Antioxidant, Anti-Diabetic, and Anti-Inflammation Activity of Garcinia livingstonei Aqueous Leaf Extract: A Preliminary Study.

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.

Role of oxidative stress in male infertility.

Abstract: Infertility affects millions of couples worldwide. Oxidative stress (OS) causes peroxidation of lipids and damage to spermatozoa, thus, reducing the quality of seminal parameters. In addition, the differences in the levels of antioxidants and reactive oxygen species (ROS) caused by intrinsic and extrinsic variables linked to lifestyle, diet, genetics, and OS also contribute to male infertility. High levels of ROS result in sperm damage of sperm parameters due to lipid peroxidation and oxidation of proteins. Other significant causes of ROS include changes in sex hormone levels, sperm DNA damage, including mutations, and immature spermatozoa. Treating the root causes of OS, by changing one's lifestyle, as well as antioxidant therapy, may be helpful strategies to fight OS-related infertility. However, the determination of male infertility induced by OS is currently a challenge in the field of reproductive health research. This review intends to describe the role of oxidative stress on male infertility and the current understanding of its management. Lay summary: The inability to conceive affects many couples globally. Oxidative stress refers to imbalances between different oxygen species which can lead to male fertility problems by damaging sperm and semen. Oxidative stress may be caused by several factors, including diets high in fats, sugars and processed foods, lifestyle (including smoking, alcohol consumption and having a sedentary lifestyle), and genetics. Treatment that focuses on the root cause may help combat male infertility. However, there is currently no consensus on the best way to treat male fertility problems, particularly those associated with oxidative stress. This paper describes the role of oxidative stress on male infertility and discusses the current techniques employed in treating male fertility issues.

Aqueous leaf extract of Moringa oleifera reduced intracellular ROS production, DNA fragmentation and acrosome reaction in Human spermatozoa in vitro.

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.

Androgenic effect of aqueous leaf extract of Moringa oleifera on Leydig TM3 cells in vitro.

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.

In vivo effects of black tea on the male rat reproductive system and functions of the kidney and liver.

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.

An Update on Oxidative Damage to Spermatozoa and Oocytes.

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.