Volume 31, Issue 4

To date, a large number of synthetic drugs have been developed for the treatment and prevention of different disorders, such as neurodegenerative diseases, diabetes mellitus, and cancer. However, these drugs suffer from a variety of drawbacks including side effects and low efficacy. In response to this problem, researchers have focused on the plant-derived natural products due to their valuable biological activities and low side effects. Flavonoids consist of a wide range of naturally occurring compounds exclusively found in fruits and vegetables and demonstrate a number of pharmacological and therapeutic effects. Tangeretin (TGN) is a key member of flavonoids that is extensively found in citrus peels. It has different favorable biological activities such as antioxidant, anti-inflammatory, antitumor, hepatoprotective, and neuroprotective effects. In the present review, we discuss the various pharmacological and therapeutic effects of TGN and then, demonstrate how this naturally occurring compound affects signaling pathways to exert its impacts.

Silymarin ( Silybum marianum ; SM), popularly known as milk thistle, is an extract that has been used for many centuries to treat liver diseases. In recent years, several studies have shown that SM is not only just another antioxidant but also a multifunctional compound that exhibits several beneficial properties for use in the treatment and prevention of different types of pathologies and disorders. This review aims at demonstrating the main protective activities of SM in diseases, such as cancer, diabetes, hepatitis, non-alcoholic fatty liver disease, alcoholic liver disease, hepatitis C virus, hepatitis B virus, metabolic syndrome, depression, cardiovascular diseases and thalassemia, in addition to its photoprotective activity in in vitro tests and preclinical studies. Its main functions include antioxidant and anti-inflammatory effects, and it acts as modulator of signaling pathways. It has been suggested that SM presents great multifunctional potential and is capable of achieving promising results in different types of research. However, caution is still needed regarding its indiscriminate use in humans as there are only a few clinical studies relating to the adequate dose and the actual efficacy of this extract in different types of diseases.

Background Ketoconazole (Keto), an antifungal drug and a common therapeutic option in the treatment of advanced prostate cancer, is known to cause reproductive dysfunctions. Like Keto, melatonin has antifungal and anticarcinogenic actions. Moreover, the hormone has been used to reverse the damaging effects of different toxicants on the reproductive system. Therefore, this study investigated the effects of Keto with/without melatonin on selected biomarkers in rats. Methods Forty rats of 10 animals per group were used in this study, which lasted for 6 weeks. The control group was administered with saline (0.1 mL/day), while group 2 was administered with Keto during the last 3 weeks of experiment; however, in groups 3 and 4, Keto was administered during the first 3 weeks; thereafter, they were administered with saline and melatonin, respectively, during the subsequent 3 weeks. Keto and melatonin were administered at 100 and 10 mg/kg b.w./day (p.o.), respectively. Results The central effects of Keto are independent of the follicle stimulating hormone (FSH) and prolactin; however, relative to the control group, the drug significantly decreased the gonadotrophin releasing hormone (GNRH) and the luteinizing hormone (LH), substantiated by the corresponding significant decreases in sperm count and sperm morphology. Keto caused significant elevations in malondialdehyde (MDA) and lactate dehydrogenase (LDH) and a significant decrease in catalase (CAT) compared with the control group. Moreover, the drug triggered pro-inflammatory events. In group 3 (Keto recovery), MDA and uric acid levels were returned to the baseline (i.e. control), but not GNRH, LH, C-reactive protein (CRP), LDH, and CAT. Treatment with melatonin after Keto administration caused significant increases in FSH, LH, superoxide dismutase, total antioxidant capacity (TAC), sperm count, and sperm morphology but significant decreases in MDA and CRP, relative to groups 2 and 3. Conclusions Melatonin ameliorates some biochemical alterations following ketoconazole administration.

