In Vitro and In Vivo Toxicological Evaluation of Avicennia africana P: Beauv. (Avicenniaceae) Leaf Extract in a Rat Model.

Avicennia africana is an important ethnomedicinal plant that has long been used to treat malaria and several other diseases. Despite the plant's antimalarial and other therapeutic properties, there is limited evidence-based data on its potential toxicity. Hence, the purpose of the current study was to assess the safety of A. africana leaf ethanolic extract (AAE). The study was designed to ascertain the cytotoxic effects of the crude extract on red blood cells (RBCs) as well as the acute and subacute toxicity in Wistar albino rats in accordance with Organization for Economic Co-operation and Development (OECD) guidelines "Test No. 423" and CPMW/SWP/1042/99. The pulverized, shade-dried plant leaves were sequentially macerated with 70% ethanol to obtain the crude extract (AAE). The extract's cytotoxic activity (CC50) against the uninfected human red blood cells (RBCs) was determined using the 3-(4,5-Dimethylythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. For the acute toxicity studies, the rats (male and female) were divided randomly into six groups of five rats (n = 5) and dosed orally once with the following dose levels: 100, 300, 1000, 3000, and 5000 mgkg-1, p.o. of the extracted AAE, with the control group receiving only the vehicle. In the repeated dose toxicity studies, the rats (both sexes) were orally administered daily with AAE at 100, 300, and 1000 mgkg-1 for 14 days. Rat body weights were measured, and blood samples were tested for haematological and biochemical markers. Internal organs like the heart, kidney, liver, and spleen were collected, inspected, and weighed, and histological examinations were performed. The median lethal dose (LD50) value is greater than 5000 mgkg-1 body weight, with no significant change in bodyweight or relative organ weight (ROWs) of the extract-treated groups or control group. The extract showed greater cytotoxicity activity (CC50), which was >100 µg/mL, compared to the reference drug (artesunate).The dosage groups of 100 and 300 mgkg-1bwt had neutrophilia and lymphocytopenia (p < 0.05). However, changes in these haematological parameters may not be dose dependent and could be stress related. All the serum biochemical markers studied in rats given AAE did not show any significant change (p > 0.05). Histopathological examination of internal organs of AAE-treated rats did not show any significant abnormalities resulting from the extract treatment compared to the control group. Based on the findings in the present study, the LD50 value of AAE was found to exceed 5000 mgkg-1 in the acute toxicity test, while the no observed adverse effect level (NOAEL) in rats was 1000 mgkg-1 p.o. In the sub-acute toxicity tests. Histopathological analysis revealed no morphological abnormalities in the vital organs.

In vitro and In vivo antimalarial activities of Avicennia africana P. Beauv. (Avicenniaceae) ethanolic leaf extract.

Background: The emergence of widespread drug-resistant strains of the malaria parasites militates against strives for more potent antimalarial drugs. Aim: The present study evaluated the antimalarial activity of A. africana ethanolic crude extract in vitro and in vivo against Plasmodium berghei -infected mice in anticipation of acquiring scientific evidence for it used by mangrove dwellers to treat malaria in Ghana. Methodology: The pulverized dried leaves were extracted with 70% ethanol (v/v) and screened for phytochemicals using standard protocols. The in vitro antimalarial activity was investigated against chloroquine-sensitive Plasmodium falciparum (Pf3D7 clones), MRA-102, Lot:70032033, via SYBR® Green I fluorescent assay method using positive control Artesunate (50-1.56 × 10-3 µg/mL). In the in vivo studies, doses (200-1500 mg/kg) of AAE were used in the 4-day suppressive and curative tests, using P. berghei-infected mice. Artemether/lumefantrine (1.14 mg/kg) and normal saline were used as positive and negative control respectively. Results: The phytochemical analysis revealed the presence of alkaloids, saponins, flavonoids, glycosides, tannins, terpenoids and phytosterols. The extract showed an IC50 of 49.30 ± 4.40 µg/mL in vitro and demonstrated complete parasite clearance at dose 1500 mg/kg in vivo with a suppressive activity of 100% (p < 0.0001) in the 4-day suppressive test. The extract demonstrated high curative activity (p < 0.0001) at 1500 mg/kg with 100% parasite inhibition and the oral LD50 > 5000 mg/kg in mice. Conclusion: The results demonstrated that A. africana crude extract has antimalarial activity both in vitro and in vivo supporting the traditional use of the plant to treat malaria.

Histoprotective Effect of Essential Oil from Citrus aurantifolia in Testosterone-Induced Benign Prostatic Hyperplasia Rat.

BACKGROUND: Benign prostatic hyperplasia (BPH) is a common urological disorder reported among ageing men. OBJECTIVE: The study assessed histoprotective effect of lime essential oil (LEO) in a rat model of testosterone-induced benign prostatic hyperplasia (BPH) and evaluated its ability to reverse testosterone-mediated changes in the testis, kidney, and liver. MATERIALS AND METHODS: Adult Sprague Dawley (aged 12 weeks, 240-390 g) male rats were intramuscularly injected with testosterone enanthate (TE) (10 mg/kg) reconstituted in olive oil for ten days to establish benign prostatic hyperplasia (serum PSA level ≥ 1.24 ng/ml) in. After confirmation of BPH (sustained serum PSA level ≥ 1.24 ng/ml), rats in all groups (LEO: 30, 100, and 300 mg/kg, po, n = 6; finasteride: 15 mg/kg, po, n = 6) except model (BPH without treatment) and sham (no BPH and no treatment) groups were treated for 21 days. At the end of treatment, rats were anesthetised and blood was collected via cardiac puncture to determine serum PSA and total antioxidant capacity (TAC) levels. The prostate gland, testis, kidney, and liver were harvested, weighed, histologically processed and stained with H&E. RESULTS: LEO- and finasteride-treated groups recorded lesser mean prostatic weights relative to their model group. Baseline mean serum PSA level of LEO- and finasteride-treated groups reduced significantly (p < 0.05) relative to model group. Serum TAC levels were also higher in LEO- and finasteride-treated groups relative to model group. LEO-treated groups had less thickened glandular epithelium, smaller acini, fewer prostatic secretions and more fibromuscular stroma relative to model group. LEO and finasteride treatment produced improved histomorphological characteristics of testis, kidney, and liver compared to model group. CONCLUSION: By the current results, Citrus aurantifolia LEO may possess active agents that can be explored for translational medicine against BPH.

