Immunomodulatory effects of Stachytarpheta cayennensis leaf extract and its synergistic effect with artesunate.

BACKGROUND: The leaves of Stachytarpheta cayennensis C. Rich. (Verbenaceae) have been reported to possess potent anti-inflammatory and anti-malarial activities. Due to close association between inflammatory and immune responses, we evaluated the immunomodulatory activity of leaves extract of S. cayennensis. The combined effects of the leaves extract and artesunate, a standard antimalarial agent with immunomodulatory effects, were also evaluated. METHODS: The immunomodulatory activity of the methanol extract of the leaves of S. cayennensis (MESC) was evaluated in mice using the Delayed-Type hypersensitivity response (DTHR), primary and secondary humoral immune responses and the in vivo leucocyte mobilization tests. The immunomodulatory effect of artesunate and the combined effects of MESC and artesunate were evaluated using the phagocytic activity of polymorphonuclear neutrophils. Acute toxicity and lethality test in addition to the preliminary phytochemical studies of MESC were also performed. RESULTS: The MESC exhibited 64.21% inhibition of DTHR at 500 mg/kg dose and evoked 139.64% of phagocytic stimulation at 100 µg/ml dose. Also MESC significantly (p < 0.05) showed dose related stimulation of humoral immunity and a highest percentage leucocyte mobilization of 10.15% at 250 mg/kg dose. Artesunate offered a non-significant (p > 0.05) percentage phagocytic stimulation (PPS) while the combined effect of artesunate and MESC exhibited a significant (p < 0.05) dose dependent PPS with highest PPS of 393.77% at 100 µg/ml. The LD50 of the MESC was estimated to be greater than 5000 mg/kg since there were no lethality and signs of acute intoxication after 48 h observation. Preliminary phytochemical analysis revealed the presence of carbohydrates, glycosides, flavonoids, saponins, alkaloids, terpenoids and steroids. CONCLUSIONS: The results of this study indicated that MESC possesses immunostimulatory action with significant synergistic effects with artesunate, and can therefore, offer immune boosting activities in disorders of immune suppression.

Phytochemicals and bioactive compounds effective against acute myeloid leukemia: A systematic review.

This systematic review identified various bioactive compounds which have the potential to serve as novel drugs or leads against acute myeloid leukemia. Acute myeloid leukemia (AML) is a heterogeneous hematopoietic malignancy that arises from the dysregulation of cell differentiation, proliferation, and cell death. The risk factors associated with the onset of AML include long-term exposure to radiation and chemicals such as benzene, smoking, genetic disorders, blood disorders, advancement in age, and others. Although novel strategies to manage AML, including a refinement of the conventional chemotherapy regimens, hypomethylating agents, and molecular targeted drugs, have been developed in recent years, resistance and relapse remain the main clinical problems. In this study, three databases, PubMed/MEDLINE, ScienceDirect, and Google Scholar, were systematically searched to identify various bioactive compounds with antileukemic properties. A total of 518 articles were identified, out of which 59 were viewed as eligible for the current report. From the data extracted, over 60 bioactive compounds were identified and divided into five major groups: flavonoids, alkaloids, organosulfur compounds, terpenes, and terpenoids, and other known and emerging bioactive compounds. The mechanism of actions of the analyzed individual bioactive molecules differs remarkably and includes disrupting chromatin structure, upregulating the synthesis of certain DNA repair proteins, inducing cell cycle arrest and apoptosis, and inhibiting/regulating Hsp90 activities, DNA methyltransferase 1, and histone deacetylase 1.

Antimicrobial Effects of a Lipophilic Fraction and Kaurenoic Acid Isolated from the Root Bark Extracts of Annona senegalensis.

Root bark preparation of Annona senegalensis Pers. (Annonaceae) is used in Nigerian ethnomedicine for treatment of infectious diseases. Extraction of the A. senegalensis powdered root bark with methanol-methylene chloride (1 : 1) mixture yielded the methanol-methylene extract (MME) which was fractionated to obtain the ethyl acetate fraction (EF). The EF on further fractionation gave two active subfractions, F1 and F2. The F1 yielded a lipophilic oily liquid while F2 on purification, precipitated white crystalline compound, AS2. F1 was analyzed using GC-MS, while AS2 was characterized by proton NMR and X-ray crystallography. Antibacterial and antifungal studies were performed using agar-well-diffusion method with 0.5 McFarland standard and MICs calculated. GC-MS gave 6 major constituents: kaur-16-en-19-oic acid; 1-dodecanol; 1-naphthalenemethanol; 6,6-dimethyl-bicyclo[3.1.1]hept-2-ene-2-ethanol; 3,3-dimethyl-2-(3-methylbuta-1,3-dienyl)cyclohexane-1-methanol; 3-hydroxyandrostan-17-carboxylic acid. AS2 was found to be kaur-16-en-19-oic acid. The MICs of EF, F1, and AS2 against B. subtilis were 180, 60, and 30 µg/mL, respectively. AS2 exhibited activity against S. aureus with an MIC of 150 µg/mL, while F1 was active against P. aeruginosa with an MIC of 40 µg/mL. However, the extracts and AS2 exhibited no effects against Candida albicans and Aspergillus niger. Therefore, kaurenoic acid and the lipophilic fraction from A. senegalensis root bark exhibited potent antibacterial activity.

