The protective effect of aged garlic extract on nonsteroidal anti-inflammatory drug-induced gastric inflammations in male albino rats

Garlic bioactive substances and their therapeutic applications for improving human health: a comprehensive review

Garlic (Allium sativum L.) is a widely abundant spice, known for its aroma and pungent flavor. It contains several bioactive compounds and offers a wide range of health benefits to humans, including those pertaining to nutrition, physiology, and medicine. Therefore, garlic is considered as one of the most effective disease-preventive diets. Many in vitro and in vivo studies have reported the sulfur-containing compounds, allicin and ajoene, for their effective anticancer, anti-diabetic, anti-inflammatory, antioxidant, antimicrobial, immune-boosting, and cardioprotective properties. As a rich natural source of bioactive compounds, including polysaccharides, saponins, tannins, linalool, geraniol, phellandrene, β-phellandrene, ajoene, alliin, S-allyl-mercapto cysteine, and β-phellandrene, garlic has many therapeutic applications and may play a role in drug development against various human diseases. In the current review, garlic and its major bioactive components along with their biological function and mechanisms of action for their role in disease prevention and therapy are discussed.

Freshwater Clam Extract Attenuates Indomethacin-Induced Gastric Damage In Vitro and In Vivo

Contemporary pharmacological studies have reported that freshwater clam (Corbicula fluminea) can provide a broad spectrum of bioactivities, including antioxidant, anticancer, antihypertensive, hepatoprotective, and hypocholesterolemic effects. The aim of this study was to evaluate the gastroprotective effects of water extract of freshwater clam (WEC) on indomethacin (IND)-induced gastric mucosal cell damage in vitro and gastric ulcer in vivo. The cell viability of rat gastric mucosa RGM-1 cells was markedly decreased by 0.8 mM of IND treatment, and pre-treated with various concentration of WEC significantly restored IND-induced cell damage in a dose-dependent manner. WEC also significantly attenuated the elevated reactive oxygen species (ROS) levels, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, and nuclear factor-κB (NF-κB) p65 nuclear translocation induced by IND. In the in vivo study, IND caused severe gastric ulcer in Wistar rats, while WEC pretreatment effectively reduced the ulcer area and edema in the submucosa. We found that WEC significantly restored glutathione (GSH) content in gastric mucosa in a dose-dependent manner (p < 0.05). The reduction of prostaglandin E2 (PGE2) caused by IND was also improved with higher doses of WEC administration. Moreover, the overexpression of COX-2, iNOS, and tumor necrosis factor-α (TNF-α) proteins in gastric mucosa was downregulated by administration of WEC. Consequently, WEC can be used as a potential nutritional supplement to improve NSAIDs-caused gastric mucosal lesions.

Single-bulb garlic oil regulates toll-like receptors and Nrf2 cross-talk and IL-17 production in mice fed with high-fat diet

The present study aimed to evaluate the effect of single-bulb garlic oil (SGO) on toll-like receptors 3 and 4 (TLR3 and TLR 4) and nuclear erythroid factor-like 2 (Nrf2) signaling pathway resulted from a high-fat diet and its underlying mechanism. Twenty-four Balb/c mice allocated into six groups: 1) N: mice fed with standard chow; 2) HFD: mice fed a high-fat diet for 45 days without any treatment; 3) HFD + Simv: mice fed a high-fat diet for 45 days and treated with simvastatin; 4–6) HFD + SGO 100, 200, 400 (mice fed a high-fat diet for 45 days and treated with single-bulb garlic oil at dose: 100, 200, and 400 mg/kg body weight for 30 days), respectively. At the end of treatment, spleen and hepar were isolated. The flow cytometry analysis was performed to analyze the relative number of nrf2, superoxide dismutase (SOD), malondialdehyde (MDA), TLR3, TLR4 and interleukin (IL-17). The results showed that HFD induction significantly reduced Nrf-2 and antioxidant enzyme levels. Furthermore, HFD induction increased TLR3 and TLR4 signaling and IL-17 production. Interestingly, 200 mg/kg BW of SGO increased the relative number Nrf-2 followed by SOD and HO-1 elevation at a dose of 100 mg/kg BW. SGO100 notably decrease the relative number of TLR3 (CD11b⁺TLR3⁺) and TLR4 (CD11b⁺TLR4⁺). The production of IL-17 by CD4 and CD8 were also reduced after receiving SGO at 200 mg/kg BW. This study suggests that the protective effect of SGO treatment on HFD mice was achieved by modulating TLR-Nrf2 cross-talks and decreasing IL-17 production. Our findings support a potential beneficial role of SGO for treating metabolic disease caused by a high-fat diet.

