Algerian propolis from distinct geographical locations: Chemical profiles, antioxidant capacity, cytotoxicity and inhibition of 5-lipoxygenase product biosynthesis.

Propolis was collected from honeybee hives in three geographically
distinct Algerian climates and extracts were characterized
for composition and bioactivity. Bees were identified as
native subspecies using an in-silico DraI mtDNA COI-COII test.
Over 20 compounds were identified in extracts by LC-MS.
Extracts from the Medea region were more enriched in phenolic
content (302�28 mg GAE/g of dry extract) than those from
Annaba and Ghardaia regions. Annaba extracts had the highest
flavonoid content (1870�385 mg QCE/g of dry extract). Medea
extracts presented the highest free-radical scavenging activity
(IC50=13.5 μg/mL) using the DPPH radical assay while Ghardaia
extracts from the desert region were weak (IC50>100 μg/mL).
Antioxidant activities measured using AAPH oxidation of linoleic
acid were similar in all extracts with IC50 values ranging from 2.9
to 4.9 μg/mL. All extracts were cytotoxic (MTT assay) and
proapoptotic (Annexin-V) against human leukemia cell lines in
the low μg/mL range, although the Annaba extract was less
active against the Reh cell line. Extracts inhibited cellular 5-
lipoxygenase product biosynthesis with IC50 values ranging
from 0.6 to 3.2 μg/mL. Overall, examined propolis extracts
exhibited significant biological activity that warrant further
characterization in cellular and in vivo models.