SESAME OIL PROTECTS AGAINST LEAD-PLUS-LIPOPOLYSACCHARIDE-INDUCED ACUTE HEPATIC INJURY

Lead detoxification of edible fungi Auricularia auricula and Pleurotus ostreatus: the purification of the chelation substances and their effects on rats

Lead is a global pollutant that causes widespread concern. When a lead enters the body, it is distributed throughout the body and accumulates in the brain, bone, and soft tissues such as the kidney, liver, and spleen. Chelators used for lead poisoning therapy all have side effects to some extent and other drawbacks including high cost. Exploration and utilization of natural antidotes become necessary. To date, few substances originating from edible fungi that are capable of adsorbing lead have been reported. In this study, we found that two commonly eaten mushrooms Auricularia auricula and Pleurotus ostreatus exhibited lead adsorption capacity. A. auricula active substance (AAAS) and P. ostreatus active substance (POAS) were purified by hot-water extraction, ethanol precipitation from its fruiting bodies followed by ion exchange chromatography, ultrafiltration, and gel filtration chromatography, respectively. AAAS was 3.6 kDa, while POAS was 4.9 kDa. They were both constituted of polysaccharides and peptides. The peptide sequences obtained by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) proved that they were rich in amino acids with side chain groups such as hydroxyl, carboxyl, carbonyl, sulfhydryl, and amidogen. Two rat models were established, but only a chronic lead-induced poisoning model was employed to determine the detoxification of AAAS/POAS and their fruiting body powder. For rats receiving continuous lead treatment, either AAAS or POAS could reduce the lead levels in the blood. They also promoted the elimination of the burden of lead in the spleen and kidney. The fruiting bodies were also proved to have lead detoxification effects. This is the first study to identify new functions of A. auricula and P. ostreatus in reducing lead toxicity and to provide dietary strategies for the treatment of lead toxicity.

Natural antidotes and management of metal toxicity

The global burden of heavy metal especially mercury, arsenic, lead, and cadmium toxicities remains a significant public health challenge. Developing nations are particularly at high risk and carry the highest burden of this hazard. Chelation therapy has been the mainstay for treatment of heavy metal poisoning where the chelating agent binds metal ions to form complex ring-like structures called "chelates" to enhance their elimination from the body. Metal chelators have some drawbacks such as redistribution of some heavy metals from other tissues to the brain thereby increasing its neurotoxicity, causing loss of essential metals such as copper and zinc as well as some serious adverse effects, e.g., hepatotoxicity. The use of natural antidotes, which are easily available, affordable, and with little or no side effects compared to the classic metal chelators, is the focus of this review and suggested as cheaper options for developing nations in the treatment of heavy metal poisoning.

Enteral sesame oil therapeutically relieves disease severity in rat experimental osteoarthritis

Background

Osteoarthritis (OA) is the most common cause of joint pain, affecting approximately 15% of the population. Recent studies indicate that quadriceps muscle weakness is directly involved in the pathogenesis of OA-associated joint pain. Oxidative stress plays an important role in skeletal muscle dysfunction. Sesame oil is a natural product with excellent antioxidative property. However, whether sesame oil can decrease OA-induced joint pain has never been investigated.

Objective

The aim of the present study was to examine the effect of sesame oil on OA-induced joint pain in rats.

Design

OA-associated joint pain in rats was induced by medial meniscal transection in rats. Sesame oil (0, 1, 2, or 4 ml/kg/day, orally) was given to rats 7 days after OA induction, while the parameters were determined 7 days after sesame oil administration.

Results

Daily sesame oil treatment for 7 days significantly decreased OA-associated joint pain. Sesame oil decreased muscular interleukin-6 and increased citrate synthase activity and myosin heavy chain IIa mRNA expression. Furthermore, sesame oil decreased muscular lipid peroxidation, nuclear Nrf2 protein expression, and reactive oxygen species generations as well as increased glutathione production and glutathione peroxidase activity in OA rats.

