Abstract:
A common practice of managing pain globally is the combination of analgesics and this is aimed
at facilitating patient compliance, simplifying prescription, and improving efficacy without increasing adverse
effects. Fruit extracts of Xylopia aethiopica are used traditionally in the management of pain disorders and
xylopic acid (XA) present in the fruit extract have been shown to possess analgesic properties in animals. There
is the likelihood of concomitant use of XA and the commonly used analgesics in traditional settings. This study,
therefore, evaluated the pharmacologic interaction between XA/morphine and xylopic/diclofenac combinations.
Methods: The formalin test and acetic acid writhing test were used to study the antinociceptive activity of
XA, morphine, and diclofenac. The isobolographic analysis was used to study the antinociceptive interactions
between XA co-administered with morphine or diclofenac.
Results: Results obtained revealed that XA (10–100 mg/kg), morphine (1–10 mg/kg), and diclofenac
(1–10 mg/kg) produced dose-related antinociception with different potencies in the formalin and acetic acid
writhing tests. Isobolographic analysis of XA/morphine and XA/diclofenac combinations revealed potentiation
of their antinociceptive effects. The degree of potentiation calculated as interaction index showed synergism for
both combinations in all the nociceptive tests.
Conclusion: In conclusion, the present study demonstrated synergism for the co-administration of XA with
morphine or diclofenac.
