Antihypertensive action of Launaea taraxacifolia and its molecular mechanism of action

Launaea taraxacifolia has been traditionally used for the management of conditions such as cardiovascular, respiratory, and metabolic diseases. High blood pressure was established by oral administration of L-Nitro Arginine Methyl Ester (L-NAME) a non-selective inhibitor of endothelial nitric oxide synthase (eNOS). The antihypertensive action of the methanol leaf extract of L. taraxacifolia was examined. Fifty male Wistar rats were divided into 5 groups of 10 animals per group: Group A (Distilled water), Group B (Hypertensive rats; 40mg/kg L-NAME), Group C (Hypertensive rats plus 100mg/kg extract), Group D (Hypertensive rats plus 200 mg/kg extract) and Group E (Hypertensive rats plus 10mg/kg of Lisinopril). The treatments were orally administered for five weeks. Haemodynamic parameters, urinalysis, indices of oxidative stress and immunohistochemistry were determined. Findings from this study showed that blood pressure parameters, urinary sodium and indices of oxidative stress increased significantly while In-vivo antioxidant defence systems decreased significantly in hypertensive rats. Immunohistochemistry revealed significant increases in expressions of mineralocorticoid receptor, angiotensin converting enzyme activity and kidney injury molecule-1 in kidney of hypertensive rats. Treatment with Launeae taraxacifolia normalized blood pressure parameters, urinary sodium, oxidative stress indices, antioxidant defence system, and serum nitric oxide bioavailability.

Impacts of cadmium on male fertility: Lessons learnt so far

Cadmium (Cd) is one of the most dangerous heavy metals in the world. Globally, toxicities associated with cadmium and its attendant negative impact on humans and animals cannot be under-estimated. Cd is a heavy metal, and people are exposed to it through contaminated foods and smoking. Cd exerts its deleterious impacts on the testes (male reproductive system) by inducing oxidative stress, spermatogenic cells apoptosis, testicular inflammation, decreasing androgenic and sperm cell functions, disrupting ionic homeostasis, pathways and epigenetic gene regulation, damaging vascular endothelium and blood testes barrier. In association with other industrial by-products, Cd has been incriminated for the recent decline of male fertility rate seen in both man and animals. Understanding the processes involved in Cd-induced testicular toxicity is vital for the innovation of techniques that will help ameliorate infertility in males. In this review, we summed up recent studies on the processes of testicular toxicity and male infertility due to Cd exposure. Also, the usage of different compounds including phytochemicals, and plant extracts to manage Cd reprotoxicity will be reviewed.

Clofibrate, a Peroxisome Proliferator-Activated Receptor-Alpha (PPARα) Agonist, and Its Molecular Mechanisms of Action against Sodium Fluoride-Induced Toxicity

Sodium fluoride (NaF) is one of the neglected environmental pollutants. It is ubiquitously found in the soil, water, and environment. Interestingly, fluoride has been extensively utilized for prevention of dental caries and tartar formation, and may be added to mouthwash, mouth rinse, and toothpastes. This study is aimed at mitigating fluoride-induced hypertension and nephrotoxicity with clofibrate, a peroxisome proliferator-activated receptor-alpha (PPARα) agonist. For this study, forty male Wistar rats were used and randomly grouped into ten rats per group, control, sodium fluoride (NaF; 300 ppm) only, NaF plus clofibrate (250 mg/kg) and NaF plus lisinopril (10 mg/kg), respectively, for 7 days. The administration of NaF was by drinking water ad libitum, while clofibrate and lisinopril were administered by oral gavage. Administration of NaF induced hypertension, and was accompanied with exaggerated oxidative stress; depletion of antioxidant defence system; reduced nitric oxide production; increased systolic, diastolic and mean arterial pressure; activation of angiotensin-converting enzyme activity and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB); and testicular apoptosis. Treatment of rats with clofibrate reduced oxidative stress, improved antioxidant status, lowered high blood pressure through the inhibition of angiotensin-converting enzyme activity, mineralocorticoid receptor over-activation, and abrogated testicular apoptosis. Taken together, clofibrate could offer exceptional therapeutic benefit in mitigating toxicity associated with sodium fluoride.

Comparative Effects of Methanol and Aqueous Extracts of Corchorus olitorius Plant on Haematology and Some Reproductive Indices of Male Wistar Rats

