14th International Symposium on Pharmaceutical Sciences (ISOPS), Ankara, Turkey, 25 - 28 June 2024, pp.112
Introduction: The family Cucurbitaceae is represented by 125 genera
and 960 species, including plants commonly used in people's daily diets (1).
Belonging to this family, Cucurbita pepo
L., Cucurbita maxima Duchesne, and Cucurbita moschata Duchesne are
economically important species that are cultivated worldwide and have high
production potential (2). It was stated that extracts prepared from different
parts of Cucurbita species,
particularly seeds and leaves, have broad pharmacological effects, including
antidiabetic, antihypertensive, antitumor, immunomodulatory, antibacterial,
antihyperlipidemic, and anti-inflammatory activities (3). The production of C. maxima and C. moschata in Türkiye is based on local cultivars (4). Further,
there is only one commercially bred winter squash cultivar (Arıcan 97) (5). Studies
on the fruit stems of C. maxima and C. pepo species are very limited. This
study aimed to investigate the various biological activities of agricultural
wastes from different parts of Cucurbita species.
Materials
and Methods: The seed of Arıcan 97 variety of C. maxima was cultivated, and the leaves and fruit stems of the
mature plant were collected. The leaves and fruit stems of C. pepo and C. maxima
species were obtained from local cultivators. The leaves and fruit stems were
shade-dried and powdered in a grinder. All plant materials were extracted with
80% methanol separately. After filtration and solvent evaporation, the crude
extracts was fractionated with n-hexane
and ethyl acetate, respectively. Acetylcholinesterase, butyrylcholinesterase,
tyrosinase, and α-glucosidase
inhibitory activities and antioxidant capacity of crude methanol extract, n-hexane, ethyl acetate, and water
sub-extracts obtained from the plants were tested by in vitro studies.
Results: C. maxima (Arıcan 97) fruit stem ethyl
acetate sub-extract (CMAr97-E), C. maxima
(local cultivar) fruit stem ethyl acetate sub-extract, and C. maxima (Arıcan 97) leaf n-hexane
sub-extract exhibited noteworthy α-glucosidase
inhibitory activity at 200 µg/mL with inhibition percentages of 57.03 ± 1.69%,
50.25 ± 5.41%, and 50.03 ± 5.39%, respectively. CMAr97-E scavenged DPPH radical
more strongly than other extracts, with an inhibition percentage of 41.83 ±
1.37% at a concentration of 200 µg/mL. There were no effects of the tested
extracts on cholinesterases and tyrosinase enzymes.
Conclusions: The
results revealed that the fruit stem of C.
maxima (Arıcan 97) has antidiabetic and antioxidant activities. This study
indicated that agricultural wastes have the potential to be utilized
pharmaceutically. Based on these preliminary findings, we suggest that further
biological activity studies should be carried out on agricultural wastes of Cucurbita species, and the compounds
responsible for the potential effect should be identified.