Conclusions

Sesame oil may relieve OA-associated joint pain by inhibiting quadriceps muscular oxidative stress, at least partially, in rats.

Daily sesame oil supplement attenuates joint pain by inhibiting muscular oxidative stress in osteoarthritis rat model

Osteoarthritis (OA) is the most common form of arthritis, affecting approximately 15% of the population. The aim of this study was to evaluate the efficacy of sesame oil in controlling OA pain in rats. Rat joint pain was induced by medial meniscal transection in Sprague-Dawley rats and assessed by using hindlimb weight distribution method. Muscular oxidative stress was assessed by determining lipid peroxidation, reactive oxygen species and circulating antioxidants. Sesame oil significantly decreased joint pain compared with positive control group in a dose-dependent manner. Sesame oil decreased lipid peroxidation in muscle but not in serum. Further, sesame oil significantly decreased muscular superoxide anion and peroxynitrite generations but increased muscular glutathione and glutathione peroxidase levels. Further, sesame oil significantly increased nuclear factor erythroid-2-related factor (Nrf2) expression compared with positive control group. We concluded that daily sesame oil supplement may attenuate early joint pain by inhibiting Nrf2-associated muscular oxidative stress in OA rat model.

Beneficial effect of sesame oil on heavy metal toxicity

Heavy metals become toxic when they are not metabolized by the body and accumulate in the soft tissue. Chelation therapy is mainly for the management of heavy metal-induced toxicity; however, it usually causes adverse effects or completely blocks the vital function of the particular metal chelated. Much attention has been paid to the development of chelating agents from natural sources to counteract lead- and iron-induced hepatic and renal damage. Sesame oil (a natural edible oil) and sesamol (an active antioxidant) are potently beneficial for treating lead- and iron-induced hepatic and renal toxicity and have no adverse effects. Sesame oil and sesamol significantly inhibit iron-induced lipid peroxidation by inhibiting the xanthine oxidase, nitric oxide, superoxide anion, and hydroxyl radical generation. In addition, sesame oil is a potent inhibitor of proinflammatory mediators, and it attenuates lead-induced hepatic damage by inhibiting nitric oxide, tumor necrosis factor-α, and interleukin-1β levels. Because metal chelating therapy is associated with adverse effects, treating heavy metal toxicity in addition with sesame oil and sesamol may be better alternatives. This review deals with the possible use and beneficial effects of sesame oil and sesamol during heavy metal toxicity treatment.

Acute and long-term hemodynamic effects of sesame oil consumption in hypertensive men

The possible effects of sesame oil on hemodynamics are unknown. The aim of the study was to investigate the acute and long-term effects of sesame oil on hemodynamic responses in hypertensive men. The authors enrolled 30 hypertensive men in a two-phase study. In the first phase, patients consumed 35 g of either sesame oil or control oil. Central and peripheral blood pressure, pulse wave velocity, augmentation index (AI), C-reactive protein, tumor necrosis factor α, malonydealdehyde, and total antioxidant capacity (TAC) were assessed at fast and 2 hours postprandially. In the second phase, patients consumed 35 g of either sesame oil or control oil daily for 2 months. The above-mentioned parameters were assessed before and following 15, 30, and 60 days of oil consumption. Sesame oil decreased central and peripheral diastolic pressures 1 hour postprandially (P=.006). Fifteen days of sesame oil intake decreased peripheral systolic blood pressure (P=.016) and heart rate-corrected AI75 (P=.017) and increased TAC (P=.007). This is the first study to demonstrate a favorable acute and long-term effect of sesame oil on hemodynamics in hypertensive men. Further research is warranted to establish the potential protective role of sesame oil.