Efficacy of phytochemicals as immunomodulators in managing COVID-19: a comprehensive view

Throughout history, disease outbreaks have worked havoc upon humanity, sometimes reorienting the history and at times, signaling the end of entire civilizations and the modern pandemic that the world is dealing with, is COVID-19 or SARS-CoV-2. A healthy immunity could be an ideal gear for resisting COVID-19 for neither medicines nor vaccines have been ascertained till date. In view of the present scenario, there is a demanding necessity to analyze innovative and valid techniques for forestalling and cure of COVID-19 by re-evaluating the structure of the natural compounds for drug designing. The Ayurveda has come forward by prescribing a lot of medicinal herbs for combating this dreaded disease. We have searched from sources in Pubmed and Google Scholar and found 1509 items. The search criteria were limited to the effect of phytochemicals in certain immunomodulatory aspects of viral infection. The original research papers related to the works on phytochemicals in the down regulation of NF-kB, activation of NK and CD8+ cells, inhibition of inflammatory cytokine release and ROS scavenging were included in our study. Here, we try to focus on the immunoregulatory cells which have a vital aspect in COVID-19 and highlight the potential effects of the restorative use of phytochemicals as drugs or dietary supplements.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-021-00706-2.

Black Garlic and Its Bioactive Compounds on Human Health Diseases: A Review

Black garlic (BG) is a form of aged garlic obtained from raw garlic (Allium sativum) via Millard reaction under high temperature (60-90 °C) and humidity (70-90%) for a period of time. Several studies reported higher contents of water-soluble antioxidants compounds (S-allyl cysteine, S-allyl-mercapto cysteine), 5-hydroxymethylfurfural, organosulfur compounds, polyphenol, volatile compounds, and products of other Millard reactions compared to fresh garlic after the thermal processing. Recent studies have demonstrated that BG and its bioactive compounds possess a wide range of biological activities and pharmacological properties that preserve and show better efficacy in preventing different types of diseases. Most of these benefits can be attributed to its anti-oxidation, anti-inflammation, anti-obesity, hepatoprotection, hypolipidemia, anti-cancer, anti-allergy, immunomodulation, nephroprotection, cardiovascular protection, and neuroprotection. Substantial studies have been conducted on BG and its components against different common human diseases in the last few decades. Still, a lot of research is ongoing to find out the therapeutic effects of BG. Thus, in this review, we summarized the pre-clinical and clinical studies of BG and its bioactive compounds on human health along with diverse bioactivity, a related mode of action, and also future challenges.

Herbal medicines to the treatment of skin and soft tissue infections: advantages of the multi-targets action

The research for new treatments of skin and soft tissue infections (SSTIs) is important due to their high prevalence and number of hospitalizations. The purpose of this review is to address the pathophysiology of SSTIs to highlight the advantages of herbal medicines to their treatment, showing examples of species and compounds with multi-targets action. SSTIs have a complex physiopathology involving the microorganism, as well as inflammation and difficult healing. Therefore, antimicrobial, anti-inflammatory, antioxidant and healing activities are an approach possible for their treatment. Herbal medicines have a wide diversity of biological compounds, mainly phenolic compounds that may act on different targets and also have synergism between them. Therefore, a single medicine may have the four key activities that allied allow eliminating the infection, control the inflammation process and accelerating the healing process, preventing complications with chronic infections.

A comparative study on the possible protective effect of esomeprazole, spirulina, wheatgrass on indomethacin-induced gastric ulcer in male albino rats

