The GI tract of an individual which is inhabited by a large number of microbes,
is under constant threat from pathogens and oxidative damage. In Indian system
of medicine, several cucurbits have been widely documented for prophylactic
and therapeutic purposes to ameliorate such situations. The total flavonoids,
observed in the extract of three cucurbits, Lagenaria siceraria (Ls),
Luffa cylindrica (Lc) and Cucurbita pepo (Cp), were 17.9±1.3,
6.3±0.2 and 2.1±0.5 mg g-1, respectively. The antioxidant
activity, determined by DPPH assay, displayed that Ls, Cp and Lc had 77±1.3,
10±3 and 10±1.0% free radical scavenging activity, respectively.
Reduction Potential (RP) assay revealed the antioxidant effects for Ls,
Lc and Cp as 44±0.8, 22±.3 and 15±.8%, respectively. Maximum
activity of quenching H2O2 was demonstrated by Lc (92±1%)
as compared to Cp (78±2%) and Ls (76±1.6%). Antimicrobial activity
of Lactobacillus rhamnosus measured through generation of inhibition
zone against E. coli was augmented maximally in presence of Ls (4.4±0.3
cm), followed by Cp (4.2±.01 cm) and Lc (4.0±.03 cm). Biofilm
formation by L. rhamnosus was maximally supported in presence of Lc (absorbance
= 0.26±0) followed by Ls (0.21±.01) and Cp (0.20±.01).
Thus, these dietary cucurbits showed appreciable antioxidant activity and enhance
antimicrobial and barrier function of mucosa by L. rhamnosus and impart
protection to gut without any toxic effects.