Riyad Sadek

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.

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.

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.

Montivipera bornmuelleri venom has immunomodulatory effects mainly up-regulating pro-inflammatory cytokines in the spleens of mice

Graphical abstract

Lethal, Hemorrhagic, and Necrotic Effects of Montivipera bornmuelleri Venom

Abstract: Montivipera bornmuelleri is an endangered viper that has been described as endemic to the Lebanese mountains. The lethal dose 50% (LD50) of M. bornmuelleri venom has been determined by performing intravenous, intraperitoneal (IP), and subcutaneous injections. However, to date, intramuscular injection has not been performed to determine LD50, nor have the minimum hemorrhagic (MHD) or the minimum necrotic doses (MND) been evaluated. Thus, this study was conducted to complete the characterization of the M. bornmuelleri venom. Our results showed that intramuscularly injected LD50 is around 5.39 mg/kg, and IP LD50 is around 1.93 mg/kg. After intradermal injection, our findings showed significant necrotic and medium hemorrhagic activities, and MHD was around 250 µg/kg. By comparing with other local venomous snakes, these results indicate that the lethality of M. bornmuelleri venom is similar to that of Daboia palaestinae venom (IP LD50=1.9 mg/kg) and is higher than that of Macrovipera lebetina venom (IP LD50=7.58 mg/kg) and that the hemorrhagic activity of M. bornmuelleri venom is lower than that of the Macrovipera lebetina (MHD=200 µg/kg). On the other hand, necrotic activity was detected at low doses of injected venom: MND was estimated at 20 µg/kg. Altogether, our findings could extend the scope of characterization of M. bornmuelleri venom and provide useful data for further in vivo studies.

Vipers of the Middle East: A Rich Source of Bioactive Molecules

Snake venom serves as a tool of defense against threat and helps in prey digestion. It consists of a mixture of enzymes, such as phospholipase A2, metalloproteases, and l-amino acid oxidase, and toxins, including neurotoxins and cytotoxins. Beside their toxicity, venom components possess many pharmacological effects and have been used to design drugs and as biomarkers of diseases. Viperidae is one family of venomous snakes that is found nearly worldwide. However, three main vipers exist in the Middle Eastern region: Montivipera bornmuelleri, Macrovipera lebetina, and Vipera (Daboia) palaestinae. The venoms of these vipers have been the subject of many studies and are considered as a promising source of bioactive molecules. In this review, we present an overview of these three vipers, with a special focus on their venom composition as well as their biological activities, and we discuss further frameworks for the exploration of each venom.

Snakebites in lebanon: a descriptive study of snakebite victims treated at a tertiary care center in Beirut, Lebanon

Background: Snakebites lead to at least 421,000 envenomations and result in more than 20,000 deaths per year worldwide. Few reports exist in the Mediterranean region. This study describes demographic and clinical characteristics, treatment modalities, and outcomes of snakebites in Lebanon. Materials and Methods: This was a retrospective chart review of patients who presented with snakebite complaint to the emergency department between January 2000 and September 2014. Results: A total of 24 patients were included in this study. The mean age was 34.6 (±16.4) years and 58.3% were males. Local manifestations were documented in 15 (62.5%) patients, systemic effects in 10 (41.7%), hematologic abnormalities in 10 (41.7%), and neurologic effects in 4 (16.7%) patients. Nine patients (37.5%) received antivenom. The median amount of antivenom administered was 40 ml or 4 vials (range: 1–8 vials). About 50% of patients were admitted to the hospital with 75% to an Intensive Care Unit and 25% to a regular bed. All were discharged home with a median hospital length of stay of 4 (interquartile range 11) days. Among those admitted, seven patients (58.3%) had at least one documented complication (compartment syndrome, fasciotomy, intubation, deep vein thrombosis, coagulopathy, acute respiratory distress syndrome, sepsis, congestive heart failure, cellulitis, upper gastrointestinal bleeding, and vaginal bleeding). Conclusion: Victims of snakebites in Lebanon developed local, systemic, hematologic, or neurologic manifestations. Complications from snakebites were frequent despite antivenom administration. Larger studies are needed to assess the efficacy of available antivenom and to possibly create a local antivenom for the treatment of snakebites in Lebanon.

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.