穿心莲内酯对大鼠辐射损伤防护的实验研究

目的 探讨中药穿心莲内酯对大鼠放射性损伤的防护作用.方法 将60只雄性sD大鼠随机分为健康对照组、模型组和中药组.中药组大鼠定期进行穿心莲内酯溶液(分为2个剂量组)灌胃,模型组大鼠给予生理盐水灌胃,健康对照组大鼠正常饮水.10 d后给予60Coγ射线一次性全身均匀照射,1、2和4 Gy.继续饲养1 d后,处死全部动物,取其肝脏,立即用4%多聚甲醛固定,常规制作石蜡切片,采用HE染色检测肝组织细胞形态学变化,TUNEL法染色检测不同组细胞凋亡情况.结果 健康对照组和模型组大鼠肝脏HE染色显示病变相似,随辐射剂量的增大,肝细胞水肿、肝窦扩张充血、炎性反应等组织损伤程度加重;TUNEL法检测肝细胞凋亡率无明显差别.同等剂量下,中药组大鼠HE染色病变较对照组和模型组轻,且肝细胞凋亡率显著降低(t=2.19～4.80,P<0.05).结论 穿心莲内酯对辐射损伤有一定的防护作用.

Abstract：

Objective To explore the effects of andrographolide(AP),extracted from the traditional Chinese herb Andrographlis paniculata(AP),on injury induced by radiation exposure.Methods Sixty male rats were randomly divided into 4 equal groups and irradiated with 60Co γ-rays at the doses of 1,2,and 4 Gy,respectively:low dose AP group(intragnstrically administered with AP at the dose of 100 ms/kg daily for 10 d before irradiation),and high dose AP group(intragastrically administered with AP at the dose of 200 ms/kg daily for 10 d before irradiation),model group(administered with the same volume of normal saline instead of AP for 10 d before irradiation),and control group(irradiated only at 3 different doses).One day after irradiation all rats were killed with their livers being fixed to make paraffin section.The morphological feature was observed under light microscope after HE staining,and the cell apoptosis was detected by TUNEL technology.Results Compared to the control and model groups,the pathological changes of liver were significantly gentler in the AP treatment groups.The apoptosis rates of the liver cells of all the AP sub-groups were significantly lower than those of the control and model subgroup(t=2.19-4.80.P<0.05).Conclusions AP might have prevention effect against radiation exposure.     

穿心莲内酯对大鼠辐射损伤防护的实验研究

Objective To explore the effects of andrographolide(AP),extracted from the traditional Chinese herb Andrographlis paniculata(AP),on injury induced by radiation exposure.Methods Sixty male rats were randomly divided into 4 equal groups and irradiated with 60Co γ-rays at the doses of 1,2,and 4 Gy,respectively:low dose AP group(intragnstrically administered with AP at the dose of 100 ms/kg daily for 10 d before irradiation),and high dose AP group(intragastrically administered with AP at the dose of 200 ms/kg daily for 10 d before irradiation),model group(administered with the same volume of normal saline instead of AP for 10 d before irradiation),and control group(irradiated only at 3 different doses).One day after irradiation all rats were killed with their livers being fixed to make paraffin section.The morphological feature was observed under light microscope after HE staining,and the cell apoptosis was detected by TUNEL technology.Results Compared to the control and model groups,the pathological changes of liver were significantly gentler in the AP treatment groups.The apoptosis rates of the liver cells of all the AP sub-groups were significantly lower than those of the control and model subgroup(t=2.19-4.80.P<0.05).Conclusions AP might have prevention effect against radiation exposure.     

