Abstract:
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Spirulina platensis is a “super-food” and has attracted researchers’ attention due to its
anti-inflammatory, antioxidant, and analgesic properties. Herein, we investigated the antinociceptive
effects of Spirulina in different rodent behavior models of inflammatory pain. Male Swiss mice were
treated with Spirulina (3–300 mg/kg, p.o.), indomethacin (10 mg/kg, p.o.), or vehicle (0.9% NaCl
10 mL/kg). Behavioral tests were performed with administration of acetic acid (0.6%, i.p.), formalin
2.7% (formaldehyde 1%, i.pl.), menthol (1.2 µmol/paw, i.pl.), cinnamaldehyde (10 nmol/paw, i.pl.),
capsaicin (1.6 µg/paw, i.pl.), glutamate (20 µmol/paw, i.pl.), or naloxone (1 mg/kg, i.p.). The
animals were also exposed to the rotarod and open field test to determine possible effects of Spirulina
on locomotion and motor coordination. The quantitative phytochemical assays exhibited that
Spirulina contains significant concentrations of total phenols and flavonoid contents, as well as it
showed a powerful antioxidant effect with the highest scavenging activity. Oral administration of
Spirulina completely inhibited the abdominal contortions induced by acetic acid (ED50 = 20.51 mg/kg).
Spirulina treatment showed significant inhibition of formalin-induced nociceptive behavior during the
inflammatory phase, and the opioid-selective antagonist markedly blocked this effect. Furthermore,
our data indicate that the mechanisms underlying Spirulina analgesia appear to be related to its ability
to modulate TRMP8 and TRPA1, but not by TRPV1 or glutamatergic system. Spirulina represents
an orally active and safe natural analgesic that exhibits great therapeutic potential for managing
inflammatory pain disorders. |