Gastric ulcer is a common problem affecting the gastrointestinal tract. Spirulina and wheatgrass are natural substances that have anti-inflammatory and antioxidant effects. The aim of the Work was to elucidate the possible protective role of spirulina and wheatgrass versus standard treatment esomeprazole on indomethacin-induced gastric ulcer in adult male albino rats. Eighty adult male albino rats were divided into eight groups: group I (the control group), group II that received indomethacin (100 mg/kg orally), group III that received esomeprazole (20 mg/kg orally), group IV that received spirulina (1000 mg/kg orally), group V that received wheatgrass (1000 mg/kg orally), group VI that received indomethacin (100 mg/kg) + esomeprazole (20 mg/kg), group VII that received indomethacin (100 mg/kg) + spirulina (1000 mg/kg) and group VIII that received indomethacin (100 mg/kg) + wheatgrass (1000 mg/kg). Six hours after indomethacin treatment, all rats were anesthetized and their stomachs obtained for measures of gastric acidity, pepsin activity, mucin content, gastrin, ulcer index, total antioxidant capacity (TAC), tumor necrosis factor -α (TNF-α), interleukin-8 (IL8), proapoptotic protein (Bax). Histological (using H&E stain, PAS reaction) and immunohistochemical (using anti Ki67 immunostain) techniques were performed. Western immunoblot analysis for heat shock protein 70 (HSP70) was also done. Moreover, a morphometric study was done for area% of positive immunoreactive cells for Ki67 and optical density and area% of PAS reaction. All performed measurements were followed by statistical analysis. Indomethacin induced loss of normal architecture of gastric mucosa with sloughing of surface epithelium and inflammatory cellular infiltration. It also led to a significant increase in gastric acidity, inflammatory mediators (TNF-α, IL-8), pro-apoptotic protein Bax and a significant decrease in TAC levels and HSP-70 expression. There was also a significant decrease in area% of Ki67 immunoreactivity and area% and optical density of PAS reaction as compared with the control group and other pre-treated rats. These disturbed parameters were associated with increased ulcer index. In pre-treatment groups, the structure of the mucosa was similar to control with marked improvement in the biochemical assay. In conclusion, Spirulina and wheatgrass can partly protect the gastric mucosa against indomethacin-induced damage to a degree similar to that of the classical treatment esomeprazole.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.

The gastroprotective effect of N-acetylcysteine and genistein in indomethacin-induced gastric injury in rats

The protective effect of N-acetylcysteine (NAC) and genistein (GEN) on an experimental model of indomethacin (IND)-induced gastric injury was investigated. A total of 50 male rats were divided into 5 groups: (1) control, (2) IND, (3) NAC pretreated, (4) GEN pretreated, and (5) NAC+GEN pretreated. Rats in groups 3-5 were orally administered NAC (500 mg/kg), GEN (10 mg/kg), or both, respectively, once daily for 7 days before the induction of gastric injury by IND (50 mg/kg). The stomach was removed for biochemical analysis and histopathological examination. Pretreatment with NAC, GEN, or both significantly improved ulcer indices and increased nitric oxide level and superoxide dismutase activity. They also significantly decreased malondialdehyde, tumour necrosis factor α levels, and myeloperoxidase activity, and downregulated matrix metalloproteinase 9 (MMP-9) gene expression compared to the IND group. NAC alone ameliorated IND-induced apoptosis, whereas GEN only significantly increased prostaglandin E₂ level. Further, coadministration of both resulted in a significantly better gastroprotective effect versus solo administration. Coadministration of NAC and GEN has an additive gastroprotective effect in IND-induced gastric injury, which may be through interaction of their potential cytoprotective, antioxidant, anti-inflammatory, and antiapoptotic mechanisms together with regulation of MMP-9 expression.

The effect of 12-week garlic supplementation on symptom relief in overweight or obese women with knee osteoarthritis

AIMS

Chronic joint pain and stiffness, and functional disability, are the major debilitating features of osteoarthritis (OA). The aim of this study was to assess the effect of 12-week supplementation with a garlic supplement on knee osteoarthritis outcomes in overweight or obese women.

METHODS

Seventy-six postmenopausal overweight or obese women (25≤BMI≤40 kg/m² ) with medically diagnosed knee OA participated in this randomised double-blind, placebo-controlled, parallel-design trial. After randomisation into 2 groups, patients received a daily dose of either 1000 mg odourless garlic tablet, or placebo, for 12 weeks. The total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), as well as pain, stiffness and physical function subscales, were evaluated pre- and poststudy. Anthropometric parameters and body composition (using bioelectrical impedance analysis) were also assessed.