脉冲1.338μm激光致青紫蓝灰兔视网膜损伤效应研究

目的研究脉冲1.338μm激光致青紫蓝灰兔视网膜损伤效应,确定其损伤阈值。方法以输出波长1.338μm、脉冲宽度5 ms的移频Nd∶YAG激光为照射光源,角膜入射光斑直径5 mm,在19.8、24.2、29.5和33.9J/cm24个剂量下照射12只青紫蓝灰兔的24只眼视网膜,于照后即刻、1 h、24 h和48 h用检眼镜观察视网膜损伤,统计各个剂量下的损伤发生率,采用加权概率单位法计算损伤发生率为50%时所对应的激光剂量,即损伤阈值ED50。于照后48 h摘取眼球进行视网膜病理观察。结果阈值水平的视网膜损伤为淡淡的灰白色凝固斑,边界模糊,较重者损伤斑为白色,有的伴有点状或环形出血。视网膜损伤发生率随照射剂量的升高而升高,随时间的延长在照后24 h内略有升高,到照后48 h不再上升。统计分析照后1 h、24 h的损伤发生率确定视网膜损伤阈值分别为4.83 J/cm2(95%置信区间4.60～5.05 J/cm2)和4.60 J/cm2(95%置信区间4.31～4.86 J/cm2)。光镜下观察视网膜损伤区向内隆起,内、外核层、节细胞层等各层细胞都可观察到胞核固缩、深染等损伤特征,但色素上皮层细胞形态未发生明显改变。结论脉冲1.338μm激光在角膜入射光斑直径5 mm,脉冲宽度5 ms条件下致青紫蓝灰兔视网膜损伤的阈值为4.60 J/cm2。视网膜损伤累及视网膜全层,但色素上皮层损伤较轻。     

578nm激光对灰兔视网膜生物学效应的研究

目的观察不同功率密度下,578 nm激光引起的灰兔视网膜的改变,探讨影响激光对视网膜生物效应的因素。方法灰兔16只,32只眼,以波长578 nm、脉宽20～40 ns的脉冲铜蒸汽激光照射兔眼底视乳头下方的后极部,按照射眼底的激光功率密度分为435、869、1 304、1 739、2 174、2 608和3 043 mW/cm2 7组,照光时间100 s,眼底光斑直径2 mm。照光后24 h用检眼镜和眼底荧光造影检查视网膜的损伤,并行视网膜的组织病理学检查。结果波长为578 nm、频率为6 kHz的铜蒸汽激光,在眼底光斑直径为2 mm、照光时间为100 s的照光条件下,其功率密度越高,视网膜损伤越重。结论在激光波长578 nm照光时间相同和光斑大小不变的条件下,功率密度是影响激光对灰兔视网膜生物学效应的重要因素。     

地甘口服液对辐射损伤小鼠细胞周期及凋亡相关基因的影响

目的　探讨中药复方地甘口服液对辐射损伤小鼠骨髓细胞周期素基因 (cyclinD1)及凋亡相关基因 (bcl 2和bax)mRNA表达的作用。方法　建立辐射损伤模型 (一次性用直线加速器给予6 0Gy的X射线照射 ) ,喂饲小剂量 10 0 %和大剂量 2 0 0 %的地甘口服液每次 0 2ml 10g小鼠 ,每日 2次。第 9天用原位杂交法检测小鼠骨髓单个核细胞cyclinD1、bcl 2和baxmRNA的表达。结果　地甘口服液组与对照组比骨髓细胞促凋亡基因baxmRNA表达显著减少 (P <0 0 1) ,而cyclinD1和bcl 2m RNA的表达显著增强 (P <0 0 1)。结论　中药复方地甘口服液抗辐射损伤可能是通过上调细胞周期素基因cyclinD1和bcl 2的表达及降低baxmRNA的表达 ,从而促进造血细胞的增生和提高机体免疫力 ,达到保护机体的目的 ,为临床用药提供理论指导     

578.2nm激光照射对视网膜功能学损伤的研究

目的从功能学的角度研究激光照射后视网膜功能的改变。方法健康灰兔6只共12只眼,按照激光进入眼底的功率密度分为正常组,阈值下组和阈值上组,每组4只兔眼。应用波长578.2 nm、脉宽20～40 ns的脉冲铜蒸汽激光照射兔眼底视乳头下方的后极部,照光时间100 s,眼底光斑直径2 mm。照光后1周用视觉电生理仪采集视网膜电图(electroretinogram,ERG),判定激光对视网膜功能学的损害。结果暗视ERG中,阈值上组和阈值下组的Ab(uv)与正常组相比存在显著差异;暗适应最大电反应中,阈值上组与正常组的Ab(uv)差异显著,阈值下组与正常组的La(ms)差异显著。结论低于损伤阈值剂量的激光照射视网膜出现视网膜功能的改变。     

牛磺酸对大鼠视网膜缺血再灌注保护作用的实验研究

 目的探讨缺血性视网膜病变中视网膜损伤的机制及诱因并研究牛磺酸的保护作用.方法选择健康Wistar大鼠108只,雌雄各半,随机分为6组,分别为正常对照组、假手术组、阳性对照组、β-丙氨酸处理组、牛磺酸处理组、维生素E处理组,通过升高眼内压造成视网膜缺血,持续60min后再灌注6 h做成高眼压模型,取视网膜进行神经节细胞凋亡测定、钙离子测定,并进行统计学分析.结果阳性对照组与牛磺酸用药组均有视网膜神经节细胞的凋亡,但牛磺酸组与阳性对照组比较,视网膜神经节细胞凋亡数明显减少(P＜0.05),同β-丙氨酸组比较也有显著性差异(P＜0.05);再灌注6 h后牛磺酸用药组Ca2+含量降低,同阳性对照组比较差异有统计学意义(P＜0.01).结论视网膜神经节细胞凋亡是视网膜缺血性病变的一个重要机制.钙离子是视网膜神经节细胞凋亡的重要诱因,牛磺酸有一定的保护作用.     

