Heat Inactivation of Garlic (Allium sativum) Extract Abrogates Growth Inhibition of HeLa Cells

Allium vegetable intake associated with the risk of incident gastric cancer: a continuous follow-up study of a randomized intervention trial

BACKGROUND

Allium vegetable components have antibacterial, antioxidative, and immune modulation properties, thus potentially exhibiting antitumor effects. Despite evidence from case-control studies, prospective studies linking allium vegetables with gastric cancer (GC) have been sparse.

OBJECTIVE

In a prospective study, we examined whether allium vegetable intake would change the risk of GC occurrence and whether the associations would be modified by vitamin supplementation, garlic supplementation, and Helicobacter pylori (H. pylori) treatment.

METHODS

The study was conducted on the basis of the Shandong Intervention Trial, a randomized, placebo-controlled, factorial-designed trial (1995-2003) in a well-recognized high-risk area for GC in China. Participants were continuously followed up to December 2017 for 22.3 y (1995-2017). A total of 3229 subjects were included, with information on the intake of allium vegetables (garlic vegetables and scallions), collected by structured questionnaires in 1994. The associations of total and individual allium vegetable intake with the risk of GC were examined, respectively.

RESULTS

During the follow-up, 144 incident cases of GC were identified. Garlic vegetable intake was associated with a decreased risk of incident GC (P-trend = 0.02; OR: 0.83; 95% CI: 0.70, 0.98, per 1 kg/y increment), whereas scallion intake showed no association (P-trend = 0.80). An inverse association of the risk of GC with total allium vegetable and garlic vegetable intake was particularly stronger among those receiving the placebo for vitamin supplementation or garlic supplementation, indicating potential effect modifications by nutritional supplementation on allium vegetable intake and the risk of developing GC. Similar findings were found for analyses of the combined prevalence of dysplasia or GC.

CONCLUSIONS

We found a significant reduction in the risk of developing GC with increasing dietary intake of allium vegetables, particularly garlic vegetables. The findings add to the literature on the potential inverse association of garlic vegetable intake with the risk of GC, therefore holding public health implications for dietary recommendations. This trial was registered at clinicaltrials.gov as NCT00339768.

Garlic intake and gastric cancer risk: Results from two large prospective US cohort studies

Although many case-control studies suggested that garlic intake may reduce gastric cancer risk, evidence from prospective cohort studies has been lacking. We examined the association between garlic intake and subsequent risk of gastric cancer among 77,086 women in the Nurses' Health Study (1984-2014) and 46,398 men in the Health Professionals Follow-Up Study (1986-2014). Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models. We additionally examined garlic intake in relation to Helicobacter pylori (H. pylori) infection among 613 participants using logistic regression. During up to 30 years of follow-up, 292 participants were diagnosed with gastric cancer. The pooled multivariable RR of gastric cancer among participants who ate garlic, as compared to those who did not, were 1.11 (95% CI = 0.81-1.51) for the intake of garlic less than once per week, 0.98 (95% CI = 0.71-1.36) for one to four times per week and 1.39 (95% CI = 0.89-2.17) for five or more times per week (p for trend = 0.23). Similarly, no statistically significant association was observed cross-sectionally between garlic intake and H. pylori infection (comparing five or more times per week to never, pooled multivariable odds ratio = 1.66, 95% CI = 0.89-3.09; p for trend = 0.11). The findings from this large prospective study do not support the hypothesis that high garlic intake reduces risk of gastric cancer.

Consumption of garlic and lemon aqueous extracts combination reduces tumor burden by angiogenesis inhibition, apoptosis induction, and immune system modulation

OBJECTIVES

Dietary agents play an important role in cancer prevention and therapy because of their low toxicity and the perception that they are not a medicine. The aim of the present study was to investigate the anticancer effect of the administration of garlic and lemon aqueous extracts against breast cancer implanted in mice.

METHODS

We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay to determine the antiproliferative effect of both extracts and their combinations. Isobolographic method was used to calculate the combination index. Balb/C mice were inoculated with EMT6/P breast cancer cells and received intragastric administration of one of three treatments (garlic alone, lemon alone, or a combination of both). Change in tumor size and survival rates were measured. TUNEL assay was used to measure apoptosis and enzyme-linked immunosorbent assay (ELISA) was used to measure vascular endothelial growth factor expression. Serum levels of interferon-γ, interleukin (IL)-2, IL-4, and IL-10 were measured using ELISA and levels of aspartate transaminase, alanine transaminase, and creatinine were determined.

RESULTS

The combination of both extracts acts synergistically against breast cancer in mice. Of the treated mice, 80% were cured using this combination. This combination inhibited angiogenesis, induced apoptosis, and caused systemic activation in the immune system.

CONCLUSIONS

The combination of garlic and lemon aqueous extracts represents a promising option to develop an anticancer food for augmenting conventional anticancer therapies. However, further testing is essential to understand the exact molecular mechanisms of this combination and to test its therapeutic effect against other cancer models.