Chemical profile and in vivo toxicity evaluation of unripe Citrus aurantifolia essential oil.

Citrus aurantifolia (Christm.) Swingle (syn. C. MEDICA var. ACIDA Brandis) (family: Rutaceae) essential oil is one of the cheapest oils found in local markets. Although, it is generally accepted as non-toxic to vital organs and cells, majority of people are cynical about it usage. Herein, the present study reports the chemical composition and in vivo oral toxicity study of unripe C. aurantifolia essential oil found in Ghana. The toxicity of C. aurantifolia essential oil extract was investigated via oral administration using two methods: The acute toxicity single dose study (SDS) and the repeated dose method. The oil exhibited no acute toxicity but in the sub-chronic studies, the effects was dose and time-dependent. Chemical profile investigation of the oil showed 9 constituent of phytochemicals (Germacrene isomers (61.2%), Pineen (14%), Linalool dimmer (2.9%), Bornane (11%), Citral (2.9%), Anethole (1.5%), Anisole (1.1%), Safrole (0.3%) and Demitol (0.6%)). Histopathological studies revealed conditions such as necrosis, edema and inflammatory reaction in the liver, spleen and kidneys. Marginal upsurge of biochemical parameters above normal and elevated levels of lymphocytes (35.20-46.40 g/dL) demonstrated mild toxicity among the 100 mg/kg and 500 mg/kg dose groups at the sub-chronic stage. Low levels of hemoglobin (13.60 to 12.70 g/dL), MCV (34.20-24.0 fL), MCH (40.20-36.40 g/dL) along with high levels of liver enzymes confirmed the mild toxicity of the oil at sub-chronic stage. These results demonstrate that, despite consideration of lime essential oil as safe, it can have mild hematotoxic, nephrotoxic and hepatotoxic effects.

Bispecific Antibody (bsAb) Construct Formats and their Application in Cancer Therapy.

Development of cancers mostly involves more than one signal pathways, because of the complicated nature of cancer cells. As such, the most effective treatment option is the one that stops the cancer cells in their tracks by targeting these signal pathways simultaneously. This explains why therapeutic monoclonal antibodies targeted at cancers exert utmost activity when two or more are used as combination therapy. This notwithstanding, studies elsewhere have proven that when bispecific antibody (bsAb) is engineered from two conventional monoclonal antibodies or their chains, it produces better activity than when used as combination therapy. This therefore presents bispecific antibody (bsAb) as the appropriate and best therapeutic agent for the treatment of such cancers. This review therefore discusses the various engineering formats for bispecific antibodies (bsAbs) and their applications.

Immunotherapy for acute myeloid leukemia (AML): a potent alternative therapy.

The standard therapy of AML for many years has been chemotherapy with or without stem transplantation. However, there has not been any tangible improvement in this treatment beyond induction through chemotherapy and consolidation with allogeneic stem cell transplantation or chemotherapy. Residual AML cells which later cause relapse mostly persist even after rigorous standard therapy. It is imperative therefore to find an alternative therapy that can take care of the residual AML cells. With a better understanding of how the immune system works to destroy tumor cells and inhibit their growth, another therapeutic option immunotherapy has emerged to address the difficulties associated with the standard therapy. Identification of leukemia-associated antigens (LAA) and the fact that T and NK cells can be activated to exert cytotoxicity on AML cells have further introduced diverse immunotherapeutic development strategies. This review discusses the merits of current immunotherapeutic strategies such as the use of antibodies, adoptive T cells and alloreactive NK cell, and vaccination as against the standard therapy of AML.

A Novel Fusion Antibody Exhibits Antiangiogenic Activity and Stimulates NK Cell-mediated Immune Surveillance Through Fused NKG2D Ligand.

A single-chain variable fragment (scFv) targeting vascular endothelial growth factor receptor 2 was previously generated from a phage display library in our laboratory. However, it has shortened half-life and lacks Fc fragment for effector cell recognition. To address these challenges, a ligand of NK-cell receptor NKG2D was fused to the scFv and created a fusion protein scFv-major histocompatibility complex class I-related chain A (MICA), which is expected to recognize tumor cells through the scFv moiety and stimulate NK cells through the MICA. The fusion protein demonstrated specific binding to both vascular endothelial growth factor receptor 2 and NKG2D in protein-based and cell-based assays. In addition, it demonstrated antiangiogenic activities including restraining the proliferation, migration, transwell invasion, and tube formation of human umbilical vein endothelial cells. Furthermore, the fusion protein exhibited significant cytotoxicity on K562, MDA-MB-435, and B16F10 cells and triggered NK92 cell-mediated cytotoxicity on MDA-MB-435 cells by stimulating the release of significant cytokines. The fusion protein targeting strategy, therefore, provides a means to engage lymphocyte effector cells against tumor specific antigen overexpressing tumor cells.