF-alpha and NO) to normal, as well as restoring the reduced activities of antioxidant enzymes (glutathione peroxidase, superoxide dismutase, and catalase). In addition, HELEPN treatment mitigated testicular DNA fragmentation and down-regulated caspase 3-activities. HELEPN at 500 mg/kg was observed to have the greatest ameliorative effect.

CONCLUSION

HELEPN protects against d-galactose-induced testicular injury through antioxidative, anti-inflammatory, and antiapoptotic mechanisms.

Nauclea latifolia Sm. Leaf Extracts Extenuates Free Radicals, Inflammation, and Diabetes-Linked Enzymes

This study was carried out to assess the in vitro antioxidant, anti-inflammatory and antidiabetic effects of Nauclea latifolia (Sm.) leaf extracts. Ethanolic (NLE) and aqueous (NLA) extract of N. latifolia leaves were prepared and assessed for their anti-inflammatory activity, antioxidant potential, α-amylase and α-glucosidase inhibitory activities, and the mechanism of enzyme inhibition in vitro using standard established methods. From the results, phytochemicals such as flavonoids, phenolics, glycosides, and tannins were detected in both extracts of N. latifolia with NLE having a significantly (p < 0.05) higher phytochemical content. NLE displayed significantly (p < 0.05) better total antioxidant capacity, reducing power, 2,2-diphenyl-2-picrylhydrazyl, and hydrogen peroxide radical scavenging activities. For anti-inflammatory activities, 70.54 ± 2.45% albumin denaturation inhibition was observed for NLE while 68.05 ± 1.03% was recorded for NLA. Likewise, 16.07 ± 1.60 and 14.08 ± 1.76% were obtained against hypotonic solution and heat-induced erythrocyte haemolysis, respectively, for NLE while 20.59 ± 4.60 and 24.07 ± 1.60% were respective NLA values. NLE (IC₅₀: 4.20 ± 0.18 and 1.19 ± 0.11 mg/mL) and NLA (IC₅₀: 11.21 ± 0.35 and 2.64 ± 0.48 mg/mL) α-glucosidase and α-amylase inhibitory activities were dose-dependent with uncompetitive and competitive inhibition elicited, respectively, by the extracts. A significant positive association (p < 0.01 and 0.05) was identified between antioxidant activity and carbohydrate-metabolising enzyme inhibitory activity. The obtained result suggests N. latifolia leaf could serve as an alternative candidate for managing diabetes mellitus due to its antioxidant and anti-inflammatory association with diabetes-linked enzymes.

Evaluation of free radical scavenging capacity of methoxy containing-hybrids of thiosemicarbazone-triazole and their influence on glucose transport

Background

Diabetes mellitus is a metabolic disease in which the body is unable to produce insulin or respond to insulin production, consequently leading to abnormal metabolism of carbohydrates, lipids and proteins causing elevation of glucose in the blood. Oxidative stress, an imbalance between the production of free radicals and body antioxidant system has been implicated in the pathogenesis of diabetes. Free radicals attack important macromolecules leading to cell damage. Antioxidants are intimately involved in the prevention of damage caused by free radicals.

Methods

The anti-diabetic effects of hybrid compounds (2a-h) of thiosemicarbazone and triazole containing methoxy groups at C (4) positions were tested against genes involved in glucose metabolism (Glut-4, Mef2a and Nrf-1) using quantitative real time PCR (qPCR). Free radical scavenging capacity (FRAP, TEAC, DPPH and ORAC) of the hybrids was also carried out by using established antioxidant capacity assays.

Results

From the results, hybrid compounds 2b and 2h showed more pronounced effects in up-regulating diabetes associated genes which are important in the up-regulation of glucose uptake. All the hybrid compounds also showed free radical scavenging abilities.

Conclusion

In conclusion, hybrid compounds (2b and 2h) can be useful as potential drugs for the management of diabetes mellitus.

Traditional uses, phytochemistry and pharmacological properties of African Nauclea species: A review

ETHNOPHARMACOALOGICAL RELEVANCE

The genus Nauclea in Africa comprises seven species. Among them, N. latifolia, N. diderrichii and N. pobeguinii are widely used by the local population in traditional remedies. Preparation from various parts of plants (e.g. roots, bark, leaves) are indicated by traditional healers for a wide range of diseases including malaria, pain, digestive ailments or metabolic diseases.

