MTT-Based Evaluation of Cytotoxic Responses to GC-MS-Profiled Psidium guajava Leaf Extract in Human PANC1 Pancreatic Cancer Cells

Abstract

Background: Pancreatic adenocarcinoma remains one of the most therapeutically challenging
malignancies, with a five-year survival rate below 12%. The resistance of pancreatic cancer cells
to conventional chemotherapy drives the search for novel bioactive scaffolds from
ethnomedicinal sources. Psidium guajava (L.) Merr. (Guava) is widely utilised in traditional
medicine for its diverse pharmacological properties, yet its regional Indian accessions remain
under-characterised against pancreatic cancer models. This study evaluates the cytotoxic
potential of GC-MS-profiled P. guajava leaf extract from Tamil Nadu against the PANC1 human
pancreatic cancer cell line.
Methods: Shade-dried leaves collected from the Kappiyarai region of Kanyakumari, Tamil Nadu
were subjected to sequential Soxhlet extraction using petroleum ether, n-butyl alcohol, and
distilled water. The n-butyl alcohol fraction (Sample TM) was profiled using Gas
Chromatography-Mass Spectrometry (GC-MS) on an Agilent 7890A/5975C system with NIST
2017 library matching. In vitro cytotoxicity was assessed via the MTT [3-(4,5-dimethylthiazol-
2-yl)-2,5-diphenyltetrazolium bromide] assay at concentrations ranging from 6.25 to 100 μg/mL
over a 24-hour incubation period against PANC1 cells maintained in DMEM supplemented with
10% FBS at 37 deg C in 5% CO2.
Results: GC-MS analysis of the TM extract identified a characteristic flavonoid-glycoside
profile, dominated by quercetin-3-O-beta-D-xylopyranoside (86.0% relative abundance),
epigallocatechin gallate (EGCG; 82.0%), isoquercitrin (73.0%), avicularin (75.0%), and gallic
acid (74.0%). The MTT assay revealed a dose-dependent reduction in PANC1 cell viability. The
maximum cytotoxicity of 35.08% was achieved at the highest tested concentration (100 μg/mL),
with cell viability decreasing from 96.10% (at 6.25 μg/mL) to 64.92%. The estimated IC50 value
was determined to be >100 μg/mL. Morphological examination revealed cellular shrinkage,
membrane blebbing, and rounding consistent with early apoptotic changes.
Conclusion: The results demonstrate that the Tamil Nadu accession of P. guajava leaf extract
possesses moderate, dose-dependent cytotoxic activity against PANC1 cells. The presence of
bioactive flavonoid glycosides such as quercetin-3-O-beta-D-xylopyranoside and EGCG
provides a biochemical rationale for this activity. These findings support the potential of P.
guajava as a source of bioactive leads for adjuvant oncology, warranting further fractionation
and mechanistic studies