Water soluble fraction (<10 kDa) from bee venom reduces visceral pain behavior through spinal alpha 2-adrenergic activity in mice.

We have previously shown that subcutaneous bee venom (BV) injection reduces visceral pain behavior in mice, but it is not clear which constituent of BV is responsible for its antinociceptive effect. In the present study, we now demonstrate that a water-soluble subfraction of BV (BVA) reproduces the antinociceptive effect of BV in acetic acid-induced visceral pain model. We further evaluated three different BVA subfractions that were separated by molecular weight, and found that only the BVAF3 subfraction (a molecular weight of <10 kDa) produced a significant antinociceptive effect on abdominal stretches and suppressed visceral pain-induced spinal cord Fos expression. Injection of melittin (MEL), a major constituent of BVAF3, also produced a visceral antinociception. However, melittin's antinociception was completely blocked by boiling for 10 min at 100 degrees C, while boiling either whole BV or BVAF3 did not prevent their antinociception. The antinociceptive effect of BVAF3 was completely blocked by intrathecal pretreatment with the alpha2-adrenoceptor antagonist, yohimbine (YOH), while intrathecal pretreatment with the opioid antagonist, naloxone (NAL) or the serotonin antagonist, methysergide, had no effect. These data demonstrate that BVAF3 is responsible for the visceral antinociception of whole BV and further suggest that this effect is mediated in part by spinal alpha2-adrenergic activity.

General pharmacological profiles of bee venom and its water soluble fractions in rodent models.

Recently, the antinociceptive and anti-inflammatory efficacy of bee venom (BV, Apis mellifera) has been confirmed in rodent models of inflammation and arthritis. Interestingly, the antinociceptive and anti-inflammatory effect of whole BV can be reproduced by two water-soluble fractions of BV (>20 kDa:BVAF1 and<10 kDa: BVAF3). Based on these scientific findings, BV and its effective water-soluble fractions have been proposed as potential anti-inflammatory and antinociceptive pharmaceuticals. While BV's anti-inflammatory and antinociceptive properties have been well documented, there have been no careful studies of potential, side effects of BV and its fractions when administered in the therapeutic range (BV, 5 microgram/kg; BVAF1, 0.2 microgram/kg: BVAF3, 3 microgram/kg; subcutaneous or intradermal). Such information is critical for future clinical use of BV in humans. Because of this paucity of information, the present study was designed to determine the general pharmacological/physiological effects of BV and its fractions administration on the rodent central nervous, cardiovascular, respiratory and gastrointestinal system. Subcutaneous BV and its fractions treatment did not produce any significant effects on general physiological functions at the highest dose tested (200-fold and 100-fold doses higher than that used clinically, respectively) except writhing test. These results demonstrate that doses of BV or BV subfractions in the therapeutic range or higher can be used as safe antinociceptive and anti-inflammatory agents.

Acupoint stimulation with diluted bee venom (apipuncture) alleviates thermal hyperalgesia in a rodent neuropathic pain model: involvement of spinal alpha 2-adrenoceptors.

UNLABELLED: Chemical acupuncture with diluted bee venom (DBV), termed apipuncture, has been traditionally used in oriental medicine to treat several inflammatory diseases and chronic pain conditions. In the present study we investigated the potential antihyperalgesic and antiallodynic effects of apipuncture in a rat neuropathic pain model. DBV (0.25 mg/kg, subcutaneous) was injected into the Zusanli acupoint 2 weeks after chronic constrictive injury (CCI) of the sciatic nerve. Between 5 and 45 minutes after DBV injection, we observed a significant reduction in the thermal hyperalgesia induced by CCI, but apipuncture failed to reduce CCI-induced mechanical allodynia. We subsequently examined whether this antihyperalgesic effect of apipuncture was related to the activation of spinal opioid receptors and/or alpha2-adrenoceptors. Intrathecal pretreatment with naloxone (10 microg/rat), an opioid receptor antagonist, did not reverse the antihyperalgesic effect of apipuncture, whereas pretreatment with idazoxan (40 microg/rat), an alpha2-adrenoceptor antagonist, completely blocked the effect of apipuncture. These results indicate that DBV-induced apipuncture significantly reduces the thermal hyperalgesia generated by CCI and also suggest that this antihyperalgesic effect is dependent on the activation of alpha2-adrenoceptors, but not opioid receptors, in the spinal cord. PERSPECTIVE: The antinociceptive effect of apipuncture was evaluated in a rodent neuropathic pain model. The relieving effect of apipuncture on thermal hyperalgesia was found to be mediated by spinal alpha2-adrenoceptors, but not opioid receptors. These data suggest that apipuncture might be an effective alternative therapy for patients with painful peripheral neuropathy, especially for those who are poorly responsive to opioid analgesics.

Acupoint stimulation using bee venom attenuates formalin-induced pain behavior and spinal cord fos expression in rats.

In two previous reports, we have demonstrated that injection of bee venom (BV) into an acupoint produces a significant antinociceptive and anti-inflammatory effect in both a mouse model of visceral nociception and a rat model of chronic arthritis. The present study was designed to evaluate the potential antinociceptive effect of BV pretreatment on formalin-induced pain behavior and it associated spinal cord Fos expression in rats. Adult Sprague-Dawley rats were injected with BV directly into the Zusanli (ST36) acupoint or into an arbitrary non-acupoint located on the back. BV pretreatment into the Zusanli acupoint significantly decreased paw-licking time in the late phase of the formalin test. In contrast, BV injected into a non-acupoint in the back region did not suppress the paw-licking time. In addition, BV pretreatment into the Zusanli acupoint markedly inhibited spinal cord Fos expression induced by formalin injection. These findings indicate that BV pretreatment into the Zusanli acupoint has an antinociceptive effect on formalin-induced pain behavior.

The antinociceptive and anti-inflammatory effect of ethylacetate extracts from Bang-Poong (Radix ledebouriellae) on the Freund's adjuvant-induced arthritis in rats.

In this study, we aimed to determine the antinociceptive and/or anti-inflammatory effect of Bang-Poong (BP, Radix Ledebouriellae) on Freund's adjuvant-induced arthritis in rats. Traditionally, BP has been used to treat several inflammatory diseases such as arthritis. Whole BP is extracted into two fractions that were ethylacetate and hexane-soluble fractions. Adult Sprague-Dawley rats (n=30, 130-150 g) were subcutaneously administered by the Freund's complete adjuvant (FCA) into the plantar surface of right hindpaw. Twelve days after the injection of FCA, the rats initially showed typical inflammatory edema and arthritis-related symptoms on the contralateral side (i.e. left hindpaw). Both antinociceptive (evaluation of mechanical, thermal pain threshold and analysis of spinal Fos expression) and anti- inflammatory (evaluation of paw edema, serum interleukin-6 level and x-ray analysis) effect of BP extracts were examined. The ethylacetate fraction of BP (BPE) significantly suppressed the FCA-induced paw edema as well as the serum level of interleukin-6 and it alleviated the radiological changes. Moreover, both mechanical and thermal hyperalgesia were attenuated by the treatment of BPE. In addition, spinal Fos expression that was increased by FCA- injection was suppressed in BPE group. Therefore, this study showed that BPE produced significant both antinociceptive and anti-inflammatory effects on FCA- induced arthritis in rats, while hexane fraction of BP did not show these effects. In conclusion, it is suggested that the ethylacetate fraction of BP is recommended to alleviate the arthritis-related symptoms in human according to the results of this study.