Corchorus olitorius is a vegetable plant/shrub and the leaves are very nutritious and rich in vitamins, minerals and dietary fibers. The study was carried out to identify the effects two extracts of this plant on the reproductive indices of male Wistar rats Forty-five adult male rats of about 12 weeks old, each weighing about 120g were used for this study, kept in a cage and fed with commercial rat pellets and water was given at ad-libitum. They were randomly divided into groups A, B and C of 15 rats per group. 250mg/kg of the leaf extract was administered orogastrically using once daily for 21 days. Group A and B were treated with methanol and aqueous leaves of Corchorus extract respectively and Group C was given distilled water and served as the control. The weekly sacrifice of five rats per group was done following treatments. In this study, it was observed at the first-week post -treatment that there was significant (p≤0.05) decrease in the PCV and haemoglobin values of group A rats compared to the control group but the values later increased at the second week and third-week post-treatments. There was also a significant decrease in spermatozoa motility in the treated groups A and B compared to the control group C at the first, second- and third-week post treatments. Also, with the results of the serum testosterone level of group A and B compared to group C. The value was higher in group A followed by group B whereas, at the second week and third week, there was no significant difference in the values of the serum testosterone levels compared to the control groups. It is therefore concluded that the methanol and aqueous extract of Corchorus olitorius leaves significantly decreased sperm motility in male albino rats hence could decrease male fertility.

Novel antihypertensive action of rutin is mediated via inhibition of angiotensin converting enzyme/mineralocorticoid receptor/angiotensin 2 type 1 receptor (ATR1) signaling pathways in uninephrectomized hypertensive rats

Hypertension is the most common cardiovascular disease that affects approximately 26% of adult population, worldwide. Rutin is one of the important flavonoids that is consumed in the daily diet, and found in many food items, vegetables, and beverages. Uninephrectomy (UNX) of the left kidney was performed, followed by induction of hypertension. The rats were randomly divided into four groups of 10 rats: group 1-Sham-operated rats; group 2-UNX rats, group 3-UNX-L-NAME (40 mg/kg) plus rutin (100 mg/kg bwt), and groups 4-UNX-L-NAME plus lisinopril (10 mg/kg bwt), orally for 3 weeks. Results revealed significant heightening of arterial pressure and oxidative stress indices, while hypertensive rats treated with rutin had lower expressions of angiotensin converting enzyme (ACE) and mineralocorticoid receptor in uninephrectomized rats. Together, rutin as a novel antihypertensive flavonoid could provide an unimaginable benefits for the management of hypertension through inhibition of angiotensin converting enzyme and mineralocorticoid receptor. PRACTICAL APPLICATIONS: Hypertension has been reported to be the most common cardiovascular disease, affecting approximately 26% of the adult population worldwide with predicted prevalence to increase by 60% by 2025. Recent advances in phytomedicine have shown flavonoids to be very helpful in the treatment of many diseases. Flavonoids have been used in the treatment and management of cardiovascular diseases, obesity and hypertension. The study revealed that rutin, a known flavonoid inhibited angiotensin converting enzyme (ACE), angiotensin 2 type 1 receptor (ATR1), and mineralocorticoid receptor (MCR), comparable to the classic ACE inhibitor, Lisinopril, indicating the novel antihypertensive property of rutin. Therefore, flavonoids such as rutin found in fruits and vegetables could, therefore, serve as an antihypertensive drug regimen. Combining all, functional foods rich in flavonoids could be used as potential therapeutic candidates for managing uninephrectomized hypertensive patients.

Melatonin ameliorates bisphenol A-induced perturbations of the prostate gland of adult Wistar rats

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) that has been demonstrated to induce alterations in reproductive organs while melatonin (ML), an antioxidant, present in plants and animals, is capable of protecting against EDC-induced alterations. Adult male Wistar rats (average weight, 240 + 10 g) were divided into four groups of ten animals each: Rats in group I (control) received oral 0.2 ml 1% dimethyl sulfoxide (DMSO)/99% canola oil as vehicle; group II received intra-peritoneal 10 mg/kg BW/day ML. Group III received oral BPA dissolved in DMSO and solubilized in canola oil at 10 mg/kg BW/day. Group IV were treated with same dose of BPA as group III with a concomitant intra-peritoneal 10 mg/kg BW/day ML. All treatments lasted for 14 days. BPA significantly increased the prostatic index of the rats while ML ameliorated it. BPA significantly increased serum levels of estrogen as well as prostate-specific antigen but decreased serum testosterone in the rats while concomitant treatment with ML ameliorated these alterations. Also, BPA caused vascular congestion, hyperplasia (functional, reactive and atypical) of prostatic epithelium as well as tubular atrophy the rats while ML attenuated the observed lesions. Decreased localization of αSmooth muscle actin, vimentin and S100 proteins were observed in the BPA-treated rats while these decreases were ameliorated by ML. The present study has shown that sub-acute oral administration of BPA induced alterations in prostatic index, serum hormone levels, down-regulated protein localization and induced morphological lesions of the prostate gland in rats while concomitant treatment with intra-peritoneal ML ameliorated these conditions. Hence, low dose of ML can protect against BPA-induced toxicity of the prostate gland of rats.