Toxicity of Nanoparticles in Biomedical Application: Nanotoxicology.

Nanoparticles are of great importance in development and research because of their application in industries and biomedicine. The development of nanoparticles requires proper knowledge of their fabrication, interaction, release, distribution, target, compatibility, and functions. This review presents a comprehensive update on nanoparticles' toxic effects, the factors underlying their toxicity, and the mechanisms by which toxicity is induced. Recent studies have found that nanoparticles may cause serious health effects when exposed to the body through ingestion, inhalation, and skin contact without caution. The extent to which toxicity is induced depends on some properties, including the nature and size of the nanoparticle, the surface area, shape, aspect ratio, surface coating, crystallinity, dissolution, and agglomeration. In all, the general mechanisms by which it causes toxicity lie on its capability to initiate the formation of reactive species, cytotoxicity, genotoxicity, and neurotoxicity, among others.

Bioactive Compounds Effective Against Type 2 Diabetes Mellitus: A Systematic Review.

BACKGROUND: Type 2 diabetes (adult onset diabetes) is the most common type of diabetes, accounting for around 90% of all diabetes cases with insulin resistance and insulin secretion defect. The key goal of anti-diabetic therapy is to increase the development of insulin, immunity and/or decrease the amount of blood glucose. While many synthetic compounds have been produced as antidiabetic agents, due to their side effects and limited effectiveness, their usefulness has been hindered. METHODS: This systematic review investigated the bioactive compounds reported to possess activities against type 2 diabetes. Three (3) databases, PubMed, ScienceDirect and Google Scholar were searched for research articles published between January 2010 and October 2020. A total of 6464 articles were identified out of which 84 articles were identified to be elligible for the study. RESULT AND DISCUSSION: From the data extracted, it was found that quercetin, Kaempferol, Rosmarinic acid, Cyanidin, Rutin, Catechin, Luteolin and Ellagic acid were the most cited bioactive compounds which all falls within the class of polyphenolic compounds. The major sources of these bioactive compounds includes citrus fruits, grapes, onions, berries, cherries, broccoli, honey, apples, green tea, Ginkgo biloba, St. John's wort, green beans, cucumber, spinach, tea, Rosmarinus officinalis, Aloe vera, Moringa oleifera, tomatoes, potatoes, oregano, lemon balm, thyme, peppermint, Ocimum basilicum, red cabbage, pears, olive oil and walnut.

Medicinal plants used by the people of Nsukka Local Government Area, south-eastern Nigeria for the treatment of malaria: An ethnobotanical survey.

ETHNOBOTANICAL RELEVANCE: Malaria is a serious public health problem especially in sub-Saharan African countries such as Nigeria. The causative parasite is increasingly developing resistance to the existing drugs. There is urgent need for alternative and affordable therapy from medicinal plants which have been used by the indigenous people for many years. AIM OF STUDY: This study was conducted to document the medicinal plant species traditionally used by the people of Nsukka Local Government Area in south-eastern Nigeria for the treatment of malaria. METHODS: A total of 213 respondents, represented by women (59.2%) and men (40.8%), were interviewed using a semi-structured questionnaire. The results were analysed and discussed in the context of previously published information on anti-malarial and phytochemical studies of the identified plants. RESULTS: The survey revealed that 50 plant species belonging to 30 botanical families were used in this region for the treatment of malaria. The most cited families were Apocynaceae (13.3%), Annonaceae (10.0%), Asteraceae (10.0%), Lamiaceae (10.0%), Poaceae (10.0%), Rubiaceae (10.0%) and Rutaceae (10.0%). The most cited plant species were Azadirachta indica (11.3%), Mangifera indica (9.1%), Carica papaya (8.5%), Cymbopogon citratus (8.5%) and Psidium guajava (8.5%). CONCLUSION: The present findings showed that the people of Nsukka use a large variety of plants for the treatment of malaria. The identified plants are currently undergoing screening for anti-malarial, toxicity and chemical studies in our laboratory.