Sesame oil prevents acute kidney injury induced by the synergistic action of aminoglycoside and iodinated contrast in rats

The aim of the study was to investigate the effect of sesame oil on acute kidney injury induced by the synergistic action of aminoglycoside and iodinated contrast in rats. Acute kidney injury was induced by a 5-day course of daily gentamicin injections (100 mg/kg of body weight, subcutaneously) and then iodinated contrast (4 ml/kg, intravenously) in male specific-pathogen-free Sprague-Dawley rats. Sesame oil (0.5 ml/kg, orally) was given 1 h before iodinated contrast. Renal function and oxidative stress were assessed 6 h after iodinated contrast injection. Renal function was evaluated by measuring serum blood urea nitrogen and creatinine levels. Renal oxidative stress was assessed by determining renal lipid peroxidation, myeloperoxidase, hydroxyl radical, superoxide anion, nitrite/nitrate, and inducible nitric oxide synthase levels. Sesame oil significantly prevented the rise of serum blood urea nitrogen and creatinine levels. Furthermore, there was a parallel inhibition of the rise in levels of expression of renal lipid peroxidation, myeloperoxidase, hydroxyl radicals, superoxide anion, nitrite/nitrate, and inducible nitric oxide synthase in rats with gentamicin-plus-iodinated contrast-induced acute kidney injury. We conclude that sesame oil may attenuate aminoglycoside-plus-iodinated contrast-induced acute kidney injury by inhibiting renal oxidative stress in rats.

Ostensibly ineffectual doses of cadmium and lipopolysaccharide causes liver damage in rats

Various hepatotoxicants co-treated with lipopolysaccharide (LPS) have the potential to cause severe hepatic damage. Whether co-treatment with ostensibly ineffectual (without effect on customary clinical liver function tests, such as aspartate aminotransferase and alanine aminotransferase) doses of cadmium (Cd) and LPS cause liver damage is still unknown. We examined the effects of treating ostensibly ineffectual doses of Cd and LPS on liver dysfunction as well as on liver histopathology. We injected rats with saline only, Cd only, LPS only, or a single ostensibly ineffectual dose of Cd (100 μg/kg body weight) plus LPS (0.1 mg/kg body weight). After 6 h, the rats were killed and their liver damage was assessed. Co-treated with ostensibly ineffectual doses of Cd and LPS had higher levels of aspartate aminotransferase and alanine aminotransferase, hepatic lipid peroxidation, peroxynitrite, nitrite, and interleukin-1β (IL-1β), but lower levels of hepatic metallothionein (MT) than did that treated with saline only, Cd only, and LPS only. Histopathological analysis of Cd only and LPS only showed apparent liver damage, but Cd plus LPS showed marked hepatic damage. We conclude that co-treating the rats with ostensibly ineffectual doses of Cd and LPS is hepatotoxic. Cd promotes LPS-initiated oxidative-stress-associated liver damage by increasing IL-1β and decreasing MT levels in rats.

Sesamol attenuates diclofenac-induced acute gastric mucosal injury via its cyclooxygenase-independent antioxidative effect in rats

We examined the protective effects of sesamol against acute gastric mucosal damage induced in rats by nonsteroidal anti-inflammatory drug diclofenac (DLF). We also measured the ulcer index, nitrite, iNOS, lipid peroxidation, hydroxyl radical, superoxide anion, reduced glutathione levels, prostaglandin E2, mucus, and cyclooxygenase activity in the rat mucosa. Sesamol attenuated gastric ulcer, nitrite, and iNOS in DLF-treated stomachs. Sesamol reduced mucosal lipid peroxidation and hydroxyl radical levels; however, neither DLF nor sesamol affected mucosal superoxide anion production. In addition, sesamol significantly maintained the reduced mucosal glutathione levels in DLF-treated stomachs of rats. Sesamol did not affect mucosal mucus production, but it further decreased DLF-induced mucosal prostaglandin E2 generation and cyclooxygenase activity. Therefore, sesamol might protect gastric mucosa against DLF-induced injury by inhibiting hydroxyl radical-associated lipid peroxidation. In addition, the cyclooxygenase pathway may not be involved in sesamol's gastric mucosal protection.