辐射损伤后大鼠鼻黏膜早期组织重塑的特点

目的 探讨辐射损伤后大鼠鼻黏膜早期组织重塑的特点。方法 清洁级SD大鼠40只,雄性,采用随机数字排列法将动物随机分组,对照组、20Gy组、30Gy组、40Gy组和50Gy组,每组8只。辐射完成后2周,取出中鼻甲进行组织学处理:采用苏木素-伊红(hematoxylin-eosin,HE)染色,计数中鼻甲黏膜内嗜酸粒细胞数并测定上皮细胞损伤程度;采用阿辛蓝-过碘酸-希夫(alcian blue-periodic acid-Schif,AB-PAS)染色,计数中鼻甲黏膜中单位面积上皮细胞中杯状细胞数;采用Masson三色胶原染色Masson trichrome(MT)法染色,测定中鼻甲黏膜内胶原成分染色的百分比面积。结果 对照组少量嗜酸粒细胞浸润,实验组均有大量嗜酸粒细胞浸润,并以30Gy组嗜酸性粒细胞浸润最多。 20Gy组未见明显的上皮细胞损伤,其他各组均见不同程度的上皮细胞损伤,吸收剂量越大,上皮细胞损伤程度越重。 20Gy组杯状细胞数略增多,但差异无统计学意义;30Gy组和40Gy组杯状细胞明显增多,50Gy组杯状细胞数明显减少。 细胞外基质沉积在20Gy组略增多,但差异无统计学意义;其他各组明显增多,且随着剂量的增大,MT染色蓝色所占的百分比面积有增多的趋势。结论 黏膜上皮细胞损伤、嗜酸性粒细胞浸润、杯状细胞化生和黏膜内胶原成分增加是早期放射性鼻黏膜损伤后黏膜上皮组织重塑的特点。组织重塑随着辐射剂量和辐射时间呈现一定的变化规律。     

穿心莲药物对辐射损伤效应影响的初步研究

目的 探讨市售穿心莲药物制剂对辐射损伤的影响。 方法 采用高效液相色谱法分析市售的穿心莲注射液和穿心莲内酯滴丸两种不同剂型药物中穿心莲内酯含量;体外实验采用乳腺癌细胞系（MCF-7和MDA-MB-231）研究穿心莲药物对γ射线照射后乳腺癌细胞生存率的影响;体内实验采用C57 BL/6鼠研究穿心莲药物对5.0 Gy和9.0 Gy的γ射线照射后的小鼠的辐射损伤的影响。 结果 穿心莲注射液和穿心莲内酯滴丸的穿心莲内酯含量分别为0.214 mg/ml和5.82 mg/粒;两种药物都上调了体外培养的乳腺癌细胞的放射敏感性;对5.0 Gy照射的C57 BL/6鼠的造血系统表现出一定保护作用,但是对9.0 Gy照射的C57 BL/6鼠则表现出辐射损伤协同作用。 结论 穿心莲药物在不同照射剂量下可对辐射损伤既表现出保护又表现出协同损伤的双向作用。     

激光照射防治移植静脉再狭窄的实验研究

目的 观察激光照射对移植静脉血管平滑肌细胞（VSMC）增殖与凋亡的影响。探索激光疗法防治移植静脉远期再狭窄的可行性及作用机制。方法 建立兔颈外静脉颈总动脉移植模型。应用IECu-10铜蒸气激光器，输出波长510.6nm。功率密度500mW/cm^2，于移植静脉血管外照射1000s。术后4周，用免疫组织化学方法检测增殖细胞核抗原（PCNA），应用DNA片段末端标记法（TUNEL）标记凋亡细胞，HE，Masson及维多利亚蓝染色后，应用计算机图像分析系统检测移植静脉内膜，中膜增生情况。结果 术后4周，激光血管外照射的移植静脉与对照组相比，VSMC增殖率降低41.5%。细胞凋亡率增加40.9%。抑制了VSMC细胞增殖，促进细胞凋亡；移植静脉内膜和中膜厚度分别减少58.5%,18.0%，静脉内膜与中膜厚度比值（I/M）减少47.2%。结论 适当能量激光血管外照射可以抑制移植静脉血管平滑肌细胞增殖，促进移植静脉血管平滑肌细胞凋亡。使移植静脉内膜和中膜的增生减轻。有防治移植静脉远期再狭窄的作用。     

