Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
18
result(s) for
"Opuwari, Chinyerum S."
Sort by:
An Update on Oxidative Damage to Spermatozoa and Oocytes
by
Opuwari, Chinyerum S.
,
Henkel, Ralf R.
in
Antioxidants
,
Antioxidants - metabolism
,
Birth defects
2016
On the one hand, reactive oxygen species (ROS) are mandatory mediators for essential cellular functions including the function of germ cells (oocytes and spermatozoa) and thereby the fertilization process. However, the exposure of these cells to excessive levels of oxidative stress by too high levels of ROS or too low levels of antioxidative protection will render these cells dysfunctional thereby failing the fertilization process and causing couples to be infertile. Numerous causes are responsible for the delicate bodily redox system being out of balance and causing disease and infertility. Many of these causes are modifiable such as lifestyle factors like obesity, poor nutrition, heat stress, smoking, or alcohol abuse. Possible correctable measures include foremost lifestyle changes, but also supplementation with antioxidants to scavenge excessive ROS. However, this should only be done after careful examination of the patient and establishment of the individual bodily antioxidant needs. In addition, other corrective measures include sperm separation for assisted reproductive techniques. However, these techniques have to be carried out very carefully as they, if applied wrongly, bear risks of generating ROS damaging the germ cells and preventing fertilization.
Journal Article
Overview of the Effects of Moringa oleifera Leaf Extract on Oxidative Stress and Male Infertility: A Review
by
Takalani, Ndivhuho B.
,
Monageng, Elizabeth
,
Offor, Ugochukwu
in
Cytokines
,
DNA damage
,
Enzymes
2023
According to a recent report by the WHO, 50–80 million people suffer with infertility. Amongst these populations, male counterparts account for 20–50% of infertility cases. The aetiology of infertility in men includes many factors such as psychological issues, lifestyle and environmental factors, hormonal disorders and chromosomal abnormalities. The pathophysiology of these aetiologies may be initiated by a local inflammatory reaction increasing reactive oxygen species (ROS) production, which can negatively affect the male reproductive system by altering the hypothalamic–pituitary–gonadotropin axis (HPG axis). Alteration of the HPG axis may affect testicular steroidogenesis, spermatogenesis, the Leydig cells and Sertoli cells, leading to poor semen quality. The prevalence of male infertility underscores the need for a thorough scientific investigation to identify treatable or reversible factors using plant adjuvants with antioxidative properties. Therefore, this review aims to provide an overview of the currently available knowledge on the aetiologies of male reproductive dysfunction, emphasising infertility risk factors, as well as elucidating the possible ways by which readily available alternatives, such as Moringa oleifera leaves, may mitigate male infertility by highlighting its role on the oxidative stress parameters, reproductive hormonal levels, testicular steroidogenesis and spermatogenesis, gene expression, weight and morphology of the testis and sperm parameters.
Journal Article
Green tea (Camellia sinensis) aqueous extract improved human spermatozoa functions in vitro
2022
Background: Idiopathic causes of infertility is associated with oxidative stress. Antioxidants are known to scavenge the excessive production of reactive oxygen species (ROS). Green tea (Camellia sinensis) contains polyphenols that enhance its antioxidant potential.Aim: This study focused on the impact of aqueous green tea extract on normozoospermic human spermatozoa.Setting: Department of Medical Biosciences, University of the Western Cape (UWC), South Africa.Methods: Semen samples obtained using masturbation method following three to five days of sexual abstinence from consenting men (n = 59) at the University of the Western Cape (UWC) were liquefied and analysed. Normozoospermic samples were selected according to the World Health Organization (WHO) 5th guideline. Thereafter, semen samples (7.5 × 106 /mL) were washed in human tubular fluid (HTF; 10 min at 300 ×g) and exposed to aqueous extracts of green tea (0 μg/mL, 0.4 μg/mL, 4 μg/mL, 40 μg/mL, 405 μg/mL) for 1 h with various sperm parameters analyzed. Human tubular fluid supplemented with bovine serum albumin (HTF-BSA; 10%) served as control.Results: Sperm motility, reactive oxygen species production, across some reaction and deoxyribonucleic acid (DNA) fragmentation decreased significantly, particularly at the highest concentration (405 μg/mL; p 0.001). A substantial increase in the percentage of viable spermatozoa and those with intact mitochondrial membrane potential (MMP) were observed (p 0.001).Conclusion: Aqueous extract of green tea prolonged sperm viability and MMP while reducing sperm intracellular ROS production, capacitation and across some reaction and DNA fragmentation, and may be attributed to its antioxidant potential. However, a high concentration of the extract appears to be detrimental to the functioning of human spermatozoa.