Background It is estimated that about 5–10% of women suffer from polycystic ovarian syndrome (PCOS) which is a major cause of female reproductive dysfunction. This study examined the role of quercetin on dehydroepiandrosterone (DHEA)-induced PCO in Wistar rats. Methods Twenty-eight pre-pubertal female Wistar rats that are 21 days old weighing 16–21 g were sorted into four groups (n = 7). Group I served as control and was given distilled water only, Group II were injected with 6 mg/100 g BW of DHEA in 0.2 mL of corn oil subcutaneously, Group III received 100 mg/kg BW of quercetin orally and Group IV received 6 mg/100 g BW of DHEA in 0.2 mL of corn oil subcutaneously and 100 mg/kg BW of quercetin orally. Rats were sacrificed after 15 days by cervical dislocation method. Blood samples and ovaries were collected for hormonal, biochemical, and histopathological analysis and expressions of mRNA androgen receptor gene were determined using RT–qPCR. All data were analysed using one-way ANOVA. Results A significant decrease (p < 0.05) in the antioxidant and metabolic enzyme activity in the DHEA treated group was observed when compared with control. DHEA co-administration with quercetin showed a significant decrease in malondialdehyde and cytokines when compared with DHEA treated group. Also a significant increase in progesterone, metabolic and antioxidant enzyme activity was observed. The histopathology demonstrates a reduction in cystic and atretic cells, improved expression of BCl2, E-Cadherin and a decrease in Bax. Conclusions Quercetin alleviated DHEA-induced PCO. These effects could be attributed to its antioxidant property.

Background The expression in the glomerular mesangial cells, papillary, and collecting duct cells demonstrated annexin A1 (AnxA1)’s role in specific renal functions. With varying concentrations of calcium (Ca 2+ ), it is considered to regulate cellular processes such as cell proliferation, apoptosis, and clearance of apoptotic cells by forming ceramides, a key lipid mediator of apoptosis. It also participates in tumorigenesis based on its location. On account of these features, we investigated the expression of this apoptosis-associated protein in fetal kidneys at different gestational periods, mature kidneys and in kidney cancer tissues in order to localize and possibly characterize its role during nephrogenesis and renal tumors. Methods AnxA1 expression was evaluated by an immunohistochemistry technique in “ paraffin-embedded” renal tissue sections from autopsied fetuses at different gestational ages, in mature kidneys and renal cancer tissues. Results The current study data demonstrated that AnxA1 is expressed in the mesangial cells and podocytes of maturing glomeruli in the developing renal cortex of fetal kidneys at 14 to 19 weeks of gestation. The expression in the mesangial cells declined in later weeks of gestation and persisted into adulthood. AnxA1 expression increased with the progression of clear cell renal cell carcinoma (CCRCC) and also in other cancer types indicating a potential role of the protein in tumorigenesis. Conclusions We presume that AnxA1 in the podocytes and mesangial cells play important roles in various signaling pathways in the functioning of the glomerulus. These results and concepts provide a framework to further dissect its biological properties and thereby develop diagnostic, prognostic, and therapeutic strategies targeting the molecule in various renal pathologies.

Background Phytoestrogens are natural compounds known as natural selective estrogen receptor modulators used as alternatives against estrogen-dependent cancers. This study aims to evaluate the antiestrogenic effects of Anthonotha macrophylla , a plant used to treat cancer in Cameroon. Methods The estrogenic/antiestrogenic activities of A. macrophylla aqueous extract were evaluated in vitro using MCF-7 cell proliferation assay. Moreover, a classical uterotrophic test was carried out to evaluate the antiestrogenic effects of A. macrophylla in rats. Changes in the uterus, vagina, and mammary glands were used as endpoints of estrogenicity. Results Anthonotha macrophylla induced antiestrogenic effects in vitro at all the tested concentrations by inhibiting estradiol-induced MCF-7 cell proliferation (p < 0.001). In vivo , a coadministration of estradiol with A. macrophylla extract led to the decrease of uterine [150 (p < 0.05) and 300 (p < 0.01) mg/kg body weight (BW)] and vaginal [75 (p < 0.01) and 300 (p < 0.05) mg/kg BW] epithelial thickness. In addition, a reduction in the mammary gland acini lumen’s diameter was also observed at 75 and 150 mg/kg. Gas chromatography-time-of-flight-mass spectrometry analysis showed that phenolic acid derivatives are present in A. macrophylla extract, which are well known to be endowed with estrogenic/antiestrogenic properties. The LD 50 of A. macrophylla was estimated to be less than 2000 mg/kg. Conclusions Anthonotha macrophylla aqueous extract has antiestrogenic properties. This could promote more studies to explore its ability to prevent estrogen-dependent cancers.