A randomised, placebo controlled trial of low level laser therapy for activated Achilles tendinitis with microdialysis measurement of peritendinous prostaglandin E2 concentrations

Background

Low level laser therapy (LLLT) has gained increasing popularity in the management of tendinopathy and arthritis. Results from in vitro and in vivo studies have suggested that inflammatory modulation is one of several possible biological mechanisms of LLLT action.

Objective

To investigate in situ if LLLT has an anti‐inflammatory effect on activated tendinitis of the human Achilles tendon.

Subjects

Seven patients with bilateral Achilles tendinitis (14 tendons) who had aggravated symptoms produced by pain inducing activity immediately before the study.

Method

Infrared (904 nm wavelength) LLLT (5.4 J per point, power density 20 mW/cm²) and placebo LLLT (0 J) were administered to both Achilles tendons in random blinded order.

Results

Ultrasonography Doppler measurements at baseline showed minor inflammation through increased intratendinous blood flow in all 14 tendons and measurable resistive index in eight tendons of 0.91 (95% confidence interval 0.87 to 0.95). Prostaglandin E₂ concentrations were significantly reduced 75, 90, and 105 minutes after active LLLT compared with concentrations before treatment (p  =  0.026) and after placebo LLLT (p  =  0.009). Pressure pain threshold had increased significantly (p  =  0.012) after active LLLT compared with placebo LLLT: the mean difference in the change between the groups was 0.40 kg/cm² (95% confidence interval 0.10 to 0.70).

Conclusion

LLLT at a dose of 5.4 J per point can reduce inflammation and pain in activated Achilles tendinitis. LLLT may therefore have potential in the management of diseases with an inflammatory component.     

雌激素α、β受体在大鼠视网膜组织的免疫组织化学定位

目的探讨雌激素α、β受体(ERα、ERβ)在大鼠视网膜组织的定位和分布。方法22只SD雌性大鼠颈椎脱臼处死,取眼球做常规石蜡包埋,连续切片,采用免疫组织化学方法显示ERα、ERβ在视网膜组织的表达,并设正常大鼠子宫作阳性对照;PBS代替一抗作阴性对照。同时采用放射免疫分析方法检测大鼠血清雌二醇的浓度。结果ERα在少数标本的视网膜色素上皮、节细胞层和神经纤维层呈阳性表达,其他区域则呈阴性反应。ERβ在视网膜组织各区域分布有着明显差异,以视网膜色素上皮、节细胞层和神经纤维层阳性表达为主,内丛状层次之,其他区域阳性表达较少。ERα、ERβ免疫阳性反应物呈颗粒状,定位在视网膜色素上皮的细胞质以及神经节细胞的细胞质和细胞核或弥散分布在相关的视网膜区域内。ERβ在视网膜色素上皮、神经节细胞层和神经纤维层阳性表达率明显高于ERα,经统计学分析两者间有显著性差异(P<0.05)。正常大鼠血清雌二醇水平经检测含量为22.13±3.54pg/ml。结论大鼠视网膜组织以表达ERβ为主,ERβ主要分布在视网膜色素上皮层、节细胞层、神经纤维层,提示雌激素通过ERβ的介导直接对视网膜功能起调控作用;同时为进一步研究雌激素与视网膜疾病之间的关系提供了分子生物学基础。     

Effects of low level electromagnetic field exposure at 2.45 GHz on rat cornea

Abstract

Purpose: To investigate the effects of low level electromagnetic field (low level-EMF) exposure, as frequently encountered in daily life, on the normal rat cornea using histological and stereological method.

Methods: Twenty-two adult male Wistar rats were randomly divided into two groups: Study group (n = 11) and control group (n = 11). Rats in the study group were exposed to 2.45 GHz microwave (MW) radiation (11.96 ± 0.89 V/m), 0.25 W/kg specific absorption rate (SAR) for 2 hours each day for 21 days. The corneal thickness and the anterior epithelium corneal thickness were measured using two different methods.

