Antimicrobial properties of tomato leaves, stems, and fruit and their relationship to chemical composition.

BACKGROUND: We previously reported that the tomato glycoalkaloid tomatine inhibited the growth of Trichomonas vaginalis strain G3, Tritrichomonas foetus strain D1, and Tritrichomonas foetus-like strain C1 that cause disease in humans and farm and domesticated animals. The increasing prevalence of antibiotic resistance requires development of new tools to enhance or replace medicinal antibiotics. METHODS: Wild tomato plants were harvested and divided into leaves, stems, and fruit of different colors: green, yellow, and red. Samples were freeze dried and ground with a handheld mill. The resulting powders were evaluated for their potential anti-microbial effects on protozoan parasites, bacteria, and fungi. A concentration of 0.02% (w/v) was used for the inhibition of protozoan parasites. A high concentration of 10% (w/v) solution was tested for bacteria and fungi as an initial screen to evaluate potential anti-microbial activity and results using this high concentration limits its clinical relevance. RESULTS: Natural powders derived from various parts of tomato plants were all effective in inhibiting the growth of the three trichomonads to varying degrees. Test samples from leaves, stems, and immature 'green' tomato peels and fruit, all containing tomatine, were more effective as an inhibitor of the D1 strain than those prepared from yellow and red tomato peels which lack tomatine. Chlorogenic acid and quercetin glycosides were present in all parts of the plant and fruit, while caffeic acid was only found in the fruit peels. Any correlation between plant components and inhibition of the G3 and C1 strains was not apparent, although all the powders were variably effective. Tomato leaf was the most effective powder in all strains, and was also the highest in tomatine. S. enterica showed a minor susceptibility while B. cereus and C. albicans fungi both showed a significant growth inhibition with some of the test powders. The powders inhibited growth of the pathogens without affecting beneficial lactobacilli found in the normal flora of the vagina. CONCLUSIONS: The results suggest that powders prepared from tomato leaves, stems, and green tomato peels and to a lesser extent from peels from yellow and red tomatoes offer potential multiple health benefits against infections caused by pathogenic protozoa, bacteria, and fungi, without affecting beneficial lactobacilli that also reside in the normal flora of the vagina.

Comparative outcome between chemoradiotherapy and lateral pelvic lymph node dissection following total mesorectal excision in rectal cancer.

OBJECTIVE: To evaluate comparative outcome between adjuvant postoperative chemoradiotherapy (postoperative CRT) and lateral pelvic lymph node dissection (LPLD) following total mesorectal excision (TME) in rectal cancer patients. BACKGROUND: Although TME results in lower rate of locoregional recurrence compared with conventional surgery, these 2 treatment modalities following TME have not adequately been appraised until the present trend of preoperative chemoradiotherapy. PATIENTS AND METHODS: Between 1995 and 2000, patients with stage II and III rectal cancer underwent TME plus postoperative CRT (n = 309) or LPLD (n = 176). Patients in the postoperative CRT group received 8 cycles of 5-fluorouracil plus leucovorin and 45 Gy pelvic radiotherapy. Patients in the LPLD group underwent lateral lymph node dissection outside the pelvic plexus. RESULTS: The 5-year overall and disease-free survival rates were 78.3% and 67.3% in the postoperative CRT group, respectively, and 73.9% and 68.6% in the LPLD group, respectively, without significant differences between these groups. Patients in the LPLD group with stage III lower rectal cancer had a locoregional recurrence rate 2.2-fold greater than those in the postoperative CRT group (16.7% vs. 7.5%, P = 0.044). Multivariate analysis showed that APR and advanced T-category (T4) were significantly associated with locoregional recurrence, whereas lymph node metastases, high preoperative serum carcinoembryonic antigen, and APR were significantly associated with shortening of disease-free survival. CONCLUSIONS: Postoperative-CRT and LPLD following TME resulted in comparable survival rates, but the locoregional recurrence rate was higher in the LPLD group. These findings suggest that initial surgery is appropriate for rectal cancer patients who are candidates for low anterior resection without extensive local disease (T1-T3), regardless of lymph node status.