Background Urate in its crystal form is a known danger-associated molecular pattern, which after its internalization activates cells of the innate immune system. However, by inducing lipid raft sequestration and clustering of membrane-bound proteins with immunoreceptor tyrosine-based activation motifs, urate crystals can also activate cells of the innate immune system without previous internalization. Also, urate crystals trigger T-cell receptor signal transduction and induce T-cell proliferation. In this study, we evaluated whether urate crystals can also initiate B-cell receptor (BCR) signal transduction and promote B-cell proliferation. Methods B cells were isolated from the blood of 10 individuals and cultured with or without urate at a concentration of 10 mg/dL, at which crystallization occurs. Phosphorylated Igα (CD79A) and c-Myc were assessed by Western blotting and B-cell proliferation with BrdU assay. Results Urate increased the level of phosphorylated Igα, a component of the BCR complex. Phosphorylation of Igα is the very proximal event in BCR signal transduction. Also, urate increased the expression of c-Myc, an essential transcription factor for BCR-induced B-cell proliferation. Finally, urate induces B-cell proliferation. Conclusions Urate crystals trigger BCR signal transduction and induce B-cell proliferation. The clinical significance of urate-induced B-cell activation remains to be elucidated.

Background Gabapentinoids are known to reduce neuropathic pain. The aim of this experimental study was to investigate whether gabapentinoids exert anti-inflammatory and/or anti-nociceptive effects at the cellular level using primary cultures of rat dorsal root ganglia (DRG). Methods Cells from rat DRG were cultured in the presence of gabapentin or pregabalin, and we tested the effects of subsequent stimulation with lipopolysaccharide (LPS) on the expression of genes (real-time polymerase chain reaction) and production of tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) by specific bioassays. Using Ca 2+ imaging, we further investigated in neurons the effects of gabapentinoids upon stimulation with the TRPV-1 agonist capsaicin. Results There is a small influence of gabapentinoids on the inflammatory response to LPS stimulation, namely, a significantly reduced expression of IL-6. Pregabalin and gabapentin further seem to exert a moderate inhibitory influence on capsaicin-induced Ca 2+ signals in DRG neurons. Conclusions Although the single inhibitory effects of gabapentinoids on inflammatory and nociceptive responses are moderate, a combination of both effects might provide an explanation for the proposed function of these substances as an adjuvant for the reduction of neuropathic pain.

Background Natural anti-inflammatory nutraceuticals may be useful in suppressing the incessant aggravation of rheumatoid arthritis. Chia seeds as a natural source of antioxidants help prevent several oxidative stress-mediated diseases. The current study was focused on arthritis combined with obesity and evaluated the validation of oil and mucilage extracted from chia seeds as anti-inflammatory nutraceuticals in obese and non-obese adjuvant arthritic rat model. Methods Chia seeds oil was extracted by pressing method, whereas the mucilage was extracted using water (50 °C for 30 min). Oil and freeze-dried mucilage were tested for their anti-inflammatory effects using 48 male Sprague-Dawley rats. Obesity was developed in rats after 8 weeks of feeding on high-fat high-sucrose diet; on the first day of the ninth week, chia seeds oil and mucilage were administrated for 21 days, and arthritis was induced either in obese or non-obese rats via the injection with Freund’s complete adjuvant. Swelling of the paw was then measured. Plasma tumor necrosis factor (TNF-α), lipid profile, liver and kidney functions, serum lipid peroxidation, and erythrocyte catalase activity were determined. Results Results emphasized that arthritis with obesity resulted in the elevation of the swelling of the paw, TNF-α, dyslipidemia, and oxidative stress. Chia seeds oil and mucilage, more promisingly the oil, attenuated TNF-α and the swelling of the paw, improved lipid profile, and diminished the oxidative stress both in obese and non-obese arthritic rats. Conclusions Results showed that chia seeds oil and mucilage exhibited anti-inflammatory effects against adjuvant-induced arthritis in obese and non-obese rats.