Some reproductive indices of the Nigerian local bitches in Ibadan, Nigeria

Some reproductive parameters of the Nigerian local bitches were studied at the kennel of the Department of Veterinary Surgery and Reproduction, University of Ibadan using 6 bitches and 1 stud aged between 2 and 3 years, weighing 10 to 12kg. The bitches were mated naturally by the stud at the second day of cytological oestrus and allowed to carry the pregnancy to term. The bitches and puppies were weighed weekly and observed till weaning.  Mean gestation length was 63.5 + 0.3 day. Mean litter size was 7.0 + 2.0 puppies.  Litter sex ratio was 1.25 females to 1 male puppy.  Mean birth weights were 308.3 + 15.3 and 286.3 +11.8 grammes for male and female puppies respectively, while the respective weaning live weights were 1.5 + 0.2 and 1.8 + 0.1kg. Litter size affected the birth weight; the mean birth weight of puppies with the litter size 10 was significantly lighter than those with litter sizes 7, 6 and 4 puppies. Mean age at testicular descent was 6.1 + 0.6 days while eyes of puppies were opened at mean age 15.4 + 0.2 days. Mean duration between whelping and first oestrus was 3.9 + 0.07 months. The neonatal mortality rate was 35.3%, more female puppies (26.4%) than male puppies (5.9%) died during the first week of life. These high mortalities might be due to cold and maternal negligence. With these basic data, the reproductive potential of the Nigerian local bitch can be harnessed.

Effects of the leaf decoction of Momordica charantia (bitter melon) on Mitochondrial Membrane Permeability Transition Pore (MMPTP) and fertility in normal male albino rats

Momordica charantia (M. charantia), a medicinal plant of the family, Cucurbitaceae, is used in treating an array of ailments including diabetes, heamorrhoids, fevers and various cancers. Programmed cell death may be modulated by an intrinsic pathway involving the release of cytochrome C when the mitochondrial membrane permeability transition (MMPTP) pore is opened. Opening of MMPT pore was assayed using the method of Lapidus and Sokolove. The results obtained revealed that there was a dose-dependent and significant increase in the opening of the MMPT pore in rats orally administered the decoction with maximum induction (11-fold increase) at 55mg/100g body weight (bw), although the extent of opening of the pore was reduced at 65mg/100g bw (9-fold increase). An assessment of the blood parameters of animals orally exposed to the decoction showed significant decrease (p<0.05) in lymphocytes and a significant increase (p<0.05) in neutrophils at 55mg/ 100g bw. Moreover, significant increases (p<0.05) in RBC levels at 45 and 65mg/100g bw, were observed. Similarly, PCV and Heamoglobin values were also elevated at 65mg/100g bw while there was a significant reduction (p<0.05) in MCV and MCH values at 45, 55 and 65mg/100g bw. MCHC values were reduced only in animals that received 65mg/ 100g when compared to control animals. Analysis of the spermiogram of the experimental rats showed significant reductions (p<0.05) in sperm motility and sperm cell concentrations for all animals that were orally exposed to the decoction. There was a significant reduction (p<0.05) in percentage viability in animals that received 45mg/100g bw and above. Morphological abnormalities of sperm cells above the proposed percentage range (10%) were also observed in animals that received 45mg/100g bw and above. However, decoction did not show any significant effect on ALT and AST levels but there were significant increases (p<0.05) in a somewhat dose-dependent pattern in ALP and ãGT levels for all groups in comparison to the control group. These findings thus suggest dose-related negative or toxic effects of sub acute (30-day) oral administration of leaf decoction of M. charantia in albino rats and may therefore pose some danger to humans especially in regard to male fertility in individuals who rely on oral administration of the decoction in treating various ailments.

Ameliorative effects of Cnidoscolus aconitifolius on alloxan toxicity in Wistar rats

BACKGROUND

Diabetes has been associated with several complications occasioned by oxidative stress. Thus, in treatment of the condition, these complications must also be taken into consideration. This study evaluates the effect of Cnidoscolus aconitifolius complications of diabetes induced by alloxan, on haematology and sperm morphometry using the Wistar rats.

METHODS

Diabetes was induced in 25 rats using alloxan. The diabetic rats were then divided into five groups B-F consisting of five rats per group. Groups C-E were administered with 100 mg/kg, 500 mg/kg and 1000 mg/kg of ethanolic leaves extract of Cnidoscolus aconitifolius, respectively, for four weeks post treatment with alloxan, while group F received Chlorpropamide (Diabenes®, Pfizer). The diabetic rats in group B were not treated while group A served as the non diabetic control.

RESULT

Following treatment with alloxan, there was anaemia, thrombocytopenia and leucopenia, while the sperm count, motility and live/dead ratio were significantly reduced. Sperm morphological abnormalities and erythrocyte osmotic fragility also increased significantly. Following treatment of alloxan treated-rats with the extract, there were significant increases in the PCV, RBC, Hb, WBC, MCV and the platelet values. Erythrocyte osmotic fragility, sperm count, motility and live/dead ratio also improved significantly.

CONCLUSION

Cnidoscolus aconitifolius extract was found to ameliorate the effects of alloxan induced diabetes on the haematology but not on the abnormal sperm morphometry in rats.