Isolation and Pharmacological Characterization of α-Elapitoxin-Ot1a, a Short-Chain Postsynaptic neurotoxin from the Venom of the Western Desert Taipan, <i>Oxyuranus temporalis</i>

Taipans (Oxyuranus spp.) are elapids with highly potent venoms containing presynaptic (β) and postsynaptic (α) neurotoxins. O. temporalis (Western Desert taipan), a newly discovered member of this genus, has been shown to possess venom which displays marked in vitro neurotoxicity. No components have been isolated from this venom. We describe the characterization of α-elapitoxin-Ot1a (α-EPTX-Ot1a; 6712 Da), a short-chain postsynaptic neurotoxin, which accounts for approximately 30% of O. temporalis venom. α-Elapitoxin-Ot1a (0.1–1 µM) produced concentration-dependent inhibition of indirect-twitches, and abolished contractile responses to exogenous acetylcholine and carbachol, in the chick biventer cervicis nerve-muscle preparation. The inhibition of indirect twitches by α-elapitoxin-Ot1a (1 µM) was not reversed by washing the tissue. Prior addition of taipan antivenom (10 U/mL) delayed the neurotoxic effects of α-elapitoxin-Ot1a (1 µM) and markedly attenuated the neurotoxic effects of α-elapitoxin-Ot1a (0.1 µM). α-Elapitoxin-Ot1a displayed pseudo-irreversible antagonism of concentration-response curves to carbachol with a pA2 value of 8.02 ± 0.05. De novo sequencing revealed the main sequence of the short-chain postsynaptic neurotoxin (i.e., α-elapitoxin-Ot1a) as well as three other isoforms found in O. temporalis venom. α-Elapitoxin-Ot1a shows high sequence similarity (i.e., >87%) with other taipan short-chain postsynaptic neurotoxins

Garcinia atroviridis fruit extract alters lipid accumulation in 3T3-L1 cell line model

Obesity is accumulation of excess body fat to the extent it may have an adverse effect on health. It is undeniably a complex disease with risk factors combination of genetics, lifestyle, nutrition, increasing age and lack of physical activity. Alarming increase of obesity prevalence since past few years brings the concern to explore effective therapy against obesity. Thus, targeting preadipocyte differentiation (adipogenesis) is one of natural product’s approaches to exert its anti-obesity property. The success of other Garcinia species for obesity management opened the gap to study the lipid alteration potential the locally underexplored Garcinia atroviridis or Asam Gelugur on 3T3-L1 cell culture model. The fresh fruit was extracted and freeze-dried. We first found that the powdered extract did not affect cell viability of both preadipocyte and adipocyte cells. The extract significantly inhibited adipogenesis by decreasing intracellular lipid accumulation as analysed qualitatively and quantitatively using Oil Red O stain. We further investigated the inhibition effect by means of quantifying the protein associated with adipogenesis, PPARγ and C/EBPα. The treatment only affects the expression of C/EBPα protein significantly. Furthermore, the extract was also enhanced the adipocytes breakdown (adipolysis) as revealed by glycerol concentration measured. Taken together, our findings indicated that the fruit extract of G. atroviridis plays a role in alteration of lipid accumulation with the intervention of protein associated with adipogenesis. Understanding adipogenesis and its molecular mechanisms may provide clues for future strategies development in preventing and treating obesity

FISH ACUTE TOXICITY TESTING OF LITSEA GARCIAE METHANOLIC EXTRACT IN ADULT ZEBRAFISH

Litsea garciae bark (LG) is currently used in Sarawak by locals to treat various diseases traditionally. However, there is no preliminary study conducted to evaluate the respective plant's acute toxicity up to the present time. The recent study's main objective was to determine the LG bark methanolic extract's acute toxicity in adult zebrafish.The research was approved by IIUM Animal Care and Use Committee (I-ACUC) from IIUM, IIUM/IACUC-2019(21). The raw LG bark underwent a successive maceration technique and freeze-dried. The methanolic extract was administered in a static system by immersion based on OECD Test Guideline No 203. The acute toxicity test implemented 96 hours of observation for any mortality or visible abnormalities related to the zebrafish's appearance and behaviors. As the results, the test group (limit 100mg/L) and the control group recorded zero mortality and no significant abnormalities. Hence, LC50 was not determined. In agreement, the present findings revealed the significance of relatively safe and less toxic methanolic extract of LG bark for further biomedical applications

Lipid accumulation modulation by garcinia atroviridis fruit extract in 3T3-L1 adipocyte cells

Garcinia atroviridis contains hydroxycitric acid (HCA) that affects obesity and obesityrelated diseases. This paper aims to quantify the amount of (HCA) available in the fruit extract of Garcinia atroviridis and investigate the lipid modulation properties possessed by the extract in the 3T3-L1 adipocyte cell line. High-performance liquid chromatography (HPLC) analysis was used to quantify HCA in the extract, whereas differentiated adipocytes were evaluated Oil Red O staining. The expression of PPARγ and C/EBPα was investigated using western blot, and the lipid content was confirmed using leptin ELISA assay. HPLC analysis quantified about 11.35 ± 0.55 % (w/w) of HCA in the fruit extract, with a retention time of 0.9 minutes corresponding to the standard. In the adipogenesis assay, an increased co-treatment concentration was observed and inhibited the formation of intracellular lipids. According to the western blot analysis, the treatment was found to significantly affect the expression of C/EBPα proteins solely. Meanwhile, the leptin assay finding was in agreement with the adipogenesis analysis as a decrement of leptin released was noted at increased treatment concentrations. Finally, the fruit extract enhanced the adipocyte breakdown (adipolysis) process as revealed by the glycerol concentration measured in the adipolysis assay. The findings indicated that the fruit extract of G. atroviridis played a role in the alteration of lipid accumulation processes by the intervention of proteins associated with adipogenesis and enhanced adipolysis

The Bold and the Beautiful: a Neurotoxicity Comparison of New World Coral Snakes in the Micruroides and Micrurus Genera and Relative Neutralization by Antivenom

Coral snake envenomations are well characterized to be lethally neurotoxic. Despite this, few multispecies, neurotoxicity and antivenom efficacy comparisons have been undertaken and only for the Micrurus genus; Micruroides has remained entirely uninvestigated. As the USA's supplier of antivenom has currently stopped production, alternative sources need to be explored. The Mexican manufacturer Bioclon uses species genetically related to USA species, thus we investigated the efficacy against Micrurus fulvius (eastern coral snake), the main species responsible for lethal envenomations in the USA as well as additional species from the Americas. The use of Coralmyn® coral snake antivenom was effective in neutralizing the neurotoxic effects exhibited by the venom of M. fulvius but was ineffective against the venoms of Micrurus tener, Micrurus spixii, Micrurus pyrrhocryptus, and Micruroides euryxanthus. Our results suggest that the Mexican antivenom may be clinically useful for the treatment of M. fulvius in the USA but may be of only limited efficacy against the other species studied