Background Colorectal cancer (CRC) is the third most prevalent form of cancer and fourth leading cause of morbidity worldwide. Surgical resection remains the only curative approach for CRC, but recurrence following surgery is the main problem and ultimate cause of death. Lycopodium clavatum and quercetin have been found to exert its anticancer properties. The aim of the present study is to investigate whether quercetin or L. clavatum extract and combination of both have any profound role in reducing major inflammatory cytokines in Colo-320 cells. Methods L. clavatum and Quercetin alone or in combination was administered to colon cancer cells and various toxicity markers, gene expression analyses of apototic genes and gelatin zymmography were performed. Results Quercetin (50 μm) in combination with L. clavatum extract (10 μL) distinctly reduced cell growth and highlighted their potential effects in extirpation of colon cancer cells. Treatment with increased dose of L. clavatum extract in combination with quercetin reduced the colony size and proliferation potential when compared to the sole treatment of plant extracts. In the antimicrobial assays, it was observed that Lycopodium alone exhibited antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa . Characterization of L. clavatum extract and quercetin was performed and confirmed the presence of flavonoids and alkaloids. Treatment with Lycopodium and quercetin combination induced significant down-regulation in activities of MMP2 and MMP9 tested by gelatin zymography. The combined treatment greatly affected the mRNA expression of p53, Bcl2, Bax, Caspase 3, Wnt 1, Cyclin D1 , and Catalase genes in colon cancer cells. Conclusion The synergistic effect between Lycopodium and quercetin might bring forward the enhanced antitumorigenic properties of combinational therapy with natural products to successfully combat the cancer progression with minimal side effects and resistance to drugs.

Background The emerging line of research suggests that neuro-inflammation and oxidative stress are linked to the development of depression-like behavior. The tryptophan metabolizing enzyme, indolamine 2,3-dioxygenase (IDO), serves as an important interface between chronic inflammation and depression. IDO is induced by pro-inflammatory cytokines and diverts tryptophan towards the kynurenine pathway, decreasing serotonin synthesis. Further, the metabolites of kynurenine pathway increase brain oxidative stress and also cause N-methyl-D-aspartate (NMDA) receptor-mediated exitotoxicity. The resulting oxidative damage and dysfunction in glutamatergic neurotransmission alters the network connectivity of the brain, which may be the further mechanism for emergence of depression-like symptoms. Methods A depression-like illness was induced in mice by injecting Bacillus Calmette-Guerin (BCG) suspended in isotonic saline at a dose of 10 7 CFU I.P. The mice were then divided into different groups and were administered MK-801 or normal saline for the next 21 days, after which a battery of behavior and biochemical tests were conducted to assess them. Results The BCG group had significantly reduced sucrose preference index and an increase in immobility time in forced swim test (FST) and Tail Suspension Test (TST) as compared to the saline group. There was also a significant increase in the brain MDA levels and a decline in the brain GSH levels. The hippocampal tissue from the BCG group had significantly more comet cells than the saline group. The NMDA receptor antagonist, MK-801, was able to reverse the BCG-induced depression-like behaviour. MK-801 also showed significant decrease in brain oxidative stress but failed to show significant protection against BCG-induced neurotoxicity observed in comet assay. Conclusions The NMDA receptor antagonist, MK-801, mitigated BCG-induced, depressive-like behavior in mice by improving the sucrose preference and decreasing the duration of immobility time in TST and FST. The overall improvement in depression-like behavior was accompanied by a reduction in brain oxidative stress and comet cells, thus suggesting the antioxidant and neuroprotective action of MK-801.

