Souad Hraoui-Bloquet

The herpetofauna of Lebanon: new data on distribution

Abstract This paper reports more than 400 original data on the Lebanese herpetofauna (covering 5 amphibians and 44 reptiles), deriving from museum collections and recent field observations. The most interesting data concern: (a) Cyrtopodion amictopholis, a species known only from Mt. Hermon, reported for the first time from Mt. Lebanon Range; (b) Lacerta fraasi, previously considered endemic to the Mount Lebanon Range, also recorded from Antilebanon; (c) the occurrence of Macrovipera lebetina is confirmed with certainty from two localities in the north. New records are given for many species known in Lebanon only on the basis of very few and often old reports.

Montivipera bornmuelleri venom selectively exhibits high cytotoxic effects on keratinocytes cancer cell lines

CONTEXT The Viperidae family venom is a rich source of bioactive compounds such as many proteases, which cause tissue necrosis and affect mostly the vascular system. However, the venom exhibits therapeutic potentials and has contributed to the development of some medical drugs. Specifically, the Montivipera bornmuelleri venom has shown to exhibit antibacterial, pro-inflammatory and antifungal activities. OBJECTIVE This work evaluates the cytotoxic effect of the M. bornmuelleri venom on human-derived keratinocytes including the non-tumorigenic HaCaT, the benign A5 and the low-grade malignant II4 cells. MATERIALS AND METHODS The toxicity of different venom concentrations (0.9, 1.87, 3.75, 7.5, 15, 30 and 60μg/mL) and their effect on the viability of the cells lines were assessed using the Lactate Dehydrogenase (LDH) activity and the Trypan blue tests after 24h of incubation. RESULTS The venom was able to reduce the viability of all cell lines in a dose dependent manner with the HaCat cells being the least affected. For example, the 60μg/mL dose induced a more significant decrease the viability of A5 (44%) and II4 (21.33%) keratinocytes as compared to HaCaT cells (70.63%). Also, this venom showed a higher cytotoxic activity on the A5 (52.45%) and II4 (98.67%) cells as compared to HaCaT cells (30.14%) with an IC50 estimated at 10μg/mL on II4 and at 60μg/mL on benign A5. DISCUSSION AND CONCLUSION Those differential cytotoxic effects of the M. bornmuelleri venom pave the road for more advanced studies which might unravel the potential anticancer effects of this venom.

Identification of L-amino acid oxidase (Mb-LAAO) with antibacterial activity in the venom of Montivipera bornmuelleri, a viper from Lebanon.

The L-amino acid oxidase (LAAO) is a multifunctional enzyme, able to partake in different activities including antibacterial activity. In this study, a novel LAAO (Mb-LAAO) was isolated from the venom of M. bornmuelleri snake using size exclusion chromatography followed by RP-HPLC and partially characterized. However, the molecular weight of the Mb-LAAO determined by ESI-MS and SDS-PAGE was 59 960.4 Da. Once the enzymatic activity test confirming the enzymes identity (transformation of L-leucine) was done, the Mb-LAAO was evaluated for its antibacterial activity against Gram-negative bacteria. It showed a remarkable effect against M. morganii and K. pneumoniae. Moreover, no cytotoxic activity was observed for Mb-LAAO against human erythrocytes arguing for an exploration of its pharmaceutical interest.

Protein Content Analysis and Antimicrobial Activity of the Crude Venom of Montivipera bornmuelleri; a Viper from Lebanon

Viperidae snakes venoms represent a source of efficient bioactive components that have already led to the development of several new drugs. In this work, we analyzed the protein content of the Montivipera bornmuelleri crude venom using LC-ESI-MS, sephadex G-75 gel filtration and SDS-PAGE and demonstrated the presence of proteins with molecular masses corresponding to metalloprotease III, serine-protease and PLA2 in three fractions collected after gel filtration. Equally, we examined the antimicrobial effect of the venom that showed an important potency, as bactericidal agent, based on MBC and MIC values obtained, against Staphylococcus aureus and Morganella morganii bacteria. However, no activity was registered against Enterococcus faecalis, being the most resistant bacteria, neither against Aspergillus flavus and Penicillium digitatum fungal. Furthermore, on eleven other bacterial strains and the Candida albicans fungus, the venom has shown an intermediate efficacy by slightly reducing the growth. Our data concerning the Montivipera bornmuelleri venom give evidence of a rich and complex content aiding the exploration of new bioactive molecules for biopharmaceuticals purposes.

Sexual dimorphism and female reproductive cycle in the scincid lizard Trachylepis vittata (Olivier, 1804) in Lebanon (Reptilia: Scincidae)

Sexual dimorphism and the female reproductive cycle were studied in a population of the viviparous lizard Trachylepis vittata at 2000 m a.s.l. on Mount Sannine, Lebanon. Females have larger body sizes than males and males have relatively larger heads than females. Females reach maturity at 56 mm snout-vent length. They spend at least six months in hibernation, from October to March. Adult females emerge from hibernation in April. Fertilization occurs mid-May and gestation lasts for 8-10 weeks. All females collected on the same date had embryos at the same embryonic developmental stage. Females produced 1-4 embryos. There is a significant positive relationship between female body size and number of embryos. Parturition lasts for two weeks and new-borns achieve adult size within about ten months.

Distribution and male reproductive system of the Bridled Mabuya, Trachylepis vittata (Olivier, 1804) (Reptilia: Scincidae), in Lebanon

The distribution of the Bridled Mabuya, Trachylepis vittata, in Lebanon is described and the male reproductive cycle was studied in a population living at 2000 m a.s.l. on Mount Sannine. Males emerge from hibernation in March, one month earlier than females. They show a short seasonal testicular cycle in which spermiogenesis occurs in spring, followed by testicular regression and subsequent recrudescence in summer. Hibernation starts in October and lasts 5 months. The development of secondary sexual characteristics was in synchrony with the testicular cycle. There was a significant difference between the reproductive stages and the testicular volume. The species is assigned to an associated reproductive cycle with short vernal spermiogenesis.

Male reproductive seasonality of the Snake-eyed Lizard, Ophisops elegans Ménétriés, 1832, from Lebanon (Reptilia: Lacertidae)

We studied the male reproductive cycle in a population of Ophisops elegans from Mount Sannine, Lebanon, by histological analysis. Testicular histology showed active spermatogenesis in spring, followed by a testicular regression at the end of summer and a subsequent recrudescence in autumn. Monthly variations in the epididymis, the ductus deferens and the sexual segment of the kidney were in synchrony with the testicular cycle. They were hypertrophied as spermatogenetic activity increased and atrophied as spermatogenetic activity decreased. Males of O. elegans showed a vernal type of spermatogenesis with a close relationship between the evolution of the seminiferous tubules and the secondary sexual characters.