Journal Article
Antioxidant, Anti-Diabetic, and Anti-Inflammation Activity of Garcinia livingstonei Aqueous Leaf Extract: A Preliminary Study
by
Nethengwe, Murendeni
,
Kerebba, Nasifu
,
Okaiyeto, Kunle
in
Anti-Inflammatory Agents - pharmacology
,
Antidiabetics
,
Antioxidants
2024
Diabetes mellitus (DM) is the second leading cause of mortality globally. The increased concern for DM is due to the underlying complications accompanying hyperglycaemia, associated with oxidative stress and consequent inflammation. The investigation of safe and effective treatments for DM is necessary. In the present study, the cytotoxicity, phytochemical analysis, antioxidant capacity, anti-inflammatory, and antidiabetic effects in an aqueous extract of Garcinia livingstonei leaves were assessed. All tested extract concentrations showed no toxicity against C3A hepatocytes. Several phenolic compounds were identified using ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS). The total polyphenol content was 100.9741 mg GAE/g, 16.7712 mg CE/g flavanols, and 2.3548 mg QE/g flavonols. The antioxidant capacity values were 253.4268 mg AAE/g, 192.232 mg TE/g, and 167.8724 mg TE/g for ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), and 2,2-diphenyl-1-pycrylhydrazyl (DPPH), respectively. The plant extract significantly (p < 0.05) demonstrated anti-inflammatory and hypoglycaemic effects in a dose-dependent manner, with the α-glucosidase inhibition of the extract being higher (p < 0.05) than in the standard conventional drug (acarbose). The findings of this study revealed the potential of the constituents of G. livingstonei aqueous leaf extract in DM treatment. Further studies on the preparation and mechanisms of action of the plant in DM treatment are recommended.
Journal Article
Antidiabetic, anti-inflammatory, antioxidant, and cytotoxicity potentials of green-synthesized zinc oxide nanoparticles using the aqueous extract of Helichrysum cymosum
by
Opuwari, Chinyerum S
,
Oyenihi, Omolola
,
Okaiyeto, Kunle
in
Absorption spectra
,
Amides
,
Antidiabetics
2024
The current research involved the synthesis of zinc oxide nanoparticles (ZnO-NPs) using an aqueous extract of Helichrysum cymosum shoots, and subsequent characterization via different analytical methods, such as UV–Vis spectroscopy, Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Transmission electron microscope (TEM), and zeta potential. The biological effects of the ZnO-NPs were then tested against C3A hepatocyte cells and L6 myocyte cell lines via series of analysis, including cytotoxicity, antioxidant, anti-inflammatory, and antidiabetic effect via enzymatic inhibition. The UV–Vis analysis showed a maximum absorption spectrum at 360, and the TEM analysis reveals a spherical and hexagonal structures, with an average dimension of 28.05–58.3 nm, and the XRD reveals a crystalline hexagonal structure. The zeta potential evaluation indicated that the ZnO-NPs are relatively stable at − 20 mV, and the FTIR analysis identified some important functional group associated with phenolics, carboxylic acid, and amides that are responsible for reducing and stabilizing the ZnO-NPs. The synthesized ZnO-NPs demonstrated cytotoxic effects on the cell lines at higher concentrations (125 µg/mL and 250 µg/mL), complicating the interpretation of the results of the inflammatory and antioxidant assays. However, there was a significant (p < 0.05) increase in the inhibitions of pancreatic lipase, alpha-glucosidase, and alpha-amylase, indicating beneficial antidiabetic effects.