Background 3-(Para-fluorobenzoyl)-propionic acid (3PFBPA) is one of the metabolites of haloperidol used in the treatment of psychotic disorders. 3PFBPA is an inhibitor of mitogen-activated protein kinase (MAPK), implicated in the development of uterine fibroids (UFs) and cellular proliferation. In this study, the effect of 3PFBPA on oestradiol valerate (OV)-induced uterine hyperplasia was investigated. Methods Uterine hyperplasia was induced by intraperitoneal (i.p.) injection of OV (3 mg/kg for 12 weeks). Expression of oestrogen receptor (ER) α, β-catenin and E-cadherin were investigated via immunohistochemistry. The histology and fibroblast cell count/μm 2 (using histomorphometry) were carried out. Results There was a significant increase in the levels of oestrogen, progesterone and total cholesterol in the OV-treated group when compared with the control, assessed by enzyme-linked immunosorbent assay (ELISA) kits. Oestrogen and total cholesterol were markedly reduced in the OV + 3PFBPAtreated group when compared with the OV-treated group. The OV-induced overexpression of β-catenin and ER were also ameliorated by 3PFBPA. Also, the loss of E-cadherin function in the OV-treated group was restored by 3PFBPA. The histological findings and histomorphometric results revealed the presence of uterine hyperplasia in the OV-treated rats which was significantly reversed by 3PFBPA. Histological studies revealed a protective role against OV-induced uterine damage that was found after OV + 3PFBPA co-administration. Conclusion This study demonstrated that 3PFBPA ameliorates OV-induced uterine hyperplasia in the female Wistar rat model. The findings warrant further investigation of the antifibrotic effects of 3PFBPA in humans.

Background Inflammation is the most common health problem faced in life relating to a vast number of diseases. The present study evaluated the pharmacological effect of three plants ( Vitex thyrsiflora , Entandrophragma cylindricum , and Anonidium mannii ) commonly used in the Cameroon pharmacopeia for the management of inflammatory response. Methods The pharmacological effect was characterized by the antioxidant capacity, anti-inflammatory, analgesic, and antipyretic properties of the ethanol extracts of the three plants. Antioxidant capacity was determined using total phenolic content, total flavonoid content, hydrogen peroxide, ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging assays. Anti-inflammatory activity was evaluated in vitro by protein denaturation and hypotonic-induced hemolysis methods and in vivo by carrageenan paw edema method. Analgesic and antipyretic activities were studied in vivo using acetic acid-induced writhing and brewer’s yeast-induced hyperpyrexia models. Results All selected extracts showed high phenolic (15.93–64.45 mgCAE/g) and flavonoid (336.03–1053.48 mgCAE/g) contents and high ferric reducing power (288.75–364.91 mgCAE/g). These extracts exhibited good DPPH (IC 50 = 0.30–1.65 μg/mL), ABTS (IC 50 = 0.52–1.90 μg/mL), and H 2 O 2 (IC 50 = 1.40–3.55 μg/mL) radical scavenging activities. All extracts inhibited protein denaturation (6.79–82.27%) and protected the erythrocyte membrane from lysis induced by hypotonic solution (18.90–88.00%). The extracts significantly reduced dose-dependent paw edema (p < 0.05), fever, and abdominal writhing (p < 0.001) especially at 400 mg/kg. Conclusions All extracts exhibited interesting antioxidant properties, as well as significant anti-inflammatory, analgesic, and antipyretic effects.

