Effect of garlic (Allium sativum L.) extract on degree of hydration, fructose, sulphur and phosphorus contents of rat eyelens and intestinal absorption of nutrients

The Influence of Plants from the Alliaceae Family on Morphological Parameters of the Intestine in Atherogenic Rats

Bulbs from the Alliaceae family have been well-known and valued spices for thousands of years, not only for their unique flavor and aroma features, but also for their high nutritional and health-promoting values. Long-term or excessive consumption of these vegetables, especially raw garlic, can have side effects in the body (including in the digestive tract), causing a number of pathological changes in the intestinal wall; these changes lead, in turn, to its damage, dysfunction, and disorder development. Therefore, the aim of this study was to investigate the effect of the addition of freeze-dried vegetables from the Alliaceae family, i.e., garlic (Allium sativum L.), white onion, and red onion (Allium cepa L.) on the morphometric parameters (intestinal villi length, crypt depth, thickness of tunica mucosa, and the thickness of tunica muscle) of the jejunum of rats fed a semi-synthetic atherogenic diet (1% dietary cholesterol). In freeze-dried vegetables administered to rats, the contents of selected bioactive ingredients and their antioxidant potentials were determined. The effect of the onion vegetable supplements on growth parameters, serum lipid profile, plasma antioxidant potential, and the intestinal morphological parameters of rats loaded with cholesterol was determined. In an animal experiment, 30 male Wistar rats were divided into 5 diet groups, diet consumption and FER were studied. Supplementation of the atherogenic diet with vegetables improved the blood plasma lipid profiles and atherogenic indices, in a manner that was dependent on the type of supplementation used, with the best hypolipidemic and anti-atherosclerotic effects found in garlic use. The atherogenic diet, as well as the supplementation of this diet with the tested vegetables from the Alliaceae family, influenced the histological changes in the epithelium of the jejunum of rats. The damage to the intestinal mucosa was the greatest in animals fed an atherogenic diet supplemented with garlic. Bearing in mind that the desired beneficial therapeutic or prophylactic effects of onion vegetables (in particular garlic) in the course of various metabolic ailments (including atherosclerosis) are achieved during long-term supplementation, it is important to remember their possible cytotoxic effects (e.g., on the digestive tract) in order to achieve real benefits related to the supplementation with vegetables from the Alliaceae family.

Preventive Effects and Mechanisms of Garlic on Dyslipidemia and Gut Microbiome Dysbiosis

Garlic (Allium sativum L.) contains prebiotic components, fructans, antibacterial compounds, and organosulfur compounds. The complex ingredients of garlic seem to impart a paradoxical result on the gut microbiome. In this study, we used a mouse model to clarify the effects of whole garlic on the gut microbiome. C57BL/6N male mice were fed with or without whole garlic in normal diet (ND) or in high-fat diet (HFD) for 12 weeks. Supplementation with whole garlic attenuated HFD-enhanced ratio of serum GPT/GOT (glutamic-pyruvic transaminase/glutamic-oxaloacetic transaminase), levels of T-Cho (total cholesterol) and LDLs (low-density lipoproteins), and index of homeostatic model assessment for insulin resistance (HOMA-IR), but had no significant effect in the levels of serum HDL-c (high density lipoprotein cholesterol), TG (total triacylglycerol), and glucose. Moreover, garlic supplementation meliorated the HFD-reduced ratio of villus height/crypt depth, cecum weight, and the concentration of cecal organic acids. Finally, gut microbiota characterization by high throughput 16S rRNA gene sequencing revealed that whole garlic supplementation increased the α-diversity of the gut microbiome, especially increasing the relative abundance of f_Lachnospiraceae and reducing the relative abundance of g_Prevotella. Taken together, our data demonstrated that whole garlic supplementation could meliorate the HFD-induced dyslipidemia and disturbance of gut microbiome.

Histological evaluation of the jejunum and ileum of rats after administration of high dose garlic aqueous extract

OBJECTIVES

This study investigated the adverse effects of excessive consumption of garlic on the small intestine (jejunum and ileum) of adult male Wistar rats.

METHODOLOGY

Sixteen (16) Wistar rats with average weight of 181.5 g were grouped into two: Control Group A which received distilled water, and Treatment Group B which received 1000 mg/kg/ml aqueous extract of garlic, orally for 28 weeks. The aqueous extraction of raw garlic was done to obtain a concentration of 1000 mg/kg/ml. The animals were sacrificed by cervical dislocation after the last day of administration, and tissues for histological studies were fixed in buffered formalin, while those for enzyme studies were homogenised, and appropriate biochemical kits used to study the activities of acid phosphatase (ACP), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH).

RESULTS

The histological sections of the jejunum of animals that received the high dose of aqueous garlic extract revealed the presence of vacuolations, cell death and loss of epithelium, and intact muscle layer; the Periodic-Acid Schiff (PAS) positivity also reduced, while the ileum also showed degeneration of the brush borders, loss of epithelial cells, reduction in the number of goblet cells, vacuolations, and a reduced intensity of PAS positivity. Activities of ACP, ALP and LDH in the jejunum and ileum were increased.

CONCLUSION

Consumption of excessive amount of garlic could cause structural changes to the intestinal tract, which are capable of affecting intestinal functions, such as decrease in glycogen activity in the small intestine, and impairment of the absorptive activities.

Effect of methanolic extract of Allium sativum (AS) in delaying cataract in STZ-induced diabetic rats

Glycemic-induced stress is a major culprit contributing to oxidative insult that has far-reaching effects in diabetic cataract worldwide. In an attempt to prevent/delay cataract, many therapeutic agents have been identified, and among these, natural dietary sources have gained pharmacological significance. Hence, we investigated the efficacy of the methanolic garlic extract against diabetic cataract in Wistar rats. Methanolic garlic extract scavenged the transition metal ion-generated H(2)O(2) with an IC(50) of 768.8 +/- 1.76 mug/ml, showing its potential ability as an antioxidant. We have noticed lenticular opacity and oxidative damage in streptozotocin (STZ)-induced hyperglycemic rats. This is evident by the elevation of Ca(2+), Cu(2+), Na(+), Mg(2+), thiobarbituric acid reacting substances (TBARS), and carbonyl content and increased activities of polyol enzymes, glutathione peroxidase (GPx), superoxide dismutase (SOD), and up regulation of iNOS transcript and protein aggregation/cross-linking followed by a decrease in reduced glutathione (GSH), K(+) content, and tryptophan fluorescence in the cataractous lenses of STZ-induced diabetic rats. Garlic administration in a dose-dependent manner attenuated the glycemia-mediated oxidative stress as all the parameters have been found normalized more or less to that of control rats and thus delaying the progression of the lens opacity. We conclude that garlic extract has hypoglycemic and anti oxidant properties that can delay the progression of cataract as revealed in this study.