MATERIALS AND METHODS

A literature search was conducted on African species of the genus Nauclea using scientific databases such as Google Scholar, Pubmed or SciFinder. Every document of ethnopharmacological, phytochemical or pharmacological relevance and written in English or French were analyzed.

RESULTS AND DISCUSSION

The Nauclea genus is used as ethnomedicine all along sub-Saharan Africa. Several local populations consider Nauclea species as a major source of remedies for malaria. In this regard, two improved traditional medicines are currently under development using extracts from N. latifolia and N. pobeguinii. Concerning the chemical composition of the Nauclea genus, indoloquinolizidines alkaloids could be considered as the major class of compounds as they are reported in every analyzed Nauclea species, with numerous structures identified. Based on traditional indications a considerable amount of pharmacological studies were conducted to ensure activity and attempt to link them to the presence of particular compounds in plant extracts.

CONCLUSION

Many experimental studies using plant extracts of the African species of the genus Nauclea validate traditional indications (e.g. malaria and pain). However, bioactive compounds are rarely identified and therefore, there is a clear need for further evaluations as well as for toxicity experiments. The sustainability of these plants, especially of N. diderrichii, a threatened species, should be kept in mind to adapt local uses and preparation modes of traditional remedies.

Medicinal Plants Used in Mali for the Treatment of Malaria and Liver Diseases

Today, ethno-pharmacology is a very important resource in order to discover new therapies for the current diseases. Moreover, another good justification for the ethno-pharmacological approach is to obtain new, effective, less expensive and simple therapies, limiting at the same time the cost of pharmaceutical research. Two major anti-malarial drugs widely used today, i.e. quinine and artemisinin, came respectively from Peruvian and Chinese ancestral treatments reported in the traditional medicines. In this contest, there is an urgent need for the discovery of new drugs, due to the critical epidemiological situation of this disease and to the growth of resistances. In Mali, malaria and liver diseases remain one of the leading public health problems. Many medicinal plants are often used, in local traditional medicine, for the treatment at the same time of malaria and liver diseases, including hepatic syndromes, jaundice, hepatitis and other hepatic disorders. Moreover, in the local language Bamanan, the word “ Sumaya” is used both for malaria and some liver diseases. In addition, we noted that some of the improved traditional phytomedicines produced by the Department of Traditional Medicine are prescribed by modern doctors both for malaria and liver diseases. In this review, pharmacological, toxicological and phytochemical data on Argemone mexicana L. (Papaveraceae), Cochlospermum tinctorium Perr. ex A. Rich (Cochlospermaceae), Combretum micranthum G.Don (Combretaceae), Entada africana Guillet Perr. (Mimosaceae), Erythrina senegalensis A. DC (Fabaceae), Mitragyna inermis (Willd) Kuntze (Rubiaceae), Nauclea latifolia Smith syn. Sarcocephalus latifolius (Smith) Bruce (Rubiaceae), Securidaca longepedunculata Fresen (Polygalaceae), Trichilia emetica Vahl. (Meliaceae), and Vernonia colorata (Willd) Drake (Asteraceae) are reported. Some of the collected data could be used to improve the actual herbal drugs and to propose new phytomedicines for the management of malaria and liver diseases.

Appraisal of Total Phenol, Flavonoid Contents, and Antioxidant Potential of Folkloric Lannea coromandelica Using In Vitro and In Vivo Assays

The aim of this study was to determine the impending antioxidant properties of different extracts of crude methanolic extract (CME) of leaves of Lannea coromandelica (L. coromandelica) and its two ethyl acetate (EAF) and aqueous (AqF) subfractions by employing various established in vitro systems and estimation of total phenolic and flavonoid content. The results showed that extract and fractions possessed strong antioxidant activity in vitro and among them, EAF had the strongest antioxidant activity. EAF was confirmed for its highest phenolic content, total flavonoid contents, and total antioxidant capacity. The EAF was found to show remarkable scavenging activity on 2,2-diphenylpicrylhydrazyl (DPPH) (EC50 63.9 ± 0.64 µg/mL), superoxide radical (EC50 8.2 ± 0.12 mg/mL), and Fe(2+) chelating activity (EC50 6.2 ± 0.09 mg/mL). Based on our in vitro results, EAF was investigated for in vivo antioxidant assay. Intragastric administration of the EAF can significantly increase levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GSH-Px) levels, and decrease malondialdehyde (MDA) content in the liver and kidney of CCl4-intoxicated rats. These new evidences show that L. coromandelica bared antioxidant activity.