Journal Article
Aqueous leaf extract of Moringa oleifera reduced intracellular ROS production, DNA fragmentation and acrosome reaction in Human spermatozoa in vitro
by
Henkel, Ralf R
,
Opuwari, Chinyerum S
,
Adefolaju, Gbenga A
in
Acrosome reaction
,
Antioxidants
,
Bovine serum albumin
2021
The effects of aqueous leaf extract of Moringa oleifera (MO) on human sperm functions and integrity was studied in vitro. Semen was obtained by masturbation after 3–5 days' abstinence from 34 healthy donors in Western Cape, South Africa. Liquefied semen was washed in human tubular fluid supplemented with 1% bovine serum albumin (HTF‐BSA;1:5) with 10 min centrifugation at 300 g. Sperm suspensions were subsequently incubated with MO extract (0.625, 6.25, 62.5 and 625 µg/ml) for 1 hr, where HTF‐BSA served as control. Sperm motility, vitality, DNA fragmentation, reactive oxygen species production, mitochondrial membrane potential, capacitation and acrosome reaction were assessed. Sperm motility, vitality, mitochondrial membrane potential and capacitation remained unchanged (p > .05). A dose‐dependent decrease in sperm reactive oxygen species production (p < .0001), DNA fragmentation (p < .0001) and acrosome reaction (p < .001) was observed. An increase in the percentage of non‐capacitated sperm (p < .01) was noted at 625 µg/ml. The antioxidant properties of MO actively maintained basic sperm functions, inhibited excess sperm free superoxide production and preserved acrosome reaction and DNA integrity. Further studies are needed to confirm the effect of aqueous MO leaf extract on fertility potential.
Journal Article
In vivo effects of black tea on the male rat reproductive system and functions of the kidney and liver
2020
This study focused on the effects of black tea on the male reproductive system as well as the kidney and liver functions. Male Wistar rats were given aqueous extract of black tea (2% and 5%) for 52 days as the only means of drinking fluid, while control rats received tap water. Black tea enhanced sperm vitality (44%–49%), total sperm motility (10%–12%) and acrosome reaction (2%–9%) (p < .05). Body weight gain, testis, epididymis, seminal vesicles, prostate, liver weight, testosterone level, sperm concentration, ferric reducing antioxidant power (FRAP) and antioxidant levels in the testes, liver and kidney remained unchanged (p > .05). Black tea (5%) increased kidney weight (p < .05). Testis and epididymis showed normal histological appearance. However, black tea significantly reduced the diameter (9%–10%) and epithelial height (9%–10%) of the seminiferous tubule, but increased the epithelial height of the cauda epididymis (8%–24%) (p < .05). A significant reduction in serum levels of alanine aminotransaminase (ALT) (38%) and aspartate aminotransaminase (AST) (23%–34%) was observed (p < .05); creatinine level, on the other hand, increased (8%–72%) (p < .05). Black tea improved several sperm parameters, but may cause subtle changes in certain reproductive organs and the kidney functions.