RESULTS

Following 12-week supplementation in overweight or obese women with OA, stiffness (but not pain, function or WOMAC total score) was significantly lower in the garlic group compared with the placebo group (1.4 ± 1.6 vs 2.5 ± 1.9, P = .023). The changes in WOMAC parameters showed no statistically significant differences between the 2 groups. WOMAC total score (38.4 ± 15.9-30.6 ± 15.7, P = .004) and all the subscales, including pain (8.3 ± 3.7-7 ± 4.4, P = .026), stiffness (2.3 ± 1.6-1.4 ± 1.6, P = .013) and physical function (27.7 ± 11.9-22.2 ± 12.4, P = .001) improved significantly in the garlic group postintervention compared with pre-intervention; although pain subscale also decreased in the placebo group (9.6 ± 3.1-6.9 ± 3.7, P < .001).

CONCLUSIONS

Although pre- to postintervention knee OA symptoms were improved in overweight or obese women receiving 12 weeks garlic supplement, there was no significant difference in WOMAC changes compared with the placebo group. Further clinical trials are required to investigate the therapeutic value of garlic ingredients, and the potential role of placebo effect, in the management of OA symptoms.

Ability of garlic-derived diallyl disulfide and diallyl trisulfide supplemented by oral gavage to mitigate effects of an acute postweaning feed and water deprivation event in nursery pigs

Compounds in garlic have been shown to contain anti-inflammatory, antioxidant, and immune modulatory properties that may be able to mitigate the effects of nursery pig stressors. The objective of the current experiment was to determine if oral gavage of garlic-derived diallyl disulfide (DADS) and diallyl trisulfide (DATS) could mitigate the effects of a 24-h postweaning feed + water deprivation event in nursery pigs. Pigs (6.0 ± 0.05 kg and 21 d old) were allotted to 4 treatments in a randomized complete block design at weaning with 8 replicate pens per treatment that consisted of with or without a 24-h postweaning feed + water deprivation event and with or without an oral gavage containing 3.6 mg DADS + DATS/kg BW. Growth performance and morbidity were recorded throughout the experiment, and on 1, 6, and 21 d after weaning, 1 pig per pen was selected, blood was collected, the pig was euthanized, and a segment of the distal ileum was subsequently excised for morphological and gene and protein expression measurements. Mucosal gene expression was conducted by reverse transcription PCR for immune, antioxidant, and cellular integrity markers. Furthermore, activity of mucosal superoxide dismutase was measured by colorimetric assay. Immediately following the feed + water deprivation event, there was a decrease ( < 0.01) in growth performance and an increase ( = 0.01) in serum cortisol. The feed + water deprivation event tended ( = 0.10) to decrease ileal villus height and supplementation of DADS + DATS by oral gavage increased ( = 0.03) villus height 1 d after weaning. Supplementation of DADS + DATS by oral gavage decreased ( = 0.03) and tended to decrease ( = 0.08) gene expression of on 6 and 21 d after weaning, respectively. Furthermore, at 1 d after weaning, ileal mucosa SOD activity was decreased ( = 0.01) by the feed + water deprivation and increased ( = 0.04) by oral supplementation of DADS + DATS. Expression of the tight junction genes and were reduced ( ≤ 0.05) due to the feed + water deprivation event 1 d after weaning. Results from the current study show that an acute feed + water deprivation event can impact growth performance, intestinal characteristics, and antioxidant status in nursery pigs, which can be partially mitigated by oral supplementation of garlic compounds DADS + DATS.

Immunomodulation and anti-inflammatory effects of garlic compounds

The benefits of garlic to health have been proclaimed for centuries; however, only recently have Allium sativum and its derivatives been proposed as promising candidates for maintaining the homeostasis of the immune system. The complex biochemistry of garlic makes it possible for variations in processing to yield different preparations with differences in final composition and compound proportion. In this review, we assess the most recent experimental results, which indicate that garlic appears to enhance the functioning of the immune system by stimulating certain cell types, such as macrophages, lymphocytes, natural killer (NK) cells, dendritic cells, and eosinophils, by mechanisms including modulation of cytokine secretion, immunoglobulin production, phagocytosis, and macrophage activation. Finally, because immune dysfunction plays an important role in the development and progress of several diseases, we critically examined immunoregulation by garlic extracts and compounds isolated, which can contribute to the treatment and prevention of pathologies such as obesity, metabolic syndrome, cardiovascular disorders, gastric ulcer, and even cancer. We concluded that A. sativum modulates cytokine secretion and that such modulation may provide a mechanism of action for many of their therapeutic effects.