Results: Using the histological method, the mean corneal thicknesses in the control and study group were 278.9 ± 54.5 μm, and 272.4 ± 85.6 μm, respectively. There was no statistically significant difference between the groups (p > 0.05). The anterior corneal epithelium thickness was 28.1 ± 4.9 μm in the control group and 31.7 ± 5.5 μm in the study group. There were statistically differences between the groups with regard to the thickness of anterior epithelium (p < 0.05). In the measurement made by the stereological method, the percentage of the cornea occupied by anterior corneal epithelium was 15.94% in the control group and 17.9% in the study group. Despite the fact that there was a relation between increased anterior epithelial area (AEA) and radiation exposure, no statistically significant relationship in area fraction of each compartment was found between the control and study groups.

Conclusions: Results of this preliminary study show that exposure to MW radiation might cause alterations in the rat cornea.     

低水平电离辐射单次或分割照射法的抗肿瘤效应比较

目的比较低水平电离辐射(LLIR)单次与分割照射的抗肿瘤效应。方法选用C57BL/6和ICR品系小鼠分别移植Lewis肺癌和S180肉瘤细胞,24h后再分别接受7.5cGy单次照射和分割照射(1.5cGy×5d);然后观察20d抑瘤率、脾NK细胞活性、T淋巴细胞表面CD4、CD8水平的变化以及荷瘤鼠的平均寿命。结果单次与分割照射对Lewis肺癌的抑瘤率分别为40.34%和51.19%,对S180肉瘤为34.26%和30.98%;脾NK细胞活性照后1～4d升高;CD4、CD8水平及CD4/CD8比值均有不同程度增高;荷瘤鼠的生命延长率分别为8.45%和8.84%。结论本实验采用的低水平单次或分割照射对Lewis肺癌和S180肉瘤均有明显的抑瘤效果,能显著增强荷瘤机体的免疫机能以及延长荷瘤鼠的平均寿命。经比较,两种照射方式在肿瘤生长抑制和免疫刺激作用等方面差异无显著性(P＞0.05)。     

低强度微波辐射环境对男性生殖健康的影响

目的　了解低强度微波作业环境对男性生殖及其子代健康的影响。方法　采用面对面问卷调查方式对已婚的 4 2 4名雷达作业人员 (实验组 )、2 0 4名对照组人员进行现场调查。结果　实验组性功能减退发生率为 2 3 8% ,对照组为 14 7% ,两组相比差异有统计学意义 (P <0 0 5 )。实验组婚后半年、1年自然受孕率分别为 13 8%、39 8% ,对照组分别为 31 3%、4 9 6 %。婚后 2年、3年后自然受孕率 ,实验组为 30 4 %、12 5 % ,对照组为 10 9%、6 1% ,组间差异显著 (P <0 0 0 1)。两组人员生殖结局及子代性别比例未见异常。结论　长期低强度微波辐射对男性性功能有不良影响 ,导致女性自然受孕时间滞后 ,但对妊娠结局及子代健康无明显影响。     

5-羟色胺受体亚型mRNA在大鼠视网膜中的表达--RT-PCR法研究

目的 观察大鼠视网膜内5-羟色胺(5-HT)受体各种亚型mRNA的表达。方法 提取大鼠视网膜中的总RNA,用RT-PCR技术检测5-HT受体各种亚型mRNA的表达。将PCR产物进一步克隆人pCRⅡ载体,然后进行序列检测,测得的序列均与已知的各5-HT受体亚型的cDNA序列进行Blast比较。结果 5-HT受体亚型在阳性对照组中均呈阳性结果,各阳性条带的位置均与预期的各亚型PCR产物相符。经测序,证实产物确为预期的各5-HT受体亚型。RT-PCR结果显示,大鼠视网膜表达5-HT1A、5-HT2A、5-HT2C、5-HT3和5-HT7受体亚型,且以上各受体亚型阳性条带的密度存在着差异,以5-HT7和5-HT2a最高,5-HT2C和5-H3次之,而5-HT1A较弱。5-HT1B、5-HT1D、5-HT1E、5-HT1F、5-HT2b、5-HT4、5-HLA、5-HT5B和5-HT6受体亚型没有阳性条带。结论 大鼠视网膜上分布有多种5-HT受体亚型,包括5-HT1A、5-HT2A、5-HT2C、5-HT3和5-HT7。提示5-HT能系统可能普遍存在于哺乳动物视网膜中,且通过不同受体亚型在介导rod感光信号的过程中扮演着重要的角色。     