Background Concomitant exposure to environmental/occupational toxicants such as aflatoxin B 1 (AFB 1 ) and arsenic in some regions of the world has been well reported. Therefore, this calls for the assessment of the efficacy of agents such as phytochemicals, which are already known for their ethno-medicinal uses in prophylaxis/remediation. We investigated the possible cytotoxic bio-interactions between AFB 1 and sodium arsenite (SA) in urinary bladder cells. We also assessed the cytoprotective effects of curcumin and the ethanol stem bark extract of Khaya senegalensis (K2S). Methods The cells were exposed to graded levels of AFB 1 , SA, curcumin, and K2S for 24, 48, and 72 h. Subsequently, using optimum toxic concentrations of AFB 1 and SA, respectively, the influence of non-toxic levels of curcumin and/or K2S was tested on exposure of the cells to AFB 1 and/or SA. Hoechst 33342/propidium iodide staining technique was used to determine the end-points due to cytotoxicity with changes in adenosine triphosphate (ATP) levels determined using Promega’s CellTiter-Glo luminescent assay. Results Co-treatment of the cells with AFB 1 and SA resulted in synergy in cytotoxic effects. Cytotoxicity was reduced by 3.5- and 2.9-fold by pre-treatment of the cells with curcumin and K2S before treatment with AFB 1 , while post-treatment resulted in 1.1- and 2.6-fold reduction, respectively. Pre-exposure of the cells with curcumin and K2S before treatment with SA ameliorated cytotoxicity by 3.8- and 3.0-fold, but post-treatment caused a 1.2- and 1.3-fold reduction, respectively. Conclusions Pre-treatment of the cells with either curcumin or K2S exhibited cytoprotective effects by ameliorating AFB 1 - and SA-induced cytotoxicity with inferred tendencies to prevent carcinogenesis.

Infertility is a problem across almost all cultures and societies. Problems in the male partner, especially as a result of unhealthy dietary habits, are the commonest single group of course. Many populations, therefore, tend more toward the use of natural dietary substitutes opined to proffer less risk to reproductive functions and more health benefits. Saccharum officinarum juice (SOJ) is a widely consumed, energy-rich, nutritious substance that has many minerals and enzymes. Saccharum officinarum plant was reported to have anti-thrombosis, anti-inflammatory and immune-stimulatory activities. This study evaluated the reproductive effects of S. officinarum juice in male Wistar rats. A sugarcane press juicer was used to extract S. officinarum juice. Twenty male Wistar rats (100–120 g) grouped into four (n = 5) received 1.0 mL/kg/day distilled water (control), and 1.0, 3.2 and 10.0 mL/kg/day of fresh S. officinarum juice once daily for 8 weeks via gavage. Sperm analysis, histology of testes and epididymides were evaluated by microscopy. Enzyme-linked immunosorbent assay (ELISA) was used in assessing the serum levels of luteinizing hormone, follicle-stimulating hormone and testosterone. Data were analyzed using the analysis of variance at a significance of p < 0.05. SOJ increased fasting blood glucose levels in 3.2 and 10.0 mL/kg groups. The 10.0 mL/kg juice caused a significant increase in testosterone level and sperm count, and it also increased the percentage of aberrant sperm and decreased sperm viability. Saccharum officinarum juice impaired the histological integrity of the testes and epididymides. Thus, S. officinarum juice adversely altered the reproductive functions of male Wistar rats by reducing sperm quality and disrupting testicular architecture.

Background Lead (Pb) is one of the metals most prevalent in the environment and is known to cause infertility and deoxyribonucleic acid (DNA) fragmentation. This study aimed to determine the association between seminal plasma Pb and sperm DNA fragmentation in men investigated for infertility. Methods Male partners (n = 300) of couples investigated for infertility were recruited after informed consent was obtained. Sperm parameters were assessed according to the World Health Organization (WHO) guidelines. Seminal plasma Pb was estimated by atomic absorption spectrophotometry after digestion with nitric acid. Results In Pb-positive and -negative groups the sperm parameters and sperm DNA fragmentation were compared using independent sample t-test and the Mann-Whitney U-test, respectively. The mean [standard deviation (SD)] age and duration of infertility were 34.8 (5.34) years and 45.7 (35.09) months, respectively, and the mean Pb concentration was 15.7 μg/dL. In Pb positives compared to Pb negatives the means (SD) of sperm count, progressive motility viability and normal morphology were lower (p > 0.05) but the DNA fragmentation was significantly higher 39.80% (25.08) than Pb negatives 22.65% (11.30). Seminal plasma Pb concentration and sperm DNA fragmentation had a positive correlation (r = 0.38, p = 0.03). A negative correlation was observed between sperm DNA fragmentation and sperm concentration, progressive motility, total motility and viability. When the DNA fragmentation was ≥30% sperm concentration and viability decreased (p < 0.05). Conclusions Pb in seminal plasma had a significant effect on sperm DNA fragmentation but not with other sperm parameters.