ABSTRACT
In present study, leaf extract of Hoya parasitica Wall. was evaluated for in vitro antioxidant and membrane stabilizing activity along with in vivo gastro intestinal motility and acute toxicity. Five different assays were performed to evaluate antioxidant activity. In DPPH free radical scavenging activity, methanol, ethanol and chloroform extract exhibited IC50 value similar to standard ascorbic acid. The presence of flavonoid and phenolic contents was also similar in all the plant extracts. However, chloroform extract showed remarkable reducing power capacity (69.10% at 200μg/mL). In case of membrane stabilization, the chloroform extract showed maximum inhibition (32.62 %) of haemolysis, whereas the ethanol extract showed a significant (p<0.001) human RBC membrane stabilizing effect. In vivo gastrointestinal motility test indicates significant (p<0.001) increase in gastrointestinal motility by Methanol extract (100 and 200 mg/kg b.w.) and ethanol extract (200 mg/kg b.w.) compared to standard. Highest dose introduced as 1000, 2000 and 3000 mg/kg body weight of each extracts in acute toxicity study and did not shown any sign of toxicity in Swiss albino mice. The result obtained from this study, can be considered as preliminary and further sophisticated investigation is needed to isolate new bioactive compounds that might act as led compounds in future.
ABSTRACT
In-utero exposure to valproic acid (VPA) has been known as a potent inducer of autism spectrum disorder (ASD), not only in humans, but also in animals. In addition to the defects in communication and social interaction as well as repetitive behaviors, ASD patients usually suffer from gastrointestinal (GI) problems. However, the exact mechanism underlying these disorders is not known. In this study, we examined the gross GI tract structure and GI motility in a VPA animal model of ASD. On embryonic day 12 (E12), 4 pregnant Sprague-Dawley (SD) rats were subcutaneously injected with VPA (400 mg/kg) in the treatment group, and with phosphate buffered saline (PBS) in the control group; the resulting male offspring were analyzed at 4 weeks of age. VPA exposure decreased the thickness of tunica mucosa and tunica muscularis in the stomach and ileum. Other regions such as duodenum, jejunum, and colon did not show a significant difference. In high-resolution microscopic observation, atrophy of the parietal and chief cells in the stomach and absorptive cells in the ileum was observed. In addition, decreased staining of the epithelial cells was observed in the hematoxylin and eosin (H&E)-stained ileum section. Furthermore, decreased motility in GI tract was also observed in rat offspring prenatally exposed to VPA. However, the mechanism underlying GI tract defects in VPA animal model as well as the association between abnormal GI structure and function with ASD is yet to be clearly understood. Nevertheless, the results from the present study suggest that this VPA ASD model undergoes abnormal changes in the GI structure and function, which in turn could provide beneficial clues pertaining to the pathophysiological relevance of GI complications and ASD phenotypes.