低剂量辐射诱导细胞遗传学适应性反应的某些规律

10mGyX射线可诱导人外周血淋巴细胞和家兔外周血淋巴细胞产生对相继较大剂量(1.5Gy)X射线诱发染色体畸变的抗性, 称之为适应性反应。在离体和整体条件下, 该反应广泛存在于体细胞和生殖细胞中, 其反应程度与低剂量辐射的剂量呈负相关, 即辑先照射的剂量愈低, 诱导的适应性反应愈明显。同时还发现该反应也受许多因素的影响, 如: 低剂量辐射的剂量、剂量率, 照射时间以及生物个体差异等因素。     

α晶体蛋白对LPS刺激及视神经损伤后大鼠视网膜小胶质细胞增殖及数量的影响

目的 研究α晶体蛋白对大鼠视网膜小胶质细胞增殖能力及视神经损伤后小胶质细胞数量的影响.方法 脂多糖激活离体培养视网膜小胶质细胞,模拟视神经损伤,采用MTF分析α晶体蛋白对激活的小胶质细胞增殖能力的影响;建立大鼠视神经不全损伤模型,损伤后玻璃体腔注射α晶体蛋白,采用视网膜铺片及免疫荧光标记小胶质细胞并计数,比较不同组小胶质细胞的数量.结果 10-g/L～10-2 g/L浓度的脂多糖均可激活小胶质细胞(P＜0.05),10-6g/L和10-4g/L浓度的α晶体蛋白可明显抑制10-6g/L浓度的脂多糖激活的小胶质细胞的增殖;视神经损伤1～3周,α晶体蛋白注射组小胶质细胞的数量明显少于损伤组(P＜0.05).结论 α晶体蛋白可抑制视网膜上小胶质细胞的增殖和活化,减轻小胶质细胞对RGCs的过度吞噬和继发性损害,可能是视神经损伤后α晶体蛋白问接保护RGCs存活的另一机制.     

He—Ne激光血管内照射对家兔纤维蛋白溶解功能影响的实验研究

为探讨低强度Ｈｅ－Ｎｅ激光（６３２．８ｎｍ）血管内照射治疗缺血性心、脑血管病的机制，设计了形成颈动脉血栓的家兔模型，观测对此模型组进行三次低强度Ｈｅ－Ｎｅ激光耳静脉血管内照射（每天１次，平均剂量６７２．３Ｊ／ｃｍ２）前后，血浆中纤维蛋白溶解酶原（简称纤溶酶原）、纤溶酶原激活剂抑制物、组织型纤溶酶原激活剂活性与Ｄ－二聚体和纤维蛋白原含量的变化，并与对照组比较。结果表明：低强度Ｈｅ－Ｎｅ激光血管内照射对纤溶系统的激活与血液高凝状态的缓解有促进作用，可能是由于低强度Ｈｅ－Ｎｅ激光血管内照射循环血液，对血液系统的调制作用所致     

Assessing the impact of low level laser therapy (LLLT) on biological systems: a review

Abstract

Purpose: Low level laser therapy (LLLT) in the visible to near infrared spectral band (390–1100?nm) is absorption of laser light at the electronic level, without generation of heat. It may be applied in a wide range of treatments including wound healing, inflammation and pain reduction. Despite its potential beneficial impacts, the use of lasers for therapeutic purposes still remains controversial in mainstream medicine. Whilst taking into account the physical characteristics of different qualities of lasers, this review aims to provide a comprehensive account of the current literature available in the field pertaining to their potential impact at cellular and molecular levels elucidating mechanistic interactions in different mammalian models. The review also aims to focus on the integral approach of the optimal characteristics of LLLT that suit a biological system target to produce the beneficial effect at the cellular and molecular levels.

Methods: Recent research articles were reviewed that explored the interaction of lasers (coherent sources) and LEDs (incoherent sources) at the molecular and cellular levels.

Results: It is envisaged that underlying mechanisms of beneficial impact of lasers to patients involves biological processes at the cellular and molecular levels. The biological impact or effects of LLLT at the cellular and molecular level could include cellular viability, proliferation rate, as well as DNA integrity and the repair of damaged DNA. This review summarizes the available information in the literature pertaining to cellular and molecular effects of lasers.

Conclusions: It is suggested that a change in approach is required to understand how to exploit the potential therapeutic modality of lasers whilst minimizing its possible detrimental effects.