Journal Article
Overview of the Effects of IMoringa oleifera/I Leaf Extract on Oxidative Stress and Male Infertility: A Review
by
Opuwari, Chinyerum S
,
Monageng, Elizabeth
,
Offor, Ugochukwu
in
Analysis
,
Avanafil
,
Infertility, Male
2023
According to a recent report by the WHO, 50-80 million people suffer with infertility. Amongst these populations, male counterparts account for 20-50% of infertility cases. The aetiology of infertility in men includes many factors such as psychological issues, lifestyle and environmental factors, hormonal disorders and chromosomal abnormalities. The pathophysiology of these aetiologies may be initiated by a local inflammatory reaction increasing reactive oxygen species (ROS) production, which can negatively affect the male reproductive system by altering the hypothalamic-pituitary-gonadotropin axis (HPG axis). Alteration of the HPG axis may affect testicular steroidogenesis, spermatogenesis, the Leydig cells and Sertoli cells, leading to poor semen quality. The prevalence of male infertility underscores the need for a thorough scientific investigation to identify treatable or reversible factors using plant adjuvants with antioxidative properties. Therefore, this review aims to provide an overview of the currently available knowledge on the aetiologies of male reproductive dysfunction, emphasising infertility risk factors, as well as elucidating the possible ways by which readily available alternatives, such as Moringa oleifera leaves, may mitigate male infertility by highlighting its role on the oxidative stress parameters, reproductive hormonal levels, testicular steroidogenesis and spermatogenesis, gene expression, weight and morphology of the testis and sperm parameters.
Journal Article
Androgenic effect of aqueous leaf extract of Moringa oleifera on Leydig TM3 cells in vitro
by
Of, Ugochukwu
,
Opuwari, Chinyerum S
,
Zitha, Amukelani A
in
Antioxidants
,
Catalase
,
Cell viability
2020
Moringa oleifera (MO) is an excellent source of dietary antioxidant. MO is used traditionally to enhance libido and as an aphrodisiac in the treatment of sexual dysfunction. This study aimed to investigate the direct effect of aqueous leaf extract of MO on Leydig cell in vitro. Specifically, the effect of MO on viability, testosterone production, antioxidant activity and lipid peroxidation on TM3 cells were evaluated. TM3 cells seeded for 24 hr were exposed to aqueous leaf extract of MO (0, 10, 50, 100, 250, 500 and 1,000 µg/ml) for 24 hr, in the absence or presence of human chorionic gonadotropin (hCG; 6 mIU/200 µl). Cell viability remained unchanged while testosterone production significantly increased at 500 and 1,000 µg/ml of the extract under stimulatory conditions by 34 and 45% respectively. Glutathione level substantially increased at 250 µg/ml, while lipid peroxidation, catalase and superoxide dismutase activity, and total antioxidant capacity remained unchanged. Our results demonstrate the androgenic effect of MO especially at high concentrations in TM3 cells. The androgenic effect may be attributed to its antioxidant enzyme activities.
Journal Article
Antioxidant, Anti-Diabetic, and Anti-Inflammation Activity of IGarcinia livingstonei/I Aqueous Leaf Extract: A Preliminary Study
by
Opuwari, Chinyerum S
,
Nethengwe, Murendeni
,
Kerebba, Nasifu
in
Analysis
,
Antioxidants
,
Bioflavonoids
2024
Diabetes mellitus (DM) is the second leading cause of mortality globally. The increased concern for DM is due to the underlying complications accompanying hyperglycaemia, associated with oxidative stress and consequent inflammation. The investigation of safe and effective treatments for DM is necessary. In the present study, the cytotoxicity, phytochemical analysis, antioxidant capacity, anti-inflammatory, and antidiabetic effects in an aqueous extract of Garcinia livingstonei leaves were assessed. All tested extract concentrations showed no toxicity against C3A hepatocytes. Several phenolic compounds were identified using ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS). The total polyphenol content was 100.9741 mg GAE/g, 16.7712 mg CE/g flavanols, and 2.3548 mg QE/g flavonols. The antioxidant capacity values were 253.4268 mg AAE/g, 192.232 mg TE/g, and 167.8724 mg TE/g for ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), and 2,2-diphenyl-1-pycrylhydrazyl (DPPH), respectively. The plant extract significantly (p < 0.05) demonstrated anti-inflammatory and hypoglycaemic effects in a dose-dependent manner, with the α-glucosidase inhibition of the extract being higher (p < 0.05) than in the standard conventional drug (acarbose). The findings of this study revealed the potential of the constituents of G. livingstonei aqueous leaf extract in DM treatment. Further studies on the preparation and mechanisms of action of the plant in DM treatment are recommended.
Journal Article